Elecraft K2 IF Amp Alignment Question/Problem

[Bruce W1UJR]

Hello all,

Finally got the K2 to the point when I am ready to do the IF  
Amplifier Alignment procedure.

All has checked out well so far, BUT, I can not hear the signal at  
7.000 MHz that is referenced in the manual.
Nada, nothing.
I scanned up and down the band, from 6990 - 7010 and can't hear it at  
all.

So following the manual's suggestion, I did the 40 meter band pass  
alignment, which went quite well.
I was able to hear CW signal and International broadcast stations  
with an outside antenna.

So, it looks like I may have a problem here, wondering if it is a RF  
gain issue, or other problem.
How strong is this signal anyway, I've done my best to carefully  
tune, and feel if it was there, I would have heard it.

Suggestions, thoughts, things to test?
I do appreciate your input!


73 Bruce W1UJR
www.w1ujr.net



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[Ron D'Eau Claire-2]

Did you have anything connected to the antenna jack when you did that? I
cannot hear the "birdie" at 7.000 with any sort of antenna connected to the
K2. Even with the antenna off it's easy to miss unless I have the preamp On!


Ron AC7AC

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of [hidden email]
Sent: Sunday, March 25, 2007 3:23 PM
To: [hidden email]
Subject: [Elecraft] Elecraft K2 IF Amp Alignment Question/Problem


Hello all,

Finally got the K2 to the point when I am ready to do the IF  
Amplifier Alignment procedure.

All has checked out well so far, BUT, I can not hear the signal at  
7.000 MHz that is referenced in the manual.
Nada, nothing.
I scanned up and down the band, from 6990 - 7010 and can't hear it at  
all.

So following the manual's suggestion, I did the 40 meter band pass  
alignment, which went quite well.
I was able to hear CW signal and International broadcast stations  
with an outside antenna.

So, it looks like I may have a problem here, wondering if it is a RF  
gain issue, or other problem.
How strong is this signal anyway, I've done my best to carefully  
tune, and feel if it was there, I would have heard it.

Suggestions, thoughts, things to test?
I do appreciate your input!


73 Bruce W1UJR
www.w1ujr.net

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[Bruce W1UJR]

Hi Kristina and group,

Using a signal generator with a signal level of .14 Vrms I injected a  
signal at the antenna connector.
Following the procedure, I can't get anything on the cathode of D6,  
as it states in the manual.
So I went back to the input to the band pass filter and checked the  
signal path, it ends at C114.

So I followed the signal along via the low pass filters and to the RX  
antenna bypass jumper, W1.
Signal level remained constant at W1, no problem.

Signal is present on one side of capacitor C114, but not on the other.
I wondered if Q2 might be shorting it to ground, so I removed Q2,  
same problem.
I double checked the board for solder shorts, damaged windings,  
etc.,nothing noted.
Checked D2, D3, D4 using an ohmmeter, they appear to be functioning  
as diodes, conduct only when forward biased.

Don't know, just know that it does not pass a signal past C114.
I was thinking that something was shunting it to ground, but could  
not find a shorted or damaged trace.
Perhaps just an open C114?

I thought C114, I'll have to sub in another cap to test, should be  
able to just couple across it if it is really open.
I will also have to check the RFC, but the color codes do match.

Maybe it is just as simple as a C114 problem.
The diodes are installed correctly, double checked that, and they are  
the correct type.

The good thing is that the signal loss is so complete should be easy  
to find, its a very black and white thing.


Tnx - Bruce W1UJR











On Mar 26, 2007, at 11:56 AM, Kristina Wright wrote:

> Bruce,
>   Are you sure you have the Preamp on?
>
> Kristina, KE7LUC
>
>
> On Mar 25, 2007, at 3:23 PM, [hidden email] wrote:
> All has checked out well so far, BUT, I can not hear the signal at
> 7.000 MHz that is referenced in the manual.
> Nada, nothing.
> I scanned up and down the band, from 6990 - 7010 and can't hear it  
> at all.
>
> 73 Bruce W1UJR
> www.w1ujr.net

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