Thursday, August 07, 2008

Cool It!

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
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?