Re: just to verify (CW over FM rig)
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CW (unmodulated carrier) on in squelched FM sounds like bursts of silence. What you hear is MCW -- the transmitter is keyed and the the tones are transmitted the same as voice.? Try monitoring the CW beacon on one of the satellites.?
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On Jun 7, 2014, at 17:11, "'Rick - yahoo' rgsparber.ya@... [FT-60]" < FT-60@...> wrote:
Anthony, ? Ah, I should have read a bit further before posing my question. ? Since I do hear Morse Code on my scanner, I guess I should conclude that these people are actually using MCW and not CW. Is that right? ? Rick ? ? ? As far as I understand this, the "real" CW transmitters would just transmit the carrier at a constant frequency and filter heavily to produce these 100 Hz bandwidth signal after you modulate it on and off to transmit your code.
If instead you put a code-modulated 1KHz tone into the SSB transmitter, it should be about the same in the ideal world, but might be somewhat more than 100 Hz bandwidth because of higher complexity or less accurate filtering. That utilized 100 Hz-wide spectrum will be 1 KHz higher than what you see on your VFO.
Now if you feed a 1 KHz tone into an FM transmitter, the math is much more complex there, it includes your tone volume and FM deviation and the transmitted audio frequency signal bandwidth i.e. 100 Hz (or frequency, i.e. 1 KHz?). And I don't fully understand that math. But I would expect the resulting RF bandwidth to be about 10 kHz.
Another option you mentioned, if you short your microphone input and just modulate with your PTT, then in theory this should simply transmit on and off the carrier, that would not deviate, because the mic input is null. And that would be near the real CW transmitter, just not as accurate. Please somebody correct me if I am wrong, but I might still expect some frequency deviation (or not?, why?). Also, the downside of this method is that now only people with SSB/CW receivers would be able to hear you. People with FM rigs will see squelch open/close as you transmit, but won't get no audio.
73
Anthony VA3IDL
From: "'Rick - yahoo' rgsparber.ya@... [FT-60]" <FT-60@...>
To: FT-60@...
Sent: Friday, June 6, 2014 8:48:48 AM
Subject: RE: [FT-60] just to verify
? I think you are saying to transmit unmodulated carrier for silence and a tone which would shift the transmitted frequency from the unmodulated value. It is my understanding that CW would represent no tone as no carrier. So the two methods should sound the same at the receiver but would have different RF signatures. I read () ?that the needed bandwidth for cw is less than 100 Hz and ideally the bandwidth is zero because the carrier is just being turned on and off. ? If I fed in a 1 KHz tone into my FT-60 to generate a dot or dash and fed in nothing for silence, then the bandwidth would be 2 KHz for FM or 1 KHz for SSB. Is that right? ? Am I all wet here? ? Thanks, ? Rick ? ? ? It's an FM rig. If you want to send cw, like as in a beacon, use the audio input with a tone.
From: FT-60@...
To: FT-60@...
Date: Thu, 5 Jun 2014 12:15:25 -0700
Subject: [FT-60] just to verify
? ? I carefully read over the table of contents of the FT-60¡¯s user manual and found nothing about connecting a key in order to transmit CW. Am I missing something? ? Thanks, ? Rick ? ?
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