KIO2 noise and remote PA

[Sam Smith-11]

I noticed this at Field Day. The club was using a repeater with output
on 146.625. As soon as I turned on the K2 we got hash on that
frequency. Since then I have checked it at home with no computers
anywhere around and confirmed the problem.

I have the PA and the KAT100 in the EC2. A short cable connects the
KIO2. It has the pin 1 ground to the shield connected at both ends. A
longer cable runs from the connector on the K2 to the PC, with the
shield only connected at the K2.

I verified that the combination that produces the noise is the K2
alone with the cable connected to the KIO2. In other words the PC and
the PA are off and not connected and I still get the noise.

My cable looks like the one on this page: http://www.kk7p.com/k2kpa100.html

Any suggestions for tracking this down?

Thanks,
Sam N4MAP
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[KK7P]

> I noticed this at Field Day. The club was using a repeater with output
> on 146.625. As soon as I turned on the K2 we got hash on that
> frequency.
> Any suggestions for tracking this down?

You must have an older KIO2 with the 16.289 MHz oscillator. The 9th
harmonic is 146.60 MHz.

You can change the crystal to 18.432 MHz as used in the later KIO2s, or
try clamping a chunk of ferrite around the cable at the K2 connector end.

73,

Lyle KK7P

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[Larry - WA2DGD]

Sam,

Funny you should mention that. In my shack, I have the K2 with a KIO2
and also a 2 meter rig nearby. Whenever the K2 is on, the 2 meter rig
stops scanning and hangs on 146.625 and just breaks the squelch. As soon
as I shut the K2, scanning resumes.


Sam Smith wrote:
> I noticed this at Field Day. The club was using a repeater with output
> on 146.625. As soon as I turned on the K2 we got hash on that
> frequency. Since then I have checked it at home with no computers
> anywhere around and confirmed the problem.
>


--
73
Larry
WA2DGD

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[Sam Smith-11]

Thanks, Lyle,
Yes, I have K2 #1013 - lucky 13. I'm sure I bought the KIO2 as soon as
it came out. I'll check the crystal fequency tonight.

Isn't there also a KIO2 in my remote PA? That one is probably the newer crystal?

Sam N4MAP
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[Jack Brindle]

On Jun 29, 2005, at 5:13 AM, Sam Smith wrote:

> Thanks, Lyle,
> Yes, I have K2 #1013 - lucky 13. I'm sure I bought the KIO2 as soon as
> it came out. I'll check the crystal fequency tonight.

The KIO2 uses a crystal frequency of 16.289 MHz. It has NOT been  
changed since the unit's inception. The KRC2 uses the same crystal.

> Isn't there also a KIO2 in my remote PA? That one is probably the  
> newer crystal?

The KPA100 has a voltage generator that uses an 18.432 MHz crystal.  
This one _has_ been changed since the original kit. The original  
frequency was also 16.289 MHz.

It might be interesting to change the KIO2's crystal to 18.432 to see  
if the spurs you are encountering go away (or get moved to somewhere  
less interesting).


- Jack Brindle, W6FB
------------------------------------------------------------------------
---------------------


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[Sam Smith-11]

I found a 16.9xx crystal on an old computer board and swapped it out.
Now the birdie has moved somewhere else.

My other choice was 16.670 but I figured that would wind up in the 6
meter band...

Thanks everyone for the help.

Sam N4MAP
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