Adjusting Antenna / Reception

[psychsploitation]

Hello, all.

I am new to the world of CB and after hooking up the SWR meter discovered that I should shorten my antenna. I know that this will improve the transmission, but will it improve the reception as well?

Thanks!

 

[PrimeNumber]

Yes. A resonant antenna is best on both transmit and receive. Receiving just isn't as critical, because you don't have energy bouncing back down the coax and into your radio the way you do when trying to transmit through a non-resonant antenna.

Again, yes. The gains may be small, too small to notice, but you have to tune things to transmit anyway.

 

[psychsploitation]

Thanks!

So after hooking up the SWR meter it looks like I will need to shorten my antenna which in my case means cutting the antenna. Aside from using bolt cutters to chip off 1/4 inch at a time and running the meter until it reads efficient, are there any other steps?

 

[milkman21218]

What antenna do you have? And what is the SWR?

 

[psychsploitation]

Nothing fancy. I have a Cobra magmount hooked up to a handheld Midland radio. Channel 1 gave a reading of about 1.6 and channel 40 was about 3.

 

[PrimeNumber]

Thanks!

So after hooking up the SWR meter it looks like I will need to shorten my antenna which in my case means cutting the antenna. Aside from using bolt cutters to chip off 1/4 inch at a time and running the meter until it reads efficient, are there any other steps?

Not really, just easy does it, maybe nibble at 1/8" when you're getting close.

I've used a Dremel cut-off wheel the same way. Bolt cutter's probably just as good and way faster.

 

[psychsploitation]

Thanks!

So as you can tell my setup is pretty primitive. I just mounted the antenna in the center of the roof of my compact car, ran the cable through the top of the trunk and then straight through to my glove compartment where the handheld radio is stored. I'm getting a pretty solid reception I think, but if anyone has any tips on how to improve my "installation" then I'm all ears.

 

[PrimeNumber]

Thanks!

So as you can tell my setup is pretty primitive. I just mounted the antenna in the center of the roof of my compact car, ran the cable through the top of the trunk and then straight through to my glove compartment where the handheld radio is stored. I'm getting a pretty solid reception I think, but if anyone has any tips on how to improve my "installation" then I'm all ears.

That's not primitive, that's a good functional installation in the finest tradition of CB! (Don't get me started on what I did to a BMW one time to get an antenna on and tuned up...)

About improving things, you're pretty much there already once you get the antenna tuned to give acceptable SWR across the band. Top-center of the roof is almost always the optimal spot –*it's highest and has the widest ground plane in all directions. After that there's not much else to do. Well, replacing that base-loaded shorty mag-mount with a full-length 1/4-wave bolt-down whip might help a little, but it would look awfully weird and would make a lot of noise on the awning at the burger drive-through window.

You're there man. Fire it up and enjoy what you've got.

 

[W8RMH]

On some antennas where the whip goes into the collar on the mount, sometimes there is a little extra room to play with by loosening the set screw and moving the whip in or out without requiring any cutting.

 

[smokchsr]

Also be sure to check your VSWR about every 5th channel to make sure that you are indeed going towards a dip on Ch 40. Some of those antennas are quite narrow and may have passed through the dip somewhere in the middle and are on their way back up again.

 

[psychsploitation]

Thanks, guys.

I tuned it yesterday in an almost empty parking lot so hopefully I got accurate readings on the meter. The highest is at channel one (1.5) and then it goes down from there. I made sure to calibrate and check the meter in five-channel increments.

I seem to be getting some pretty bad feedback/squealing. This was the case before the antenna was tuned though and I wasn't necessarily thinking that tuning the antenna would fix the problem. I've heard people say that they have this problem when they try to transmit, but for me it just happens while listening to a station. I disconnected the antenna from the handheld CB I use and connected the factory antenna just to see what happened and I still got feedback. I also disconnected the power (cigarette lighter) and put in batteries but got the same results. After a process of elimination, I guess it is the radio itself that is causing this? Is there anything else I should troubleshoot?

Also, I'm not sure people can hear my transmissions. Well, at least not the people who I am picking up in my radio. I don't know if this is out of the ordinary, but it seems like everything coming through my radio is from a completely different state. I'm in Texas but I've heard guys from the east coast, west coast, and even Canada. Getting a skip like this with my cheap little radio was a surprise to me and while it guarantees a very cool listening experience, I am doubtful that they can hear me.

 

[psychsploitation]

Well, after further research I guess the answer to the second part of my last post is that this is caused by transmissions that go well over the legal limit for wattage. Needless to say, I won't be taking the necessary measures to talk back to them.

As a CB rookie, I must say that it is shocking how much clearer these transmissions are compared to what I receive locally.