TM-271 Transmit Issue

Joined
Apr 2, 2009
Messages
2
Location
Cleveland, OK
#1
Hello everyone, I have recently moved and setting up my shack. I have a Diamond X510HDM 2m/70cm antenna mounted at about 12 feet ( I know, not very high). I have it hooked up to my Kenwood TM-271 powered by an MFJ-4225MV, 25A switching power supply. I have good recieve, but when I try and key up the radio, it shuts off and immediately powers back up. I have switched the antenna to a discone antenna that is rated for TX on 2m just to check, and it does the same thing. I have tested the power supply on a Kenwood TM-V708 to insure it is working, and it does.

Does anyone have an advice to try and figure out what I going on with the radio? I appreciate any information you may have.

73,

WX5JCL

**I figured it out shortly after posting, I apologize for posting too soon**
 
Last edited:

KE5MC

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
706
Location
Lewisville, TX
#2
Hello everyone, I have recently moved and setting up my shack. I have a Diamond X510HDM 2m/70cm antenna mounted at about 12 feet ( I know, not very high). I have it hooked up to my Kenwood TM-271 powered by an MFJ-4225MV, 25A switching power supply. I have good recieve, but when I try and key up the radio, it shuts off and immediately powers back up. I have switched the antenna to a discone antenna that is rated for TX on 2m just to check, and it does the same thing. I have tested the power supply on a Kenwood TM-V708 to insure it is working, and it does.

Does anyone have an advice to try and figure out what I going on with the radio? I appreciate any information you may have.

73,

WX5JCL
Look at the part of the power cord connected to the 271 that was not used to power up the 708. You have a classic high resistance connection that drops to much voltage on key up powering off the 271.

Mike
 
Joined
Mar 30, 2005
Messages
3,063
Location
So Cali
#3
Look at the part of the power cord connected to the 271 that was not used to power up the 708. You have a classic high resistance connection that drops to much voltage on key up powering off the 271.

Mike
Bad fuse holders, a common problem on KWD radios.
 
Joined
Jul 27, 2005
Messages
9,740
Location
WTVLCA01DS0
#4
If the voltage is set correctly (13.8 volts give or take a bit) then I'd agree with the others, bad connection, bad crimp, etc.

Other thing to rule out is that the power supply is somehow faulty. When this sort of thing happens, it's often current starvation. That shouldn't be an issue with a 25 amp power supply, IF it's working correctly.

Any sort of crimped connector should be suspect. The cheap hardware store crimp connectors and/or the "smash and pray" crimpers are often the cause.
 
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