[AMPS] Kaput 8877s from AL-1500 arrive

[measures]

>Thanks Rich.  Any news to report?
>
Thr autopsy is finished, Paul.  There is minimal loose gold.   And why 
not?   10uA of leakage at +4000v is below normal for a typical 
gold-sputtered 8877.    There are no bare spots where the grid's base 
metal is exposed like the 8874 in "Parasitics Revisited" (9-90 QST).  
There is one gold blister on the grounded end of the grid cage.  In my 
opinion, this dud would have been useable if the loose gold had been 
moved to the base by tapping with a hammer.  Perhaps Ameritron should 
provide a  "free"  4oz. ball-peen hammer with each AL-1500.?  Or, perhaps 
the time has come for a R/L suppressor device?

cheers

>----- Original Message -----
>From: "measures" <2@vc.net>
>To: "AMPS" <amps@contesting.com>
>Sent: Wednesday, September 13, 2000 10:51 AM
>Subject: Re: [AMPS] Kaput 8877s from AL-1500 arrive
>
>
>>
>> >Rich,
>> >
>> >Can you tell us more about your plan for inspecting these tubes including
>> >any methods, procedures, and validation of results?  Thanks.
>> >
>> 1.  Using a high-pot.  set to 8kV, apply negative to the anode and
>> positive to the grid.
>> 2.  measure leakage current.
>> 3.  reverse polarity.
>> 4.  If leakage current remains the same with either polarity, there is no
>> gold-sputtering.
>> 5.  If leakage current is more with + on the anode, loose gold is
>> indicated and an autopsy is warranted.
>>
>> cheers, Paul.
>> >
>> >----- Original Message -----
>> >From: "measures" <2@vc.net>
>> >To: "AMPS" <amps@contesting.com>
>> >Sent: Wednesday, September 13, 2000 9:39 AM
>> >Subject: [AMPS] Kaput 8877s from AL-1500 arrive
>> >
>> >
>> >>
>> >> AT 5pm yesterday, the duds arrived.  I will publish the test results
>here
>> >> a.s.a.p.   Will Rich be having a crow sandwich for lunch?
>> >>
>> >> -  Rich..., 805.386.3734, www.vcnet.com/measures.
>> >> end
>> >>
>> >>
>> >> --
>> >> FAQ on WWW:               http://www.contesting.com/FAQ/amps
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>> >>
>> >
>> >
>>
>>
>> -  Rich..., 805.386.3734, www.vcnet.com/measures.
>> end
>>
>>
>> --
>> FAQ on WWW:               http://www.contesting.com/FAQ/amps
>> Submissions:              amps@contesting.com
>> Administrative requests:  amps-REQUEST@contesting.com
>> Problems:                 owner-amps@contesting.com
>>
>
>


-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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