Hi Breck & Eugene - Interesting on the new gear with noise squelch....I think that the Tone squelch idea was incorporated in military sets due to bad experiences with the PRC-8/9/10 and RT-66/67/68 series sets in the 1950's.  Mis-setting or just bumping the variable noise squelch knob resulted in No-Comms.  I think Tone "New" squelch was an attempt to soldier-proof the FM sets in the later VRC-12 /PRC-25/77 series sets.  But at a complexity, planning and training cost! 
Jamming via squelch-cature is effective on minimally experienced troops...The yellow lamp on the RT-524 panels helped, but the Old/New portables were all vulnerable.. Civvy PL did make sense on crowded public service nets with shared channel assignments. (Which came first?)
Tim
N6CC

On Tue, Apr 12, 2022 at 10:32 AM W2HX <w2hx@w2hx.com> wrote:

The more modern systems (like modern harris) seem to have settled on noise for receive but continue to send 150 Hz on transmit for backward compatibility.

 

73 Eugene W2HX

Subscribe to my Youtube Channel: https://www.youtube.com/c/w2hx-channel/videos

 

 

 

From: mrca-bounces@mailman.qth.net <mrca-bounces@mailman.qth.net> On Behalf Of Gene Smar via MRCA
Sent: Tuesday, April 12, 2022 1:28 PM
To: smithab11@comcast.net; mrca@mailman.qth.net
Subject: Re: [MRCA] PRC-77 Squelch

 

 

 

 

-----Original Message-----
From: B. Smith <smithab11@comcast.net>
To: Military Radio Collectors Association <mrca@mailman.qth.net>
Sent: Tue, Apr 12, 2022 1:03 pm
Subject: [MRCA] PRC-77 Squelch

 

(snip)

<Tone squelch was a stupid, expensive, often dangerous  over engineered  program.
Z>

(snip)

 

Yeah, just like mandatory CTCSS on our repeaters.  Don't get me started!

 

73 de

Gene Smar  AD3F

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