[TenTec] Paragon Finals and other woes

[Ben Hall]

On 1/28/2019 8:35 PM, Bwana Bob wrote:
> on the power control board was open.  I fixed that, but found a short on 
> the 13.8 V bus.  I haven't dug into it yet, but fear that the Astron 
> supply zapped the finals.

I've got a Paragon here with a short in the RF power amplifier 
somewhere.  It's strange - the radio will power-on for a few seconds 
before current on the supply (proper Ten-Tec supply) ramps up shutting 
it off.  I know it is in the power amp module - if I disconnect the 
heavy gauge red wire to the power amp, it will power-up without any 
issues.  The power supply is fine - no issues there.

I'm almost thinking that with this behavior, it's not the transistors 
themselves, but something goofy in the other components leading to a 
turn-on of the finals?  Not sure.

I too am wondering if I should fix it or not.  Before it broke it was a 
good running Paragon - sent and received fine.  It's sentimental, it was 
my father-in-laws rig before he became an SK suddenly in a motorcycle 
wreck.  But like some others have already posted, it seems like these 
radios have a lot of issues over time so that if I fix the problem in 
the finals, what's next?

FWIW, if the problem is in the driver MRF476, haven't found a mainstream 
place that sells those yet.

Thanks much and 73,
ben, kd5byb