[Elecraft] K3 with subrx - intermittent main RX problem and pwr out

[Fred Jensen]

"Two countries separated by a common language."  I believe "tag washer" 
is a "solder lug" on our side of the Atlantic.  I think Alan might mean 
the screw connection on that lug becoming intermittent due to oxidation 
and/or inadequate tightening.  Generally speaking, cold solder joints 
are "cold" immediately after the soldering process and don't develop 
later, although I've seen that happen due to very minor extended 
vibration of the joint.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 5/4/2017 9:43 AM, Matt Zilmer wrote:
> Sorry to be thick....  Is a dry joint same as a cold joint?
>
> Thanks and 73,
>
> matt W6NIA
>
>
> On 5/4/2017 9:12 AM, Alan. G4GNX wrote:
>> FWIW we thought that a relay was failing on our club's KAT500. I 
>> bought a new one from Elecraft and replaced it without thinking about 
>> it. They're quite cheap and it wasn't worth chancing an intermittent 
>> relay.
>> Whilst I was re-assembling the tuner, I discovered that the tag 
>> washer connecting Ant 1 to its screw terminal had developed a dry 
>> joint, which was the real cause of the intermittency. I don't know 
>> whether it was a manufacturing fault or someone had been heavy handed 
>> when assembling it.
>>
>> It would be worth checking soldered joints and other connections 
>> before replacing a relay. You may need to use a magnifying glass as 
>> it may not show up on a meter test. Another thing to try is what we 
>> used to do as service technicians; use an aerosol freezer spray in 
>> small areas around the suspected area and possibly a hair dryer on a 
>> warm setting (not hot) and observe for changes under test.
>>
>> 73,
>>
>> Alan. G4GNX