There is an easier way. Attach the shop vacuum to the top of the tube and
work on the bottom side. That's how I did some under side work on my Alpha
77. But in this case I hooked the shop vacuum to the exhaust port on the back
of the AMP.
Bob
K8MLM
In a message dated 10/19/2006 3:32:25 P.M. Eastern Daylight Time,
bmaser@tampabay.rr.com writes:
Blow air down thru the fins from up on top.
Bob W6tR
----- Original Message -----
From: "k7rdx" <k7rdx@charter.net>
To: "Harold Mandel" <ka1xo@juno.com>; <amps@contesting.com>
Sent: Thursday, October 19, 2006 3:06 PM
Subject: Re: [Amps] Testing amp with no air flow
> Hal,I think you are stretching things a bit far out...Jim..
> ----- Original Message -----
> From: "Harold Mandel" <ka1xo@juno.com>
> To: "'k7rdx'" <k7rdx@charter.net>; <amps@contesting.com>
> Sent: Thursday, October 19, 2006 8:07 AM
> Subject: Re: [Amps] Testing amp with no air flow
>
>
>>
>>
>> -----Original Message-----
>> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
>> Behalf Of
>> Dear Jim,
>>
>> It's a question of economics and habit.
>>
>> If you feel confident in powering up ceramic
>> devices without any airflow you are the one
>> who footed the bill.
>>
>> The whole idea of the airflow scenario is that is the tube's
>> normal operating environment.
>>
>> 8877's are about $1,000.00 these days, yes?
>>
>> I would think twice about powering any ceramic triode up
>> without airflow going, just as seriously as I would
>> think twice about immersing our tomcat in a sink full of
>> warm, sudsy water for a shampoo.
>>
>> Hal
>> W4HBM
>>
>>
>>
>> [snip]
>> I just checked fil voltage on my 8877 here (No blower ) watched it
>> ramp-up
>> to 4.9vac in less than 10 secs and then pulled switch...No heat felt on
> tube
>> base in this short time interval...What`s the big deal unless you want to
>> test with rf conduction?(I do that too but with blower running&safe
>> connections) Jim K7RDX.
>> [snip]
>>
>>
>> _______________________________________________
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