Over the past week I installed a Uniden 520xl and mounted a Firestik antenna with a spring mount on the teraflex taillight fixture at the rear left. The radio is powered straight from the positive terminal and grounded to the tub in the driver wheel well. Ran my 18' of cable, did a nice figure 8 with the slack as instructed. Tuned it with an SWR in the middle of an 40 acre alfalfa field, I'm dead at 1 on 40 and about 1.2 on 1.
Reception seems nominal, I got good radio checks perched on a hill above two highways near a truckstop, but only with the Jeep turned off. When I turn the key to the on position and start the engine an overwhelming whine takes over, I have to turn the squelch about another 45 degrees to the right to get rid of it, and any transmissions I receive are masked by whine and static. It should be noted that the whine is not related to engine speed. There is a very slight background noise that correlates to RPM but it is very subtle.
I thought I might have a grounding issue, so I removed the third bolt on the tail light mount (the one you have to drill to tub for) and took some paint off around the hole down to bare metal, then I did the same thing on the tub side for the nut. I added some washers on both sides to ensure a solid ground from the mount to the tub and verified about .8 ohms to ground.
I also checked for ground isolation on the antenna side of the mount. At first I was reading 2.2k ohm to ground which seemed odd, but I forgot to disconnect the cable (is that a normal reading to ground shooting into the radio? I have no idea...). With the cable disconnected the antenna side of the mount is open to ground. I also disconnected the cable from the back of the radio unit to check the cable itself, and the inner/outer conductors are isolated from one another like they should be.
Any ideas how I can get rid of this terrible whine and static?
Reception seems nominal, I got good radio checks perched on a hill above two highways near a truckstop, but only with the Jeep turned off. When I turn the key to the on position and start the engine an overwhelming whine takes over, I have to turn the squelch about another 45 degrees to the right to get rid of it, and any transmissions I receive are masked by whine and static. It should be noted that the whine is not related to engine speed. There is a very slight background noise that correlates to RPM but it is very subtle.
I thought I might have a grounding issue, so I removed the third bolt on the tail light mount (the one you have to drill to tub for) and took some paint off around the hole down to bare metal, then I did the same thing on the tub side for the nut. I added some washers on both sides to ensure a solid ground from the mount to the tub and verified about .8 ohms to ground.
I also checked for ground isolation on the antenna side of the mount. At first I was reading 2.2k ohm to ground which seemed odd, but I forgot to disconnect the cable (is that a normal reading to ground shooting into the radio? I have no idea...). With the cable disconnected the antenna side of the mount is open to ground. I also disconnected the cable from the back of the radio unit to check the cable itself, and the inner/outer conductors are isolated from one another like they should be.
Any ideas how I can get rid of this terrible whine and static?