TM-V71A Welcome Screen when Xmiting on high power

[Shillelagh]

Just set up a new Kenwood TM-V71A and when trying to transmit on high power, the screen flashes the welcome screen and fails to transmit. I hooked this radio up in the house for testing before installing in a vehicle. I connected it to a regulated power supply that supplies13.6 volts but only 6 amps. I'm hoping the problem is that the power supply is not providing enough amps to transmit on high. Does that sound reasonable to anyone???

Thanks and 73
KK4EXJ

 

[SCPD]

Have you tried transmitting on low power with the same power supply? If the problem doesn't exist when you transmit on low power your power supply may be the issue, i.e., can't provide enough amperage. I've never used anything less than a 20 amp supply when I use my radios in the house. Check the radio specs too, the manual should tell you what the amperage draw is on high power.

 

[Shillelagh]

Thanks for the reply. The radio works fine on low and medium power. I suspected that it was not providing enough amps on high. My supply is 6 amps only. Tomorrow I'll put the radio in the vehicle and on truck battery power to see how it works on high power.

 

[mmckenna]

Yep, that is exactly the issue. Power supply can't provide enough current to drive the radio on high power transmit, so the voltage takes a dump, the radio restarts and never transmits. Not a radio issue, an insufficient power supply issue.

Like was said above, you need a bigger power supply to run high power as a base, 15-16 amps would be plenty, more would give you a bit of head room. Other option is to throttle back on the power to a point that your power supply can keep up.

If you are going to install it mobile, then you don't need to worry about this. Just do a good job on the install, proper connections to the battery, don't cut corners, and you'll be fine.

 

[Shillelagh]

Thanks, I learned an important lesson. (Don't skimp on power supply!)
KK4EXJ