[Elecraft] K1-4 receiver sensitivity problem

[Phil Wheeler]

Thomas,

I just re-aligned my K1 after changing all 16 trimmers (Work!) and=20
noticed what you say here:

>A possible hint: The pre-mix band-pass filters all peaked
>the receiver gain. The trimmers in the receiver side of the
>RF band-pass filter (CA, CC, CE, and CG) peaked the gain as
>well. However, the corresponding filter trimmers CB, CD,
>CF, and CH, all behaved as though there wasn=92t a peak.
>
in my case, too.  But the latter trimmers do have a definite peak in TX=20
alignment.

One thing:  Make sure you have the jumper from Pin to to Pin 10 of J2.=20
 Otherwise, you will not have an antenna connected to hear noise from=20
<grin>.  An easy mistake: As many times as I have aligned my K1, I just=20
made that mistake today.

73, Phil


ac7a@gci-net.com wrote:

>Hello,
>
>I am in the process of assembling a 4-band, K1 transceiver,
>and have ran into a bit of a problem with the receiver
>performance. This has been observed at the receiver
>alignment procedure.=20
>
>The problem is very poor receiver sensitivity. In fact,
>only the strongest of signals can be detected. This is the
>case on all bands. The audio gain is very good, so it looks
>like a RF or IF signal problem.
>
>A possible hint: The pre-mix band-pass filters all peaked
>the receiver gain. The trimmers in the receiver side of the
>RF band-pass filter (CA, CC, CE, and CG) peaked the gain as
>well. However, the corresponding filter trimmers CB, CD,
>CF, and CH, all behaved as though there wasn=92t a peak.
>These trimmers are on the T/R, antenna path side of the
>filter.
>
>Can anyone tell me if CB through CH exhibit broad peaks
>that don=92t seem to affect the gain very much?=20
>
>I am interested in any other ideas you may have with regard
>to the sensitivity problem as well.
>
>Thanks, Thomas =96 AC7A (Tucson)
>