[AMRadio] 813 Triode Connected Bias question.

Paul Baldock paul at paulbaldock.com
Sat Mar 21 18:15:47 EDT 2015

On a sample of 3 tubes, 4 diodes in series (1N4007 about 2.8 volts) 
in the cathode gives my 24-28mA, which is down from about 40mA with no doides.

- Paul

At 07:03 AM 3/21/2015, Larry Szendrei wrote:

>However, there is no data for use in the triode class B connection, 
>and that is what Paul is looking for.
>In the absence of that data I think his suggested approach of 
>putting a pot in the cathode lead (center tap of fil. xfmr) to find 
>the correct operating point and then replace with a Zener (or 
>forward-biased diode string) of the correct value is a good one, and 
>the one I would probably use.
>Our Main Website: http://www.amfone.net
>AMRadio mailing list
>Archives: http://mailman.qth.net/pipermail/amradio/
>List Rules (must read!): http://w5ami.net/amradiofaq.html
>List Home: http://mailman.qth.net/mailman/listinfo/amradio
>Post: AMRadio at mailman.qth.net
>To unsubscribe, send an email to amradio-request at mailman.qth.net with
>the word unsubscribe in the message body.
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html

This email has been checked for viruses by Avast antivirus software.

More information about the AMRadio mailing list

This page last updated 21 Jan 2018.