Question regarding CB-

[ImTheWeasel]

Does anyone here know the best way to determine if the finals in a CB are blown?

Have a friend who just got a cb that was working the day before from a guy he works with, we hooked it up to a known good antenna, and could not get out to anyone. We reconnected the antenna back to the CB it was originally on, and could talk to people just fine. SO im wondering if the finals arent blow in the CB he got.

 

[BANDIT]

If it works on one antenna and not the other does not mean the finals are blown. Best way is to get a watt swr meter and put it in line and check for output and swr. The antenna that it is not working on I would think has a short in the coax and the swr is high and shutting down the output. If the finals are blown it would not work on any antenna.

 

[ImTheWeasel]

well see thats the thing. The antenna we had it connected to. we had just unhooked from a CB in another friends car that he uses everyday and had been using up until like 2 minutes before we asked to use his antenna. And his equipment worked fine.

The CB is a Cobra 25LTD, it has the SWR/WATT meter on the front, dont know how trustworthy that is, so i hooked it up to one my friend has and it was showing that i was getting around 1.3 SWR and it was showing output right around 3.5.

So i dont understand whats wrong. We had a guy we know very well listen for us on a selected channel on the cb using the Cobra 25LTD radio, and he was unable to hear us. When we reconnected the antenna back to the cb in my other friends car who had just been chatting with people a little earlier, then the guy we had listening could hear us just fine.

So i dont know what the deal with this Cobra 25LTD is. It's a nice radio and all, but it seems like its toast, even though it was working for the guy we got it from the day before.

The antenna we were using was a trunk lid mount K40.

 

[Al42]

You've already eliminated any problem with the antenna (another radio worked in it) and the radio (it worked on another antenna), so the problem is somewhere else. That doesn't leave much. Bad battery connection? You didn't have the antenna connected properly the first time?

 

[ImTheWeasel]

No.

We had the same antenna and were swapping it between the 2 radios.

UNIDEN CB - Connect to antenna and power leads directly to battery. We are able to talk to people just fine.

Cobra 25LTD - Connect to same antenna and power leads directly to battery. We are unable to talk to anyone.


Thing is this Cobra that the guy gave to my friend was working the day before the guy gave it to my friend. We sat right outside the shop and used it to talk to some people in town. And we know the guy wouldnt have pruposely screwed up the radio before giving it to my friend, because the guy has given him numerous things before because he constantly buys the latest and greatest stuff he can get. And we know the power is good, because we were powering it directly from the battery terminals. The antenna connection is good because the antenna is a trunk lid mount K40, And ive screwed this antenna onto many radios and had no problems. And it is working with the Uniden CB, but not the Cobra, so i know its not the antenna.

I know it is not antenna or power related. Which is why i beleive that the finals are blown in this Cobra.

My friend is ready to throw it in the trash, but i told him to wait until i could be sure its dead.

 

[BANDIT]

In your first post you said the radio would work on a different antenna. If it will work on one antenna and not another the finals are not blown otherwise it would not work at all... Borrow a watt meter and dummy load and check the power. It should put out 3 to 4 watts. That is the only to check the finals other than other real technical stuff.

 

[ImTheWeasel]

i've check the watt it was 3.5, swr is fine, antenna is good, the cobra radio is still good, the mic had a problem with the wiring in the connector turns out.

thanks anyways.