[Amps] Can I cool too much the tubes?

[Roger]

On 8/18/2010 2:29 PM, Bill, W6WRT wrote:
> ORIGINAL MESSAGE:
>
> On Wed, 18 Aug 2010 10:34:58 -0700 (PDT), Rudy Bakalov
> <r_bakalov at yahoo.com>  wrote:
>
>> Experience trumps specs. The amp goes into standby mode after about 30 minutes running at full power, i.e. about 1200 W.  If I run it at around 400-500 W it is fine.
The transformer ratings/temp are another important point.  I've no 
experience with the Ten Tec amps, but I've always liked their 
transceivers. The transformers in some of these amps get HOT! As long as 
they don't get too hot it doesn't hurt them, but are they rated to run 
full power over long periods? I think many are rated for Intermittent 
amateur service rather than CAS or CCS.

However, when you look at various amps in the same power range and not 
today's legal limit Vs the "old" legal limit AND the prices differ 
notably the transformer is one of the major expenses. Labor, tubes, 
quality, plus fit and finish are the others. Only the Alphas come close 
to the present day Japanese for fit and finish. That is not to say all 
US made look cheap in comparison, but a number of them do. OTOH fit and 
finish are not what makes contacts. The Chinese are beginning to produce 
some stuff with pretty good fit and finish as well as quality with 
inexpensive labor.  I'd not be surprised to see Korean amps show up to 
compete with them before long. Note how they are making inroads into the 
automotive market.

Even with my long winded transmissions the transformer in mine barely 
gets luke warm.  What it'd do with a lot of digital or contest, I 
haven't seen...yet, but as it's rated for continuous carrier 33% higher 
than the legal limit, I figure it'd handle digital at the legal limit 
all day long as well and then next size up has a notably heavier 
transformer.

73

Roger (K8RI)
> REPLY:
>
> If it were mine, I would measure the tube seal temps when it goes into
> standby. It could be that Ten-Tec has been ultra conservative on it's
> shutdown point.
>
> 73, Bill W6WRT
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