Technical information

New Sprockets and Chains – Whew!
Sprocket Alignment
The pre-selector alignment is well documented where the chain tensioner needs to go etc. The band
switch was challenging so some additional experience notes could be useful.
1. Loosen the tensioner, it slides up and down with a set screw and shaft threading.
2. Install all the new sprockets and don’t tighten set screws.
3. Wrap the new chain around the full path, cut and reattach chain links with the tensioner all the
way down such that the chain does not have much slop in it. The tensioner sprocket set screw
is not tightened so it can spin freely on the shaft. I put some lithium grease on this shaft.
4. Alignment
a. Using a flathead screwdriver, rotate the band switch shaft full CCW (15Mhz position).
b. Now rotate the LO shaft and the RF board full CW with the screwdriver.
c. Looking at the back of the 1
st
driver board wafer switch, rotate the shaft until the wiper is
on the empty position. That is the 15Mhz position.
5. Now tighten all the set screws.
6. Slide the tensioner up to take up chain shack.
7. Final tweaks
a. First test the LO switch alignments by rotating all band switch positions and noting the
proper display. If off, rotate shaft, looking at the switch pads, retighten and retest.
b. Test RF output on all bands to verify driver switch positions are correct. Zero output
indicates misalignment on driver switches.