I can hear fine, but when I try to transmit, no power makes it to my antenna

[BlueCoyote]

So I recently bought a cb radio, it's an old hy-gain 1 681 (the forty channel model), and a mag mount mic, I don't yet have an swr meter, so I don't know if it's tuned or not.

I can hear just fine, but when I try to transmit, nobody hears me.

I started troubleshooting the problem, and found that no power was getting to my antenna, I even went so far as to key up the mic, and grab the antenna, to see if it shocked or burned me, but nothing happened.

Both of my fuses are good, and I can hear just fine.

When I key up my mic, the power meter on the radio goes up to a seven, and if I talk loud enough, it moves a little bit, so I'm pretty sure the final, and mic are good.

When I use a multimeter, it shows no resistance between the antenna and any metal part of the radio, including the radio mount.

My setup is (very temporary) the antenna mounted on one truck, and the radio running off the cigarette lighter in a different truck, because one truck has a steel body, and isn't currently running, and the other has a fiberglass body, and is running.

I only mention this, as I don't know if it could cause some sort of trouble with the antenna getting it's electrical ground through the coax.

I'm very new to having a cb radio, and don't know a whole lot about maintaining one, except what I could find on the internet.

I opened the radio, and there are a few components I don't recognize, but all of the capacitors, and resistors, look good, and I can't find any broken solder joints, or torn wires.

I assume there is some sort of audio processing circuit, but don't actually know what to look for, or how to test it, and I wouldn't think that would keep the antenna from receiving any sort of voltage, but I'm out of ideas, and thought I'd ask for help here,

I'll include a picture of the inside of the radio if that helps at all.



I know I could just buy a new radio, but I'd like to make this one work if possible,
If anyone has an idea of what could be wrong, and what could fix it I'd greatly appreciate the advice

 

[trentbob]

Interesting, just want to let you know as a newbie you might find a delay in seeing your posts show up, at least for a few more posts.

I like the way you use to test to see if your radio is transmitting by grabbing the antenna. NO shocks or burns LOL.

For not being familiar with CB radios you certainly do know how to troubleshoot. Are you a ham operator?

So here's my question. When you say you transmit and nobody hears you, is that because you're just not getting any response from anybody or is someone having a conversation very close to you and you are breaking in and they are not responding? Is it because you've attempted to have a conversation set up with someone but they couldn't hear you? Are you able in any way to have any kind of receiver that can pick up 27 MHz? An old shortwave portable radio or an old scanner?

I'm not really sure what could be the problem with your radio other than your transmitter was fried but if it was a short in the coax or connectors you wouldn't be able to receive either. Interesting to see what kind of replies you will get. Welcome to radio reference.

 

[BlueCoyote]

Thanks for the quick response, and for welcoming me to the forum.

I'm not a ham operator, I just have some basic experience repairing old electronics, and when I realized something was wrong, I looked through the internet for any old forum posts, and troubleshooting guides I could find, and used that to try anything I could before making a post of my own.

I haven't actually set up a conversation with anybody, because I don't actually know anybody local that has any sort of radio equipment,
but when I hear a conversation, I usually wait until there's a bit of a pause, and try to break in, but so far nobody has responded
, but that could be in part due to most of the conversations I hear being through what I'd figure to be skip, because a lot of them are in canada, or on the other side of the us, although I did hear a few conversations from a lake about 15 miles from where I'm at.

And I tried Listening with a few am radios, and an old walkie-talkie, but none of them work below 250 MHz, I was mainly trying to see if I could get any interference by broadcasting, but I didn't notice anything different.


If it is the transmitter, is that something easily replaced, or is it more expensive than a new radio at that point?

 

[mmckenna]

Well, first step would be to get an SWR meter.
The SWR meter will show you "forward" power, RF energy leaving the radio going towards the antenna. That'll tell you if you are actually transmitting anything.
The meter will also show you "reflected power, or RF energy that isn't properly radiated by the antenna, usually caused by an untuned antenna.
You can get halfway decent ones for $30 or so on Amazon. Not lab grade stuff, but enough to tell you what's going on. It would be a wise investment if you are planning on being active with CB. Other option is to find someone that has one you can borrow...

I think your likely issue is that there just isn't anyone nearby that can hear you. CB is nothing at all like it was 20-30 years ago. It's pretty rare to hear/see CB's being used on the major highways. Yes, some do, but not like it used to be. If you can hear other users, that probably means your antenna is generally working. But some of those guys have much bigger antennas and better setups. Plus, the atmosphere can bounce signals around pretty well, so no guarantee they are nearby.

 

[KK4JUG]

If it is the transmitter, is that something easily replaced, or is it more expensive than a new radio at that point?

I haven't done CB in several years but I'm pretty sure it would be cheaper to get a new radio, assuming you could even find someone who would work on it.

 

[trentbob]

BlueCoyote, no problem, I see that you're still being moderated, that was quite a delay. Yes we are entering a new sunspot cycle and will be enjoying great skip peaking in about 1 + 1/2 years and no they would not respond to you.

That's why I was asking if you were trying to break in on an obviously local conversation or if you had any kind of a receiver in the 11m or 27 MHz area. Your transmitter very well might be working.

As far as your questions... What the other guys said LOL.

 

[wtp]

some of the people out there could be using 1000 to 2000 watts out.
i would say 4 watts out will not let you answer someone hundreds of miles away.
and do not try anyone on channel 6.

 

[KE5MC]

When I key up my mic, the power meter on the radio goes up to a seven, and if I talk loud enough, it moves a little bit, so I'm pretty sure the final, and mic are good.

As mentioned the swr meter a helpful tool. The meter indication at best might indicate working mic with the wiggle, but the metering point for RF output is at best indirectly related and is of little value of RF power out of the radio.
Good Luck!
Mike

 

[BlueCoyote]

Thanks for all the replies, I will be getting an swr meter as soon as I can, but that won't be for another couple of days at least.

I hope that it's just that there's nobody close enough to hear me, and I'd have an easy time believing it, because I live in the middle of nowhere, but not being able to read any voltage on my antenna through my multimeter when broadcasting has me worried that the problem is worse.

 

[trentbob]

Thanks for all the replies, I will be getting an swr meter as soon as I can, but that won't be for another couple of days at least.

I hope that it's just that there's nobody close enough to hear me, and I'd have an easy time believing it, because I live in the middle of nowhere, but not being able to read any voltage on my antenna through my multimeter when broadcasting has me worried that the problem is worse.

Well let's hope that you're not out of range of Amazon. As mentioned, just pick up an inexpensive swl meter and it'll tell you everything you need to know. It's good to have the meter anyway as you can use it in the future!

 

[wtp]

do you have a scanner that gets the CB range. or even a friend or neighbor ?

 

[Trucker700]

Thanks for all the replies, I will be getting an swr meter as soon as I can, but that won't be for another couple of days at least.

I hope that it's just that there's nobody close enough to hear me, and I'd have an easy time believing it, because I live in the middle of nowhere, but not being able to read any voltage on my antenna through my multimeter when broadcasting has me worried that the problem is worse.

Your multi-meter won't register voltage at the antenna when you transmit. That is the reason for the suggestion to get an SWR meter. Install the radio and antenna on the same vehicle. Drive to a truckstop or nearby interstate, and see if you can hear any of the truckers talking on channel 19.
If you can then try talking to one of them.
Also, if there is a CB shop in the area, go by there and talk to the tech. If you are set on using this particular radio, have the tech check it out for you.
It may not be worth spending the money getting it repaired if it has transmit problems.
But, unless you know how to test and properly repair the radio, that's your only real choice.
James

 

[Trucker700]

Oh and it's unlikely that you would get shocked or burned by the output of that radio when grabbing the antenna while transmitting.

 

[KE5MC]

To enhance Trucker700 comment...
BC, at some point you might get a ham License and mobile radios in that class can output as much as 50 watts on high power. I can't say at what power level an RF burn will happen, but suspect that is the threshold. I'm sure other will know, likely by experience. ☹️ RF burns take a long time to heal, not sure why.
Good Luck with your project!
Mike

 

[arudlang]

I've picked up a couple of oldie-but-goodie handheld CB radios on ebay lately for cheap (~$10-$25) and although I agree an SWR meter is pretty important and probably the next thing to purchase or borrow, if you can find another cheap radio to use just for testing its been worth it for me to have those so I can quickly and easily test send/receive on new radios that arrive (Somehow I have about 8 CB radios now and I just started in November!)

Garage sales are a bit out of season here but another possible source of cheap radios to test with. Facebook marketplace, etc.