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Re: [RTTY] Re: AFSK/FSK etc

To: Kok Chen <chen@mac.com>, RTTY <rtty@contesting.com>
Subject: Re: [RTTY] Re: AFSK/FSK etc
From: George Johnson <w1zt@comcast.net>
Date: Thu, 12 Aug 2004 17:44:43 -0400
List-post: <mailto:rtty@contesting.com>
Chen,
That is a nice package and good description. Now to really confuse Jonathan, K9JS:


At 01:22 PM 8/12/2004, Kok Chen wrote:

I have attempted to explain it for the Mac community with a documentation that can be found at

http://homepage.mac.com/chen/cocoaModem/Documentation/main.html

In Appendix A (after Section 8) there is a discussion of RTTY and in Section A.4 of the Appendix is a section on "Where am I transmitting?"


And, in my case, I have decided to work with the software I have and the equipment I have to use in both DXing at contesting.

In my case, I use LSB digital mode (Icom radio) with AFSK tones centered at 1500 Hz. Those are lower than the "high tones" but higher than the "low tones". They are centered in my nice Icom DSP filters. My "mark tone" is about 1.4 KHz lower than my dial frequency.

When I see a DX frequency spotted on the DX Cluster, I mentally note the frequency and set my VFO about 1.4 KHz higher to start to listen for the station. I tune around until I find it. Sometimes this works. I have just gotten into the habit of tuning over a lot of years.

And when I send a DX spot during my frequent DX activities I read my VFO and correct my text to note the mark frequency in my spot. I will tell you the frequency is 1.4 KHz lower than my VFO.

However, when I contest and occasionally use the DX Cluster I seldom adjust my spot text. So it will be 1.4 KHz higher than the "real thing".

This has the "terrible" side effect of making someone else tune around for the spot instead of being able to "point and shoot" (read transmit blind) in order to be on that DX frequency.

In this world of constant efforts to automate operations, save keystrokes, and shave milliseconds off the exchange this bad behavior on my part is certain to elicit strong opinions. But when you run into one of my DX spots in a contest, you will now know exactly where to tune !!

73, George .. W1ZT (flame suit and shields now up)






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