Problem with TX and RX

[martyemtp]

I just installed my yaesu 8800 in my Tundra. Once I got everything together and did a radio check, I noticed it was not receiving and transmitting correctly. It acts like the antenna is not there. The radio worked fine with out any problems when I had it in my home. I believe it has something to do with the Antenna setup. I used one of the four bed rails post holes. It is a NMO Breedlove bracket. It does sit on top of a plastic bed-liner. I wondering if I should run a wire from the bracket to ground the antenna better to solve my problem.

I am not sure if it could be the coax running from the base of the antenna bracket to the radio. I purchased a pre-made cable, but had to cut one end to run in to the cab of the truck. I put on a new Connector at the radio end. The coax does not fit all that well, plus the coax core is strained wire, not solid. Not sure if I should try another connector or replace the coax.

My previous antenna on the Tundra was a magnet mount, which worked better that I thought it would. I replaced it for a more permanent one.

Brian
N1VLZ

 

[N5TWB]

Do you have an SWR meter? What does it say? Have you used a multi-meter to check the cable and your new connections? What were the results?

Since the radio performed at home and when connected to a mag-mount antenna, that just leaves the new antenna mount (yes, it should be grounded - another check for the multi-meter) and the coaxial cable. Trouble-shooting requires eliminating the obvious plus the tools to gather information on the remaining possibilities.

BTW, everything I've read on the Breedlove mounts say they are excellent quality so I'd eliminate that as a possibility, except for the grounding issue, as long as you followed their instructions for the install.

 

[jim202]

I just installed my yaesu 8800 in my Tundra. Once I got everything together and did a radio check, I noticed it was not receiving and transmitting correctly. It acts like the antenna is not there. The radio worked fine with out any problems when I had it in my home. I believe it has something to do with the Antenna setup. I used one of the four bed rails post holes. It is a NMO Breedlove bracket. It does sit on top of a plastic bed-liner. I wondering if I should run a wire from the bracket to ground the antenna better to solve my problem.

I am not sure if it could be the coax running from the base of the antenna bracket to the radio. I purchased a pre-made cable, but had to cut one end to run in to the cab of the truck. I put on a new Connector at the radio end. The coax does not fit all that well, plus the coax core is strained wire, not solid. Not sure if I should try another connector or replace the coax.

My previous antenna on the Tundra was a magnet mount, which worked better that I thought it would. I replaced it for a more permanent one.

Brian
N1VLZ

Most mobile antennas are designed to work with a ground plane under them. Mounting a mobile antenna on a bed liner is probably about as poor of an installation as you could come up with. Break down, drill a hole in the roof and do it the right way. You will find it will work much better.

 

[prcguy]

I've got a 2008 Tundra and one of my antenna mounts is a military HUMVEE mount with an adapter for NMO on the inside bed wall at top rail height towards the rear. The VSWR on various VHF/UHF antennas is noticeably worse on this mount due to the lack of ground plane but it does get out just fine. Its not quite as good as other antennas with permanent roof mounts but not down that far.

Sounds like you have something else going on like a bad cable.
prcguy

 

[martyemtp]

The information that you all provided confirms what I was think. I have to investigate to find out what the real cause of this problem. I will to get some pre-fab coax later this week and try that. I will also look at the grounding plate for the mount.

Brian
N1VLZ

 

[Project25_MASTR]

I've seen this on the newer dodges where the plastic rail cover extends down into stake pocket so when the mount is installed it doesn't actually ground out to the body. Also it may have not dig into the paint enough to grounds out.

I gave up with bed mounts (most of the local work tricks don't have the OE bed on the anyway) and started primarily mounting on the headache racks, cab, our hood channel where holes must be drilled ensuring electrical ground.

 

[martyemtp]

There is screw on the underside of the mount. I was wondering if this will help ground it. I can run a wire from the screw to another part of the truck body.

Brian
N1VLZ

 

[WA0CBW]

I would go back to the part where you said "the coax doesn't fit well". The coax SHOULD fit well. Did you use the right connector for the cable? If the cable was RG58 and a PL259 connector did you use the correct adapter (UG175/UG176)? Did you use a crimp-on connector or a solder-on?
BB