[Elecraft] non-linear power adjust pot]

Sat Oct 25 17:52:00 2003

Sverre,

Thanks for the tip, but the pot is the correct one.  Also, in addition 
to being non-linear, there are spots where the power setpoint value 
jumps suddenly.  Starting from 0.1 watts, it will move fairly smoothly 
to 1.8, jump back to 0.1 go gradually to about 4, jump around to 8 or 9, 
then clear up to 11 or 12.

For example, adjusting to exactly XX.0 watts is difficult, with the 
setting jumping several tenths with the slightest touch of the knob.

Sverre Holm wrote:

>Could you have swapped the audio pot and the power pot? That would give
>you a log pot for the power, which could give you the kind of behavior
>you are describing. Just a suggestion for something to look for.
>
>--
>73, 
>Sverre
>
>------------------
>Sverre Holm, LA3ZA
>www.qsl.net/la3za
>
>
>
>  
>
>>-----Original Message-----
>>From: [email protected] 
>>[mailto:[email protected]] On Behalf Of Carl Strode
>>Sent: 25. oktober 2003 22:25
>>To: [email protected]
>>Subject: [Elecraft] non-linear power adjust pot
>>
>>
>>
>>
>>The POWER level pot in my newly completed K2 is real spooky.  On the 
>>bottom end it is very touchy, and will go from 0.1 watts to about 9 
>>watts with just a tweak.  Advancing it past about 10% of travel it 
>>starts over at about 1.5 watts and progresses up to full 
>>power with fits 
>>and starts.  It is very difficult to adjust and acts as 
>>though  the pot 
>>substrate is cracked, or the wiper has been bent.
>>
>>During assembly, the knobs were a very tight fit on the pot 
>>shafts.  The 
>>manual said to apply pressure and twist the knobs on.  After 
>>the first 
>>aborted installation attempt I was force to shave off the 
>>shafts a bit 
>>with an Exacto knife.  (Yes, the set screws were backed out and 
>>completely removed).  The first try without the trim job 
>>resulted in one 
>>pot being rotated past its stops.
>>
>>I have not yet taken the front panel board out to look at it, 
>>but plan 
>>to do so when I install the audio filter option a bit later.
>>
>>Would you suggest that I try another pot for the power adjustment, or 
>>should I look elsewhere fo another problem?
>>
>>Please advise.
>>
>>73
>>Carl
>>WA7CS
>>
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