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Re: [Amps] Weird tubes in an amplifier

To: Carl <km1h@jeremy.mv.com>
Subject: Re: [Amps] Weird tubes in an amplifier
From: MU 4CX250B <4cx250b@miamioh.edu>
Date: Wed, 29 Jan 2014 16:42:29 -0700
List-post: <amps@contesting.com">mailto:amps@contesting.com>
I vaguely recall the amp had a link coupled output and no input
network other than a coupling cap to the cathodes. World's simplest
amplifier.  And I may be way off base, but I also seem to remember a
scaled up amp in the same article using a pair of...803s maybe.  Be
fun to read the article again.
Jim w8zr

Sent from my iPhone

> On Jan 29, 2014, at 3:49 PM, Carl <km1h@jeremy.mv.com> wrote:
>
> I also copied that article in CQ maybe? Used 3 of them also with a 10A into 
> the 4 GG modified 1625's that were the in thing for awhile for poor high 
> schoolers.
>
> I have no idea what any of the output powers were or the combined IMD but 
> they did work 80-15M.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
> To: "MU 4CX250B" <4cx250b@miamioh.edu>; "William Turner" 
> <dezrat1242@wildblue.net>
> Cc: <amps@contesting.com>
> Sent: Wednesday, January 29, 2014 2:22 AM
> Subject: Re: [Amps] Weird tubes in an amplifier
>
>
>> I also ran 4 6AG7s in grounded grid. Slowly conditioned them by raising the 
>> plate voltage to
>> 1kV. My 200 Watt lamp dummy load got quite hot. I tried one first and then 
>> got a large block of
>> aluminum that I drilled four 1 inch holes into.  Then using a carbide saw 
>> blade that my father had
>> on his table saw, I slotted the block to make fins. I mounted it on a 
>> chassis with a color TV power
>> transformer and voltage doubler. My filter capacitors were some AC run 
>> capacitors I got from
>> a scrap pile at a heating and air conditioner shop. I only had a few Watts 
>> drive from my
>> CE10A. I had bandswitched it since it only came with a 80 meter coil set. So 
>> my output was
>> not coupling was not ideal.
>> It worked well from 80 to 20 meters but could not get much output on 15.
>> I still have the heatsink but can't find the rest of it.
>> 73
>> Bill wa4lav
>>
>> ________________________________________
>> From: Amps [amps-bounces@contesting.com] on behalf of MU 4CX250B 
>> [4cx250b@miamioh.edu]
>> Sent: Wednesday, January 29, 2014 12:00 AM
>> To: William Turner
>> Cc: amps@contesting.com
>> Subject: Re: [Amps] Weird tubes in an amplifier
>>
>> When I was a kid I built a linear amp running four 6AG7s, from an
>> article in CQ. The author had discovered that the nominal 3W plate
>> dissipation of the 6AG7 could be pushed to 100W. The tubes  got
>> so hot the black paint blistered. As I recall, the tube life was
>> measured in minutes, not hours. (Those were the days when
>> Burstein-Applebee sold JAN 1625s for $0.25.) I'm sure some of you guys
>> remember the article!
>> 73,
>> Jim W8ZR
>>
>> Sent from my iPhone
>>
>>> On Jan 28, 2014, at 9:50 PM, William Turner <dezrat1242@wildblue.net> wrote:
>>>
>>>
>>>> On 1/28/2014 7:24 PM, Mark wrote:
>>>> Just when I thought I had heard of almost every type of tube in an 
>>>> amplifier
>>>
>>> Betcha you never saw an amplifier with a 6SJ7 as the final. When I was a 
>>> poverty-stricken teenager, that was what I used on 40 meters. Three watts 
>>> DC input and I worked the east coast from California. I was so proud I 
>>> almost hurt myself smiling.
>>>
>>> 73, Bill W6WRT
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
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