Antenna tuning

You should have an external meter, calibrating it before
every test. Channel 1,40,20. Then if your swr is higher
on 40 than 1 the antenna needs to be shorter. If the swr
is higher on 1 than it is on 40 the antenna needs to be
longer. Or take it to someone that has an antenna analizar.

 

Sounds to me like you didn't calibrate the SWR meter. Here's a quick run down of what I do:

First you make sure you're in an open parking lot away from trees, buildings, and especially anything metal. Make sure the truck doors are closed when you do this.

Next install an SWR meter inline with the coax between the radio and the antenna. Follow directions on the meter and calibrate the meter if there are any. This is especially important.

- All SWR meters are different. I know the Radio Shack 21-534 meter, you put the SWR meter in the "CAL" mode, then key up, DON'T TALK INTO THE MIC, and while holding down the key, turn the knob until the sweep needle on the gauge gets to the calibrate marking on the meter, then you are calibrated.

Now, tune to channel 1, key up the mic, DON'T TALK INTO THE MIC and see where the needle falls. Write this down. Next tune to channel 40, do the same thing, then again on channel 20 and do the same thing.

Then review your findings. if the SWR is higher on 1 than it is 40, then your antenna is too long. If it's higher on 40 than it is 1, your antenna is too short.

Some antennas have a tuneable tip at the top where you loosen the allen screw and raise the tip to make the antenna longer, or you can lower the tip to make the antenna shorter. Not all antennas have this; some of them are what they are.

In the case of steel whip antennas such as the Wilson 2000, you can actually pull the whip out and trim if needed, using a hacksaw, but don't cut off too much as if you do cut off too much, your whip is now useless for the 11 meter band (might be ok on 10 meters if you're a ham operator) and a new whip will be required. Measure twice, cut once. These steel whip antennas are also adjusted by moving the steel whip up and down in the holder and using the same type of set screw to hold in place.

Also keep in mind, if you're using a 10 meter export and if you don't have a frequency display and/or you're in the 10 meter band (anywhere that reads "28.XXX"), then your SWR may be high, as CB is 27 MHz and usies a slightly longer antenna that isn't suitable (in most cases) for 28 MHz use.

Other reasons for high SWR are: pinched coax, lose coax, water in the antenna/antenna coil, improper grounding (base of the antenna HAS to be bolted to a piece of metal making contact with vehicle ground), etc.

Hopefully this helps.

 

Swr higher on ch1 than ch40, antenna is electrically short (need to lengthen the adjustment). Higher on ch40 than ch1, antenna is electrically long (need to shorten the adjustment).

 

I once had a guy trying to convince me he had an "SWR calibrator", and he could dial up any SWR he wanted...

 

Also known as an antenna tuner.. never herd it referred to as a swr calibrator tho LOL

 

Boss I'm not sure what you got going on there. First what kind of meter is showing a 1.00 if it's a SWR meter I assume you had to go through the Calibration procedure and then set it show reflected power if that is not the case then I need to know what meter you are using. It could be a meter built into the radio that is self calibrating but I don't know.. Anyway if you have done everything correctly in that respect and you are getting that reading with no antenna on the unit I need to know what kind of system you have for antennas if this is in a truck with factory installed antennas sometimes they have matching units or "boxes" in the dash somewhere and I have seen these units show a good match without antennas..If that is true then any antenna you put on it will show a good match when you check the swr at the radio. You would need to check the antennas at the mount which can be done with the right adapters..