Kenwood TK-8160 receives but won't transmit

[pigheaded]

Aloha, I have three TK-8160 radios. One transmits and receives just like it should but the other two which are programmed the same will receive but when I try to transmit the screen goes blank then displays the Kenwood name. I anyone has any ideas as to why this is happening I would much appreciate your input, mahalo, Len.

 

[mmckenna]

Usually that's voltage starvation.
Either a low battery, undersized power supply, or wiring issues.

How are they powered?

 

[krokus]

Have to agree with a power problem. The voltage drops with the high current p, and resets the radio.

 

[kd4efm]

Voltage issue, check grounds and power source as noted above
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

rf issue, open ground can cause this also, check antenna connections or move mag mount away from radio (rf feedback / foldback)

 

[DeoVindice]

Voltage issue, check grounds and power source as noted above
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

rf issue, open ground can cause this also, check antenna connections or move mag mount away from radio (rf feedback / foldback)

I'll second the RF issue comment. I had a similar issue with a TK-880 that would shut off on keyup when the antenna was too close to the radio.

When you describe one radio working properly, are you swapping out radios with the same power supply and antenna, or are all three radios separate installations?

 

[pigheaded]

Usually that's voltage starvation.
Either a low battery, undersized power supply, or wiring issues.

How are they powered?

I have a cigarette lighter plug attached to two of the radios, the ones that don't transmit. The one that does transmit I use as a base and it is powered by an ICT Comm Series power supply 13.8 VDC. The two that won't transmit are powered by a different power supply that measures at 13.8 as well. Tested all three with the same antenna. Guess the next thing to do is test the two on the same exact power source as the working radio. I appreciate all the feedback and will let you guys know what happens.

 

[pigheaded]

I'll second the RF issue comment. I had a similar issue with a TK-880 that would shut off on keyup when the antenna was too close to the radio.

When you describe one radio working properly, are you swapping out radios with the same power supply and antenna, or are all three radios separate installations?

So far I've just swapped the antenna but next I'll try the power supply from the working radio on the others, thank you for your suggestions.

 

[mmckenna]

I have a cigarette lighter plug attached to two of the radios, the ones that don't transmit. The one that does transmit I use as a base and it is powered by an ICT Comm Series power supply 13.8 VDC. The two that won't transmit are powered by a different power supply that measures at 13.8 as well. Tested all three with the same antenna. Guess the next thing to do is test the two on the same exact power source as the working radio. I appreciate all the feedback and will let you guys know what happens.

Cigarette lighter sockets/plugs can be problematic at best.
They will supply 12 volts to the radio, but often they are fused at 10 amps, which might be below what the radio will pull at full power. That usually blows the fuse, though.
The spring contacts don't always work well, either. It might make contact enough to power the radio, but when transmitting, it'll pull higher current and result in a voltage sag. That voltage sag/drop will result in the radio restarting.
The wiring for cigarette lighter plugs is usually bundled in with all the other circuits in the vehicle, that can include CAN Bus stuff, or other noisy circuits.

You'll be doing yourself a favor by ditching those cigarette lighter plugs on the radio and wiring directly to the battery as Kenwood recommends. There's a good reason that's what they tell you to do.

The antenna can also be an issue. Make sure the antenna is outside the vehicle and mounted properly. Make sure the antenna is properly tuned for the frequencies you are using. High SWR or a high RF field near the radio can result in issues when transmitting.

Trying out those two radios on your base power supply would be a good troubleshooting step. It'll tell you if it's a fault with the radio or the power/RF.

 

[pigheaded]

Voltage issue, check grounds and power source as noted above
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

rf issue, open ground can cause this also, check antenna connections or move mag mount away from radio (rf feedback / foldback)

I have been using the antenna from the working radio on the two others, great reception, no transmission. Thanks for your suggestion,.

Cigarette lighter sockets/plugs can be problematic at best.
They will supply 12 volts to the radio, but often they are fused at 10 amps, which might be below what the radio will pull at full power. That usually blows the fuse, though.
The spring contacts don't always work well, either. It might make contact enough to power the radio, but when transmitting, it'll pull higher current and result in a voltage sag. That voltage sag/drop will result in the radio restarting.
The wiring for cigarette lighter plugs is usually bundled in with all the other circuits in the vehicle, that can include CAN Bus stuff, or other noisy circuits.

You'll be doing yourself a favor by ditching those cigarette lighter plugs on the radio and wiring directly to the battery as Kenwood recommends. There's a good reason that's what they tell you to do.

The antenna can also be an issue. Make sure the antenna is outside the vehicle and mounted properly. Make sure the antenna is properly tuned for the frequencies you are using. High SWR or a high RF field near the radio can result in issues when transmitting.

Trying out those two radios on your base power supply would be a good troubleshooting step. It'll tell you if it's a fault with the radio or the power/RF.

I appreciate your advice and am going to wire directly to the battery, thank you.

 

[mmckenna]

I appreciate your advice and am going to wire directly to the battery, thank you.

It's important to do it correctly.
Use 14 gauge or larger stranded wire. Not solid/stranded house wiring (THHN etc.). Go to a good auto parts store and get stuff rated for automotive use.
Positive power feed should be continuous run from the radio to the battery with a suitable size (15 amp) fuse close to the battery connection.

Negative wire should be grounded to the vehicle chassis close to the radio.

Use high quality wire, crimp connectors, fuse holders, etc. Anywhere the wiring passes through the firewall, a grommet should be installed. Use split loom over all the wiring to protect it.

It takes some work, but it's worth it in the end. It'll be much more reliable and prevent issues.

 

[a417]

I have a cigarette lighter plug attached to two of the radios, the ones that don't transmit. The one that does transmit I use as a base and it is powered by an ICT Comm Series power supply 13.8 VDC.

Cigarette lighter sockets/plugs can be problematic at best.
<snip>
Trying out those two radios on your base power supply would be a good troubleshooting step. It'll tell you if it's a fault with the radio or the power/RF.

Solid advice. Diagnosis by subsitution, figure out what the problem follows. I highlighted your orig. post, as you said it yourself. I'll bet you wouldn't have even had to have posted here if you swapped the working radio with the non-working radio without the lighter plug.

You are now seeing how seemingly inconsequential things like cigarette lighter plugs are huge pains in the ass. Pop back in when you have it sorted, things are working well, and you've eliminated those nasty things from your life. You'll feel better.

 

[TNDispatcher]

I have a cigarette lighter plug attached to two of the radios, the ones that don't transmit. The one that does transmit I use as a base and it is powered by an ICT Comm Series power supply 13.8 VDC. The two that won't transmit are powered by a different power supply that measures at 13.8 as well. Tested all three with the same antenna. Guess the next thing to do is test the two on the same exact power source as the working radio. I appreciate all the feedback and will let you guys know what happens.

amperage is different. needs some juice