[Jeffhs]

I did some tweaking on the trimmer capacitors located on the chassis (under the battery box), and managed to get the low end of the AM band back. I can now hear several stations, including CFZM-AM 740 in Toronto, that I wasn't hearing before. I also noticed that the location of the radio has a decided effect on the number of stations I can receive. When I listen to my TO3000-1 in my bedroom, I notice a lot of noise and interference. Move the radio into the main part of my apartment, however, and the difference is like night and day. I can then hear AM 740, WJR 760 in Detroit, and many other stations, in the Cleveland area and elsewhere in northeastern Ohio, that are all but inaudible in the other location.

There is even less noise in the living area of this apartment than there is in the bedroom; I don't know why that should be. I do notice, however, that, since the switch to digital TV, and since a lot of my neighbors in this apartment building now have flat screens rather than CRT sets, there is a drastic reduction in horizontal-oscillator harmonic noise on the AM broadcast band. Makes DXing on AM much easier, and yes, I have heard some stations on my TO3000 I never heard before, such as a Canadian AM station identifying itself simply as "Newsradio 1310" (this one may be new in the Toronto or southwestern Ontario area) and a few other small stations I have yet to identify. Of course, the big 50kW clear-channel stations such as WBBM 780 and WCFL 1000 in Chicago, WBZ 1030 in Boston, KYW 1060 in Philadelphia, as well as other 50kW stations in the Great Lakes region, not to mention up and down the East Coast.

When I shifted the alignment to get back the low end of the broadcast band, however, it caused another problem. The dial calibration is just about correct from about 970 kHz to the top of the band, but below 970 the calibration is off. I read somewhere that this is a common problem when aligning these radios; I wonder why. Was there something about the design of the local oscillator in Zenith TO's (my TO 1000 has the same problem) that makes it difficult, if not downright impossible, to get proper tracking across the entire broadcast band? I have read that it is quite difficult with these radios to get accurate tracking across the entire band, so most owners of these sets just tolerate the problem. Was this problem actually as bad as it seems, or is there some trick to aligning these radios so that the tracking is reasonably good across the entire band? One thing that comes to mind is setting the oscillator trimmer so that a station on 1000 kHz comes in with the dial pointer set just to the left of "110" on the dial; this should work since 1000 kHz is roughly the center of the North American AM broadcast band. If this does not cause proper tracking across the BC band, what else (if anything) could be causing the problem? I'm thinking it is just a quirk in the design of the AM section of the TO's, from the 1000 through and perhaps including the 7000 series.