In a message dated 2/8/2007 3:25:42 P.M. Eastern Standard Time,
rbonner@qro.com writes:
How many bulbs have you had fail the first time you turned it ON? I have
had a lot. When you are cycling, you will have results all over the map
whether you step start it or not as each tube is an individual. Some die at
birth, and some live to be 114 years old.
I have been thinking about this subject a lot myself. This is what I have
concluded. Since ham radio is an occasional thing we do with little transmit
time compared to off time or listening time. Seems like it would be
senseless to leave your filaments running 24/7. On the other hand if you
cycled them
a lot that could be costly too, so for hams as Bob says it probably makes
little difference. But I think the ideal situation would be to turn off the
filament when not in use and to bring the filament up slowly with a variac to
proper operating voltage every time you use the amp. It would be a pain to do
that every time, but all that hassle aside, it might be "the best" thing.
Of course you could argue that one mistake could be costly, but I am speaking
only as everything being perfect. It's just not practical though.
For what is it worth, here is what I do. When I go on the air I do not turn
on the amplifier unless I need to use it. If I know I am going to use it, I
will then turn it on, it will stay on until I am done hamming for that
session. I won't shut it off if I know I might be using it again even an hour
later like after dinner or something. I would NOT cycle it on and off as I
needed it for a hamming session. This is why I always put a standby switch on
all my SB-220 amps. Many times I did not use the amp and then suddenly I
would
and then again I would not. The standby switch came in handy so I didn't
have to cycle the filaments. You all notice that USUALLY when a light bulb
burns out it is when you first turn it on. Only my 2 cents. Lou
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