[GreenKeys] oddball mark space frequencies

[Rokumon Cat]

That is what I thought. Someone, somewhere litterally sawed a NR 153 Model 2 dual tone keyer in half. I too have a brand NIB, shiny NR 152 Model 2 (complete) that has everything except any moduals. I would love to use this somehow, and was just wondering.
 
Best,
 
Joe
--- On Thu, 2/28/13, Nick England <navy.radio at gmail.com> wrote:


From: Nick England <navy.radio at gmail.com>
Subject: Re: [GreenKeys] oddball mark space frequencies
To: "Rokumon Cat" <rokumoncat at yahoo.com>
Cc: GreenKeys at mailman.qth.net
Date: Thursday, February 28, 2013, 7:06 AM


Center frequency of 2295 kc with an 85 cps shift was one of the standard channels in a 8 or 16 channel frequency-division multiplexed system a.k.a. "tone pack" or VFCT (Voice Frequency Carrier Telegraphy). There were many commercial as well as military systems that used this scheme. A block diagram of the Navy's AN/UCC-1 is at
http://www.navy-radio.com/rtty/ucc1/ucc1-sys-31.JPG
and info on more of these systems is at
http://www.navy-radio.com/rtty-mux.htm

The item on eBay is 1/2 of a Northern Radio 152 dual tone keyer that has the plug-in filter for 2252.5/2337/5 - FWIW a nice shiny complete Type 152 (but without filters) is also up on eBay.

cheers,
Nick K4NYW
www.navy-radio.com 


On Thu, Feb 28, 2013 at 7:58 AM, Rokumon Cat <rokumoncat at yahoo.com> wrote:






Hi,
 
I was wondering what use would an audio pair of 2337.5/mark and 2252.5/space would be for AFSK?
 
I found on the e-place a tone unit with this pair for my northern radio AFSK generator.
 
I know that the recommended amateur frequencies are 2125/mark and 2275/space.
 
Thanks once again!
 
Joe
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