[Elecraft] SSB xtal replacements

[DHK2BOB@aol.com]

K2  - new crystals mod

I replaced the 7 xtals on the SSB board but have not yet gotten around to the 
CW filter ones. I can notice a difference on SSB Rx - no doubt about it.  
"Better audio" would summarize it.  Good mod!  Not really that hard or time 
consuming to do. Also, the upper and lower SSB background noise now sounds 
almost the same. I no longer have to choose between "good LSB or good USB." 
The picture on Spectrogram is flatter. As with all tinkering, three new 
questions have arisen and I would appreciate some comments.  The problem is 
that over the past few months I've added the KPA100 and done the 2nd filter 
mod and I'm not certain if that is where the answers lie. 

1.  Using Spectrogram6 I still can't tell when L34 is aligned! I just left it 
one and one half turns from the top!  This is not a problem but just an 
observation which I'm sure relates to my inability to detect the subtle 
differences. I had AGC off and fiddled with the RF gain control. I thought 
that the only difference I noticed was not in the "height" of the spike but a 
slight change in the distance between the top of the spike and the "noise" 
down below. That is, tuning L34 seemed to change the noise but not the spike. 


2.  When tuning L34 I noticed for the first time that there are now  two 
spikes on the 7.000 birdie, and it sounds like that too! Any ideas? I doubt 
that was the case previously, but naturally, I can't be sure!  Perhaps this 
is related to the installation of  the 100 Watt amp or the fact that I didn't 
replace the CW xtals although the dual signal is present on LSB USB and CW. 
The 7.000 birdie tones were at 680 and 600 but can naturally be moved with 
the VFO control.  On the other hand, CW signals around 7.040 are clean. (I 
long ago did the mod to "purify" the sidetone although I'm sure that's not 
related to this birdie problem.)  

3.    Now for something that really concerns me! On ten meters it appears 
that the bandpass filter is off. The Rx is too quiet. At first I thought this 
to be dead band but last weekend, during the contest,  the band was opened 
but I still had little background noise although I could hear all the 
stations calling. My thoughts are that while building the 100W amp I used the 
wrong cap in the ten meter band pass filter. As I recall there was a choice 
between two caps and given a fifty/fifty chance I will always lose!  Maybe 
I'll try the other one. With the "QRP top" there was no such problem on ten. 
Therefore, I'm blaming the amp filters. Also, I did not yet upgrade the amp 
to eliminate the ten meter overdrive problem or whatever that was. I have the 
parts someplace!  Any thoughts? 

Thanks, - Love this radio!
Bob WB2DHK