[Elecraft] K2 high current on 15 meters

[Don Wilhelm]

Brett,

If that relay pin was either 1 or 10, the 40 meter LPF would have been 
active all the time - which would have an effect on the operation of all 
other LPF bands - I am surprised to hear that you did not have problems 
on 10 and 12 meters too, but that is 'how it goes'.

Don't feel bad, we all overlook some things at some times - the eyes get 
tired during an intense and repetitive soldering session.

I am not certain of the rating for the resettable fuse, but it does seem 
to work up to 3.50 amps which is required when the KPA100 is installed.  
As a matter of fact, the new transistor used at Q6 will require a CAL 
CUR setting higher than the manual suggested 2.50 amps *if* the K2 is 
operated at maximum power output.  I have seen K2s produce 18 watts or 
more on 80 meters with this new transistor, and that power does require 
greater than 2.50 amps.

Note also that a HiCur message does not necessarily indicate trouble - 
it just says that the K2 current draw is greater than the CAL CUR setting.

73,
Don W3FPR

Brett Gazdzinski wrote:
> Don,
> Thanks for the tips.
> I did check the parts, they were/are correct.
>
> I am ashamed to admit (as a former quality control inspector  of circuit 
> boards)
> that I missed an unsoldered relay pin, on the 40 meter low pass filter relay 
> I think it was, one pin on the end was not soldered.
>
> 15 meters now does full power at just under 3 amps.
>
> When I had the problem and was testing, I had put the current limit up to 
> 3.5 amps, and the rig would trip the self resetting fuse inside, I thought 
> it was rated for 3 amps???
> Not sure if it was the fuse or something else, but the rig would do a quick 
> reset...
>
> Anyway, the rig now seems to work fine in every respect, the receive seems 
> better than 6065 was, no missing parts, a very nice kit indeed!
>
> I just ordered the antenna tuner and ssb option, the high power tuner and 
> 100 watt amp comes later.
>
> Brett
> N2DTS
>
>
>
>
> ---- Original Message ----- 
> From: "Don Wilhelm" <w3fpr at embarqmail.com>
> To: "Brett Gazdzinski" <Brett.gazdzinski at verizon.net>
> Cc: <elecraft at mailman.qth.net>
> Sent: Thursday, January 22, 2009 1:01 AM
> Subject: Re: [Elecraft] K2 high current on 15 meters
>
>
>   
>> Brett,
>>
>> Check the components in the 15/17 m Low Pass Filter carefully.  Examine 
>> C218, C219, C220, C221 and C222 for correct values.  Then count the number 
>> of turns on L23 and L24.  Count the number of times the wire passes 
>> through the center of the core rather than the turns around the outside.
>>
>> Go ahead and set the CAL CUR to 3.50 amps.  If you add the KPA100, you 
>> must increase the setting to 3.50, and with the higher gain using the new 
>> transistor at Q6 it is often necessary to increase the CAL CUR limit - it 
>> does no harm to increase it.
>>
>> 73,
>> Don W3FPR
>>     
>