[RTTY] FSK Readouts vs AFSK

[John Merrill]

Be careful of harmonics with low tomes.


On Feb 6, 2012, at 2:41 PM, Bill wrote:

> I agree simply do the math hi.
> 
> I wanted really to see if there are anything I can't think of, wrong 
> with his approach. He feels the only advantage to FSK was the readout, 
> if so his solution is fine for him...
> Bill
> 
> 
> On 2/6/2012 4:21 PM, Al Kozakiewicz wrote:
>> I'm not 100% sure I'm following the point, but if the point is that you can decide to decode something other than 2125/2295 when running AFSK in order to make the math for the conversion to the "FSK frequency" simple to do in your head, why not?  When I was first trying RTTY and running AFSK I never ran the standard part because 2295 Hz was usually just outside my SSB filter passband.
>> 
>> If you're using AFSK, you will probably eventually want to use a narrow SSB filter whose upper limit will end up being lower than 2kHz anyway, forcing you to change to a different tone pair.  From a technical standpoint, it doesn;t much matter at all what tone pair you choose as long as the separation is 170 Hz.
>> 
>> Al
>> AB2ZY
>> 
>> ________________________________________
>> From: rtty-bounces at contesting.com [rtty-bounces at contesting.com] On Behalf Of Bill [bmarx at bellsouth.net]
>> Sent: Monday, February 06, 2012 3:44 PM
>> To: RTTY reflector
>> Subject: [RTTY] FSK Readouts vs AFSK
>> 
>> Someone sent me this comment when the subject of FSK readouts came up.
>> Any thoughts on his plan?
>> 
>> "You don't have to pick the 2.1 kHz offsets for tones, I use the
>> 915/1085 (that is, 1 kHz +/- 85 Hz) to make the spotting arithmetic easy
>> (about 1 kHz)."
>> 
>> Bill Marx W2CQ
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