C. J. Clegg wrote:
I have an IC-706 mounted on my Honda Gold Wing motorcycle. The
motorcycle has a dealer-installed CB radio with the CB antenna mounted
in back on the left side of the trunk. I have a 7-foot loaded
vertical for 40 meters mounted to the rear crash bar, only about a
foot to a foot and a half from the CB antenna.

My question is, if I transmit on 40 meters SSB at full power
(nominally 100 watts, actually more like about 70 watts or so), am I
likely to damage the front end of the CB radio? Will it matter if the
CB radio is turned on or off?

I could crank the power on the IC-706 back to as little as 10 watts
but it's going to be hard enough to raise any QSOs with the full 100
watts of power.

On the other hand, the motorcycle CB is big bucks to replace and I'd
be just as happy not to damage it...

Thanks...

Hi C.J. With the antennas that close, you could cause damage to the
cb rig. You should have the cb turned off when transmitting with the
ham rig, you will overload the front end and get garbage out of the
speaker.
Some cb rigs ground the antenna with the rig off, and if yours does
then you are OK as long as the cb is off. If your rig does not do this
then you need to add a switch or relay to ground the antenna when the
cb is off, or you are transmitting with the ham rig. As you stated,
you will need all the power you can get to have QSOs, but at what point
does this damage the cb, too many variables?
Gary N4AST