[Premium-Rx] Racal 1781 information

[Ben Dover]

Greetings, All.

Thanks to everyone who responded to my call for information on the 
rig. It would appear that this idea isn't as simple as it seems...
manuals, pinouts, and schematics aren't going to do a whole lot of
use with using the existing control system, that's pretty clear;
the system is just too strange to interface to.

There's two ways I can go here. 

The first is to stay with the original plan for the rig; use it as
a source of Module McNuggets to keep the RA1772s in shape. Once you
get past the SCORE control system, the various remains (RF, IF, audio,
power supply, PLL, etc. modules) seem to be pretty much standard 1700
series boards.

The second is a bit more radical. Completely eliminate the existing
remote control, and get down to the level where the actual board control
inputs and outputs are. Bring them out to a multipin connector, and
look at connecting them to the existing manual controls on an RA1772.
Most of those board inputs & outputs are a simple DC voltage that 
controls diode switching. The main dial is an optical encoder on the
RA1772; feeding that to the PLL might be tricky, but is probably do-able.
The main strangeness is the preselector; that's COMPLETELY different,
apparently tuned by an analog voltage to varicaps in the RA1781.

As if I didn't already have ENOUGH projects here...   <<grin>>


Once again, thanks for the assistance.


73's,

Tom, W9LBB