Radio going quiet in the afternoon

Your welcome. I get what you're saying about the older radios. I have several myself that I just can't part with. They definitely used better parts compared to today's radios. Seems like the Cobras really went downhill when they had china build them.

 

Yes, sir 2000 Peterbilt

 

Okay, usually the older conventional style trucks don't have as much trouble with the antenna system compared to the newer plastic trucks. I drove a 2006 short hood Pete for many years using a Hustler 48" FS27 antenna. I couldn't talk 30-40 miles with it, but that was okay since it was a 4 watt CB radio, i didn't expect it to talk that far. But even after saying that, I would recommend finding a good CB shop that owns an antenna analyzer. The SWR meters can't tell you what's going on compared to an analyzer. From what your describing it sure sounds like an RF ground issue.

 

I'll do that thank you so much. Have a great day.