KAT100-1 Tuning Problem

[DL9HDA-2]

Hello,

I bought a used KAT100-1 (ROM 1.04). But the tuners is not working
korrekt. If I press the tune button some relays are making a lot of
noise, but the SWR is still bad. If I run the manual relay test in the
menu, the relays n1,n2,l1...l8 will not work.

But: If I turn the case upside down, the tuner suddenly works!

So one example: Switching to 80m Band 3570KHz. Tuning: After fife
seconds 1.7 SWR in indicated. But if I use the morse key, the SWR rises
up to 3.

If I turn the case arround during tuning (within the 5 seconds) the
tuner works right and the SWR is 1! The rotation direction don't care.

Or: The SWR is bad. Menu --> ATU --> L0...L8 no relay is making a click.
While tuning from L0 to L8 and vice versa with one hand and turning
around the case with the other hand: Suddenly: click click!

This phenomenom is 100% reproducible. All cables are ok. I checked
everything and I changed every cable.

And I think there is no bad soldering. In my opinion there is a bad
relay, which switches not back. But I cannot measure them, because I can
only reach the soldering points if the tuner is upside down!

Any hints

Vy 73 Holger/DL9HDA
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[DL9HDA-2]

Dear Doug,

there Is a circuit board. And I did all the test you wrote. I flexed and
bent the board up with high force. I shacked It and I tried to jog the
relays. Nothing. And I resoldered most of the connections.

73 Holger, DL9HDA.

> Holger,
>
> I have no knowledge of that tuner.  Is it built on a circuit board?
>
> I have seen problems similar to what you describe.  There were broken
> traces on the circuit board and the traces re-connected when the board
> was flexed or bent by turning it upside down.  One way to test this
> theory would be to intentionally flex the board while it is upright to
> see if the problem goes away.
>
> Of course, if there is no circuit board then none of what I said matters!
>
> 73,
> -Doug, W7KF

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