[GreenKeys] oddball mark space frequencies

[Jack Hart]

Those frequencies are 85 HZ apart, which is the standard for multiplexed
commercial

landline telegraph circuits. The standard RTTY tones are 2125 and 2295.  

I have noticed a lot of the Northern Radio tone keyers are showing up NEW,
but

all without filters. "Back in the day..." RTTY'ers built their own filters
for these units.

You might be able to modify the non-standard tones filters.

 

Jack K0TTY

 

NNNN

 

 

From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Rokumon Cat
Sent: Thursday, February 28, 2013 6:59 AM
To: GreenKeys at mailman.qth.net
Subject: [GreenKeys] oddball mark space frequencies

 


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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