Guest

[Guest Tim]

I’m considering installing a GMRS and a Ham dual band radio in my SUV.  Both will be 50w radios. I can see receiving on both, but can’t imagine transmitting on both at the same time.  Any problem powering both from the same power leads from the vehicle battery?  Also, is there any recommended distance between antennas (I’d like to mount both on the roof)?  Thanks. 

[dosw]

1 hour ago, Guest Tim said:

I’m considering installing a GMRS and a Ham dual band radio in my SUV.  Both will be 50w radios. I can see receiving on both, but can’t imagine transmitting on both at the same time.  Any problem powering both from the same power leads from the vehicle battery?  Also, is there any recommended distance between antennas (I’d like to mount both on the roof)?  Thanks. 

If the power leads are sufficient gauge for the length of the runs, you have no problem. But in case of "oops" moments, the wiring should be selected with a gauge big enough to handle transmitting on both radios at the same time. You never will do this, intentionally. But if the wiring is inadequate, you'll do it once on accident and blow a fuse or melt the wiring.

Take the maximum draw of both radios combined, and plan your fuse and wiring accordingly.

 

As for antennas, you need at bare minimum 1/4 wave, which at VHF is 2'1", minimum. And that will still mess with your propagation pattern somewhat. Pumping out 50w with that antenna spacing is not ideal. It's probably not great for the other radio either.

Another alternative is a dual-band radio with certain unspecified adjustments that will allow you to get by with a single radio, passed into a broad-band antenna like a Comet CA2X4SR.

[Guest Tim]

Good information.  I'll do some research into "unspecified adjustments."  Thank you much.