Re: [K2] Hi Current...still

[bdenley]

Don:

You hit it right on the head.  Hooking up my W2 (only calibrated as it is programmed by Elecraft), then p ressing TUNE (very) momentarily pegs the met er on the 20 W scale!  So the K2 is putting out plenty of RF but cannot control the power out.  Where do I look next?



Thanks again

Brian KB1VBF



From: "Don Wilhelm" <[hidden email]>
To: "b denley" <[hidden email]>
Sent: Sunday, February 19, 2012 8:39:08 AM
Subject: Re: [Elecraft] [K2] Hi Current...still

Brian,

I did not realize that it was the same K2 - so in that case, the toroids
have not likely changed.
Make the check on power control that I mentioned in response to your
most recent reflector post.

73,
Don W3FPR

On 2/19/2012 1:15 AM, [hidden email] wrote:

> Don:
> After sending the unit to you to align last year, I haven't touched T3.  The K2 was working fine until around the time I tried to install the KNB2.  I never could get that to work so I just put the jumper in.
>
> It's very late here.  I will check the PA voltages and current tomorrow and report back.
>
> Brian KB1VBF
>
> - Original Message -----
> From: Don Wilhelm&lt;[hidden email]&gt;
> To: b denley&lt;[hidden email]&gt;
> Cc: Wayne Burdick&lt;[hidden email]&gt;, [hidden email] Wilhelm&lt;[hidden email]&gt;, Gary Surrency&lt;[hidden email]&gt;
> Sent: Sun, 19 Feb 2012 05:33:19 -0000 (UTC)
> Subject: Re: [Elecraft] [K2] Hi Current...still
> Brian,
> Is this condition on one band, or does it exist on all bands?
> The winding of T4 will affect all bands,
> A Low Pass Filter problem will affect one or two bands.
> Transmit into a 50 ohm dummy load - then:
> Quickly measure the voltage at the base of Q7 or Q8 during a TUNE. It
> should be between 0.60 and 0.64 volts.
> Count the turns on T4 carefully, the green winding should have 2 turns
> and the white winding should have 3 turns. The "link" wires should go
> from the front of the transformer directly to the back (they do not wrap
> through both holes)..
> 73,
> Don W3FPR
> On 2/18/2012 10:15 PM, Wayne Burdick wrote:
>> Did you check the winding on the PA transformer? If the impedance were
>> much too low, the current could be too high. Could also be excessive
>> bias current. What's the current drain in transmit mode, key up (i.e.
>> tapping XMIT but not the key)?
>>
>> Wayne
>> N6KR
>>
>> On Feb 18, 2012, at 7:09 PM, [hidden email] wrote:
>>
>>>
>>> After getting the HiCur message, I replaced the two PA transistors,
>>> the associated hardware, Q11 and Q13, and R50. Unfortunately I stll
>>> get the same message: HiCur when I press TUNE with power any higher
>>> than about 1.5 watts inot a 50 ohm dummy load. Any have any ideas
>>> about what else might cause this problem?
>>>
>>>
>>>
>>> Brian KB1VBF
>>>
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