[ARC5] C-30A, ARC-5 remote Tx control surprises

[Mike Morrow]

>If anyone by chance has the cable & plugs, or cable substitute, 
>that would work between the C-30A and the MD-7 modulator, I'd be 
>interested in buying it.  Please contact me.

The wiring harness for the typical AN/ARC-5 system would be open wire.  The connector at both ends of the cable between the C-30A and the MD-7 is the A.R.C. 9585 (18-pin).  This is THE most difficult connector to find in the AN/ARC-5 system, and is typically expensive (> $75) IF you can find one.  The A.R.C. 9589 (12-pin) has also traditionally been similarly rare and expensive, but Steve (ebay KB4DMF) has been selling that for $12.  The AN/ARC-5 is the only command set that uses the 9585 and 9589.

>The other surprise was that the mode selector switch is located 
>under a "fuse like" cover on the back of the box.  Therefore a 
>C-30A provides a selector switch (A-D) for the VHF Tx's, a selector 
>switch (1-4) for the MW Tx's, and a mode switch (CW, Tone, & Voice).

Covering the transmitter mode switch made 100 percent sense.  By the era of the AN/ARC-5, the command set assumed that AM voice would be the only mode of interest to the pilot.  Also, communications receivers R-25, -26, -27 were locked fixed-frequency and AM voice...no tuning dials or mode switches were used for them.  The most common receiver control box was the C-38*/ARC-5, which also had controls for the AN/ARR-2 homing receiver.  The C-38* also used control covers over controls that are not used in specific installations.  No need to have all of the superfluous controls exposed!

The C-30A was a vast improvement over the horrific push-button C-30.  The ABCD switch selects the channel for both the T-23 or T-126 VHF transmitter...AND the channel for the R-28 VHF receiver.  

The C-30A could be used in place of the identically-sized MF/HF-only C-29...which explains the great rarity of the C-29.

Mike / KK5F