[Elecraft] K1 4 bander issue

[Don Wilhelm]

Fred,

If 40 meters works, then 30 should also.  They share the same low pass 
filter and the inductors of the bandpass filter and Pre-Mixer bandpass 
filter.

One possibility is that the crystal for 30 meters has gone bad.  You can 
check for that with an oscilloscope or RF Probe at P1 pin 4.  You should 
have at least 200mV peak to peak - which is 70mV RMS as seen on the RF 
probe.

If you have oscillation at P1 pin 4, then the most common cause is that 
30 meters has not been properly aligned.  Initially set C5, C6, CE and 
CF to their mid-point then feed a strong signal into the antenna jack 
with the K1 tuned to the frequency of the signal - you may have to hunt 
around that frequency for the signal.
Then adjust the 30 meter trimmer capacitors to peak that signal.
After peaking in receive, set the OUT parameter to 1.5 watts and peak 
those same trimmers on transmit.  If the power goes over 4 watts, stop 
and reset OUT and then continue.

Once you have peaked 30 meters, you will have to peak the filters on 40 
meters.

73,
Don W3FPR

On 8/4/2018 8:10 AM, Fred VE3FAL wrote:
> I just acquired a K1 4 bander from a ham in Ottawa. It has 40,30,20 and 15 meters in it. All bands operate and function as they should except for 30 meters. Have done some searches on this possible issue but nothing solid as of yet. Anyone have a starting point where I might look to see or find the issue.