Kenwood Tm-221a Keyup problem
 

Hello,

I've finally got my 221A back in my car and I've run into a problem. When i Keyup the radio shuts off.I've wired the radio directly to the battery with fuses on both + -. It's been sitting for about 2 years.

Thanks

Kenwood Tm-221a Keyup problem
 

In article ,
OCradioman wrote:

I've finally got my 221A back in my car and I've run into a problem.
When i Keyup the radio shuts off.I've wired the radio directly to the
battery with fuses on both + -. It's been sitting for about 2 years.

OC-

I've had that problem with Icom IC-706 and IC-7000 radios. The problem
is that they are not able to operate with less than some critical
voltage.

To start, you need to have the car's engine running to be sure battery
voltage is 13.8 Volts. I assume you have a good connection to the
battery and sufficiently heavy cables connecting the radio. If it is
the same setup as you had before, it should still work.

That leaves the fuse connectors and the radio connector as possible
sources of resistance. You can try using pliers to tighten the fuse
clips by bending them slightly. If the radio power connector has been
reconnected numerous times, its sockets may have become spread. You may
be able to use a jeweler's screwdriver or a small blade on a pocket
knife, to bend the socket sides inward. In either case, be careful not
to overdo the bending.

In my installation, the problem first arose when I went to using
Anderson Powerpole connectors with a Rig-Runner multiple outlet box to
feed an additional rig. Each Powerpole connection introduced slightly
more voltage drop, compared to wiring the radio directly to the battery.

In order to keep the Powerpole connectors in line, I purchased an
MFJ-4416 "Super Battery Booster". It is a DC-to-DC switching power
supply that takes a variable input voltage as low as 9 Volts, and
produces a constant 13.8 VDC output at 25 Amps peak. (When it is turned
off, the battery voltage is fed through to the output.)

If low voltage is your problem, using the MFJ-4416 would probably solve
it. It also would solve a problem you may not be aware of. Output
power of solid state transmitters is extremely sensitive to battery
voltage. With a constant 13.8 volts, you always have full power.

Fred
K4DII

Fred-

Thanks a lot! The problem did turn out to be the fuse contacts. I made them a little tighter and problem solved!


Thanks

Kenwood Tm-221a Keyup problem
 

In article ,
OCradioman wrote:

Thanks a lot! The problem did turn out to be the fuse contacts. I made
them a little tighter and problem solved!

OC-

I'm glad to hear the problem is solved.

After I posted, it occurred to me that you might also have a blown fuse
in the minus battery lead. The radio might still have power through the
antenna ground connection, but circuit resistance would be higher.

Fred
K4DII