[Amps] 813 Amplifier Article

[Carl]

In the 60's I even tried the 715B/C. It was OK grid driven but very little 
gain in GG. Of course IMD was just a bunch of letters back then when some 
commercial sweep tube rigs/amps were around -18dB.

Other experiments were 100TH, 6C21, a quad of 35T's, VT-127A/100TS and 
several industrial triodes. I had to find out the hard way why they often 
made poor SSB tubes but it was a good education.

Carl
KM1H



----- Original Message ----- 
From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
To: "Rob Atkinson" <ranchorobbo at gmail.com>; "Carl" <km1h at jeremy.mv.com>
Cc: <amps at contesting.com>
Sent: Friday, April 01, 2011 1:28 PM
Subject: RE: [Amps] 813 Amplifier Article


I once knew a guy in Nashville, John Brown, who loved building amplifiers in 
the 1960's.
He made a RF deck that he drove with his TR3 or TR4 which he could change 
sockets and
try different tubes that most people would not try or had be advised not to 
try.
   One setup was four 4-65As in grounded grid. Talk about hot plates when he
pushed up the plate input power. They were a bright yellow
  Another set up was 4x  4CX250bs or were they 4X150A/7034? No difference 
really.
He tried direct grounded grid, they were toasted.  Then connected the g1 to 
k and low
power gain but worked well and lastly he tried g1 to ground via a resistor 
to limit grid dissipation.
None worked out to his satisfaction.
   73
Bill wa4lav

________________________________________
From: Rob Atkinson [ranchorobbo at gmail.com]
Sent: Friday, April 01, 2011 12:45 PM
To: Carl
Cc: Fuqua, Bill L; amps at contesting.com
Subject: Re: [Amps] 813 Amplifier Article

I guess I am mistaken, I somehow got the impression they were hard to
find because I never see them at hamfests or on eBay but I guess I
have looked at the wrong times and places.

73

Rob
K5UJ

On Fri, Apr 1, 2011 at 8:23 AM, Carl <km1h at jeremy.mv.com> wrote:
> Ive never understood the claim that 4-65A/8165's are scarce. The USAF used
> them and NIB surplus seems to be ignored just like the 803, 814, 4E27A and 
> a
> few other tubes.
>
> Henry also used them in the driver stage of a 3CX3000A7 13.560 MHz ISM
> transmitter they private labeled.
>
> Carl
> KM1H
>
> ----- Original Message ----- From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
> To: "Rob Atkinson" <ranchorobbo at gmail.com>; <amps at contesting.com>
> Sent: Thursday, March 31, 2011 11:07 PM
> Subject: Re: [Amps] 813 Amplifier Article
>
>
>> On ebay there are 2 NOS 4-65As at $10 and one day left.
>> And another one BUY NOW for $12
>> I checked completed sales and some went for less than a $ recently.
>> I think you can get them cheap.
>>  EIMAC had a data sheet for the 4-65A that had a spec running them hard
>> at SSB service with more output than a 4-125A but no IMD data.
>> I think this was perhaps for the mobile and portable military rigs like
>> the PRC-47 and
>> others.
>>  73
>> Bill wa4lav
>> ________________________________________
>> From: amps-bounces at contesting.com [amps-bounces at contesting.com] On Behalf
>> Of Rob Atkinson [ranchorobbo at gmail.com]
>> Sent: Thursday, March 31, 2011 10:08 PM
>> To: amps at contesting.com
>> Subject: Re: [Amps] 813 Amplifier Article
>>
>> The Temco RA-150 used the 4-65A.  I don't have that rig so I'm not
>> interested in the tube but anyone owning that rig might not mind
>> picking up a few extras if they don't have them already.
>>
>> A pretty cool rig... 
>> http://www.amfone.net/Vintage%20Radio/temco_ra150.htm
>>
>> 73
>>
>> Rob
>> K5UJ
>>
>>
>> <<<
>> Rob, K5UJ wrote...
>>
>>> Glad to hear it.  I had thought 5-125 was almost unobtanium; even
>>> harder to find than 5-500s and 4-65As.
>>
>> I've got two NOS, sealed in their plastic envelopes, 4-65A's.  If anyone
>> is
>> interested,
>> make an offer.
>>
>> 73,
>>
>> George T Daughters, K6GT
>> CU in the California QSO Party (CQP)
>> October 1-2, 2011
>>>>>
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>