KAT/100 not working

[charles-70]

My KAT/100 was completed and put into service on 28th January 2007.
Today (2nd March) it was working on 80m when first switched on.
I changed frequency from 3525 to 3577 and it would not retune.
Normally this would have been retuned instantly.

Now it will not tune on low power into a dummy load on any band except 40m.
When trying to tune on low power into the dummy load on other bands it mostly
comes to rest at 5:1 or some other unworkable SWR.

My suspiscion is that this is a firmware glitch.  Is there any way that I can
confirm this?
I have removed the lid for visual inspection and can see no obvious signs of
damage.

I would be most grateful for any helpful advice.

The K2/100 is still working perfectly but through a manual matching unit :-)

Charles - M0BIN - K2/100 Nr 5901
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[Tom Hammond-3]

Hi Charles:

There are MANY KAT100s out there, and to my knowledge, there have
been no such firmware problems reported.

Rather than expecting damage, were I you, UNLESS you truly SUSPECT
damage for some reason other than PURE MAGIC, I'd start looking for
an UNsoldered joint, or possibly a poorly-soldered joint.

That fact that the KAT100 once worked (and apparently properly) tends
to imply that everything is in its place. However, it only takes one
'flakey' connection to cause problems. Sometimes a flakey connection
will allow things to work for a period of time, but then, after a few
days, the connection will build up a thin layer of oxidation which
acts as an insulator and then only allows the connection to appear to
work correctly following a bit of 'agitation' (movement, or other
jolt to cause the oxidation to be broken for a short time).

Good luck,

Tom Hammond    N0SS

>My KAT/100 was completed and put into service on 28th January 2007.
>Today (2nd March) it was working on 80m when first switched on.
>I changed frequency from 3525 to 3577 and it would not retune.
>Normally this would have been retuned instantly.
>
>Now it will not tune on low power into a dummy load on any band except 40m.
>When trying to tune on low power into the dummy load on other bands it mostly
>comes to rest at 5:1 or some other unworkable SWR.
>
>My suspiscion is that this is a firmware glitch.  Is there any way that I can
>confirm this?
>
>I have removed the lid for visual inspection and can see no obvious signs of
>damage.
>
>I would be most grateful for any helpful advice.
>
>The K2/100 is still working perfectly but through a manual matching unit :-)
>
>Charles - M0BIN - K2/100 Nr 5901

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[charles-70]

Hi Tom,

Many thanks for your quick reply

On Friday 02 March 2007 16:13, you wrote:

> There are MANY KAT100s out there, and to my knowledge, there have
> been no such firmware problems reported.
> Rather than expecting damage, were I you, UNLESS you truly SUSPECT
> damage for some reason other than PURE MAGIC, I'd start looking for
> an UNsoldered joint, or possibly a poorly-soldered joint.
> That fact that the KAT100 once worked (and apparently properly) tends
> to imply that everything is in its place. However, it only takes one
> 'flakey' connection to cause problems. Sometimes a flakey connection
> will allow things to work for a period of time, but then, after a few
> days, the connection will build up a thin layer of oxidation which
> acts as an insulator and then only allows the connection to appear to
> work correctly following a bit of 'agitation' (movement, or other
> jolt to cause the oxidation to be broken for a short time).

There's nothing like the voice of experience :-)
There's sound logic in what you say.
You could well be right, I suppose we can all be guilty of a dry joint at some
time.  I suffered a dry joint when I built K2 nr 439, so I tend to solder
very carefully and often re-wet the joint to make sure. I use a Weller temp
controlled iron. However, I will take your advice and have a good check
around. I guess dry joints must be the most common reason for failure and as
it had been working faultlessly for 35 days then your suggestion of possible
oxidisation is a high possibility.

I'm not certain, but I could have noticed a heat/burnt smell around the PIC in
the front right corner when I took off the lid.  It was a very very faint
smell and could have just been my imagination - the thing had been working
very hard clattering the relays while I was testing it on all bands (low
power into the dummy load) just to make sure.

Is there a good reason why it should still be working just on 40m ?

Thanks again for your comments Tom.

73 from Charles - M0BIN - K2/100 Nr 5901
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[charles-70]

Hi Tom,

It's ALIVE !!!

On Friday 02 March 2007 17:24, you wrote:

> Probably... but I can't think of one at this juncture... Probably to
> tell you that it's a SIMPLE failure, and that (almost) everything's really
> OK.

It must have been a simple failure as you said.
I couldn't find anything positive but I touched a few joints on caps etc.
I reckon the most suspect area was P5 on the front panel - I put some extra
solder on three of the pins.  Then put it all back together not feeling very
optimistic and IT WORKED :-))

I shall never know what the real problem was - that's the trouble with wetting
a few joints.  I suppose it might have been cured by just unplugging the
front panel and re-plugging.

Hoever, I'm extremely grateful for your suggestions and support Tom.
I'm now smiling - so I hope you are too.:-)

Have a good week end and keep up the good work.

It's the BERU contest this week end which requires a bit of band
hopping/search and pounce so the auto atu back in service will be a great
help.

Many thanks and best regards
73 from Charles - M0BIN - K2/100 Nr 5901

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