VHF transmit power

Most problems with radios that receive but do not transmit are antenna or antenna wire/connector issues. It's easy to receive with a marginal antenna but transmitting requires a good working antenna. If you have a SWR meter or can get your hands on one, install it in line with the antenna and test for reflected power. Of course, make sure your TX light comes on when you depress the mic switch. If not, switch mic and try again.
Hope this is helpful! Reply if u can.

The ratio for reflected power is 1:10, if your radio have 10watt fwd power then 1 swr is ok. its better if you tuned your antenna according to frequency chart which you are using. see the antenna cable for any damage, use low loss cable, also change the mic.

You appear to be aware of you antenna system with the separate meter attached so the tells me you dont punish a radio with an high swr. I am just guessing red wire/solder in mic cord at plug given that it is a side mic mic jack.
Stock mic
1- Shield (Ground)
2- Yellow (Audio)
3- Red (Transmit)
4- White (Receive)

Standing wave ratio is standing wave ratio. This meter is not reading based on frequency. It is reading based on the measurement of electrical energy. I see no reason why it wouldn't work.

1st. You cannot "set" the swr. The swr is not set on the radio. The antenna must tuned to attain an appropriate SWR reading.

2nd, If this doesn't solve your problem then you could have a worse problem. If there is a problem with the mic such as a break in one of the wires, the radio's receive will be off until you put a good mic on it. Try a different mic, and see if the receive comes back. Then check and see if your transmitting better.

As well, your meter could just be bad, as well your coax or antenna. Your receive could be poor if the antenna is not tuned to lowest SWR.

If it has been working up till recently, and you have "set" the SWR on the radio, which is not what the SWR function is for, because you don't set SWR on the radio, you could have been using the radio with the SWR super high and blown the final or other sections of the radio out.

SWR is basically signal reflection. If the antenna is not the right length, it will reflect energy back into the radio and damage it over time. The more an antenna is off from the correct length, the more reflect you will get.

The meter in the radio is used to determine how much reflect you are getting. You ideally want to have the lowest SWR possible.

To check the SWR, you set the meter switch to CAL. Key the mic. while holding the mic key down, turn the CAL knob up until the needle is at the little triangle at the top right of the meter marked by "CAL", Then while still holding the key, flip the meter switch to SWR. where ever the needle is at that point is your SWR.

You want ch 20 to have the lowest SWR. If the swr reading on channel 40 is higher then channel 1 then your antenna is too long. if it is higher on 1 then 40, its too short. Make small adjustments until 1 has almost the same reading as 40. then check ch 20 and it should be real low.

As I have said, if you haven't tuned your antenna as I have just explained, and have been using it as is, the possibility is high that you have already hurt the radio.

Although it could also have a bad meter. Use an external meter to read the SWR.


Other things to check. Make sure cable connections are tight. Make sure coax is not damaged. try another antenna.

I bought Kenwood TK 7102 VHF radio, but it was programmed and I can listen the dispatcher but can not transmit to him. Any solution please help.

The CAL is to calibrate meter for reading SWR (standing wave ratio) which is reflected power when transmitting back to receiver(radio) from antenna system.
This CAL switch position when selected and mic keyed uses the CAL knob to align the meter needle with inverted red triangle next to cal on meter. Then when you select SWR switch position meter will display accurately when mic is keyed for that channel. Now notice the difference when you go between channels 1 and 40. The ant led light will act as idiot light if it is not lit then you are most likely safe to transmit.
I say system because your vehicle, antenna and coaxial cable are all part of this system. When you have a high reading and have to trim you antenna this is really calibrating the antenna to the vehicles body which acts as a ground plane.

make sure your s/rf switch is in the right place on the radio is the most common problem i have found

Check your microphone by swapping with another duplicate. If no differance, you will need a SWR meter (standing wave ratio) to find the culprit. It attaches in line of the coax and determinds power out and reflected power. The reading should be 25 watts foward and max of 1 reflected.

Hi,

Based on your post/description:

1. how do i set the swr
Normally SWR are calibrated on your operating channel (where you usually stand-by). This is to maximize transmit power and receive sensitivity. To set SWR, switch to channel of your choice, switch SWR control to CAL, key or press PTT, while pressing PTT rotate ADJ knob until max deflection of needle on meter, release mic, switch control to SWR, key/press PTT, needle reading/deflection is SWR for that channel.

I would suspect that your SWR will vary from your current 1.4. This is because you have too big excursion of channels (240 channels).

2.reading a 1.4
This reading is good enough and should do. However as earlier stated, you seem to have 240 channels which would mean that your radio + antenna moves in a wide bandwidth and since the antenna tuning is affected by frequency, your SWR will also be affected by channel.

Best if you can further lower it down.

3. some cb cant get me
This is because the standard CB radio is only 40 channels. The next would be a 80 channel and then 120 channels.

4. is it my radio
Yes, you have a wide coverage radio almost an extended 10 meter rig.

5. do i have to set my radio on high or low to set my swr
I will assume you are referring to power output, set it to HIGH when doing SWR calibration

Hope this be of some help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.