[AMRadio] Triode connecting 803's for a Modulator

Mike Dorworth, K4XM k4xm at arczip.com
Sun Apr 9 13:08:53 EDT 2006

----- Original Message -----
From: "Bob Deuel" <k2glo at jkasystems.com>
To: <AMRadio at mailman.qth.net>
Sent: Sunday, April 09, 2006 11:52 AM
Subject: [AMRadio] Triode connecting 803's for a Modulator

> I have a bunch of 803's. In the past, I have seen modulator articles
> featuring triode connected 813's. Physically, the 803 also looks like it
> would be a good candidate for the same application. Has anybody tried
> connecting 803's for a modulator? If so, what were the design parameters
> you used? Tnx, Bob K2GLO

On page 662 of the 15th Edition of  RADIO HANDBOOK by Editor and Engineers.
Paragraph 30-8 the use of 803 in triode connection is fully discussed. A
schematic (figure 20)  shows 2500 volts at 18000 ohm plate to plate being
driven by a 8 watt speech amplifier through a Stancor A-4761 Class B driver
transformer set for 2:1 Ratio. Eg-g =170 volts
Driving power 7-8 watts
Resting current = 50 mA.
Power output = 510 watts
Supressor volts = 280-340 volts

A Chicago CMS-3 was used for the output transformer..

More information about the AMRadio mailing list

This page last updated 16 Dec 2017.