[Amps] Amp for sale on eBay

[Will Matney]

Peter,

The old D&A's had several faults. First, was a low plate voltage (about 750 VDC). Second, he had wire run under the chassis for miles. He tried to mount the driver tank circuit at the front of the chassis with the tubes in the rear. All that wire made things squirelly. Last, the tubes were ran straight G-G with no screen voltage, and on some no control voltage. Some, all three grids went to ground where the gain was lowered over it. Plus, the 6LQ6 was about 3/4 as powerful as a 6KD6 or 6LF6. The larger models like the Maverick 250 and the Phantom 500 really need a third stage pre-driver to get it up to where it needed to be.

Best,

Will

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

On 2/3/06 at 1:21 AM peter.voelpel wrote:

>With sweep tubes like 4xPL509 or 6KD6 the usual output was 1KW,
>seems to be a quit inefficient amp.
>DJ4ZC and others did 6KW with 5xPL509 in his class D amp using L.Kahns
>"Envelope Elimination and Restoration" principles in the seventies.
>
>73
>Peter
>
>-----Original Message-----
>From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
>Behalf Of Will Matney
>Sent: Freitag, 3. Februar 2006 00:42
>To: amps at contesting.com
>Subject: Re: [Amps] Amp for sale on eBay
>
>Alek,
>
>It had 4 drivers and 4 finals. The drivers were something like used as
>vertical output tubes, I cant recall the number, 6JM6 maybe? The finals
>were
>6LQ6 horizontal sweep tubes. The other tube was like a 6BA6 used to key the
>relay off the RF. About 300 watts was the max with a good set of tubes.
>
>Best,
>
>Will
>
>*********** REPLY SEPARATOR  ***********
>
>On 2/3/06 at 7:33 AM Alek Petkovic wrote:
>
>>Wow! 9 Tubes for 250W!
>>
>>What are they? 6GK6?
>>
>>73 from sunny Perth,
>>Alek VK6APK
>>
>>
>>At 05:47 AM 3/02/2006, Bob Maser wrote:
>>>Just when you thought you had enough amplifiers, along comes a deal
>that's
>>>hard to pass up. Check this out!  Don't forget I saw it first.  No
>>cheating
>>>in line guys.
>>>
>>>http://cgi.ebay.com/VINTAGE-HAM-RADIO-LINEAR-AMPLIFIER-EXCELLENT-CONDITION
>_W0QQitemZ5862246566QQcategoryZ48700QQrdZ1QQcmdZViewItem
>>>
>>>Bob W6TR
>>>
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>>
>>http://www.qrz.com/vk6apk 
>>
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>
>
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