As a side note to this topic, I found it interesting to see how the
MCW was produced in the LF NDB Aircraft Beacon transmitter that I modified to be a linear amp for the 500-KHz ARRL Experimental Program. It was common for them to have CW that shifted 400-Hz upward in frequency, but instead of AM tone modulating a carrier they ran two xtal oscillators: One as set on the carrier frequency and ran continuously and a second xtal oscillator set a at f1 = fo +400 Hz and was keyed by a CW memory keyer. This resulted in both "carriers" being transmitted by the linear amps as CW modulated USB + carrier. On an AM receiver it produced 400 Hz MCW. For my use I disabled both xtal osc. and disconnected the CW keyer ckt. I substitute the TEST signal from my K3 for the oscillator carrier. The rest of the transmitter is linear amplifiers. I can drive the 100w 500-KHz xmtr with only 0.1 mw and in any mode that is possible on the K3. However we are restricted to CW, QRSS, psk-31 and its variants, and WSPR. Our 15-KHz wide band is not sufficient to support SSB and is not allowed. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw*, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [hidden email] ====================================== *temp not in service ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Ed, that explanation goes a long way into explaining why NDBs are such a lousy
navigation aid and the identifiers are sometimes loud and sometimes near uncopiable, particularly when not very close to the station. It is amazing that such poor techniques are used for navigation critical equipment! Willis 'Cookie' Cooke K5EWJ ________________________________ From: Edward R. Cole <[hidden email]> To: [hidden email] Sent: Wed, February 16, 2011 5:49:15 AM Subject: [Elecraft] K3: re CW ID macro on SSB As a side note to this topic, I found it interesting to see how the MCW was produced in the LF NDB Aircraft Beacon transmitter that I modified to be a linear amp for the 500-KHz ARRL Experimental Program. It was common for them to have CW that shifted 400-Hz upward in frequency, but instead of AM tone modulating a carrier they ran two xtal oscillators: One as set on the carrier frequency and ran continuously and a second xtal oscillator set a at f1 = fo +400 Hz and was keyed by a CW memory keyer. This resulted in both "carriers" being transmitted by the linear amps as CW modulated USB + carrier. On an AM receiver it produced 400 Hz MCW. For my use I disabled both xtal osc. and disconnected the CW keyer ckt. I substitute the TEST signal from my K3 for the oscillator carrier. The rest of the transmitter is linear amplifiers. I can drive the 100w 500-KHz xmtr with only 0.1 mw and in any mode that is possible on the K3. However we are restricted to CW, QRSS, psk-31 and its variants, and WSPR. Our 15-KHz wide band is not sufficient to support SSB and is not allowed. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw*, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [hidden email] ====================================== *temp not in service ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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