Search This Blog

Saturday, 23 November 2013

Now that the smoke has settled

Well,

You may remember the mishap I had with my FT-847 back here:

http://g0mgx.blogspot.co.uk/2013/11/my-ft847s-got-no-nose.html

It's been repaired, and as predicted I had melted some of the components in the 4/6M low pass filter. I had also burned some of the PCB tracks - I got lucky really as the PA itself survived.

To further my adventures on 4M Meteor Scatter I think I need to find a better way of generating some high power RF without running the 847 at maximum bananas. Hence a new linear project has been born.

I've scribbled down my thoughts over the design, I want to include some software based control and alarms so I can watch out for:


  • To much drive
  • High SWR
  • PSU problems
  • Over temperature
It would also be good to include a software based power measurement and SWR reading on the output.

Here's the rough starter design:

I've stuck the appropriate numbers into Elsie and have the Low Pass Filter design also:


I've ordered a 300W 50-75 MHz RF module (no PSU, heatsink or cooling) so I'll start to think about the software for the linear controller over the next week or so - it will be Arduino based for sure.

There was a lovely UK morning captured on Antenna Cam here today:

Good, egh?

No comments:

Post a Comment