[CQ-Contest] TS-850 trouble

Dave Hachadorian k6ll at juno.com
Tue Apr 29 12:41:30 EDT 2003

On Mon, 28 Apr 2003 22:36:17 -0400 "K8KHZ" <k8khz at k8khz.com> writes:
> I have the following conditions of my rig.......
> has power out on 80-30M.
> no power 20-10M .
> tune was having troubles finding that sweet spot just before this.
> wonder how this could be.

Is receiver sensitivity reduced on the high bands also?

If so, it is probably the common 74LS145 Decoder Chip failure.
See http://n6tr.jzap.com/850repair.html

Look for the article "Reduced receiver sensitivity and
transmitter power output as you increase frequency."

Depending on the particular part of the chip that has
failed, you may get by without replacing it right away.

In my case, the broadcast band filter was being switched
in on all bands, so I just cut that one pin off the IC.
I never listen to the BC band on that radio anyway. If it
ever goes into the shop for something else, I'll have them
fix it.

Dave Hachadorian, K6LL
Yuma, AZ

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