It's a very common behaviour on the AL1500.
Output power on 20m is lower than on the other bands (for the same input).
You need to increase the input power, and the effect is a higher grid
Within 50 mA, it is not critical.
----- Original Message -----
From: "Junior" <email@example.com>
Sent: Sunday, July 29, 2007 1:59 PM
Subject: [Amps] AL-1500 question
> On 20 meters the amp takes close to 100 watts to get 1500 watts out.
> The other bands only take around 55 watts (max ever used on 10m is 1000w).
> Same results on two different antennas
> In standby the HV meter reads around 36-3700 volts.
> The amp tunes ok on 20 meters. Only difference is the grid is up around 50
> on 20 whereas on the other bands it is around 20 on 1500w out. Ameritron
> states the meters could be up to 25 percent off on the readings.
> I do not use ALC to the amp.
> On occasion I can hear a barely audible crack or pop. This is in standby
> full op whether I am keying the amp or not keying.
> Removing the cover I see no arching indication or black spots on the band
> The amp is around 10 years old and has seen a lot of contesting (rtty).
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