Hi All, I have found that using an old analog HV type VOM, such as Tripplet
630, as a current limiting resistor works very well. These meters
typically have a series resistance of about 100 megohms and limit the current
to
less than 30 microamps at 3 KV plate voltage.
Additionally, you can monitor the process by watching the current
indication. Hopefully it will decrease with time.
The actual voltage impressed on the tube is the plate voltage minus the VOM
reading. So, if the leakage causes the meter to read 2000v, the actual
voltage across the tube is only 1000v and the current is 20 microamperes (in
this case).
73,
Gerald K5GW
In a message dated 3/30/2013 7:46:34 A.M. Pacific Standard Time,
crc@cyberlink.bc.ca writes:
Just don't connect the plate caps while doing this gettering. Fern
----- Original Message -----
From: "Rick Stealey" <rstealey@hotmail.com>
To: "john starr001" <jstarr001@hotmail.com>; <amps@contesting.com>
Sent: Saturday, March 30, 2013 8:33 AM
Subject: Re: [Amps] Alpha 87A - Gettering NOS 3CX800A7's
> If they need gettering, putting full HV on them will cause them to arc,
by definition.
> Maybe you could put a large value resistor in the HV lead temporarily
and see if they can take it.
>
> Rick K2XT
>
>
>
>
> _______________________________________________
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|