well, here goes ;)
I'm very close finishing my 2m amplifier that I'm going to use on EME
here is a brief description of how I made the amplifier.
http://www.tf3cy.is/1-2-kw-144-mhz-sspa
(sorry for bad Engish)
I decided to get a Low pass filter from Philippe F5CYS - my junk burned in few
seconds !
but the amplifier is working as expected - when I have time I'm going to go
over the source code of the controller and post. Still allot of junk in it.
73, Benni TF3CY
________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Benedikt Sveinsson
[benedikt@ok.is]
Sent: Friday, April 25, 2014 9:49 PM
To: Amps
Subject: [Amps] low pass filter fail ;)
I have been building a 2M SSPA - final part in the puzzle has been the low pass
filter.
After building this filter, copied the design from W6PQL - but I have limited
resources here in TF land, so I don't have access to good PCB materials. But
the filter was measured using a mini VNA Pro analyser with good results. 1:1.2
SWR on the operating frequency and cuttoff starts around 150Mhz
well, after transmitting about 10s I noticed a drop in output power, I took the
cover off and aimed the camera while transmitting
This is what happened on youtube: https://www.youtube.com/watch?v=9lU3I3BgmkE
I suspect there is something else wrong, as this happened very fast 10-15s -
and solder melts!
Guess I will go and find teflon sheets and make my own capacitors with copper ;)
73, Benni TF3CY
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