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K2 high current on 15 meters

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Brett Gazdzinski

K2 high current on 15 meters

I built K2 #6673 last week, and everything works well, except for a high
current warning on 15 meters. The current is set at 3 amps.

Things seem fine up to about 10 watts, above that, the current goes up and
the power out stays the same.

In doing the initial receiver alignment, 15 and 17 meters did not have a
peak like the other bands did when adjusting the band pass filters, 17 meter
power out seems fine.

I checked that the correct components are in the correct places, and have
the correct values, and that the solder is good, could I have a bad relay?

The adjustments for 15 and 17 meters do peak the power output, and not at
the end of their adjustments...

Not a big issue, but I don't remember 6065 acting that way, I don't think I
ever got the high current warning on that K2.

Brett
N2DTS

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Don Wilhelm-4

Re: 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

Brett Gazdzinski wrote:

> I built K2 #6673 last week, and everything works well, except for a high
> current warning on 15 meters. The current is set at 3 amps.
>
> Things seem fine up to about 10 watts, above that, the current goes up and
> the power out stays the same.
>
> In doing the initial receiver alignment, 15 and 17 meters did not have a
> peak like the other bands did when adjusting the band pass filters, 17 meter
> power out seems fine.
>
> I checked that the correct components are in the correct places, and have
> the correct values, and that the solder is good, could I have a bad relay?
>
> The adjustments for 15 and 17 meters do peak the power output, and not at
> the end of their adjustments...
>
> Not a big issue, but I don't remember 6065 acting that way, I don't think I
> ever got the high current warning on that K2.
>
> Brett
> N2DTS
>
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Brett Gazdzinski

Re: K2 high current on 15 meters

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" <[hidden email]>
To: "Brett Gazdzinski" <[hidden email]>
Cc: <[hidden email]>
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
>
> Brett Gazdzinski wrote:
>> I built K2 #6673 last week, and everything works well, except for a high
>> current warning on 15 meters. The current is set at 3 amps.
>>
>> Things seem fine up to about 10 watts, above that, the current goes up
>> and the power out stays the same.
>>
>> In doing the initial receiver alignment, 15 and 17 meters did not have a
>> peak like the other bands did when adjusting the band pass filters, 17
>> meter power out seems fine.
>>
>> I checked that the correct components are in the correct places, and have
>> the correct values, and that the solder is good, could I have a bad
>> relay?
>>
>> The adjustments for 15 and 17 meters do peak the power output, and not at
>> the end of their adjustments...
>>
>> Not a big issue, but I don't remember 6065 acting that way, I don't think
>> I ever got the high current warning on that K2.
>>
>> Brett
>> N2DTS
>>
>> _______________________________________________
>> 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
>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - http://www.avg.com Version: 8.0.176 / Virus Database:
>> 270.10.10/1906 - Release Date: 1/21/2009 7:07 AM
>>
>>

Don Wilhelm-4

Re: K2 high current on 15 meters

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" <[hidden email]>
> To: "Brett Gazdzinski" <[hidden email]>
> Cc: <[hidden email]>
> 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
>>
>