Squelching issues

[Spadinator]

Hello all,

I have a Radioshack TRC-481 CB with a Laird antenna on a lip mount NMO base. It is about a 1.3 on the SWR on channel 19. My issue is that when I turn on the turn signal, hit the brakes, roll down the windows I get squelch on the radio. Any ideas what is causing this? This does not occur on my VHF ham radio or scanner.

 

[zz0468]

A CB radio on AM or SSB is much more susceptible to electrical noise in a vehicle than a VHF FM radio is. Vehicle accessories with motors and relays creates noise, which your receiver hears.

 

[LtDoc]

I'm not going to get into the 'why' of it, but it amounts to inadequate filtering of the power line to the radio, OR inadequate filtering of the motors of those various thingys. Most electrical noise is of a lower frequency than VHF/UHF. Not all noise, but most of it in general. The best solution is to stop the noise where it's produced. That's also the hardest solution, getting to those noise producers. So, how hard do you want to work?? I'm lazy, so 'filtering' is easier for me than disassembling things to get to those 'producers'...
- 'Doc

 

[Spadinator]

Thanks.....I'll look into it

 

[majoco]

Motors in the turn signals and the brakes? Surely not!

I'd be inclined to suspect that you have the squelch set right on the limit where it would break and when you use a bit of power from the battery via the fuses and all the wiring the voltage drops a smidgeon - changes the squelch level just enough to open it. Try wiring the supply for the CB direct to the battery terminal.

 

[zz0468]

Motors in the turn signals and the brakes? Surely not!

I said "Vehicle accessories with motors and relays..."

 

[Spadinator]

I have moved the power source from a power block to the battery and it has helped.......I don't have alternator noise so I may try ferrites and see if that takes the noise away.