[Elecraft] K2 Only 30-metre Band Works

[Don Wilhelm]

I would suggest that since 30 meters is working OK, the K2 is capable of 
both transmit and receive.
Furthermore, I would expect the problem to be in the bandpass filter tuning.
Be certain to follow the band order for tuning, otherwise you will be 
chasing your tail.

Use the RP Probe (provided with the K2 kit) to measure RF voltage.  If 
the bandpass filter adjustment does not provide adequate Power Output, 
put the RF Probe on W6 while making the adjustments to the bandpass 
filter.  Tune the bandpass filter for maximum RF voltage at W6.

Then look at the power output.  You may want to 'tweek' the bandpass 
filter a bit, but it should be very close to correct.

Your name and call on your posts please - I know your call is in your 
email address, but your name would make it a bit more personal.

73,
Don W3FPR

On 7/1/2021 5:34 PM, VA1CQ wrote:
> Further troubleshooting of my new K2 build reveals that transmit and 
> receive on the 30-metre band works well. But all other bands, transmit 
> and receive, don't work.
>
> On transmit on non-working bands, the output signal doesn't make it 
> past the output of the band-pass filters (W6). But on 30 metres, the 
> band-pass filter output is in the correct range of 25 mV with 5 watts 
> of transmit power. On 30 metres, the band-pass coils tune as you would 
> expect and I can peak the band on receive and transmit. On receive on 
> 30 metres, I can hear RTTY, CW and WWV as well as SW stations in the 
> 31-metre band. On other bands, I hear nothing except on 40 metres at 
> night when signals are strongest. I can hear an occasional strong 
> station on 40. When transmitting, I am using the DL-1 dummy load.
>
> I am trying to think of what's common among all bands except 30 
> metres, transmit and receive, where a problem could lie. The fact that 
> 30 metres works OK confirms that much of the rig is working correctly. 
> Since 30 and 20 metres share a band-pass filter as well as a low pass 
> filter makes this all the more confusing.
>
>