[Amps] Amp Warm-up??
jim.thom at telus.net
Fri Apr 6 12:26:18 EDT 2018
Date: Fri, 06 Apr 2018 03:27:21 +0000
From: Bill Ashby <n6ffc1954 at gmail.com>
To: Amps at contesting.com
Subject: [Amps] Amp ?Warm-up??
<Good Evening All!
I have an Ameritron AL-80B Amp, which i have had for just under a year, and
have a Question about
?Warming-up? the Tube!
First, i must confess that I?m in the generation that held that Tubes
Should be ?Warmed-up Prior to
Actually hitting them with ?Full Power, and my Question is this: Should i
After turning the Amp ?On?
Should I Wait for the Tube to ?Warm up? Prior to using the Amp. Or is it
?Safe? to just Turn the Amp
?On, and Not Worry about Warming the Tube Up Prior to using ?Full Power?
The Beauty of ?Solid State devices is that the Power Transistor(s) DONT
?Need? to ?Warm-up and
Can be used, running Full Power when the Amp is Turned On!
Thanks for Any and All of your Comments!
### The Ameritron AL-80B uses a single 3-500Z TRIODE. The 3-500Z
uses whats called a directly heated cathode. Its an instant on tube. There is NO
## The only delay in there is the step start for the HV supply...which I believe also
step starts the instant on tube. So maybe 1-2 secs at most. If you look at the HV meter,
you will see it comes up most of the way...then jumps to max, normal HV. Typ step start
delays range form 1/2 sec to perhaps 1-2 secs.
Tubes like the 8877 etc, used whats called an indirectly heated cathode. These type of tubes
jave a separate heater..aka filament, in addition to the normal cathode. These types of tubes
typ have a minimum of a 3 min warm up delay. But these types of amplifiers using INdirectly
heated tubes..also have a 3 minute timer built into em, so you cant apply drive. The timer
inhibits the TR relay inside the amp.. for 3 mins. TX, and the amp is still forced into stand by mode, and
the 100watts of drive from the xcvr will pass through to the ant. Its just protection so there is NO way you can apply
drive to the tube, without going through the 3 min warmup.
## In the case of your AL-80B, you dont have to wait, just turn it on and go for it.
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