Common to many discussions, about reliability and life of Ham amplifiers and
power supplies,
include an aspect where an effort is made to economize and "push" limits of
components in hopes of
money or space savings. I started in 1968, with a Drake TR-3 with the 3 ea of
the tiny 12JB6 sweep tube
finals, ( about $4.00 ea, $12 BUCKS a set!) and as a kid who liked CW, was
cautioned about the low duty cycle, and plate dissapation of those tubes.
I longed for a "sturdy" 6146W radio. TX. I remember also as a kid, my
stockinged feed sitting on the drake
Power supply transformer, sitting under the ops table, and noticed how HOT
things got when operating. In more modern times I noticed my Drake L-4B also
got Very hot both the RF Deck, and the power supply, esp in contest mode, so I
used to, and still do, hang some muffin fans at strategic locations on P/S and
Rf decks, to cool them down.
I also remember my library of Eimac Amp Notes, by Bill Orr, W6SAI, a statement
that, the only time you have added too much blower capacity or flow, is if a
tube is pushed out of its socket.... Mo' is better, until that point.
Nowadays, there are a lot of mini fans that might even be locatable inside
cabinets that could move air around to dissapate heat.
Back in the 60s; pre PC era, muffin fans were EXPENSIVE, (for a kid) something
like $25, (1968 Dollars) Now they are all over the place, surplus pulls out of
computers, etc. So.. the question is, will judicious use of external muffin
fans really do much to increase life of amateur radio QRO amp components, like
capacitors, resistors, diodes, and transfomers? ( or even modern Transceiver
SS PA's?)
Or, do the engineers who designed the gear actually determine and build good
heat management schemes, without the need for outside cooling help?
All the best, Pat Barthelow aa6eg@k6bj.org
Jamesburg Moon Bounce Team
http://www.jamesburgdish.org
"The most exciting phrase to hear in science,
the one that heralds new discoveries, is not
"Eureka!" (I found it!) but...
"That's
funny..."" --Isaac Asimov
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