BMH95

I've got a tuned up Cobra 29 NWSTWX or whatever the order should be. At any rate, it shows that it's putting out around 100W on my meter, but truckers and a buddy are telling me that it sounds sick. It won't get out, and they say they can hear me but it's quiet and or fuzzy. I had a Firestik Firefly 4', and it used to get out great. Then all of a sudden the trucks stopped responding. I put the SWR meter on it and it was pegged. I figured a bad antenna, so I got a new one, two, three. I can't get any new antennas tuned well accross the board, but can get it to around 1.8:1ish on 1 and 40 and 1.3:1ish on 20. I still can't get out. This thing used to be loud and clear. So did I burn it up on a shorted antenna, or would you guess a grounding or coax problem? With the original antenna it was at 1.1:1-1.2:1 on 1, 40, and 20.

haloman

I would use a new cable and double check all of your grounds, unless something in the radio burned out from being cranked up.

donnee

I would agree with the previous poster.
I d also try the radio in another truck, if possible, to see if it is the radio.

tslewisz

You got 100 watts out of a 29?

Coincidentally, my buddy with my old 29 (stock) had the same thing happen. It's like there's no antenna at all. We tried swapping antennas, stubs, coax, even tried my old Lil Wil on his truck. SWR is always 10. We plugged into my antenna system in my truck and it's fine. Then it got cold and we haven't messed with it.

BMH95

I didn't get 100 watts out of it -t's more like 90 . I had a shop do it.

BMH95

Well, the radio doctor sais the radio is fine, but he microphone is not. So I got a new mic, and will be re-installing the radio and tuning it later today.

13MWZ

LOL I was just fixin to say that. I had the same problem on my Cobra 29 in my old Pete. Drove me crazy till I replaced the mic on a whim (the TA had a purdy lil American flag mic) and BOOM, all of a sudden it worked again! Glad you got it figured out, sorry I didnt see this post sooner.

mrblond

I was going to say check the mic too.

BMH95

Live and learn, I guess. Thanks for all the advice, guys.

Here's another question for you:

I've got an SWR of 1.85:1 on 1 and 40, and 1.3:1 on 19. Does that mean it's as good as it'll get with this antenna / set up? Or does an equal 1 and 40 reading not mean that?

surfram

That is probably the best SWR you are going to get with a 4' fiberglass antenna. A mag-mount Wilson 1000 in the center of your roof would get out alot better and allow a SWR close to 1:1.

tslewisz

Equal 1 and 40 means that's as good as it gets. Your numbers aren't that bad.

My mag mount SWR's better more toward the rear of the cab, FWIW. It's a 4.5" Astatic mount and a Skythumper Twist 'n' Shout antenna.

92 Bob

I drove truck for 30 years and never had much luck with fiberglass antenna's. The firesticks are about the best. Get a Wilson and you will get your swr lower and get out farther.

BMH95

I've got a Wilson Silver Load Flex 4' in the garage, but haven't used it yet because I have to remove my antenna in order to get in and out of garages occassionally. That's a problem for the Wilson line, because of the impedence wire that needs to be grounded for my set up. I need to engineer a quick detach ground method for that one, then maybe I'll switch to the Wilson. I asked for a radio check last night, and got a response that I could barely make out - even with the rf gain turned all the way up and the squelch low enough that I had static coming through. I guess if I can talk further than I can hear that's good.

CD in NM

I have a Firestick 4' tunable 5/8th wave top load fiberglass antenna on my Jeep, SWR adjusted right down to a 1:1 across the band. It's mounted on a bracket that is installed at the tail light. Also using a spring to help absorb any strain from impacts. Coax multiples ARE done in 3' segments, don't coil any up anywhere, it will screw up your match big time.

I have a Wilson 1000 roof mount on the truck, drilled through the roof at the center overhead light, excellent ground plane, match is also a 1:1 across the band. One of the most important things associated to a good match is a good ground. Magnetic mounts are above ground at the mount, rely on your ground being made via the coax connector at the radio, then via the ground in your power cable, that is actually a lousy system of grounding asssociated to the length of the ground circuit as a whole, really does change the SWR quite a bit. Second to grounding IS location. Your antenna needs to be able to radiate without signal feedback, a closely associated structure, like a mounting on the bed rails or toolbox interferes with performance and will drive the match up. You can tune a radio up to some great numbers, but if your antenna is not right you will loose what you gained in the tune up and then some.


CD

BMH95

I'd like to have a 102" whip back there, but it isn't practicle for the amount of times I go into the parking lot at O'Hare airport, or into areas where the thing would be bouncing around in the trees and such. I also would like to have a nice base loaded whip style antenna on the roof, but I need to be able to get my truck in the garage. As it stands now, I only have about an inch between my roof and the garage door frame. So, I don't have the space to have a mount on the roof - especially if I move up to 35" tires the next time they are due for replacement.