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MDH33
08-01-2008, 12:18 PM
Please don't flame me because I don't have a HAM. Money is tight. :o

I recently installed a CB in my 60 and SWR tested it and it seems to be getting nice low readings. So, I tested my CB set-up in my 40 last night with the SWR meter and I'm getting really strange readings. I have a Firestick tunable antennae and the reading are really high and inconsistent. I can't get it to drop below 2.5, and sometimes, when I key the handset after calibrating and switching to the swr setting, the needle actually jumps past infinity. Tuning the tip doesn't seem to affect the readings much. It's either at 2.5 on channels 1 and 40 or pegged.

I checked the coax connection to the antennae and it looks correct. I followed the directions when installing it and I have it grounded as suggested. Is there a way to diagnose what the problem is or test if I'm grounded?

The CB seems to work well enough. I tested it with the 60 parked down the street and the incoming signal (from the 60) sounds very clear in my 40, the signal going out (from the 40 to the 60) sounded ok but with some noise.

I know almost nothing about radios, I just want these things to work clearly for trail use without frying the components. Any thoughts/ help appreciated. :bowdown:

MDH33
08-01-2008, 12:47 PM
Also, I am wondering if I may have already damaged the radio with the high SWR because it occasionally jumps to other channels on it's own (no scan feature).

Beater
08-01-2008, 01:56 PM
Is this a new unit? It sounds like a intermittent electronic failure in the unit itself. The first thing I would check is dissasembly the mic and check the contact area, and swap out all periphials on a diag basis.

MDH33
08-01-2008, 02:04 PM
Is this a new unit?

No, about two years old. I SWR tested it when I installed it, and had readings of about 2. At that time I was running hard top and doors. Now I have no top, no doors.

The first thing I would check is dissasembly the mic and check the contact area...

I'll try the mic from my 60 and see if it changes.

...swap out all periphials on a diag basis.

I'm not sure what this means.

Thanks!

wesintl
08-01-2008, 02:13 PM
http://www.firestik.com/Tech_Docs/swr-trblshoot.htm

MDH33
08-01-2008, 02:24 PM
http://www.firestik.com/Tech_Docs/swr-trblshoot.htm

Good info, i missed that on their site. thanks! :thumb:

DaveInDenver
08-01-2008, 02:25 PM
What model SWR meter do you have? Remember to zero the SWR on FWD or CAL, using the adjust knob to max needle swing. Then switch to REF or Read or SWR or something similar to see VSWR. Never need to touch the knob after calibrating it. Making sure the meter is giving you a valid reading.

MDH33
08-01-2008, 02:56 PM
What model SWR meter do you have? Remember to zero the SWR on FWD or CAL, using the adjust knob to max needle swing. Then switch to REF or Read or SWR or something similar to see VSWR. Never need to touch the knob after calibrating it. Making sure the meter is giving you a valid reading.

It's just a cheap meter I got off Ebay. I'm using it as you describe, it has the Calibrate/SWR switch. Once calibrated, when I key the handset and switch to SWR, it sometimes moves forward past infinity rather than dropping. It's not consistent though. After reading the troubleshooting link that Wes posted, I'm gong to try some continuity tests and maybe add a jumper ground to the frame. Right now the ground wire runs to the sheetmetal of the cowl.

Groucho
08-01-2008, 03:39 PM
Possibility of a random short? Can you do a continuity check on all individual pieces of the coax from the SO-239 at the radio end all the way to the antenna? If you have continuity from the center conductor and the shield, this would do similar to what you describe.

MDH33
08-01-2008, 03:52 PM
Possibility of a random short? Can you do a continuity check on all individual pieces of the coax from the SO-239 at the radio end all the way to the antenna? If you have continuity from the center conductor and the shield, this would do similar to what you describe.

Center conductor meaning the pin on the radio end of the coax, and shield being the "fastener" that connects the coax to the radio?

Groucho
08-01-2008, 06:12 PM
Center conductor meaning the pin on the radio end of the coax, and shield being the "fastener" that connects the coax to the radio?

Yes. Lets hope this picture helps. If the center conductor and outer conductor or shield have continuity, that means there is a short. Bad when not intentional.