Since I last contacted you I have finalized things with the 712. The following is what I have done:
I use a dynamic microphone/headset arrangement from
2. I have made a case for the control panel (714-E3) which I purchased from Fair Radio as a control panel for an ARC-95 system.
3. Inside the case I have mounted a 317 three terminal adjustable regulator to provide 12 volts from the 32 volts which
is supplied via the main cable from the 712.
4. This regulator powers an 8 pin IC pre-amplifier for the microphone and a 5 terminal 3 watt amplifier for headphones and speaker.
5. A provision for PTT is also provided for the headset and a separate front panel jack for a foot switch.
6. A TUNE ENABLE miniature switch is mounted on a panel at the rear (actually the front) of the 712 for tune-up.
7. From the front panel on the 712 a cable runs to my case which supplies switching for the main antenna/receive
antenna connectors on the 712. This cable also takes voltages to jacks on my case so as to enable metering important voltages from the 712.
8. The original main antenna connector on the 712 has been changed to a type “N”.
I have today had QSO’s with two of the Route 66 special event stations. Conditions were deplorable and other than the signal being very readable it was too difficult to comment on signal quality. I run about 400 watts PEP with no problems.
The 3 phase 400 Hz. 110 volt supply is a Pacific Power Systems ASX-315 laboratory supply. This is overkill but I obtained it rather inexpensively.
I also have a PP-2352/UR solid state supply (I think made for the ARC-75 system) which is a 2 kilowatt, 3 phase, 400 Hz, 110 volt supply which runs off 28 (24) volts.
Phil Grimison VE6ABW
Here's an interesting site, about the ARC-105