RE: [CQ-Contest] Advice about HF amplifiers

[Pete Smith <n4zr@contesting.com>]

At 03:01 AM 9/6/2004, jukka.klemola@nokia.com wrote:
> TL922 cooling is compromised.
> The socket of the 500Zs do not get sufficient air flow.
>
> Phenomena: the solder inside the filament pins melt.
>
> Cure: just re-solder but add a fan.


It appears, from my experience, that adding a muffin fan somewhere on top 
of the amplifier (in my case an SB-220), exhausting hot air from inside, is 
sufficient to solve this problem.  I used a pair of 110V muffins connected 
in series across my 110V supply, so that they turn a little more slowly; I 
use the other one to pull air off the transceiver heat sink.


73, Pete N4ZR
The World HF Contest Station Database
was updated on August 2, 2004
2753 contest stations at
www.pvrc.org/WCSD/WCSDsearch.htm  

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