[Milsurplus] 150c tone on 51mc

[Mike Morrow]

David Stinson wrote:

> I think running the 150 hz tone squelch isn't a good idea.

Fibber wrote:

> the problem is no noise squelch on the rigs (PRC-77/PRC-25) being
> used. We have about 5 get-togethers (NWMRE) each year and just 
> about always operate 150c mil tone.

It never hurts to *transmit* a signal with 150 Hz tone, if possible.  All the "carrier operated" squelch sets like WWII and 1950s-vintage US FM gear, and east-block/foreign FM radio sets will work fine, along with the tone-squelch sets like VRC-12-series in "new squelch" mode and the PRC-25/77.

I think it was a bad design that "old squelch" (carrier operated) mode couldn't be selected for the PRC-25/77 just like it can be on the contemporary VRC-12-series sets.  There were years of PRC-6, -9, and -10 operation along with the PRC-25/77, but the squelch had to be turned completely off at the PRC-25/77 end for it to hear the earlier sets. 

>Really, civi radios don't handle the wide FM very well anyway,
>so we'd be looking for mil radio folks anyway.

I've gotten a ham 6 meter FM rig to work well with PRC-25/77, and VRC-12-series units in "new squelch" mode, by setting the ham rig to transmit the standard 151.4 Hz PL subaudible tone.  The squelch system of the military rigs seem fairly tolerant of the tone frequency being in the ball park of 150 Hz.

73,
Mike / KK5F