[Elecraft] K1 Receiver Issues

[Don Wilhelm]

Randall,

Is this a K1 with the 2 band board or with the 4 band board?

The Pre-mixer and the bandpass filter must be tuned before you will hear 
much of anything.

Since you have no strong signal source (like another transceiver that 
you can operate into a dummy load)  to help you tune the Pre-mixer and 
the bandpass, things are a bit more difficult.

I would suggest that you start by constructing an RF probe to help you 
adjust the Pre-mixer.   There is a schematic for an RF probe in the 
Troubleshooting section of the K1 manual.  If you choose to do it that 
way, I can give you some pointers about how to go about preliminary 
adjustments (that procedure is not in the manual) - so let me know if 
you have an RF probe available or have built one and we can continue.

It is normal to have a significant dropoff in signal level between the 
input to the product detector and the remainder of the filter crystals 
because the filter itself is restricting the RF fed through it to the 
center frequency of the filter - that fact is not present at the filter 
output (C38 to X4 junction) because there the product detector can 
respond to the full RF spectrum input rather than just the 4913 kHz 
slice of the spectrum.

73,
Don W3FPR

Randall H. Sanborn wrote:
> I am completely new to amateur radio, the K1 is my first xcvr, and I 
> don't even have my license yet.
>
> I have recently completed the assembly of my K1 and I'm not able to 
> pick anything up on the receiver. I worked with someone on the 
> #hamradio channel at irc.freenode.net, and hopefully we've narrowed 
> some things down. I will attempt to explain what we've looked at so 
> far with my butchered lack of understanding.
>
> I've tested all the toroids for continuity and they all check out, and 
> I've also gone through the and filter baord portions of the voltage 
> tables, and those check out as well.
>
> With some quick and dirty signal tracing (30ft of wire with a probe on 
> the end), I tried inputing rf into various points in the circuit. I 
> got responses at the following points, all on the rf board:
>
> U2 Pin 1
> C38
> X4, the leg connected to C38
>
> I didn't get any response at the following points on the rf board:
>
> C39
> X1-X4 (except for X4 mentioned above)
>
> Checked the voltages on D6-8 and they are all installed and working 
> properly.
>
> Any ideas where I should look next?
>
> Randall H. Sanborn
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