This is the ADF Control Head that I chose for my project.  It is a Collins 614L-8. they are plentiful on eBay614L-8.black.jpg

The Analysis    The Unit is tuned via a 400Hz synchro transmitter. So it looks like I will have to find a replacement for the synchro.  The Loop Switch in the upper left must be rewired and the switch logic for the Band Selector Switch behind the Tuning Knob seems ok, but that will have to be verified. The Gain Control is just a 5k pot,  and the Function Switch behind it just needs some pull-up resistors. It looks like I can drive the Tuning Meter with a PWM signal from the controller.  Also, there is a BFO Switch which induces 142.5 Khz signal on top of the audio.

PS: In TM 11-5826-225-35 section 1-32 Receiver Tuning Meter page 40  says:

"Tuning Meter is M301 mounted on the control unit front panel is a dc microammeter requiring 100 microamperes of current for full-scale deflection. The negative side of M301 is grounded.."

The Plan  Well first I need to score a copy of the maintenance manual they are kind of pricey on eBay so I dug a little more. In the military, the Control Unit is part of AN/ARN-83 and I found pdf copies of TM 11-5826-225-12 and TM 11-5826-225-35 with schematic, part diagrams, etc. Also, you can score the operators manual here.

Next, we have to identify the goes inta and the goes outas, so here goes:

 

Connections Map
PINI/ODESCRIPTIONCPU PORTCPU PIN
OLoop Ant, Right Step
OLoop Ant, Right Slew
OLoop Ant, Left Step
OLoop Ant, Left Slew
OFunction Switch, ADF
OFunction Switch, ANT
OFunction Switch, LOOP
ORange Switch, 190 – 400
ORange Switch, 400 – 850
ORange Switch, 850 – 1750
OBFO Switch
OGain Control, Bottom
OGain Control, Top
OGain Control, Arm
ITuning Meter
GGROUND
PDial Lamps
PPanel Lamps
DSyncro - L1
DSyncro - L2
DSyncro - L3
DSyncro 400 hz power
**NOTE: O = Output; I = Input; P = Power; D = To Be Deleted

 

 

keep tuned in more to come

Cris ~