[Amps] Muffin Fan on Swan Mark 1

[Ian White, G3SEK]

Tom Rauch wrote:

>By the way, it is permissible to allow the envelope away from the
>seal exceed the rated seal temperature. The seals are the critical
>area you should test.
>
That is much more tricky, because the temperature-sensitive labels are 
way too big. It would either require dots of temperature-sensitive paint 
(and I only have 200C and 250C, which wouldn't be enough to tell me 
anything useful) or else I'd have to wire the tube with thermocouples 
and do the whole test at DC. Since the whole thing started with "While 
the cover's off, how about trying those temperature-sensitive labels..." 
it just didn't get that far.

>I'm not sure how it would behave on 50Hz.
>
Less well than at 60Hz, but well enough because the SB-1K's fan is much 
better than marginal. Amps with marginal cooling at 60Hz are in real 
trouble at 50Hz... and often so are their mains transformers.

-- 
73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                           'In Practice' columnist for RadCom (RSGB)