Collins 310W-1 Exciter

[REW]

Anybody got a schematic for a 310W-1 AM exciter? I am helping a friend that wants to use one to drive a small amp on 160 meters. The info I found on this forum had pictured, description of circuits and parts list but no schematic.

Thanks for any help

[Dale H. Cook]

Anybody got a schematic for a 310W-1 AM exciter?

There are three principal versions of the 310W-1 for different frequency ranges. The broadcast band version (which I believe was designated 310W-1/MF) comes in two flavors. The oscillator frequency is four times the carrier frequency for frequencies from 540 to 1080 kHz with two flip flop dividers, and two times the carrier frequency from 1090 to 1600 kHz with a single flip flop divider.

The 310W-1/HF is a variant for shortwave, with the crystal frequency equal to the carrier frequency and no dividers. The copy of the 310W-1/HF manual that I have doesn't specify the frequency range. It is apparently a copy of a late version of the manual supplied by Continental showing production changes but without the frequency that would have been typed into the copy supplied with the 820E/F-1 transmitter for which the exciter was sold. In the broadcast band version of the manual the exciter specs show a crystal frequency range of 2160 to 4230 kHz. The HF versions of the 820E/F-1 manual shows output networks with frequencies from 3.385 to 6.025 MHz.

I see no reason why the 310W-1 cannot be run between 1.8 and 2.0 MHz using the 310W-1/HF design. The original divider ICs appear to be a flavor of RTL for which I have never found a datasheet and which appear to be unobtanium. The only 820E-1 that I have worked on had them replaced with a 7474. For a simpler approach to 160m I would suggest starting with the 310W-1/HF manual which I have posted on my site for you.

[REW]

Thanks Dale. That is what I was needing. I have not looked to see what freq this unit is on. I do know it was in the broadcast band. I found a spare crystal for 1440khz so I think it is in the upper end of the band. Plans for the amp are still in the works. The exciter is my part of the project and so far it is looking good.

Thanks for the help and Merry Christmas
Robert Williams

[Dale H. Cook]

I found a spare crystal for 1440khz so I think it is in the upper end of the band.

Only the divider and crystal freq change - the rest of the exciter is broadband 540 kHz to 6+ MHz.