[ARC5] AN/ARC-5 support for CW

[Mike Morrow]

Neil wrote:

> ...although it's less wrong for AM (for which the AN/ARC-5 was
> exclusively designed).

I am curious of the source for that notion.  An earlier post also states that the AN/ARC-5 is AM-only.  This is not accurate.

The AN/ARC-5 has VOICE, TONE, *and* CW emission switch positions on each of its three varient transmitter control boxes (C-29, C-30, C-30A), just as found on the ATA CBY/CCT-23243 and SCR-274-N BC-451-A units.  The emission switch is wired identically and switches the same circuits in ALL three systems.  The AN/ARC-5 MF/HF transmitting system supports CW operation as just fully as the two earlier systems.  The AN/ARC-5 LF/MF/HF receiver system supports CW as well, of course.

In order to simplify pilot controls some ergonomic changes to the control units had been made:
1.  The most commonly-used-in-service transmitter control box C-30A/ARC-5 has the emission switch located on the top of the box, with a screw-held metal cover completely enclosing it.  Cover removal would be a rarely-exercised option.
2.  No transmitter control box contains a key.
3.  The only "official" key jack is on the MD-7/ARC-5 modulator, although any mic jack (like on a J-16/ARC-5) can accept a key using a mic-type plug.
4.  The most common receiver control box C-38/ARC-5 allows receiver operation in lock-tuned VOICE-only mode.  A receiver like R-23*/ARC-5 that required tuning needed the C-26/ARC-5 control box (also allows CW or VOICE operation) or the later C-125/ARC-5 control panel (allows VOICE-only operation).

It is true that ergonomic design of most AN/ARC-5 controls reduced access to CW operation to eliminate rarely-used pilot controls.  But the system behind the controls is as **fully CW capable** as ATA and SCR-274-N.  All it takes is emission switch cover removal on C-30A and use of external key at MD-7 or J-16, and use of C-26 receiver control box.  CW operation is fully described in AN 16-30ARC5-2.

Mike / KK5F