[Elecraft] K2: Low Output Only on 160M

[Don Wilhelm]

Sorry, that page 14 is at the back of the manual in the Troubleshooting 
Appendix.

73,
Don W3FPR

On 5/12/2013 5:50 AM, mteberle at mchsi.com wrote:
> Don, thanks for your reply.  I do not understand your reference to page 14.
> Page 14 in my manual is nothing but resistors being installed.
>
> I have noticed that it is drawing 3.3 amps when set for 2 watts and displays Hi-Cur.
>
> I have checked all the components you mentioned and everything appears to be correct.
> Checking the TP1, I get 6714 khz.
>
> ----- Original Message -----
> From: "Don Wilhelm" <w3fpr at embarqmail.com>
> To: mteberle at mchsi.com
> Cc: elecraft at mailman.qth.net
> Sent: Saturday, May 11, 2013 2:57:55 PM GMT -06:00 US/Canada Central
> Subject: Re: [Elecraft] K2: Low Output Only on 160M
>
> Mike,
>
> The easiest way to troubleshoot that problem is to isolate the problem
> to the failing stage.
> Use the RF Probe and measure the points given for the transmit path
> starting halfway down the left column on page 14
> Making those measurements on 40 meters will not be meaningful for your
> problem, but if you switch between 80 meters (or another working band)
> and 160 meters, you can compare the amount of RF voltage at each stage.
> Make the measurements in the order listed.  The first point where the RF
> voltage is significantly lower on 160 meters is a likely suspect.
>
> Possible problem spots are:
> 1) The Transmit Buffer - are C94 and C150 the correct values and well
> soldered?
> 2) The Bandpass Filter - are C13 and C14 the correct value (1200 pF
> marked 122) and well soldered?
>
> Check the VFO frequency at TP1 with the internal counter probe when
> tuned to 1800 Hz.  It should be near 6715 kHz.  If it is not, check the
> value and soldering of C75 (470 pF marked 471).
>
> Low pass filter problems usually result in both low power out and high
> current draw, but check the soldering of the K160RX toroids again.  Make
> certain the toroid leads are in the correct holes.
>
> 73,
> Don W3FPR
>
> On 5/11/2013 10:57 AM, Michael Eberle wrote:
>> Hi,
>>
>> I am having problems with my output power on 160M.  It will only put
>> out about 1.5 watts when set for 10 watts.  On all the other bands I
>> am getting between 9.4 and 10.3 watts.
>> I have double checked capacitors in the BPF section, double checked
>> capacitors and counted turns on toroid inductors on the low pass
>> filter board and found nothing obviously wrong.
>> relay K3 is switching properly and I really don't know what else to
>> check.  It is my guess that someone on here will know exactly what I
>> did wrong or some other things to check.
>>
>> Thanks,
>> Mike
>> KI0HA
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