[Top] [All Lists]

Re: [Amps] Looking for help with AL-811 repair

To: "Mark Thompson" <>," AMPS" <>
Subject: Re: [Amps] Looking for help with AL-811 repair
From: R.Measures <>
Date: Mon, 1 Dec 2003 02:45:16 -0800
List-post: <>
Are all of the filaments lit?  

>I'm looking for some help in troubleshooting an Ameritron AL-811
>amplifier (600 watt version) and am hoping someone on the reflector can
>I can only seem to get about 200 to 300 watts of output power into a
>good 50 ohm load in CW mode.  After tuning the amplifier to the
>manufacturers specification I increase the drive to the amp and can run
>it up to about 300 watts when the output stops increasing.  The Ip
>stops increasing after getting up to about 300 to 350 mA.  The Ig
>starts to increase very rapidly at this point.
>The plate voltage is resting at about 1500 volts with no drive (a bit
>low) and decreases to 1350 volts under the described drive.  I have
>verified that the line voltage is 120 VAC and only drops to 118 VAC
>when the amp is driven.  All the diodes in the high voltage circuit
>appear to be good (measured using a DVM) in both the forward and
>reverse directions.
>I have also substituted a different 811 one at a time for each of the
>tubes with no difference in the results.
>Any suggestions on where to head next?
>Mark  K2AY
>Amps mailing list
Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>