G8UBJs-hamdy-spot

The FT-1907R UHF Mobile

2012-01-21T12:16:00.000-08:00

I recently started looking for a UHF transceiver for the shack. I know its easy enough to buy something like the FT-8900 but I have separate antennas for each band & I really wanted something I could leave running.

I thought Alinco were about the only company left selling single band UHF transceivers until I discovered the FT-1907R.

As you can see its a companion to the FT-1900 2M transceiver from Yaesu.

I found a Greek company selling this on eBay which surprised me as its not listed on the Yaesu dot com site. Either way it was quite a reasonable price and delivery was quick.

Initial testing showed that it did provide 55 watts output as specified and on the air was reasonably sensitive. I'm sure that if this gets to the states we can rely on the ARRL to put it through its paces so I won't go further into testing as my facilities are limited.

Transmit and receive runs from 400 - 470 Mhz continuous.

At the heart of the The PA stage is Mitsubishi RF Mosfet module capable of 60 watts

http://pdf1.alldatasheet.com/datasheet-pdf/view/169066/MITSUBISHI/RA60H4047M1.html

I found that like the FT-1900 this gets quite warm during extended transmit so I will publish a fan modification in my next post.

As its a UHF rig an N-type connector would have been a nice addition. This was quickly fixed.

The rig comes with the usual Yaesu accessories (Even the sticky Yaesu label). I found the user guide listed on the Yaesu Russian site but strangely its only mention is on a brochure where it says Asian market only

http://www.yaesu.ru/instruction/FT-1907R.pdf

I'm not sure why its not more widely available; maybe its early days or maybe Yaesu are trying to protect sales of their multi band transceivers in Europe and North America?

Look Mum no Hands, or - FSK without using an RS-232 port

2011-12-30T01:15:00.000-08:00

In a recent QST (August 2011) I spotted an article showing a way to implement FSK keying using only the audio output from your PC.
The article was written by Doug Hall K4DSP who can take full credit for this brilliant design!

You can find more information on this project at - http://k4dsp.homeip.net/~doug/regenerator/

That may sound easy but up to now the only solutions that provides true FSK without using an RS232 port have required conversion from the USB port which is quite complex in order to achieve a stable 45.45 baud rate.

The FSKit from Doug converts transmit AFSK tones from your PC into FSK keying and also PTT. In addition it provides isolation between the PC and transceiver.

I wanted to build a portable station for field use using my IC-706 and a lap top PC (No RS232 ports) and I didn't want to use AFSK as -

1 - You have to keep an eye on the drive levels to ensure a clean signal

2 - The displayed frequency is incorrect

3 - You need a work around to use the narrow RTTY filter.

The article from Doug was easy to follow; at the heart of the project was an AMTEL AVR micro-controller (ATTiny 45). The binary is available online but in reality it was easier to email Doug and purchase the micro-controller and at the same time a PCB...

The circuit was fairly easy to assemble although obtaining the op-amp and transistors required a little searching around.

I decided to house the FSKit in a Maplin enclosure and add a few bells and whistles..

1 - Powered from the IC-706 8v line

2 - Incorporate CI-V control for logging and spotting

3 - Some indicator lamps (Power - PTT - FSK - CI-V)

4 - Audio out gain control for transmit of PSK and other modes

5 - Audio in gain control and isolation

6 - Audio transmit side tone

I tried using an L78L05 to run the board but it was a little fussy a 3.3 volt regulator worked perfectly. The board uses very low current so the low power version is best.

I have a simple CI-V and tried an isolation circuit for this, unfortunately I couldn't get this to fly so just routed the CI-V through the terminal unit with some in-line ferrites to provide a little protection.

All the indicators were LEDs -

Power just needed a 1K resistor in series
PTT and FSK lines run to LEDs with a 2k and 1k resistor in series to the 3.3v line
CIV was a high brightness LED across the CI-V line with a 2k resistor in series (Flashes to showing active data present).

Doug provides an isolated audio output on his board. I fed this to a potentiometer and then on to the rig.

Audio receive was from the rig to another potentiometer and then an isolating transformer to the PC audio input - I use N1MM with MMTTY RTTY which uses audio in so just needed some isolation.

Last was a simple moving coil microphone insert that was across the audio input line. This is useful to check the tones sound okay on transmit and gives the operator confidence that something is happening (I find complete silence on transmit a little disconcerting.

As you can see the whole project went into an aluminum enclosure. I could have squeezed it into something smaller but the box I used made for an easy life.

The cable from the rig to the terminal terminates in a 9way D-type so I can make up other cables for other rigs in future. I used an old VGA cable as it has ferrites pre-installed and several screened conductors which are useful to keep the audio lines quiet.

I haven't labeled the terminal unit yet but that's the only thing left to do.

Its not a microHam interface but its inexpensive & does the job for /P operation.

I think this probably the best and least expensive way of implementing true FSK. I have made a few contacts from home but I'm looking forward to summer when I can try it portable.

I do desire we may be better strangers.

2011-09-23T19:55:00.000-07:00

Or - "It was hard to code so it should be hard to use"

Who would have thought eBay could implement a feaure thats so poorly thought through that I gave up on them.

Their new "Shopping Basket" function has to be the worst thing. Worst still buyers can't opt out or remove it.

I'm sure some green horn functional analyst specd it out but I don't think the Product Owner tested it.

If you use the Bay be very careful with this feature (Totally avoid it if possible!) as it lacks controls to remove items and auto comitts you to purchases you don't want.

This sort of thing isn't rocket science, just pop over to Amazon and you can see how it should be done. Then again I don't suppose Amazon have the highest NPS scores by being careless.

Adios ebay - I do desire we may be better strangers.

P.S. Employing professional analysts with a web background may help you solve this problem.

After 33 years of RTTY operating here are my 33 whys of RTTY ;o)

2011-05-15T00:56:00.000-07:00

This rant is dedicated to Ted who thought I didn't Blog often enough!

Why don't some RTTY stations insert a space at the end of their callsign so it doen't run into the following text?
Why is there always an Italian or Ukranian calling CQ on the spot frequency of the DX you need?
Why do stations running a split listen to every frequency but the one I call on?
Why doesn't eveyone use unshift on space so I don't have to use mousover to decipher their serial numbers?
Why don't any Nigerian stations use LOTW?
Why can't I ever seem to work Utah or Delaware when Alaska and California are so easy?
Why is RTTY on 14.08 21.08 28.08 and then 50.3?
Why am I still waiting for my first country on 4M RTTY?
Why can't some stations spot frequencies correctly i.e. carrier f0 = mark frquency?
Why do some stations use AFSK and then compound the sin by using AFC?
Why doesn't N1MM remember my comment for all spots when re-started?
Why use 75baud RTTY when its 50% faster but 50% more errors?
Why is PSK 31 and RTTY so mixed together on 10Mhz?
RYRRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRR Why?
Why are there only about two stations active in each African country except ZS?
Why do some sations have strange shifts wider than 170Hz?
Why can't some stations seem to net correctly?
Why do I seem to miis the leading "I" when first tuning a station on 20M so I stop thinking its K6NNN when its only IK6NNN?
Why are there more licenced hams in Japan than in the US?
Why do some stations seem to have a line feed fetish (Didn't they ever run RTTY on a Teletype machine)?
Why do conditions deteriorate exactly one minute before a contest starts?
Why don't more stations run RTTY on Top Band (I only have seven countries confirmed)?
Why do some stations stop transmitting at the end of their over with no CR LF?
Why does RTTY rock and PSK suck?
Why are all the finest hams on RTTY?
Why is it called RTTY (Radio Teletype) and not RTTE?
Why is there still no software for AMTOR when the available firmware is getting really ancient?
Why isn't more RTTY/Ham software written for Linux distros (I'm tired of having to run Micro$oft Windoze in my shack)?
Why don't contest organisers set operating frequency limits and exclude contacts (Or disqualify competitors) who go outside these limits to stop interference to other band users?
Why do some Russian RTTY stations never copy you even when you run QRO?
why do some RTTY stations sign/QRP when we already know how weak they are?
Why are there only about four RTTY hams in China none of whom ever seem run more than a noodle for an antenna?
Why do I enjoy RTTY operating so much?

WHY? WHY? WHY?

The ANYTONE 5189 4M FM Mobile

2010-11-24T10:08:00.000-08:00

Martin Lynch and Son have taken delivery of their first batch of the new ANYTONE 5189 Transceivers. These cover 4M and output is about 40 Watts on high power. I think the specification is 60 watts so some internal tinkering may be considered in the future? That said the 20 watts difference is not great and probably won´t make a difference on the air.The radio come nicely packaged with a double fused power lead, fist microphone, mobile mount and of course a fairly easy to read manual. The manufacturer is Qixiang Electronics (Never heard of them!)
I have only just bought this today (24th November), one of the initial batch of ten. Initial on the air testing has been positive.
It has a very large integrated heat sink. I imagine that this can actually dissipate the power on 60 watts.

The rig is a little sensitive to SWR, changing the coax length by 1/4 wavelength resulted in just shy of 40 watts out.

I took a few photos of the display, with and without the flash. As you can see its not huge, but acceptable for mobile use. Still no S meter...sigh!

Tuning of the VFO is on the front panel dial (Finally no more up down buttons!). The dial doubles for volume if you press it once. The squelch is on a menu (Can´t have em all....) but can be defeated by a button press for those DX contacts?

On the air reports were good although the default deviation of 25Khz was too wide and had to be turned down to 12.5K

Sensitivity was slightly better than my ASCOM SE550 and the integral speaker was very clear and produced good audio. the microphone is a good size and comes with up/down buttons for mobile use. It connects to the rig using the RJ45 type connector, similar to most modern rigs.

There is a speaker jack at the rear.

This is one of the first batch and the next batch should be in before Christmas. At £149.95 they aren´t giving them away but if you compare it to the Yaesu FT-2900 single band 2M transceiver its not too expensive and hand helds aside the only new 4M transceiver available on the market (So put it on your Christmas list now?)

6M band pass filter

2010-03-16T01:23:00.000-07:00

I recently lost the 6M front end transistor in my FT-897D. This is a tiny SM transistor nestled in the middle of the PA board.

I can't be sure if this was due to early failure of the component (The 897 was only a month old) or a stray RF field from my HF or other VHF transmitters. Initially I looked for a replacement transistor. I found out its a Japanese part (Doh!!) and although there are equivalents available the original part is only available from Japan. I gave up and went back to Martin Lynch & Son who had the part (and a competent technician to fit it).

Very soon they put the magic factory smoke back in my FT-897D (They did it while I waited) and while I waited I thought about ways keep it in there. I decided on a two prong approach -
- Fit a low pass filter on my HF amplifier
- fit a bandpass filter on my 6m station

Prong one was reasonably easy. Fitting a good quality low pass filter on my HF station was a good move and fairly easy. It helped reduce TVI and other unwanted nasties although my neighbors TV still dies if I TX on 12M. I assume that must be something directly unacceptable in his set to 24mhz as I have fitted an HF choke and 6M stub in his down lead. Maybe I will try a 24Mhz stub as well...

Anyway the 6M bandpass filter proved to be more tricky. I ordered one from ICE but after a few months nothing arrived and no reply to my emails (no charge on my card either) so I gave up on that avenue. I was looking through the ARRL Handbook and found a reasonable design for a 6m bandpass filter and decided to build that. I also downloaded the original article from 1968 QST as my membership of the ARRL gives me access to their archives (Are you listening RSGB?) The article gave a little more detail on construction such as doubling up the air spaced capacitors to achieve the 100+ pf required.

It took me about a month to scrape together all the bits (Enclosure, caps , copper line etc) but eventually I felt ready to build the filter. I could procrastinate no further.

It took a Saturday to complete the project. To ensure the comb lines were properly connected to the enclosure I cut it from a single sheet of copper and sandwiched it to the rear using a strip of aluminum (an off-cut from the Maplin box I had to cut down) fixing it all in place with about 15 4M brass nuts and bolts and washers..

I found that the filter worked very well but was far narrower than I expected. The article said it should be reasonably flat across about 4Mhz. Mine was about 300Khz wide... I could live with about 1.5Mhz as the UK 6M band is only 2Mhz wide and I never go above 51.34 (local repeater) so I started to explore what was wrong.

I had built the filter from 26awg sheet and the design used this may have had a small effect but I didn't think it would make that much difference?

It was suggested by G4MDC that to improve the bandwidth I would need to increase the coupling between the comb lines. Rather than pull the whole thing apart I tagged copper strips over the existing lines. This thickened the combs and increased the coupling.

The finished filter was still quite narrow (about 900Khz ) but its easier to tune and with a Maplin knob fitted to the central tuning capacitor I can easily adjust the filter to center on the FM (51.34Mhz) or SSB (50.15mhz) frequencies.

I'm still a little baffled by the design. Did the original filter cover 4Mhz as claimed? Had anyone else built this in anger?

that said I can now run full legal on 6m with not a spot of interference (The filter really does handle QRO as claimed) and so far my front end transistor hasn't blown again!

A budget LCR meter

2010-03-15T08:39:00.000-07:00

It seemed to good to be true, but so far the LCR meter I bought on eBay appears to have been excellent value at only £12.98 (including delivery!!!) - Yes you heard me right!

I have been looking to buy an LCR meter for some time. One use I intended for it was to replace the variable capacitors in my HB9CV antennas with fixed capacitors (Made of PTFE coax). that only requires a comparison but being able to measure is always a plus point!

Having placed my order on eBbay I awaited delivery. The eBay shop was in HK so I wasn't expecting fast delivery. It arrived within the week which was very quick and costing only £12.98 (including delivery)it didn't attract VAT or import duty.

I have added some shots of the unit which came with battery included.
All the instructions are in Chineese (maybe I should get them translated) although its pretty self explanatory.

The meter came with a set of leads which I decided against using. Instead I purchased some croc clips and mounted them on some old 4mm posts.. that gave me a nice set of short leads and an easy way to secure components whilst testing.

It seems reasonably accurate across the range but I'm a bit skeptical about the 2000Mohm range (I don't think I have a 2KMeg ohm resistor to test it....).

It even has an internal lamp for the display!

If you want a cheap and cheerful LCR meter this seems as good as any other. I will do some further testing and comparison at the local club....

Oh yes it comes with a transistor tester as well.

The G5RV jr on steroids?

2009-10-01T03:14:00.000-07:00

A few years back I only had a very short garden (Even shorter than the one I have now!). I guess thats what comes of living in London and not being a millionare. I opted for a 6BTV as it didn't have a large footprint.

Of course one neighbour took exception to this and instead of talking to me went to the authorities to waste some time & money. I decided it wasn't worth the effort fighting my corner so I replaced it with a GRV junior. Stringing it from the roof I could just fit the short 5RV in the garden. It sloped, and the last five foot of feed line needed supporing but it was better than nothing. Actually on 40 M and 10 M it seemed to outperform the 6BTV.

Thus began a long love hate relationship with the G5RV jr. when I moved house I installed the G5RV between my dormer window (3rd floor) strund to the top of my 6BTV and then down to the garage. This worked reasonably well but I sooon found the high impedance it presented to my tuner and loss in feeder meant that things started to heat up running QRO. Also the plastic insulators became slightly conductive after a time.

I looked around for an alternative antenna and tried the short Carlina Windom. For all the hype it didn't perform any better in the same position, the SWR drifted all over the place on 15M. and was difficult to support. Over a number of months testing and upgrading I settled on a modified version of the short G5RV. These are the changes I made -

Replaced all insulators with glass/ceramic
use open wire feeder with spacers instead of the 450 Ohm ladder line
Increased the open wire feeder length to improve SWR on 15 and 40m (
replaced all the antenna wire with flexi-weave (I only did this as the original stuff wouldn't solder) The length is 7.844M each side
Installed an 8 turn high power 1:1 balun at the feedpoint.
Replaced the coax feedline with 10M of Andrews 450
Increased the centre support by 1.5 m (Part of changing the 6BTV into an 80m inverted L

The finished antenna works well on 40 and 10m, ok on 30, 20 and 15M and although its a high SWR tunes on 17 and 12M. The SWR doesn't drift on any of the bands whilst running 400 watts RTTY so whilst things may be warming up in the system or tuner its not enough to be a problem.

Here is a photo of the finished antenna -

And the balun -

The balun is 4 inches in diameter and constructed form RG393 which is a large as RG214 but has a double silver plated screen and conductor + PTFE dielectric so its a bit more stable.

I constructed the open wire feeder using spacers from Sandpiper Aerials. Very inexpensive but you have to thread them on individually which is a bit of a chore.

This is looking up the ladder line. One side of the antenna runs trough an insulator attached to the vertical.

Originally I modelled the antenna on MMANA which indicated that it would resonate at about 28.1Mhz. In actual fact it came up at about 27.78Mhz which may be due to the height? Either way I found shortening it slightly brought it into resonance on 28.1Mhz? Most importantly it doesn't look to be a horrible match on 20 or 40m so I assume the loss in the coax isn't to high. I did consider running a tuner at the balun, I may experiment with this in the future to see if it makes a big diggerence. Does anyone make reasonable 500 Watt auto tuner?

Do or do not - there is no try - in HF RTTY contesting!

2009-09-01T03:09:00.000-07:00

I have finally integrated my whole shack so my Microham MKII Keyer, PC, FT-2000 and AT-AUTO tuner are now all in step.

I found operating MMTTY and MMVARI as separate appications a bit troublesome. The frequency readout just wouldn't work on MMVARI and MMTTY is good for QSOs but not really the thing for contests. Someone kindly suggested on the MMTTY reflector that the two ran well under N1MM Logger.

Until now I have tried a few of these fancy applications for RTTY (Mixw, HRD etc) but I always ended going back to MMTTY and MMVARI, I guess old Mako San really knows his stuff!

BTW - wow the USB Micro Keyer II is one brilliant piece of hardware. If you run RTTY or PSK for that matter you should check it out http://www.microham.com/index1.html The unit includes a really low noise off board sound card and FSK keyer. MMTTY fans should note - NO MORE EXTFSK!!

Anyway I digress.. At first I found N1MM quite challenging to use, but I soon realised the benefits outweighed the downsides. After typing a cople of replies in the logging window I adjusted to slecting the QSO window.. Its really just a habit thing and sorted now.

You can finf N1MM logger at - http://www.n1mm.com/

Having got it working I decided to use it in anger and enter a few contests. Again this is a bit of a step change but was worth the effort. I figured after all this thing was written for contesting.. I wasn't wrong!

After initial teething problems and about 20 minutes delay I was on the air and working everything I could hear in the TARA Grid Dip RTTY Test. Numbering and exchange is all automated.. The band scope shows you stations to chaise, multipliers. Yeah this thing rocks .. better still its using the MMTTY RTTY engine.. sweet!!

I haven't got the biggest antenna system going so I guess I'm not a big gun.. more of a littel pistol.. well more like a big pisol, or maybe a sawn off shotgun would be a better description.. Loads of power but no beams...

So I managed 7th place in the TARA Grid Dip test. Okay for a first go..

The RSGB 80M Club Championship was a blast at only 1.5 hours and yeilded 17th place. Next time I will try working a few more PSK stations to up my score.

Last week I entered the SCC RTTY contest and the week before the SARTG RTTY Test. I wonder how well I will do? One way or another I am really starting to enjoy RTTY contesting.

VY 73 to all G8UBJ

FT-897D Transverter interface

2009-08-18T02:55:00.000-07:00

The FT-897 has a transverter offset feature, its nice to display the frequency you’re actually working on. But be aware it only adjusts to within 1Khz so you may still have to tweak your transverter to get it exactly on frequency!

My OZ2M transverter for 4M (70Mhz) has a 28Mhz IF so I thought I would have a look at using the FT-897d to drive it.

Initially I wanted to create an internal breakout point between the main board and PA module. These boards are connected via two Taiko Denki leads and work at all frequencies HF to UHF. I had some spare Taiko Denki connectors -

http://www.scsiglobal.com/Vendors/Taiko_Denki/29tmp-S.pdf

and found a nice coax relay by Omoron which would switch the IF with low loss.

http://www.omron.com/ecb/products/pdf/en-g6y.pdf

The omron relay was of particular interest. Its capable of 10 Watts and using micro strip line technology can offer low loss up to UHF.

My initial plan was to internally switch out both the RX and TX lines for driving the transverter.

The first issue I encountered was the power level for the PA drive. Unlike most rigs it’s not a few milliwatts but 10 watts! Far to high a level and requiring significant attenuation.

The other issue was space and my willingness to modify my FT-897d.

In the end I decided against the internal board and built a simple external interface.

The advantage of this is not having to modify or change the FT-897d in any way (I bought it new from Martin Lynch & Sons and I decided to maintain the warranty).

On transmit the unit attenuates the 5 watts output by 37db to give the required 1mw drive and on receive I determined a simple 24db attenuator by trial and error.

Building an internal unit would have required the construction of double sided PCB with the incorporated micro strip line to work effectively up to UHF. An external unit only has to switch 28Mhz and in reality a simple change over relay would have been sufficient as I could have compensated for any loss with the attenuators.

But I had the Omoron relays so I thought I would try one out on strip board.

The switch is built into a small Eddistone box with all the RF connectors. Relay switching and power is provided directly from the CAT connector on the rear of the FT-897d. This minimises the number of connections.

As a fail safe the relay switches the antenna line to the transmit attenuator when released or no power is present.

This ensures that should the CAT connector become disconnected RF power won't be applied to the transverter output!

I continued the PTT line to a separate DIN output and this is used for switching the transverter.

Here is the schematic -

Of course a picture paints a thousand words so here is the finished unit.

I started by using an external RX attenuator. Once I knew the correct values I incorporated it onto the switching board. For convenience I built the power attenuator on a separate board. Fine adjustment of the transmit drive level is via the 1K pot.

Be very careful of the 12V supply. This is fed from the FT-897d via a .5 amp surface mount fuse. I did consider an external fuse but in my opinion the greatest risk is a short in the connector. Also SM fuses aren't hard to replace if you have the equipment.

I used the transceiver for transverting to 70Mhz and directly on UHF using the separate coax connector. I leave the switching box connected when its in the shack and for portable operation I simply unplug, switch off the transverter operation and turn up the power.

This is a very simple project and maybe useful to anyone considering transverting from the FT-897d

73 Rex – G8UBJ

The Wouxun KG-699E

2009-05-21T02:54:00.000-07:00

I recently worked a local station on 4M FM and was impressed by the audio. I was even more impressed when he said he was using a hand held! I normally expect a somewhat muffed audio but this was crystal clear and excellent modulation. He was using a Wouxun hand held.

I had seen these on eBay but lumped them with similar makes in the “Cheap Chinese copy category” and so I had ignored them.

A search of the 4M website revealed them to be quite good on receive as well. Naturally they won’t have the strong signal handling capability of a fixed or mobile rig. I thought I would see what they cost? They were £86 on eBay but going directly to a shop in Hong Kong they were $113 including P&P.

http://www.409shop.com/

409Shop don’t take cards but payment was okay through PayPal so I decided to take the plunge, registered with the shop and placed my order. The total cost came to £79

The radio arrived in about 7 days of the order and I noticed that customs said they opened it for inspection. Importantly they hadn’t decided to add any extra duty.

The photos says it all really – The radio was well packaged and came with a charger, belt clip, mobile phone type of microphone and ear piece. The two helical antennas cover upper and lower half of the radios coverage which is 66 – 88MhZ. The blue antenna covers 4 meters.

The user guide is fairly easy to understand and the menu system contains more features that I will ever use on 4M

You can monitor two frequencies at the same time. I like the way that you can set different step sizes on each VFO. So I have 12.5K on one and 10Khz on the other.

Its a nice size and the antenna isn't too long! Removing the lithium battery pack (Lasts about 24 hours on standby) reveals excellent construction.

This photos a bit under exposed (can you say that for digital snaps?) but I could obtain about 5 watts into a load. And 3 Watts into an infinite SWR. The antennas are a fairly good match so I expect its delivering close to the specified 5 watts. The power is adjustable down to 1 watt. Its a shame the squelch is in the menu but thats the only niggle I found.

So there you have it! I'm quite impressed with this radio and it fills a niche left by the big boys. They also make similar hand helds for 2M and 70cm and now a combined 2/70cm.

I have since purchased a nifty speaker mic ($12) which make the rig more convenient for long overs.

A word of caution. These radios can transmit out of band so only I would only recommend them to licensed amateurs i.e. Senior OMs who know the rules.

At last a good Zepp - or a J-Pole that actually works!

2009-01-19T05:31:00.000-08:00

There seem to be a multitude of antennas based on the Zeppelin. Above HF they are usually know as J-Poles but whatever they are called the principle is the same. The basic antenna consists of a ¼ wave stub to match a ½ wave radiator. An antenna of this type is reasonably simple to construct for HF but due to the stub it tends to be a single band affair, also at ¾ of a wavelength its pretty long which isn’t very useful for HF.

That said you could probably build it as an inverted L feed and it wouldn’t require a ground plane so it may have its uses.

Maybe a tuneable stub combined with a fan arrangement for radiating elements would work but at ¾ of a wavelength its going to be very long at anything below 20M!

On the VHF and UHF bands the concept becomes a lot easier to realise and there are almost as many J-pole designs on the web as there are web sites. If you need to understand the principles of how this antenna works have a look in the ARRL handbook.

For me three things attracted me to the j-pole –

1 – no Ground plane required - Quite an issue at 6M or below!

2 – it’s a ½ wave so exhibits more gain than a ¼ wave

3 – Its end fed so realising it as a vertical antenna is mechanically simple

Like many others these features prompted me to build several J-Poles; some from the web, and one from the ARRL handbook. To date I have been unsatisfied with the match I could obtain with any of the published designs - finally I found one exception, a J-Pole design that actually works!

I have a reasonable J-pole on 6m which I use for spotting. I made it from aluminium pole with a steel whip at the top to reduce the wind resistance. However my 6m J-pole is a bit of a Heath Robinson affair. It performs okayish but although its tuned to 51 Mhz its still about 1.2:1 at its lowest point. This isn’t a big deal as the auto tuner in my transceiver can take care of the mismatch.

On UHF I have been getting by with a simple ¼ wave ground plane. I made this out of an N-socket and five pieces of insulated copper wire. This exhibits quite a low SWR and was light and easy to construct. But of course I wanted a bit more gain and something a little sturdier so I started looking for a suitable J-pole design.

Eventually I thought would have a go at the design from WB8ERJ -

http://www.wb8erj.com/440jpole.htm

What attracted me to this design was his pragmatic approach, i.e. he built the antenna and then started adjusting it for best VSWR, the dimensions he gives work even if the dimensions seem odd. Most of the designs I have seen for this type of antenna make lots of false claims backed up by theory and K-factors and they have a lousy SWR, I really doubt whether half of them work as well as claimed.

The most important thing to note in the design is the distance between the radiating element and the stub. This is ¾” between centres which works out as ¼”!!

To achieve this spacing I had to attack the t-connector and 90 degree bend with an angle grinder. After some careful soldering I had the copper cactus assembled. Pay careful attention to the dimensions! The measurements are to the centre line of the horizontal (Not that there’s much of it!)

I tuned the antenna by attaching it to an old chair and adjusting the feeder until it gave the best match at 435Mhz (Centre of the UK 70cm band). I just held the feeder against the antenna for this exercise and marked the spot with an indelible pen.

The design suggests using jubilee clips but this isn’t very elegant and could corrode. To ensure this was reliable I used PTFE coax which can be connected to the pipe using some light work with the blow torch and solder (The same one I used for assembling the antenna). Obviously you still have to be careful, use a very small flame, get the solder on the pipe then the coax. N.B don’t inhale any fumes if you burn the PTFE insulaton!

I finished the antenna with a few turns of coax as a choke an used amalgamating tape to protect the end of the coax. The finished antenna was mounted on a short stub pole so its more than ¼ wavelength from my 6M j-pole and gives a near 1:1 match at 435 Mhz rising to about 1.2:1 at the band edges.

And yes it works very well, I have about 2s points improvement on the GB3BN repeater in Bracknell (About 30 miles away) and some repeaters I can hear for the first time. I notice the dimensions of this antenna are for 440Mhz so maybe if I increase the overall length slightly the bandwidth may improve? I now appreciate the importance of the stub distance, maybe this is the real secret to successful J-pole designs?

I notice WB8ERJ constructed a two meter version, I’m sure it works just as well. Maybe I will pull down that 6M J-pole and see if I can get it to match properly…

QRO a go-go

2008-12-15T06:30:00.000-08:00

I had some spare cash and with the pound falling fast I decided it would be a good time to invest in a reasonable HF amplifier for my station while my money was still worth something.

I already have a Tokyo Hy-Power THP-200BDX which has given me three years of good service. This is really a mobile amp and delivers 200 watts. Although its got good gain I thought something that could provide UK full legal was in order.

I had my eye on the Tokyo Hy-Power THP-700B for a while and at £800 seemed like the best bang for buck out there. Tokyo Hy-Power advertise this amplifier for mobile operation but I think the remote control of the 200BDX and small size are more suited to this. The 700B can be run in two configurations giving either 400 watts out for 10watts in or 600watts for 100watts in. The amp contains four parallel amplifiers each containing 2 THP120 devices.

In the 400 watt configuration one of the amps is a pre-driver with three delivering the required output. For increased resilience I decided to drive mine in the 600watt configuration but only to 400 watts (legal limit in the UK) which gives me plenty of overhead for safety.

The amp arrived much sooner than I anticipated and I was soon wiring it up to see how it performed on RTTY and SSB.

Unlike valve amps solid state devices present a different set of issues to successful use. The amp requires about 72 amps at 13.8v for full output so most supplies aren’t man enough for this job. Luckily I run the shack off a single supply 13.8V supply capable of 120amps, the PSU was made by Manson and is a prerequisite if you intend to run lots of power at this voltage. I found the cable THP provided with the amp was getting warm on transmit so I shortened it and doubled it up to ensure there was very little voltage drop.

The photos below will give you some idea of how well this amp is constructed. I think this amplifier design has in service for a few years now and it doesn’t have automatic band switching but I can live with pushing a button. Once open the main amplifier boards on their heatsink hinge upwards for easy maintenance

In service I found the two fans a bit noisy so I have modified them to run at 8 volts on receive. Full overload, VSWR, and thermal protection is built into the amp. This all works well but I really value my Palstar AT-Auto antenna auto tuner which ensures the correct antenna and tuner settings are always selected.

The amp easily provides 400 watts continuous for RTTY on all bands so even those KW Russian and US stations will now copy me. I have set up my FT-2000 to give the correct input power on each band which is between 35watts on 3.5Mhz to about 42 on 21MHz. If I run the FT-2000 at 100 watts output I can drive it to the full 600 watts for SSB but of course that really isn’t necessary. I just keep that option for busting those big DX pileups ;o)

So now its back to improving the antennas…!

Waifs and Strays

2008-09-16T03:47:00.000-07:00

You come across some strange descriptions in the ham radio section of eBay. Some must be strays. But I guess some descriptions enable us to quickly sort out whether it’s a non ham selling something.

“RF power reducer” – Yes sir, that would be… an attenuator?
“PL259 9mm-10 PIECES - HIGH QUALITY - BROWN INSULATOR” - Obviously superior to the cheaper PTFE versions?
“Ham Radio” -Well that narrows it down.
“MARCONI RC690 Ex Police Radio - No longer in service” - The radio or the police?
“Ex Police Radio removed from Police Volvo T5.” - Aren’t they still looking for it?
“HAM INTERNATIONAL CONCORDE II PLUS EXTRAS EWO RADIO 10M” - are you sure? Oh look 80 channels!
“CO-AX CONNECTOR (FEMALE) X 5. SOLDERLESS!” -Yes , we all use Belling Lee to achieve our quality coax connections
“QRP / Radio CRYSTALS” - no good I only run QRO.
“Morse Code MouseMat” - Just in case you need reminding?
“Bird Wattmeter Element, 1 Watt, 200 to 300 Mhz” – covering so many ham bands in Europe.
“ANTIQUE MORSE KEY - MADE IN BLACK PLASTIC TYPE MATERIAL, INSCRIBED HI-MOUND, MADE IN TOKYO”- I believe that "black plastic type material" is in fact black plastic. I think we can date that for you.

By the way if you want to learn or brush up on your CW have a look at this site –

http://lcwo.net/?p=main

Learn CW online. Does exactly what it says on the tin. Ideal for those wet lunch breaks at work!

Cool It!

2008-08-07T01:57:00.001-07:00

The FT-950 + 6m amplifier from Tokyo Hy-Power is a good combo and works well. In Europe if I can hear them they can always hear me. Actually running 200 watts they can sometimes hear me when I can only just hear them. In short its a real pileup buster. The FT-950 works surprisingly well on 6m but there are some things that are a bit annoying about it.

Here’s a list of my likes and dislikes –

Likes –

The filters and control work well and I especially like the notch filter that’s set to come up right between the two tones when running RTTY.
Its nice to have all the HF strength QRM fighting features available on 6m
I like the size. Not to large or small, so a good choice for field day.
Nice big controls for audio, squelch etc
The frequency readouts nice and big and when required bright.
I like the easy to use meter menu.
The 6 pin mini din for combined RTTY and packet is a neat and easy solution

Dislikes -

The power control is only adjustable from the menu
Connection to the linear is via 10 pin non standard mini din, why?
There’s no transverter output. Such a small thing but its really annoying.

You can get to the PTT from the other 8 pin socket so at least there’s a work-around for that. For me the FT-950 will only ever be a backup rig for HF and something to leave running on 6M.

Running RTTY, the Tokyo Hy-Power amplifier gets quite warm. It’s a two hundred watt amplifier but running only a hundred watts it soon gets too warm and starts to reduce power.

Surfing the web I noticed a neat fan tray design for a mobile amplifier and realised that a little bit of work with an aluminum Maplin project box http://www.maplin.co.uk/Module.aspx?ModuleNo=1728&criteria=enclosure&doy=29m7#Faq
and some 12 volt dc fans would probably supply the cooling I needed.

As you can see the design is quite simple.

I used the mobile mounting bracket as a template for the mounting holes. Both fans are run from the auxiliary socket on the rear of the amplifier and I used an 8volt regulator so there isn’t too much noise.

I added an additional switch so if I need to I can switch off the fans when running SSB.

With the fans running the amplifier can provide a steady 100 watts on RTTY and nothing gets dangerously warm. I could run it at 200 watts carrier but instinct tells me that I should reserve that for the occasional RTTY pileup for VP or VK on 6m. Well I can dream can’t I?

My 6M Junkbox Tuner

2008-07-29T07:32:00.000-07:00

Shopping in the local emporium found me face to face with a Tokyo Hy-Power HL602V 6M amp which is their 200 watts beast. I had been considering one of these for a while to complement my FT-950 which I use on 6m. Knowing how long they take to arrive when ordered, the quality, and also that the price was only going to increase I decide to buy it.

Having got it home (And smuggled it past the XYL) I installed it and tested it into a load.

Having spent so much on the amp I was concerned about running it into a bad VSWR. My HB9CV would easily take the power but was presenting the amp with about 1.5:1 which is quite a few watts of reflected power when running 200 watts. What I needed was a tuner to protect my investment.

I had seen a couple of designs on the net so I decided to have a go and build my own. The design used two variable capacitors and an inductor in a pi network. But the designs I saw tended to use plastic enclosures to avoid interaction with the coil.

As I was going to run 200 watts I decided a metal enclosure would be safer and more stable. To avoid interaction the sides of the box would need to be 3.5 times the diameter of the coil from the coil.

So I needed a fairly large enclosure for this project. The most suitable product I found is provided by Maplin Electronics. Their enclosure AB15 is 202mm in length, 152mm deep and 76mm tall.

http://www.maplin.co.uk/Module.aspx?ModuleNo=1728&criteria=enclosure&doy=29m7#Faq

The last two figures were the most important. The coil would only be 3x the diameter of the coil from the top and bottom of the box but I felt this would be okay.

Aluminum has to be the easiest metal to work with and 20 minutes had all the holes drilled and punched ready for all the components.

The tuner didn’t have to match a very broad range so the coil is 3 turns of 2.5mm copper wire at ¾”diameter

I had a couple of variable capacitors in my junk box which were about 50pf. I made sure the capacitors were properly secured to the chassis and all the joints soldered. You can see that I suspended the coil from the wires between the coaxial sockets and the capacitors so it was in the middle of the box (Away from the sides). This also makes it easy to remove and adjust or replace the coil.

Initial testing on low power went well; the tuner easily matched the antenna. I screwed the box closed, re-tuned and everything worked fine running 100 watts. I increased the power while carefully watching the reflected power. The unit needed a small re-tune but everything still seemed fine.

On the air I went back to an EA calling on SSB from southern Spain. The band was closing and he was just about readable but gave me a 59 in return so the amp and tuner were doing their thing.

This tuner handles plenty of power and although it has a limited range I could tune my G5RV jr with it!

The ATU needs some cosmetic finishing + knobs but it will do for now… I can beautify it when the sporadic e season ends!

6M Swiss Style?

2008-07-23T02:43:00.000-07:00

With only a sloop I thought it about time to put up a reasonable antenna for the 6M band. About a year ago I bought a 6M HB9CV which I had left in the garage until I felt ready to tackle it.

This was a second hand antenna and I have no idea who originally manufactured it. Initial inspection revealed that all the parts were there so I put it together on the garden table to see how it looked.

Apart from an end cap for one of the elements it looked okay. I noticed the matching section is kept away from the boom and elements by a set of grommets. That’s quite a neat idea as keeping the matching section the correct and even distance from the elements and boom is one of the common issues with this antenna and the idea appeared to work okay.

The antenna is driven through a variable capacitor and I was concerned that the one supplied with the antenna was a bit wimpy. Short term it needed to handle 100 watts pep & 40Watts on RTTY.

But I’m considering running a couple of hundred watts RTTY in the future and could already see the cap disintegrating in a molten glob ruining the antenna. As I had some ptfe coax left over from the trap project I decided this would make a useful capacitor.

I adjusted the existing capacitor for minimum SWR and then measured it on the MFJ analyser. It came up at 36pf so I cut an appropriate length of coax and trimmed it to the same capacitance.

Its worth trimming off about 3mm of screen at the far end so ensure the home-brew capacitor won’t flash over (I imagine this capacitor will need to work at quite a high voltage when running a few hundred watts through it!).

The finished coax capacitor was curled up and fitted to the antenna feed point. When complete the SWR was about 1.4:1 which was about as low as I could get it in my back garden. I have an ATU in the transceiver and it was capable of tuning that out so I decided not to fiddle further. Also experience has told me that you can adjust all day only to find things change once the antenna is installed.

The antenna is mounted below a small 2m beam on the back of my dormer window. It clears the rooftop and I can turn it using the Armstrong method. The other advantage of this set up is that there are no ladders to climb. All I did was assemble the antenna reach out and fix it in position.

I usually leave it pointing south east towards Easter Europe but I only have to reach out and I can rotate it towards W-land or wherever the DX is coming from. I can see a big improvement compared to the sloop with 59+20 signals form Italy and Hungary. The SWR is below 1.4:1 between 50.0 – 50.3 mhz so the rigs internal tuner easily takes care of it, most importantly testing it with 100watt carrier it appears quite stable. I’m sure this antenna can easily handle full legal, I wonder if the neighbours can?

Fire!

2008-07-21T01:37:00.001-07:00

Well its been an interesting summer (Not that we have had much sun yet) conditions on the HF bands have been poor but its motivated me to make some improvements to the new antenna farm.

I finally constructed a trap for 80m out of RG58 and extended my inverted V for top band. This should have been simple but I noticed that the trap tended to drift during transmit. I’m not sure if the coax was warming up or what but its very annoying as my auto ATU could start to re-tune half way through a QSO. The top of the vertical was very hot & experiencing very high voltages.

I decided to replace the trap with a simple coil and capacitor. I also tuned the trap away from resonance to cool things off. Being the skin flint I am I thought that I would build the 100pf capacitor out of coax.

Well that worked well and was very stable for about 2 minutes at which point I exceeded the breakdown voltage of the coax and it burst into flames! It was in the air so apart from the coil former no damage was done.

I tried again but used a 100pf doorknob capacitor with low drift... it cost me a bit but still drifted >:-(

I had a re-think and decided to have another go building a coaxial trap. This time I used RG412 PTFE coax and a larger 2.5” coil former. RG412 coax is the same dimensions as RG58 so easy to wind into a coil but its not cheap.

Success! The trap was tuned to 3.8Mhz and there is no drift running full legal (400 watts in the UK). Now I have Top Band as well as 80m. You can find me on 1.84Mhz or 3.85Mhz RTTY

Get going on 4M before the commercial manufacturers kill it!

2008-05-01T04:52:00.000-07:00

The four meter band (70Mhz) has been available to UK hams since 1956, about that time quite a few European countries also had 4M. Whilst Britain retained the band, most of the European countries lost their allocation to commercial services.

I found my Elmer G6HG through 4M. I lived a few doors away from Jim and his 4M signal used to cause chronic interference to our old VHF TV. We had a look in his shack (A real shack in the back yard!) he had a few filters to try… very soon I was hooked!

For years the best DX that could be worked out of G land was South Africa.

This lead to an interesting phenomenon, as up to then anyone wanting to get on the band had to make or modify their own equipment to get there. In the past this was quite an obstacle but plenty of us modified commercial AM kit or home brewed transceivers/transverters. Now there are a few kits available and one or two commercially produced products, but the economies of scale aren’t there so prices tend to be a bit higher. On the whole 4M is quite a different band and I think mainly because it feels like ham radio used to be 20 years ago. The emphasis isn’t so much on operating, but experimenting and construction as well. When you work someone there is always a story to be swapped ;o)

But the times they are a changing…

At the end of 2006 we have the following countries with allocations on 4M - Azores (CU), Crete (SV9), Croatia (9A), Cyprus (5B), Denmark (OZ), Dodecanese (SV5), Faroe Islands (OY), Gibraltar (ZB), Greece (SV), Greenland (OX), Ireland (EI), Luxembourg (LX), Madeira Is (CT3), Monaco (3A), Portugal (CT), Slovenia (S5), South Africa (ZS), UK Sovereign Base areas on Cyprus (ZC4) England (G), Isle of Man (GD), Northern Ireland (GI), Jersey (GJ), Scotland (GM), Guernsey (GU) and Wales (GW). Italian hams were given permission to use 4M during 2007 and I’m sure their allocation will be renewed.

More countries are being granted access to 4M every day. Depending on your viewpoint this has its good and bad points.

Its good to see more countries on 4M, but how long will it last before the big commercial manufacturers wake up to a “new market” and start pumping out 4M boxes and whatever .

Will 4M become like all the other bands where an “XYZ ur 599 XX91XX QRZ DX?” is the sum of 99% of QSOs. Maybe; but that’s progress?

If 6M is the magic band 4m is the constructors’ band!

If you are interested in the 4M band have a look at the 4M website at - http://www.70mhz.org/

73 and see you soon on 4M the constructors' band?

A Better Mouse trap?

2007-11-13T03:19:00.000-08:00

I finally moved house and so the 6BTV could be re-assembled. Thankfully the gardens a bit longer at the new QTH but there’s no lawn and a garage filling most of the end. I guess we would all like to own a 4square on 80m but for me (And I reckon most hams) it’s about squeezing a quart into a pint pot.

One area of severe disappointment with the 6BTV for me was its performance on 80m. I know it’s a shortened vertical and the traps don’t help but that loading coil and whip at the top just didn’t impress me. I could hear lots of stations but even with 3 full size radials for 80M the signal reports I got were very low!

So I asked a few questions and came up with a new idea for 80m. Remove the 80M resonator and whip replacing them with a 40m trap and long wire.

Last month I finally bit the bullet and invested in an antenna analyzer (MFJ259B) I must say that having used it to set up the 6BTV I was impressed!

First I assembled the 6BTV without the resonator and tuned it for the higher bands (10/15/20/30M).

I had to install it a bit close to the garage which has an effect of slightly de-tuning the antenna but I was anxious to site it as far down the garden as practical. I did get a few questions from neighbours but I explained what it was and chatted about ham radio. The woman next door looked a bit dubious but I think I won her over? Or maybe she was just please not to hear any more about my pastime?

So now the challenge was to build the 40m trap. I read a few articles –

http://degood.org/coaxtrap/

And downloaded a coax trap calculator -

http://www.planker.dk/oz6ym/Projects/DOWNLOAD/coaxtrap.zip

So that’s all the theory. Now the practical bit…

I could have made the trap with a pvc pipe as former but I couldn’t work out how to mount it easily. I decided to throw caution to the wind and dissect the resonator! My idea here was to re-use it as the coil former for the trap.

At this point major surgery occurs. I am sure there are plenty of you who would like to know what is inside the 80m resonator so the following photos are an account of the disassembly of the resonator and construction of the trap.

First I removed the outer cover.

Next the four screws securing the top were removed, and unwind the coil.

Leave some of the coil to attach the ends of the trap to.

Remove the whip and wet the end with solder ready for the wire.

So this confirms what everyone has said. The resonator on top of the 6BTV is a simple coil. Remove the coil and construct the trap using “good quality” RG58 (Is that an oxymoron?).

The antenna analyzer was pressed into service to check the resonance of the trap (7.050 Mhz). The pickup loop was particularly useful for this job. Has anyone used the accessory coils they supply to use the analyzer as a dip meter?

I finished the construction with silicone sealant for the coax ends, a layer of amalgamating tape over the coil and plastic tap for weatherproofing. To ensure the tape stays put I used a black zip tie to secure it at the bottom.

The last job was to mount this on the antenna, Solder the wire to the top of the resonator and tune it for 40/80M.

I started with about 35 foot of wire and shorten it until I reached 3.59Mhz which is where we RTTY types live!

Its not as pretty as the straight 6BTV but it appears to radiate more efficiently (even next to the garage!). I managed to work most of Europe and about 6 US stations on 80M during the QTC contest last weekend. At the top end of the band the antenna doesn’t perform so well. So choose which part of the band you need.

I may add a trap for 3.8Mhz and add some wire for the RTTY end of the band? I was impressed at how easy it was to construct and adjust the traps!

Spam & Ham and eBay

2007-03-27T03:34:00.001-07:00

I have to admit I am a fan of eBay and most of my experiences have been pleasant. I have picked up some bargains and on the whole dealing mostly with other licensed hams or recognised retailers is trouble free and fun.

However I guess the old saying, “If it looks to good to be true it probably is” is as true on eBay as anywhere else.

There will always be an underclass of seller who’s approach to business will be “If I’m not scamming someone there’s no profit to be made”.

A Wolf in Sheep’s Clothing?

I guess there are a few dodgy hams, lets face it nowhere in the exam is there a section on business ethics. But hiding amongst us are a few very bad apples.

Most of the stuff I buy is okay, but here are -

The Magnificent 7 deadly eBay sins

1 - Passing of faulty goods and pretending they are 100%.
I guess this is really easy, but of course there are shades of grey. I picked up one of my FT-107Ms on eBay and the fan was faulty. No biggie it worked after I replaced a few components. But I bought a few items that were totally dead, I fixed some easily - Shame on calling yourself a Ham and not being able to fix something so simple - double shame for passing it off as working!

2 – Overcharging for postage and packing.
And of course they won’t let you collect in person. eBay has clamped down on this but it still goes on. Check before you bid!

3 – Passing off goods with a dubious background.
eBay shouldn’t be a place to fence stolen goods, but I have one radio with dubious ownership. Not much the buyer can do about this but eBay could be a bit more careful.

4 – Using a dodgy delivery system.
There is one delightful seller who uses the most flaky delivery company. He claimed that they called but nobody was there. How it is the Royal Mail (Which you would think were the lower marker for service) can consistently deliver packages to my parents address with no issues and this chump couldn’t manage it. He then has the cheek to ask for more money for postage. If you buy from chalesantennaman you may get lucky, but plenty of hams don’t. Here is a sample of his negative feedback -

• Never Received , no tracking number , 12 pounds to shipping ?!?!
• poor quality item seller would not refund will not use them again
• Raped me on shiping, so watch out for this one - - - - - - -
• never received. Bad communication.Refund via request paypal necessary
• I have PAID for the item through PayPal, I have received NO CARDS & NO GOODS

So use chalesantennaman http://myworld.ebay.co.uk/chalesantennaman/ and this is what you can expect?

5 – Taking ages to dispatch an item
I dispatch the next day or as soon as payment is received. If you don’t have time to send stuff, don’t sell on eBay or like the better eBayers state that delivery will take a bit longer. DON’T deliver it late and then try and blame it on the Post Office!

6 – Bidding and never buying
This runs from new comers bidding too much and realising the mistake they made to a real toe-rag who actually claimed to have sent me a postal order. I think he was under the mistaken belief that I would send him the goods before I got paid. Of course he couldn’t provide a receipt for the order, but the retaliation cost me my only negative feedback.

7 – Leaving negative feedback as a means of retaliation.
“The lady doth protest too much, methinks”

Of course there are a few scammers who can achieve nearly all of the above in a single transaction!

So before you bid check out only the sellers negative feedback. Ask yourself, what if this guy does this to me (He probably will!). Any more than 1 negative over the last 3 months and you can be fairly sure the seller is dodgy.

Now have a look at watersstanton one negative feedback with an apology from them.

Back to eBay & I know who I will be buying from in future!

My God bender is Evil, I mean Bender is Eviler!

2006-11-08T08:46:00.000-08:00

Idly surfing the web turns up the odd boat anchor now and then. Any ham worth his salt will have owned one of these monsters at some early point in their career (I started with an R1155 and still chuckle when they turn up on eBay). Of course most of us learned the lesson and moved on, and of course there are the stupid ones who stuck with them (Probably didn't have a YL or XYL to draw the line!).

This is all well and good. Ultimately we need to preserve some of these anchors for prosperity, there’s a museum waiting for some of them... somewhere?

Have you noticed that the old car you once owned had a feature or gizmo that modern cars lack? My rusty old MK1 Consul had a brilliant bench seat and three speed column shift (Great for dates!). The rest of it was a total nail and so I was glad to get rid, but I can’t buy a car with bench seats or column shift anymore.

Probably some Euro-dork (The same idiot who banned lead in solder) outlawed them as they couldn’t count the exact seating capacity! What is it with car makers, they throw away perfectly good ideas?

This doesn’t seem to be the case with transceivers. Okay I’m sure there were some features that have been lost (Drift, magic eye, heat, weight, hollow state technology and lethal HT voltages) but on the whole if there is a good feature its been retained.

But I digress, boat anchors by their nature are on the weighty side but you can see that early on the basic layout made them pleasing to the eye, but they do whisper "just don’t try to move me and we will be best chums okay!"

But there are some exceptions to this rule…
They say function follows form or is that form follows function? Whatever, I can only surmise from the form of the following devices that they were built for some evil function?

They are often mounted on something like a toolbox or crate. I wonder if their owners think this will make them look more appealing or portable? Of course they all seem to be "Buyer collects", I wonder why?

Vote on them if you wish at -

I guess beauty is in the eye of the beholder. They may be getting on and prone to testing the truss but I still love my FT-107Ms...

At least they come with a handle on the side :o)

RYRYRYRYRYRTTY

2006-10-16T04:39:00.000-07:00

Back in the good old bad old days of 1979 I caught the RTTY bug. In those days my first machine was a Creed 7E which was a veritable boat anchor of the teleprinter world.

http://home.iprimus.com.au/oseagram/creed1.html

Returning to RTTY or MMTTY which I now use seems a world away.

My first challenge (After lugging aforementioned 7E up two flights of stairs) was to build/buy a terminal unit. In those day the easiest way to achieve this was to buy the BARTG ST5 Boards. A couple of 88Mh post office toroids and a few MJE340s later and voila, away you went.

Of course it wasn’t that easy. For some obscure reason UK hams worked AFSK with a 1275 and 1445Hz tones, Why? I guess it was an historic thing but this was bad news if you were trying to run FSK through an SSB rig (The 2nd harmonic was right slap bang in the audio pass band). Also all the Japanese rigs with HF were set up for high tones (i.e. the tones we use as standard today). Some time between my going QRT and reactivating the world saw sense and high tones rule (Well I only run pure FSK so they do for me).

Another problem was the motor running the 7E which was DC governed. This was good and bad.
Good as the machine was set up for 50 baud and was easily adjusted down to 45.45, and bad as it had more in common with a Marconi spark gap transmitter than a teleprinter. I tried everything to silence the beast but relief only came in the form of the Creed 444.

Technology was moving apace and these machines were just becoming available on the market. With a pair of BARTG gears to get it down to 45.45baud I at last had a quiet machine. Okay it was even heavier than the 7B but in its day was the best you could get.

If you were wondering I was a member of the local radio club EADARS (G3UUP) which did a lot of RTTY contesting in the 70s so I had no problems finding help or learning the RTTY ropes. I also learned that I was not built for 24hr contesting. At about 3am on the keyboard my body would realise it wasn’t going to bed and would start to scream for sleep. But it was a blast. We had a nice ST6 a reasonable linear, a TH6DXX and with the sunspot cycle at max could work the world.

I think the very difficulties RTTY presented in those days generated a sort of camaraderie amongst the RTTY orientated Ham community. Anyone could bung up an aerial and plug in a rig and holler CQ but it wasn’t so easy to get RTTY up and running in those days (Then try running the WAE QTC contest with punch tapes! definitely a multi-op multi-machine affair!).

Of course personal computers were the next step and slowly we observed the steady increase (through observation of the increasing black mark on the right of the print roll -No CR LF) of computer based RTTY.

When I came back to radio I discovered MMTTY.

http://groups.yahoo.com/group/MMTTY/

Of course I am an old dog and MMTTY was a bit of a new trick. But I had a PC and compared with all the problems with terminal units and teleprinters MMTTY is a breeze. Better still the FT-107 is set up for proper * FSK so connections couldn’t be easier.

Actually I cheated and bought a MicroHam interface, but there is no serial port on my pc so it was the easiest option.

I now have a nice tight 300Hz CW filter fitted in the FT-107m (Courtesy of Carol W4CLM and Fox Tango). After 25 years the 107 needed a bit of realignment (that’s a whole ‘nuther story) but less than me. For now there’s nothing more pleasant than a few hours working the HF RTTY contests during the weekends.

Only thing is 100w + on 80 or 40m and my internet connection dies, something I have yet to sort.

RYRYRYRYRYRRY A final Word

Please do not adjust your set! Maybe its just a few lids out there but I spent a long time aligning my RX to TX frequency. Its good to about 10Hz! I find there is nothing more annoying than to reply to a station who is call CQ who then comes back at a different frequency? If you must run AFSK or cant align your TX frequency and or shift please switch off the wretched ATC button on MMTY. By all means use the RIT but remember it’s a Receiver Incremental Tuning control not a TIT!

** FSK is obtained in the FT-107 and FT-902 etc by creating a carrier and shifting it by 170Hz not by using SSB and tones.

UHF Connectors are just Wrong!

2006-07-14T07:27:00.000-07:00

I haven't got anything new in the shack, well the odd item. Most of its 2nd hand and most of its Yaesu. My latest exploits have been setting up a 6m station.

Wanting to keep it all looking nice I though I would use the 6m module in the FTV-107 transvertor.

Well sounds easier than you would imagine...

originally I bought an FT-107M with matching FTV-107.
But that had no 6M module...
Then I saw an FTV-901 with a 6M module which I bought.
Then i saw a 70cm mopdule for sale which I had to have.
But the 144 Mhz module in the FTV-901 was faulty so before I sell that I have to fix it.
It needs a 3SK51 which seem a tad pricey. But I notice an old FT101Z IF board for sale, has a good few 3SK51s on it... can you see where this is going!

Anyway, I restored the FT-107M + Transverter and replaced those dodgy SO239s with N Sockets and now it all works well.

Do I have a word for those trusty UHF (PL/SO239) connectors. Well yes, they are just wrong at every level.

How did they get that name. I couldn't think of something that was less suited to UHF?

I though Magnum was a TV cowboy, or an ice cream?

2006-06-04T01:51:00.000-07:00

With all this commuting I though its time to go mobile!

I picked up a Magnum 257 on eBay for 10m mobile, it had an audio problem but that was easily sorted with a bit of switch cleaner.

It looks like a bit of an unusual rig but searching about I can see its sold under different badges. It’s a multi-mode transceiver with 30watts out on SSB AM and FM and was obviously originally built for the CB market. I stuck it on the Thruline and it delivers a comfy 32watts output.

It’s been in the shack for the last month whilst I sort out how it works.

Pros –

Cheap as chips 10m multi-mode
Reasonable power out
A small light-weight unit (I won’t be leaving it in the car for any tea leafs so it has to be carried)
Variable power out 6 – 30Watts on all modes (Very useful)

Cons

The RX audio quality could do with improving
Best used mobile as it looks a bit dirty on the spectrum analyser
The 10KHz steps show its CB heritage?

I started tuning about on FM using a dipole in the loft and soon encountered a local who gave it a good report. FM was Okay, SSB was good, AM was dire (More to do with the mode than the rig?)

The next day I could hear a Swedish repeater on 29.620 with some locals rag-chewing. Managed to work through using the repeater shift and have had a few simplex QSO since - 59+40 into OE land (Austria) on FM so this is going to be fun!

The 10Khz steps are a bit annoying on SSB, to get 1Khz you have to press a button or two, which is a bit fiddly. It comes with a combined TX/RX clarifier (No RIT), but the range of this is only +- 1.5khz

If anyone knows of a mod to take this to +-5Khz or just a circuit diagram get in touch!

I think I will stick to FM when mobile, and maybe sideband when parked up.

One advantage of 10m is all the CB stuff you can pick up. This either works on 10M or just requires a minor re-tune. I decided an amplifier would be useful and picked up one for £26. Again this is meant to be 150watts or something silly. I checked it out on the power meter and it gives a reasonable 80 watts out for about 6 watts in so I guess these CB watts drop off as the power level increases?

Anyway 2 minutes at 70 watts and the unit was hot to the touch, 4 minutes and you could leave your fingerprints (Plus skin) on the heat sink. Another 2 and I think the unit would have automatically un-soldered itself.

I had a little 12-volt fan going spare in the shack, so this was wired into the unit and tie-wrapped to the heat sink. It will be on all the time the amp is running but won’t be noticeable in the car, and should keep it from going into thermal meltdown?

I have the aerial ordered (a sort of springy 1.5m loaded whip thing) and will soon be able to create a bit of noise on 10m.

That should give me something to do whilst driving home through Richmond Park in the evening. I wonder how long before I get pulled over by some over enthusiastic pimply policeman hoping to nab a cb’er?

FT-227R Memorizer (Thats Memorise with a Zed)

2006-04-30T23:03:00.000-07:00

Back in the early 70's I lived two doors down from a local radio ham. G6HG, Jim Bassett (AKA Bertie) was licensed before the war and his exploits on the 4M band would play havoc with our TV (Old black and white 405 line system on 50Mhz).

I used to visit him on Saturdays and we would chat about everything from Ham radio to his wartime work (Taking down CW and feeding it to Bletchley). Articles about this always focus on the hero's like Turing etc. But behind them was an army of ex-hams carefully taking down hour after hour of encrypted CW. He did get feedback, usually to say that the other two working on the frequency disagreed on a group so could he be more careful...

Can you imagine how good his CW was?

You can't imagine how pleased he was at the end of the war when they returned all of his equipment (Confiscated on grounds of national security!).

Anyway, Jim had a motley collection of equipment (Heathkits, an HRO etc) but also a newly purchased FT-227 RB memorizer and an IC-202.

When I was first licensed I never owned an FT-227 but after a few years they started showing up 2nd hand so I got my paws on one. Of course I kept it for a while and then traded it for the next gadget. One of these recently turned up faulty on eBay so I put in a bid and once again became the proud owner of an FT227-R memorizer!

The first thing that surprised me was the weight of the unit. I think the FT-817 weighs about half as much! Its got a cast frame and was built to last (Chimps permitting).

This box had no audio, and a missing power cable (Why it was cheap!). Someone had soldered some skinny wires directly to the two-pin power socket (Nasty!). No biggie I thought; a trip to Maplins sorted out the power connector.

I powered it up, no audio. I removed the base of the unit where someone had connected the speaker wires in reverse (One side of the speaker is connected to the chassis). Reversing the speaker wires was the worlds speediest fix of audio.

Tada! It sprang to life, but came up on 146 Mhz >:o I checked the power out on the Thruline; 8watts, that’s good. Then suddenly 0watts WTF?

If you own any Yaesu equipment (I own lots) join Fox Tango

http://groups.yahoo.com/group/FoxTango/
http://foxtango.org/foxtango001.htm

The unit came with documentation, but I also downloaded it in Handy pdf format from Fox Tango.

I got the voltmeter out and had a look inside. 1st thing I noticed was the PLL unit was not fixed (Some chimp had obviously been inside this unit). I tracked the faulty output down to a blown transistor in the PA control circuit. A quick replacement and off we go again.

When I turned the unit on its back the loose PLL board had dropped down and shorted the transistor. So I found some spare screws and fixed it back in place.

Lesson 1 - If you go inside something, please make sure you put everything back where it came from! I think this chimp must have closed the unit and wondered what the spare screws were for?

Let put it another way, if a surgeon was working on you and you woke up with a kidney missing you might be slightly annoyed. Yeah you have two but there is a reason for that!

Anyway, I modified the unit to come up on 145 Mhz -

http://www.printlife.co.nz/radiomods/yaesu/yaesuft227.html

I Replaced the crappy SO239 with an N-Type and tuned the unit up.

The last problem I had with it was over-deviation. I guess it was set up for 25Khz channel spacing of the 70's. That was just an easy adjustment to VR202 on the main board.

It works fine, 10 watts is good for local chitchat. It will need a tone squelch board if I want to work through some of the local repeaters. Obviously obtaining an original tone squelch board would be like finding hens teeth.

One of the basic features of the FT-227 is that it can memorise 1 channel, wow be still my beating heart! The 10Khz steps and +5K button are a bit annoying but it gets me the whole of the 2m band on a budget - £30 + £1.49 and 32p for the power plug and blown transistor.

This is a really well built transceiver! I don't think you will find commercial rigs built as well as this.

So if you see one of these up for sale and you know some basic electronics grab yourself a bargain & see you on 2M FM!

It's Been a Long Time

2006-04-29T12:32:00.000-07:00

I recently returned to amateur radio after nearly a 10 year break. A lot has changed, and as far as I can see, mostly for the best.

Meet the twins, and my trusty (or should that be rusty) FT-227.

I found the FT-227 on eBay; it had no audio and the tx was faulty. These transceivers were top of their class when I was first licensed in '79 so I thought it worth a punt. £30 later it was mine; I will go through the '227 story later.

I picked up the IC-202 from Martin's emporium in the early 90's and never let it go. Okay it only does SSB and CW and puts out 3watts PEP but don't be fooled. These are great fun to operate and like the '227 easy to fix. I couldn't leave the 202 on its own, and I wanted something for 6 Meters so the IC-502 seemed ideal.

This 502 is a recent addition. I found this ancient model in Hong Kong. Again 3 watts PEP but it produces a fairly clean output and it drives a PA.
It still has the protective plastic over the front, unbelievable? Its so un-touched that I'm now agonising whether to open it up and do the band spread mod?

So that’s the VHF kit. 20 years ago it would have seemed a bit lightweight, but in those days I only ran VHF/UHF so I had nothing better to spend my pennies on.

When I get round to it I will cover the rest of the shack, HF equipment, RTTY and of course the aerials.

73 Rex (G8UBJ)