[Elecraft] KAT100 - Reluctant to come on, K2 often displays "not inst"

[Bill Coleman]

That’s not the way Elecraft recommends. The KAT100 contains an electronic switching mechanism. Power must be present at the KAT100 coaxial connection before the K2 is switched on. The KAT100 uses the 12CTRL voltage from the DB-9 connector to turn on it’s internal supply.

> On Aug 5, 2018, at 7:29 PM, Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
> 
> I would configure the station power such that the tuner is powered from the switched source on the radio.   Thus the power supply is on first and then the radio is turned on and powers the tuner at the same time. 
> 
> Bob, K4TAX
> 
> 
> Sent from my iPhone
> 
>> On Aug 5, 2018, at 6:02 PM, Don Wilhelm <donwilh at embarqmail.com> wrote:
>> 
>> Bill,
>> 
>> If it were a bad PIC chip, the results would be consistent. Reseat the KAT100 firmware Ic to clear away oxidation.
>> Look for a flaky connection on the Control cable - at both ends.
>> 
>> There is not much that you can diagnose with a 'scope other than to determine that the chip is getting transitions to it.
>> If you want to reverse engineer the K2 AUXBUS, then you could make some determination of the AUXBUS correctness, but that is a difficult exercise in futility IMHO.
>> 
>> 73,
>> Don W3FPR
>> 
>>> On 8/5/2018 5:36 PM, Bill Coleman wrote:
>>> Jack screws appear to be tight on both ends.
>>> 
>>> After I cycle the power 6-12 times, it will eventually come up. I wonder if I have a bad PIC chip in the KAT100. I may try an older version of the firmware, I think I have one. That will take a few days.
>>> 
>>> I can put a scope on Pin 40 of the PIC chip. I see transitions. Anything I can diagnose with a scope?
>>> 
>>> 
>> 
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> 
> 

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Web: http://boringhamradiopart.blogspot.com
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