[Milsurplus] AN/PRC-74 and CW??

[Richard Arland, W3OSS]

In a personal correspondence with Mark Francis, KI0PF, he wrote me the 
following:


I just realized I didn't include that in the book.  Pinouts for
both audio connectors:

A: GROUND
B: RECEIVE AUDIO
C: PTT
D: MIKE INPUT
E: CW KEY
F: +12VDC ON

CAUTION: Pin F is switched 12VDC.  When the set is on, 12V is present
here.  CARE must be taken not to short this pin to the others!  USE THE
CORRECT (U-229) connector.

When you push the mike button, you ground pin C and send audio in on
pin D.

Grounding pin E will transmit CW.  When you let off the key, there is a
slight pause before the set goes back into RX.  This keeps the DC-DC 
converter
going between letters at about 20wpm but allows break-in between words.

If you ground the PTT continuously, the break-in is bypassed and then
grounding pin E will send CW without the break-in (which I find
annoying because I don't send fast enough).

So I have a key with an extra toggle switch on it that grounds pin C.
The key itself goes between A and E.  A key can be hooked
to either audio connector.

----------
>From CQ Communications,

            "MIL SPEC RADIO GEAR"
                   by Mark Francis, KI0PF
And that is how you make the PRC-74 talk CW!

My thanks to Mark, and GL with your rig/

73 Rich W3OSS

> Subject: [Milsurplus] AN/PRC-74 and CW??


> Hello,
>
> I just would like to ask is PRC-74 manpack
> able to transmitting CW?
> I am asking because I dont see any markings
> regarding CW or Key on the front plate.
> There are only two connectors labelled AUDIO.
>
> 73,
>
> Oskar