[RTTY] Transmit Technical Problems

Wed Aug 25 14:14:50 EDT 2004

There is a dearth of information on websites, e-lists and e-groups concerning the proper methods to use to ensure a clean signal on any digital mode via AFSK.

So it amazes me to see so many that still have dirty digital signals on the air. It's not really a big problem in my personal opinion on modes like RTTY and even MFSK16 but it's a very serious problem on PSK31. Any given day when I look at the waterfall on 20 meters I see 25-50% of the signals 100-300 hz wide with many sidebands. I also see at least one station per week wiping out 2+ "KC" of bandwidth.

If you try to politely advise and assist someone of a problem on the air or even in a one on one email the response is usually indifferent and/or hostile. I think a major part of the problem is a continued lowering of technical standards and increase in the number of appliance operators. And this is not a stuffy elitist attack on appliance operators just a simple observation.

You see the same thing with computers. I have a sister in law who is a computer owning disaster. She and her family members use their computer like a TV, turn it on and just use it. They immediately pollute the registry with horrendously buggy AOL software, use no surge suppression, no active antivirus or spyware software scanning, no disk defragging, no hard drive error scanning. Within six months the OS is destroyed and they just buy a new computer. What a waste.

73,
Thomas F. Giella, KN4LF
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 31 44N 82 09 51 98W
kn4lf at arrl.net

Propagation eGroup: http://lists.contesting.com/mailman/listinfo/propagation
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KN4LF Amateur & SWL Radio History: http://www.kn4lf.com

  ----- Original Message ----- 
  From: Kok Chen 
  To: RTTY Reflector 
  Sent: Wednesday, August 25, 2004 1:43 PM
  Subject: Re: [RTTY] Distortion

  On Aug 25, 2004, at 9:14 AM, Dave Hachadorian wrote:

  > On afsk, one thing you have to be very careful of
  > is rf getting into the transmitted audio.

  How very true.

  Just last weekend, I was trying to call a CQing station to tell him 
  that there appears to be RF in his signal but he could not copy me.  He 
  also kept reversing his tones back and forth, like he might be trying 
  some new equipment out and was unsure of the transmit polarity.  No one 
  else was calling the poor soul.

  Could be he couldn't copy me because I also have RF in my AFSK, HI HI.

  73
  Chen, W7AY

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