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[Amps] 8874's

To: "Amps Amps" <amps@contesting.com>
Subject: [Amps] 8874's
From: "Bob Arenella" <rja12@comcast.net>
Date: Sun, 6 May 2012 21:53:42 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>
Hi All,
         I recently picked up a small VHF Hi band (166.xxx Mhz) transmitter 
from the late 70's. In as-new condition, inside & out and over built like it 
was designed for the military. The owner thought it was used in conjunction 
with weather sats.

         It had a solid state exciter driving an 8874 driving a second 8874. 
The power transformer was a about the size of a 60's TV power transformer. 
There wasn't a spec of dust anywhere inside the driver module or the PA 
module.
No dust on the squirrel cage of the blower, either.

         The fluke 87 shows filament continuity & no inter-electrode shorts. 
they look like they just came out of the box. Based on the size of the 
transformer, I'm guessing these tubes weren't run hard. I would like to 
verify these tubes are full output, but don't have an early alpha to test 
them in. Just an Alpha 86 & a Titan 425.

         Anyone in the Hudson Valley, NY or Western CT area have an early 
alpha amp and be willing to check these out for me?

Tnx & 73 de Bob,
N2oam


----- Original Message ----- 
From: "chas" <chasm@texas.net>
To: "Amps Amps" <amps@contesting.com>
Sent: Friday, May 04, 2012 8:23 PM
Subject: [Amps] Failure Notice


>
> I am estimating that as being 5 months, could be a year.
>
> I have it swapped out for a 374A  which I use all the time.
> Hard to believe that there is nothing that needs to be done to perserve 
> tube
> vacuum and the capacitors.
>
> thanks
> chas  k5dam
>
>
> On 5/4/12 6:48 PM, Gudguyham@aol.com wrote:
>> 5 months isn't really that long since the last use. If you used it just
>> before the 5 months of storage then plug it in and use it. no problem.
>> Leaving it run won't do a thing to help it. In a message dated 5/4/2012
>> 7:40:37 P.M. Eastern Daylight Time, chasm@texas.net writes:
>>
>> I have an SB220, fully modded which I have had sitting in a closet for
>> the last 5 months or so. What do I need to do to keep these capacitors 
>> and
>> tubes in good condition? just plug it in and turn it on but don't 
>> transmit
>> with it for a few days???
>>
>> thanks chas k5dam
>
>
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> 


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