10-11-2023, 03:38 PM
Igor,
Another thought : some (commercial) transceivers are supplied with two transmit (and receive) options - Wide and Narrow. Users may not recognise what the correct setting is and unknowingly leave them set to Narrow. The Narrow option arrived when some countries implemented either a 10 or 12.5 KHz channelling plan as user growth was expected, but my appraisal is that it simply didn't happen in the amateur service in VK. What happened in lieu was the arrival of the various digital voice modes (DMR, etc) so we still ended up with 12.5 KHz digital channelling interspersed with 25 KHz voice-only channelling !
Historically we all set up our 6M, 2M and 70CM transmitters for 5KHz FM deviation but nowadays almost no one actually posesses the gear to measure it and it is pure guesswork if it is close to optimum. The chances are that if you overhear someone with low voice deviation, that particular radio may be set up for "Narrow" operation..
There is no easy fix for it - except education.
Doug
PS I have a Marconi Modulation Meter so I can directly measure FM deviation, one of the few I guess !
Another thought : some (commercial) transceivers are supplied with two transmit (and receive) options - Wide and Narrow. Users may not recognise what the correct setting is and unknowingly leave them set to Narrow. The Narrow option arrived when some countries implemented either a 10 or 12.5 KHz channelling plan as user growth was expected, but my appraisal is that it simply didn't happen in the amateur service in VK. What happened in lieu was the arrival of the various digital voice modes (DMR, etc) so we still ended up with 12.5 KHz digital channelling interspersed with 25 KHz voice-only channelling !
Historically we all set up our 6M, 2M and 70CM transmitters for 5KHz FM deviation but nowadays almost no one actually posesses the gear to measure it and it is pure guesswork if it is close to optimum. The chances are that if you overhear someone with low voice deviation, that particular radio may be set up for "Narrow" operation..
There is no easy fix for it - except education.
Doug
PS I have a Marconi Modulation Meter so I can directly measure FM deviation, one of the few I guess !
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
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If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.