[Elecraft] K2/100, half power output on 17-10M

[David Wilburn]

I have a spot for L16, I did not inventory the toroids as I ordered 
those from the toroid guy.  I did not receive an RFC10, and I do not see 
a spot for RFC10, though I am quite capable of missing it.

David Wilburn
dave.wilburn at verizon.net
K4DGW
K2 #5982


Don Wilhelm wrote:
> Dave,
> 
> FB that your C31 is .033 uF - but that alone is not an indicator. Do you 
>  also have a toroid at L16 AND no RFC10 as well (and blue toroid cores 
> at L15 and RFC1)?  All these things must go together.  The prior design 
> KPA100 with RFC10 and L16 installed did properly use a .033 uF capacitor 
> at C31.
> 
> If you have no toroid at L16 and no RFC10, then request a .22 uF 
> capacitor for C31 from Elecraft.
> 
> If you do have an L16 toroid and RFC10 installed, the proper value for 
> C31 is .033 uF.
> 
> 73,
> Don W3FPR
> 
> David Wilburn wrote:
>> Ok, where do we find out more about this?  I just finished inventory 
>> and my C31 is a .033uF.
>>
>> David Wilburn
>> dave.wilburn at verizon.net
>> K4DGW
>> K2 #5982
>>
>>
>> Don Wilhelm wrote:
>>> Jeff,
>>>
>>> In that case, what is the size of C31?  If it is the old .033 uF it 
>>> must be changed to the new .22 uF value.  You can get one from 
>>> Elecraft when they get back in the office, but if you have two .1 uF 
>>> caps with a voltage rating of 50 volts or more, you can parallel them 
>>> for the time being.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> Jeff Kinzli N6GQ wrote:
>>>> Don, thanks, it's the newest KPA100, just bought/built it about a
>>>> month or two ago...
>>>>
>>>> -Jeff
>>>>
>>>> On 4/7/07, Don Wilhelm <w3fpr at earthlink.net> wrote:
>>>>> Jeff,
>>>>>
>>>>> Before we give any answer, we need to know the level of the KPA100.
>>>>> Did you build it from the manual Revision D or the earlier Rev C?
>>>>> Another way of checking - do you have a toroid at L15 and is RFC10 
>>>>> present?
>>>>>
>>>>> It is not likely to be a sticking relay problem - that almost never
>>>>> happens with the KPA100.
>>>>>
>>>>> 73,
>>>>> Don W3FPR
>>>>>
>>>>> Jeff Kinzli N6GQ wrote:
>>>>> > My K2/100 (#5945) has been working well lately, until I started
>>>>> > noticing higher output at times, more pronounced with higher SWR
>>>>> > antennas (i.e. it would more often spike it's output power if
>>>>> > connected to an antenna with more than 1.3:1 SWR, the output power
>>>>> > would rise to 140W).
>>>>> >
>>>>> > About the same time, I started noticing lower output power on 10, 
>>>>> 12,
>>>>> > 15, and 17M. Output remains full on 20, 30, 40 and 80M.
>>>>> >
>>>>> > Today I pulled the KPA100 apart, went though and checked and
>>>>> > resoldered everything around the SWR bridge, and anything that 
>>>>> looked
>>>>> > remotely cold-soldered.
>>>>> >
>>>>> > Put it back together, same issue (well, at least the lower power 
>>>>> issue).
>>>>> >
>>>>> > With a setting of anything over 50W, the max output is 50-52W, as
>>>>> > indicated on the K2 internal wattmeter, or my external wattmeter.
>>>>> >
>>>>> > Any ideas why I'd only get half power on half the bands (and this 
>>>>> is a
>>>>> > new occurrance, I was getting full power before).
>>>>> >
>>>>> > Thanks for any ideas,
>>>>> >
>>>>> > Jeff
>>>>>
>>>>
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>>
>