K2: Hi Cur on 30m

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

K2: Hi Cur on 30m

Mike Markowski
I just noticed I'm getting a Hi Cur message only on 30m.

The set up:

- K2/100 into dummy load (KAT100 disconnected)
- Power set to 100 W
- CAL CUR set to 3.50 A
- When CAL CUR is 4.10 A, current drawn on 30m levels out at 4.02 A
- When I drop to 85 to 90 W, 30m draws just under 3.50 A
- All other bands draw less than 3.50 A
- I qso on all bands with no apparent problems

If anyone has been through this, what do you think - have I possibly
zorched my PAs?  Should I recalibrate?  (It could have even been this
way all along & I never noticed, since I often have the power level less
than 100 W.)  Or am I being paranoid over a half amp?

Thanks for any ideas,
Mike  ab3ap
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: K2: Hi Cur on 30m

Mike Markowski
Mike Markowski wrote:
> ...
> If anyone has been through this, what do you think - have I possibly
> zorched my PAs?...

That should have said...."have I zorched my PA's power transistors?"
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

RE: K2: Hi Cur on 30m

Don Wilhelm-3
In reply to this post by Mike Markowski
Mike,

First, count the number of turns on L4, L5 and L6 in the KPA100 - count the
turns that go through the center of the core rather than the outside.  An
extra turn on these windings would produce the Hi-cur on 30 meters.

How old is your KPA100?  If the kit was ordered mid-2005, then you may have
the inductive resistors at R19 and R20 - that problem usually appears at 20
and 17 meters, but occasionally shows up on 30 meters as well.  You can
obtain replacement resistors from mailto:[hidden email] .

I don't think you have 'zorched' the PA transistors.  If the turns on the
KPA00 low pass filter toriods are correct and all the C3x capacitors are
correct, you may want to install the KPA100UPKT and see if that brings
things under control (that upgrade kit does include new R19 and R20
resistors).

73,
Don W3FPR

> -----Original Message-----
>
> I just noticed I'm getting a Hi Cur message only on 30m.
>
> The set up:
>
> - K2/100 into dummy load (KAT100 disconnected)
> - Power set to 100 W
> - CAL CUR set to 3.50 A
> - When CAL CUR is 4.10 A, current drawn on 30m levels out at 4.02 A
> - When I drop to 85 to 90 W, 30m draws just under 3.50 A
> - All other bands draw less than 3.50 A
> - I qso on all bands with no apparent problems
>
> If anyone has been through this, what do you think - have I possibly
> zorched my PAs?  Should I recalibrate?  (It could have even been this
> way all along & I never noticed, since I often have the power level less
> than 100 W.)  Or am I being paranoid over a half amp?
>
> Thanks for any ideas,
> Mike  ab3ap
>
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.432 / Virus Database: 268.15.18/585 - Release Date: 12/13/2006
11:49 AM

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: K2: Hi Cur on 30m

Mike Markowski
Just to close this thread in case anyone was wondering about it, I
installed the KPA100UPKT today and it solved the HI CUR on 30m problem.
  The K2 now draws less than 1.7 A on 30m with 100 W tx into dummy load
compared to 4.1 A before.  What a nice change.  My thanks to Don and the
Elecraft Parts crew!

K1 #2298 was just finished this morning as well.  What will I do with
all this extra time now?  Not sure I still remember how to operate the
rigs.  :-)

73,
Mike  ab3ap

Don Wilhelm wrote:

> ...If the turns on the
> KPA00 low pass filter toriods are correct and all the C3x capacitors are
> correct, you may want to install the KPA100UPKT and see if that brings
> things under control...
>
> 73,
> Don W3FPR
>
>> -----Original Message-----
>>
>> I just noticed I'm getting a Hi Cur message only on 30m.
>> ...
>> Mike  ab3ap
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com