Bruce,
I just got a Series 73 (does that mean it was built in 1973?) and have questions.
What is the pushbutton next to the throttle used for? (Picture enclosed)
Why is the Tx battery center tapped?
The DIN plug for charging has 6 wires to it. What are they for?

I assume the charging voltage is 12v or less rather than line voltage with an onboard diode like in my Heathkit.

I was surprised about this radio. I thought I'd just use the case & gimbals for a MS2K upgrade, but this thing has been gold sticker'd. I could using it as is on channel 40.
The reciever has 6 plug-ins and a separate cable (4 wire) coming out of the case. Which is the power plug for the Rx?

If I go 2.4 conversion I'll have to scrap the Kraft encoder board because it would block the module.

Do you know of anyone who has a service or owners manual?

I'm not trying to hijach this thread, just need some answers. Anybody out htere help?