[Elecraft] Elecraft K2 IF Amp Alignment Question/Problem

[Bruce J. Howes]

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, w1ujr at mac.com 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