|[AMRadio] 813 Triode Connected Bias question.|
ars.w5omr at gmail.com
Fri Mar 20 21:47:55 EDT 2015
Hook up a 9v battery, reversed, in the center tap of the filament
transformer secondary and put some voltage to it. If that's not enough,
add another until you have too much voltage, then wire a pot across the
I did this without the pot on a pair of 810's... I think I wound up with 5
or 6 9v batteries strung together for 45 or 50v of bias.
On Mar 20, 2015 5:16 PM, "Paul Baldock" <paul at paulbaldock.com> wrote:
> I am building a 2x813 pp triode connected modulator. This means the screen
> grid and control grid are connected together for each tube.
> I haven't found any characteristic curves for the 813 in this configuration
> On a sample of one, with 0 volts on the grid I measure about 40mA Idle
> Current (single tube). 40mA means about 100W per tube. Does anybody have a
> guess at what negative bias I would need to reduce this to around 20mA?
> - Paul KW7Y
> This email has been checked for viruses by Avast antivirus software.
> 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
More information about the AMRadio mailing list
This page last updated 16 Jan 2018.