Keep in mind that there are two notches, one on each side of the pass. They are spaced about 10-15 MHz apart. When the low notch is at 146MHz, you will find the upper notch in the 154-156MHz area roughly. The reject coaxial capacitor (or the piston cap in the newer version) adjusts both notches in tandem. To get a low pass can, you have to move the high notch down close to the pass band. This takes more capacity in the reject capacitor. You may even have to lengthen the center conductor in that capacitor to get it to tune low enough.
The proper length of cable harness may also help to lower the maximum capacity needed on the reject adjustment. Good luck in your tuning Burt VE2BMQ>>> kk2ed wrote: snipped > > The pass (146.200) tunes just fine, with 1.5db or so of insertion > loss, but reject is an issue. The cavities on the low side act as if > they are another set of high-side cans. The reject rods appear to > tune properly, and I can get 80+db of rejection 600KHz low of > 146.200, but no matter what I do, the reject will never go ABOVE the > pass frequency. > > I doubt the cable harness lengths would cause this, no? From the past > posts I read, it sounds like if I were running out of room on the > reject rods, then the cable lenghts might be the issue. But my issue > is that the low side's reject is sitting below the pass, not above > the pass where it needs to be. >
