[Amps] low pass filter fail ;)

[Benedikt Sveinsson]

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 at contesting.com] on behalf of Benedikt Sveinsson [benedikt at 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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