Further Notes: To access those crystal slug tuned adjustments you will need
to lift the aluminum cover. You can disconnect all of the cables for the
FM board, and any RF connectors. The exciter board also provides DC
regulated voltages and must remain connected. Be very careful when moving
the cover, allowing the RF driver transistor to hit ground will cause
component damage! Be sure to use Fig 4-16 and Fig 4-15 to ensure you are
using the right adjustment for the band in question! Be very careful NOT
to damage the delicate slugs in those coils! Note that on some bands the
same crystal is used for two bands: ie: Y2 is used for 80 and 20 meters.
If you adjust the questionable crystal inductor and the problem returns
when the rig is back together and gets hot then there is a problem with the
related band crystal(s). My solution was to remount the two DC regulator
pass transistors that use the top cover as a heatsink to the rear apron,
and to cut a 1" wide slot on the cover between the FM and the LL Driver
board. That was a rather desperate move on my part on two Omni's, but they
are still working. I don't suggest you hack your rigs as I did.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|