[Amps] The maximum amount of 811As and 572Bs in parallel

[Will Matney]

Peter,

The Galaxy 2000 amp used (10) 6HF5 sweep tubes. It was also grid driven, and was an amateur amplifier. It was made by the Galaxy Electronics Company in Council Bluffs, Iowa. One thing to note that this amp used an anode voltage of 800 Vdc. This is really the region where these type tubes should be used. This one also had a "linearity control" built into the bias circuit. It adjusts itself to different power levels keeping it at class AB1.

Palomar amplifiers, which were built in California, were technically amateur amps. They had a band switch and thus could be used as amateur amps. They used 6LF6, and 6KD6 sweep tubes, and were meant for low drive power transceivers. CB'rs though bought these and converted them. These were built before the law was changed that they could not be made to operate on 10 meters. One similar was featured in the ARRL Handbook in the 70's. It was almost the same amplifier in the way it was built.

There was a few other companies like D&A and Pride that actually made amps that would work in the amateur bands. The RM and Zatagi sweep tube amps now are strictly CB amps and have no bandswitch. This even though they claim to be for 10 meters, etc. They have a circuit that supposed to inhibit 11 meter operation, but by just moving a jumper does away with the circuit. They are using the EL509 tubes though. If I recall, the PL version has a 40 volt heater?

Galaxy amp;

http://www.radiowrench.com/sonic/so02192.html

Best,

Will

*********** REPLY SEPARATOR  ***********

On 7/24/06 at 7:55 PM Peter Voelpel wrote:

>Sweep tube amps were quite common in Germany in the past when our power
>was
>limited to 150W total dissipation in the final stage.
>I built several myself, one GG with 5xPL519 doing 2KW out on all bands and
>another one with 12xPL36 at 3KW, with some drop in power on the higher
>bands
>but not less then 1,8KW on 10m.
>DJ4ZC developed for his dissertation his HELAPS using "Envelope Elimination
>and Restoration technique" amp with 5xPL509 in the sixties which did 5KW
>out
>in SSB, a total of 7 were originally built and 5 of them are still in use.
>Some qro amps were also built very successfully using 2x12 PL519 in
>push-pull.
>Even at todays higher price for sweep tubes they are today an alternative
>and still built and used over here.
>
>Multiple tube amps using 5-6 4CX250B were commercial built in quantities
>for
>the military by RFT in Eastern Germany and by Zellweger in Switzerland
>
>73
>Peter 
>
>
>-----Original Message-----
>From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
>Behalf Of Will Matney
>
>Rich, you better watch as someone will start pointing their finger at you
>like they did me for even mentioning an 11 meter amp HI HI! Remember, those
>are cheap junk. The thing is, I've seen some of those built back in the
>60's
>that has outlasted many amateur amps like are being built now by a few
>manufacturers.
>
>
>
>>>
>
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