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Narrowbanding VHF CDM1250/HT1250
Posted: Sat Jan 03, 2009 8:39 pm
by Troyfire801
I'm trying to reprogram a channel from 5 KHz to 2.5 KHz on both a CDM1250 and an HT1250. I changed the choice from 25KHZ channel spacing to 12.5 Khz but the radio still appears to be transmitting wideband. Is there another setting I'm missing? Thanks for any help you can provide.
Re: Narrowbanding VHF CDM1250/HT1250
Posted: Sat Jan 03, 2009 9:23 pm
by escomm
That is the only setting you need to adjust. What leads you to believe it's still transmitting wideband?
Re: Narrowbanding VHF CDM1250/HT1250
Posted: Mon Jan 05, 2009 4:22 am
by dsheli
How would you determine if a radio is transmitting in 25 hz vs. 12.5? Any scientific method?
David
Re: Narrowbanding VHF CDM1250/HT1250
Posted: Mon Jan 05, 2009 8:07 am
by jackhackett
dsheli wrote:How would you determine if a radio is transmitting in 25 hz vs. 12.5? Any scientific method?
David
um.... measure the deviation?
http://en.wikipedia.org/wiki/Frequency_deviation
http://en.wikipedia.org/wiki/Frequency_modulation
Re: Narrowbanding VHF CDM1250/HT1250
Posted: Mon Jan 05, 2009 9:30 am
by HLA
or the non scientific way would be two radios side by side, one set to wide and one set to narrow. if the tower is sending out narrow band the wide band recieve radio will have a lower volume and the narrow recieve radio will sound normal