Question about Uniden PC78ELITE 40-Channels Base CB Radio

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Swr to low?

Hi i have a trc 48 std 5 watts on a clr 2--.5/8 wave..my swr is low.its lower than 1.5 .is this bad..... i can get out a good 30 to 40 miles with it... and also i can here short wave radio not all the time but it fads in and out just in the day time. ...help

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The lower the SWR the better!

SWR is actually a ratio, e.g. 5:1, but generally speaking only the first number (5 in this case) is written as the second is always a 1. The lowest SWR you can get is 1 (1:1). So if you've got 1.5, that is very good.

Hope this helps,

Matt

Posted on Mar 03, 2008

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I have a Realistic TRC-457.It has very low power and modulation.It is a virgin radio other than someone has replaced the final and driver.I noticet that I cant set the modulation and swr levels on my dosy...


How many watts does it do? If it swings say: 1.5 watts up to 4 watts, someone has installed a swing kit which has a very small carrier. In AM, carrier is not important, its modulation and swing that makes it loud. If its low Audio modulation then it may be that final has went bad too.

May 31, 2011 | Radio Shack TRC-503 CB Radio

1 Answer

Swr meter not moving


follow these steps to adjust the
standing wave ratio(SWR).
1. Turn on the CB.
2. Set S/RF/SWR/CAL to CAL.
3. Key the Mic and rotate SWR CAL so the meter points
to CAL.
4. Unkey Mic.
5. Set S/RF/SWR/CAL to SWR.
6. Key Mic again and note the actual measurement on
the SWR scale. Refer to the following table to interpret
the reading.

1:1 - 1.5 Great
1.5 - 2:1 OK
2:1 - 3:1 Not So Good
Higher than 3.1:1 Terrible

Jan 14, 2011 | Cobra 29 LTD CB Radio

2 Answers

I don't understand how to adjust the SWR or how the built in meter works for my DX949.


Here is a basic instruction on how to adjust the SWR. When you adjust the SWR, you are not changing anything on the radio. You are actually tuning the antenna for best SWR. The lower the better. SWR stands for "Standing Wave Ratio" Or in layman's terms, SWR is energy that is reflected back into the radio. The higher your SWR reading, the more RF energy that is not leaving the antenna, and getting reflected back into the radio. This can cause damage to the transmit section of the radio. The length of the antenna is what will change this. The length of the antenna must match the length of the radio wave. The following instruction will explain how to take an SWR reading, and how to use that reading to ascertain weather the antenna is too long or too short.

Here is a quick explanation of the meter. There are 3 settings for the meter. SWR, MOD, and PWR. When you are not keying the radio the meter will show you your receive signal. How strong some ones signal is. When you have the switch on MOD and key, when you talk it shows you modulation. How much audio you are putting through the radio. When its on power, and you key the radio, it shows you your dead key wattage.

Tuning your antenna:

It is important to tune your CB radio antenna to the proper length. The length must exactly match the wavelength of the frequency you transmit on. Or be really really close.

All Cb antenna's have a way to adjust the length of the antenna. If it's a mag mount, the metal whip can be slid in and out of a metal collar. Usually a set screw. If its a fiberglass whip, the way to tune it is on top. It either has a small metal rod with a set screw to adjust the length, or it threads in and out to adjust length.

Either type you have it will need to be adjusted for proper length. Here is how to tune the antenna to lowest SWR.

Some radios have a built in SWR meter. Some do not. If yours doesn't have an SWR meter, then you have to use an external SWR meter. Radio shack carries one, and you can find them cheap on ebay.

If you have a built in SWR meter or external, the procedure is the same:

1. Turn the radio to CH 20.(This is the center of the band.)
2. Switch the meter switch to SWR
3. Key the radio. (Important. Do not talk while keying the radio.)

Where the meter falls after that point is you SWR reading. If its above 3, that is real bad. 2 is not gonna kill your radio but its not the greatest. 1.5 and under is a good place to be, but the lower the better.

If your SWR is high, Here is how to find out if your antenna is too long or too short.

1. Turn to CH 1
2. Repeat SWR procedure. You must calibrate every time you do it.
3. Remember the SWR reading.
4. Turn to CH 40.
5. Again repeat SWR procedure.
6. Compare the reading between CH 1 and CH 40.

Now if the SWR is higher on channel 1 then channel 40 your antenna is too short. You must make it longer.

If the SWR is longer on channel 40 then on channel 1, then the antenna is too long, you need to make it shorter.

Make height adjustments about an eight inch at a time, and take reading each time.

once the SWR is significantly lower and the reading on channel 1 and 40 are about the same, you a about matched. At this point turn the radio to the center of the band, channel 20 and take an SWR reading.

You should now have a low SWR reading, 1.5 or under. If you are 1.5 or under, you are good to go.

If you cannot get the SWR to an appropriate level, there may be an antenna problem.

Nov 16, 2010 | Galaxy Radios DX-949 40-Channels Base CB...

2 Answers

Tunning the antenna on radio shack cb trc-447


After installing the antenna, follow these steps to adjust the
standing wave ratio(SWR).
1. Turn on the CB.
2. Set S/RF/SWR/CAL to CAL.
3. Key the Mic and rotate SWR CAL so the meter points
to CAL.
4. Unkey Mic.
5. Set S/RF/SWR/CAL to SWR.
6. Key Mic again and note the actual measurement on
the SWR scale. Refer to the following table to interpret
the reading.

1:1 - 1.5 Great
1.5 - 2:1 OK
2:1 - 3:1 Not So Good
Higher than 3.1:1 Terrible

The ideal standing wave ratio (SWR) is 1:1, or a meter
reading of 1 on the SWR meter's top scale. A SWR ratio
of 1.5:1 to 2:1 is excellent for most mobile CB antenna
applications.

Check the SWR on Channel 1 and Channel 40
If the SWR is higher on 1, make the antenna longer
If the SWR is higher on 40, make the antenna shorter
Most antenna's are adjustable. Make small adjustments at a time.

Oct 10, 2009 | Radio Shack TRC-447 CB Radio

2 Answers

When i key up the mike the tx/rx light and the ant


your swr setting are off wack fix your swr

Oct 02, 2009 | Cobra 29 LTD CB Radio

2 Answers

I need the manual/s for a Cobra CB radio, 29LTD Classic,ser#105129711,manufactured 5/01. Thanks for any help you might have, This radio has a built in SWR meter and I need to know how to tune it or do I...


1) push the button marked S/RF / SWR / CAL to CAL

2) Hold in the button on the mic

3) Turn the SWR CAL knob until the needle is over set to the far right of the meter

4) flick the switch (in step 1) to SWR

Your SWR reading will be displayed. The more to the left the better..

Jun 22, 2009 | CB Radios

2 Answers

Swr to hi and can t get it down


I hope this will help you on setting your swr put the radio on channel 1 check your swr.
now go to channel 40 check the swr. If the swr is lower on 1 than it is on 40 the antenna must be shortened buy 1/4 inch.until you reach your desired swr.if the swr is lower on 40 than it is on 1 the antenna must be lenthened by 1/4 inch until desired swr.

Mar 28, 2009 | Cobra 29 LTD CB Radio

1 Answer

I want to know about the range with handheld cb radios


It depends on lots of factors....

First, the output power of your radio. Many claim 5watts output, but when measured on an accurate SWR / power meter, they are usually closer to 4 watts. Also, they usually output full power only with external power supply, not internal batteries.

Second, the antenna. If you are using a "rubber duck" helical, range will be at its minimum. If it has a quarter (1/4) wave telescopic whip (about 2 meters!) then that would be better.
If it has a socket for external antennas, then a (1/4) quarter wave car mag mount on something metal and 1/4 wave in radius this would be pretty good, especially if mounted above any local restrictions like buildings and walls.
The ultimate would be a half 1/2 wave antenna, mounted at least 1/2 wave (5 meters!) above ground, on a scaffoling pole or similar at least 1/2 wave long (5 meters).

The station you are speaking to also has a lot to do with range, if they have a good station, then range will be better.

With 5 watts, at the right time of day, with the right antenna, and under the right conditions, CB can reach across the globe! Yes really.

You need to post more info on the type of set up you have.

Hope this helps
M3ODQ

Feb 01, 2009 | CB Radios

2 Answers

Short wave


hi..yes i here broadcast stations and foreign voices..i know its
shortwave..but it fades in and out.. like skip. ch 8 will have the same broadcast as ch23. or ch3 or ch11.. but like i said it fads in and out..thanks for your help

Mar 04, 2008 | Uniden PC78ELITE 40-Channels Base CB Radio

4 Answers

Cobra 29 ANT light


I believe it to be feedback but be aware of your Standing wave ratio because using a linear amp radiates signal to the point that it could cause that light to come on. There is a problem if the radiated signal is feeding back into the amp a a higher level that it can withstand over time.

Sep 08, 2007 | Cobra 29 LTD CB Radio

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