Use of Coolant Spray OK?

[Todd Fonstad]

Greetings,

 

I have K2/100 #1130 which I use for field day and occasional mobile use. A
couple of years ago, an instability on receive began which would eventually
disappear after a few minutes of warmup. Signals sounded ‘chirpy’ and
somewhat raspy. Later, I found that the same problem manifested itself on
the transmitted signal. I went through the Control and RF boards and
resoldered many connections in hope that a poorly-soldered joint would be
the culprit. That seemed to clear the problem up for a few months, but it
reappeared. I’m just now getting around to troubleshooting the problem after
a hiatus of about a year and hope to have the rig ready for the Wisconsin
QSO Party as a mobile entrant four weeks from now. I spent the better part
of today re-resoldering <g> the same places I had done so before, but the
instability remains.

 

The rig stabilizes as it heats, usually after about five minutes, but band
as well as filter changes can bring the instability back for a few moments.
Eventually, the problem disappears with extended use.

 

I would like to spray components with a short burst of coolant to isolate
what seems to be a thermal problem. Is there any danger in to the rig and
its components in doing so?  I won’t snort the stuff!

 

Thanks for your consideration. I’ve read the digest for years but have
rarely posted recently.

 

73

Todd

N9NE

 

 


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[Don Wilhelm-3]

Todd,

That means that you have not found the offending bad solder connection.
Keep trying, and use a soldering temperature of 750 degrees F when reflowing
the joints.  If you see a 'bubble' of flux when you heat the solder
connection, that is a sign that insufficient temperature was applied when
the soldering was initially done.  Often a bit of extra flus and solder will
help, but be prepared to wick away any excess solder too.

Keep trying, you are on the right track.

73,
Don W3FPR

> -----Original Message-----
>
> I have K2/100 #1130 which I use for field day and occasional mobile use. A
> couple of years ago, an instability on receive began which would
> eventually
> disappear after a few minutes of warmup. Signals sounded ‘chirpy’ and
> somewhat raspy. Later, I found that the same problem manifested itself on
> the transmitted signal. I went through the Control and RF boards and
> resoldered many connections in hope that a poorly-soldered joint would be
> the culprit. That seemed to clear the problem up for a few months, but it
> reappeared. I’m just now getting around to troubleshooting the
> problem after
> a hiatus of about a year and hope to have the rig ready for the Wisconsin
> QSO Party as a mobile entrant four weeks from now. I spent the better part
> of today re-resoldering <g> the same places I had done so before, but the
> instability remains.
>
>
>
> The rig stabilizes as it heats, usually after about five minutes, but band
> as well as filter changes can bring the instability back for a
> few moments.
> Eventually, the problem disappears with extended use.
>

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.441 / Virus Database: 268.17.33/678 - Release Date: 2/9/2007
4:06 PM

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