04-15-2013, 07:40 PM
Check to make sure your tuner rotor has a good connection to ground. If it doesn't, it will cause this problem. Basically, you have indicated that over the range of the tuner, you are getting almost no capacitance change. Additionally, you have no reception at the bottom of the band, which also indicates insufficient capacitance to tune the lower frequencies. This condition doesn't affect the SW frequencies as much, though it does to some point, e.g. you can tune a smaller range of frequencies than what is intended, and likely these will be higher in frequency. As far as BC band, you are tuning all stations with the trimmer. When you use the tuner, you are moving the LO only a tiny amount, so your tuning appears wide, and the peak will be in only a small part of that. Additionally, with the frequencies you indicate for your LO, it would appear that you will only receive stations in a range of approximately 800-850 KC.
To reiterate, check for ground continuity from the tuner rotor. It has to be on the order of less than 1 ohm (0.14 or so). You may have a bonding strap loose, or you may need to clean the rotor bearings with something like DeOxit (or both).
To reiterate, check for ground continuity from the tuner rotor. It has to be on the order of less than 1 ohm (0.14 or so). You may have a bonding strap loose, or you may need to clean the rotor bearings with something like DeOxit (or both).