[Elecraft] K2 C22 Adjustment Method Question

[Jim KO5V]

Good afternoon,

A couple of weeks ago, I pulled # 7225 out of its long hibernation and finished it Friday night. It lives, and it has passed all of its tests! The only problem I had was during the VCO test. It was showing 0000.00, and after about 4 hours, I found that C68 was not a 10pf cap - it was a 1pf cap labelled "1D" - which looked a lot like a "10" to me. I built and added the SSB adapter yesterday, and I plan to set up the mic this afternoon. So far, I've heard signals on 80M-17M, and it sounds pretty good, although I still need to properly set up the filters with Spectrogram. 

This is my third K2, I stupidly sold #1, and #2 was killed because some idiot forgot to unhook the antenna a couple of days before an electrical storm. Anyway, I really enjoy building these kits!

For adjusting C22, I don't have a receiver that I trust to be accurate @ 4MHz. Looking at Don's page, I decided to use Wayne's method of moving the internal probe from TP1 to TP2 after zero-beating WWV @ 10MHz. The signal was weak, but in cw mode, I could hear the carrier (I hope that's what it was...). My K2's tone is set to 600hz, so using "Spot", I zero-beat WWV's carrier in cw and cwR, which seemed to occur within 10Hz of each other. I then switched to usb and adjusted C22 so the readings at TP1 and TP2 were within +/- 20Hz (best I could do). I ran CAL PLL, and CAL filter on 40M. WWV seems to be almost right on at 10000.01MHz. However, when I switch to 20Mhz, and use then same method to zero-beat with Spot and cw and cwR, the reading is 19.999.92MHz.

Is this a normal thing, or is my understanding of the method flawed? I would bet on the latter...

Thanks in advance. 

73, Jim KO5V