cold weather fronts

[robertson40]

would cold weather fronts affect 800 mhz and vhf signal

[jackj]

That would depend on the front. A sharp enough temperature change could cause a temperature inversion and that could cause the signal to be refracted back down toward the surface so that a system could be heard hundreds of miles away. Although this is quite common on VHF, this will NOT happen on 800 MHz with the majority of fronts.

[robertson40]

thanks and check this out VHF Propagation Map

[N2ICV]

Originally Posted by jackj

That would depend on the front. A sharp enough temperature change could cause a temperature inversion and that could cause the signal to be refracted back down toward the surface so that a system could be heard hundreds of miles away. Although this is quite common on VHF, this will NOT happen on 800 MHz with the majority of fronts.

It does happen on 800MHz! I have heard Baltimore City and Connecticut State Police TRS's from here in Southern New Jersey.
Good ducting between SNJ and VA

[ka3jjz]

I have, in fact, heard stories about having to shut down parts of the Delaware system due to ducting across the water from NJ. Yes it doesn't happen that often, but it certainly does.

Mike

[scancapecod]

I've monitored the Delaware 800 MHz TRS from Cape Cod, MA on numerous occasions. It's by and large a water path but it is certainly the result of ducting.