MT1000 UHF noise problem

[ve9arz]

Hey all!

I have a UHF MT1000 on the 438-470MHz split. It works fine except when transmitting, there's a high pitched buzz on the carrier. It's not that loud, as my voice can clearly be heard over it, however its more of an annoyance. I've noticed that whenever I place my hand near the antenna, a "click" in the carrier can be heard on a monitor receiver and the problem goes away.

I took the radio apart and checked the antenna solder connection to the circuit board and even tightened all the RF shields on the radio, but the problem persists.

Any ideas what might be causing it?

Thanks,

Don
VE9XF

[Monty]

Hi:

I have seen that problem many times !!

In most of the cases, that small SMC Cap
mounted on the Flex near the Mon / Reset
Buttons either gets cracked, or falls off.

Best to replace !

In any case, try replacing that cap. What
happens is that the componet in question
is a de-coupling cap for the DC Lines while
in Transmitt.

MS

[Will]

Also check the strap from the circuit board to the antenna mount's base. Check for broken solder on the circiut board both sides.