Runnig two CB Radios...

[02RangerXLT]

Running two CB Radios...

Has anyone ever ran two CB radios at once? (Both using their own individual antenna...) Or is this not feasible?

 

[4x4junkie]

You can do it, however the two antennas will have some influence on each other (sortof "sucking" some of the signal out of the air in the direction toward the other antenna).

About the only thing I can see it being useful for is to receive on two channels at once, as you will not be able to receive on one while the other is transmitting, and transmitting on both is likely to make intermod between the two radios too.

A few radios out there have Scan and Priority Scan functions built into them that might be able to take the place of needing two radios to receive two channels, might be something to look into.

 

[3.0ranger1227]

I've seen a CB alongside a Race radio, but not really a pair of CBs

 

[02RangerXLT]

You can do it, however the two antennas will have some influence on each other (sortof "sucking" some of the signal out of the air in the direction toward the other antenna).

About the only thing I can see it being useful for is to receive on two channels at once, as you will not be able to receive on one while the other is transmitting, and transmitting on both is likely to make intermod between the two radios too.

A few radios out there have Scan and Priority Scan functions built into them that might be able to take the place of needing two radios to receive two channels, might be something to look into.

Copy that. Yeah the Midland 1001Z I have doesn't have the channel scan. Great radio and works well, but the scan feature would be nice because there are two primary channels around here, and it would be nice to be able to monitor them both. Thanks for the advice!

Same here 3.0... I've used a CB and a Business Band 2-Way next to each-other but never two CB's.

 

[feellnfroggy]

we run two radios on our humvees in iraq all the time on multiple channels, the icom radios are awesome for that, as far as two cb's you would have to have some kind of interference resistor so they could maintain independant signalling. Like said above only on two different channels

 

[Spott]

Two CB's will interfere with each other, even when just receiving. It'll be especially bad when transmitting with one or the other.

When receiving, radios still generate a small signal (called the "Intermediate Frequency") in order to change the radio signal down to audio frequencies. This signal, while small, will still radiate out of the radio for a good distance (several feet or yards). Many radios have two or three IF's. And radios use a lot of standard IF's (such as 455 kHz), so it's extremely likely that one or more of the IF's in any radio, will interfere with one or more IF's in another radio.

So, I wouldn't recommend running two CB radios in the same truck.

Spott

 

[02RangerXLT]

Thanks for the information folks!

 

[4x4junkie]

Two CB's will interfere with each other, even when just receiving. It'll be especially bad when transmitting with one or the other.

When receiving, radios still generate a small signal (called the "Intermediate Frequency") in order to change the radio signal down to audio frequencies. This signal, while small, will still radiate out of the radio for a good distance (several feet or yards). Many radios have two or three IF's. And radios use a lot of standard IF's (such as 455 kHz), so it's extremely likely that one or more of the IF's in any radio, will interfere with one or more IF's in another radio.

So, I wouldn't recommend running two CB radios in the same truck.

Spott

I've never once run into this myself, though a way to avoid it for sure is to have two radios with full metal cabinets, and different 1st IFs (the 2nd IF (455kHz) is unlikely to be radiated out the antenna, it's much too deep within the radio's circuits and too low freq).

10.695MHz is the most common 1st IF, but some radios such as the Cobra 148GTL use a 7.8MHz 1st IF.

A good quality radio (Uniden, some Cobra, most SSB radios) should have very little IF radiation however.