Quote Originally Posted by LostBenji View Post
Correct.

GQ was correct and on the money. 25KHz Vs 12.5KHz channel spacings, deviations halved result in exactly what he said. Now somebody transmitting on Channels 79 or 80 nearby the troubled radio that could be an old 40 (Full DIN size is likely an 80ch radio) would see possible issues, not likely here.

Incorrect, noise can come from anything such as bad radio front-end, bad antenna, loose fittings, corrosion on the fittings, hot-dry air blowing over antenna, poorly mounted antenna and location, etc. etc. Common issues seen now are bad/noisy electrical devices in the vehicle like cheap phone or USB chargers, cheap mains inverters or even in some cases, failed alternator diode. An AM guy who has been playing with radios since the 70's should know this....
These days with better electronics and manufacturing this is not as bad as in the dark old days of HF with crystal phazing ..... with the way IC's are now it is not as bad as it was .......the old truck i was in had a 40 and never had a issue talking truck to truck or through repeaters the new truck i have a lot of people have issue hearing me especially when close together been through every thing makeing sure that all joint are good and there is no corrosion . i dont have issue talking to other 80 ch radio users only people with the 40 ...... and only sometimes as i stated if the wide band radio is out of tune slideing of frequency the narrow band radio will get the carrier but not the modulation... yes there are other factors but this is the main reason .....