[Amps] Amp Warm-up??

[Jim Thomson]

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!

Please Advise!

Thanks for Any and All of your Comments!

-73-
Bill
N6FFC

###  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
warm up. 

## 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. 

Jim   VE7RF