Running high power linear with CA and Scanner

[Akosikojak]

Will running my bilinear amp/CB setup hurt my scanner? My scanner is on a separate antenna than my CB antenna and is about 6 feet apart. Linear max output is 300 watts. I am running this on my pickup truck as a mobile setup.


Any help would be greatly appreciated.

[gallatinarms]

I would be careful. You may get a lot of front end load on the scanner. I have a Uniden Trunktracker IV and it went bad after I was transmitting with 50 watts on 2 meter ham. The antennas we prety close to each other. I believe my transmissions are what fried the scanner.

I got a replacement Uniden and now whenever I transmit on more than 5 watts I unplug the external antenna for the scanner. I don't want to chance frying a $500 scanner.

[Akosikojak]

Copy that, I appreciate the advice.

[Duke]

I'd still be careful but you're likely to have less of a problem, since there is such a large difference between CB 27mhz and 2m 146mhz, than the other guy had. Scanner antennas are typically resonant on VHF/UHF and not on 27mhz, so I can see how it could pick up a LOT of that 146mhz energy. Since 27mhz is so far removed from the typical VHF freqs it shouldn't be as bad but you could still have some issues since you are planning to run 250w.

[R.J.]

I'm running an amp ( only 200 watts) on my CB with a 2 meter radio and no interference even with both antennas spaced no more than six inches apart on the roof (NMO mount). You might want to also run your power wires away from the coax and both coax cables away from each other to minimize interference.

The only thing the amp interferes with on my truck is the electric trailer brake controller. It will lock up the trailer brakes if I'm braking and keyed up simultaneously.

[Akosikojak]

I'm running an amp ( only 200 watts) on my CB with a 2 meter radio and no interference even with both antennas spaced no more than six inches apart on the roof (NMO mount). You might want to also run your power wires away from the coax and both coax cables away from each other to minimize interference.

The only thing the amp interferes with on my truck is the electric trailer brake controller. It will lock up the trailer brakes if I'm braking and keyed up simultaneously.

Good to know thanks. How far apart should the power cables & the coax's be to keep the interference to null?

[R.J.]

What I did on my truck was ran all of the power cables low on the floor boards. From the center of the roof, the 27mhz (CB) antenna coax was ran down the left side A-pillar and the HF radio coax was ran down the right side A-pillar. By routing them this is way, the cables don't have a chance to cross paths. While it's possible running them bundled together might not cause any issues, it's probably worth the extra effort especially if you've gone through the trouble of removing the headliner and other interior components.

[Duke]

If your install is correct there should be no currents flowing on the coax shield and it shouldn't matter if you run them together or not and it doesn't matter if they cross paths. If currents are flowing on the coax you need to address that.

You do want to route the power wire(s) away from the coax. A few inches away should be ok.

The only thing the amp interferes with on my truck is the electric trailer brake controller. It will lock up the trailer brakes if I'm braking and keyed up simultaneously.

Are you using a mag mount antenna?

[STiMULi]

I'm running an amp ( only 200 watts) on my CB with a 2 meter radio and no interference even with both antennas spaced no more than six inches apart on the roof (NMO mount). You might want to also run your power wires away from the coax and both coax cables away from each other to minimize interference.

The only thing the amp interferes with on my truck is the electric trailer brake controller. It will lock up the trailer brakes if I'm braking and keyed up simultaneously.

Good to know thanks. How far apart should the power cables & the coax's be to keep the interference to null?

You may never win the battle depending on the quality of the Amp.

Grounding is the best solution. Magmounts are good up to about 50 watts and then the issues begin

[crazyVOLVOrob]

Magmounts are good up to about 50 watts and then the issues begin

Really my Mag mount has a capacity of 2,000 watts