[Jeffhs]

One of the reasons Zenith's high-end table sets (C845, MJ1035, C835, et al.) work so well on AM as well as FM is because they have an RF amplifier stage ahead of the antenna, a feature not commonly found in AM radios of the '60s and later. Zenith's 800 series radios were designed for DX as well as for high fidelity, the former because many of these radios were sold and used in areas that were located tens or hundreds of miles away from the nearest stations.

The AM section of my C845 is so good I sometimes wonder why Zenith did not include an external AM antenna terminal in addition to the external FM terminals. I suppose, however, if someone wanted to connect an external AM antenna they could use a dodge such as disconnecting the internal Wavemagnet and connecting the external antenna (through a blocking capacitor, of course) to the leads going to the tuning cap. The use of a blocking capacitor is absolutely vital in these sets because they are hot-chassis series-string radios, meaning one side of the AC line is connected directly to the chassis and will be hot with the full line voltage, depending entirely on which way the plug is inserted in the wall socket. There is exactly a 50-50 chance of finding the hot side of the chassis; many people used to find out purely by accident that the chassis was hot when they touched the radio chassis and a grounded surface at the same time. This is why I do not care for metal-cased tube-type AA5 radios such as the Arvin 540T, et al. These sets may have been decent performers in good signal areas, but they were accidents waiting to happen, even though the chassis of these radios were secured in the cabinets by means of screws going through rubber grommets. This arrangement may have worked well when the radio was new, but over time the grommets hardened and lost much or most of their insulation capabilities. Another problem was that many times the grommets would be left off the screws (or lost) when the radio chassis was returned to the cabinet after servicing by a novice technician or budding radio serviceman. I've heard of cases where these radios were operated for years or decades without those grommets in place, which again is a disaster waiting to happen.

One thing I've noticed with my C845 is that the RF amp stage (a single 6BJ6 tube, used as an RF stage for AM as well as FM) seems to work too well (!) on AM. I say this because the set will pick up the horizontal-oscillator harmonics from every TV set in the apartment building in which I live, making daytime AM DX difficult if not impossible. There are several small AM music stations about 80-90 miles from here that I'd like to hear sometime, but those horizontal-oscillator birdies seem to appear right on or very near them. On the other hand, nighttime AM DX on my C845 is great. I live near the south shore of Lake Erie and can hear many stations in southwestern Ontario, Canada, as well as Detroit, Pittsburgh, Chicago, New York, Philadelphia, et al. just using the radio's built-in Wavemagnet antenna. IIRC, I even heard WBAP-AM 820 in Minneapolis on this radio one night not too long ago, although with all the noise in my apartment I consider myself lucky if I can hear anything other than New York, Philly, Pittsburgh, or Chicago 50kW stations here after dark. Oh well. AM radio stations are programmed by mostly talk-based formats these days, so I guess I'm not missing much if I don't hear much music on the broadcast band. The C845 more than makes up for that on FM, as the sound and sensitivity are excellent, better than just about any modern radio coming from Korea or elsewhere in the Orient.

IMHO, Zenith should never have left Chicago and abandoned radio production. The company's older radios are among the best there were, as were their hand-wired TVs of the '50s through the '70s. The Zenith name and their trademark lightning bolt Z are now used by Gold Star on flat-panel HD televisions that are nowhere nearly as good (or last nearly as long) as the original Zeniths. I believe this is a terrible black eye on the memory and history of the original Zenith Radio Corporation, but.....what can we do? There will be no turning back, now that Zenith as we used to know it is gone. I suggest we keep our old Zenith radios, TVs and other gear in good shape and to use them often, as this equipment (and the memory of the company that manufactured it) is all that is left of a once-proud organization. The founders of the Zenith Radio Labs in Chicago, later to become the Zenith Radio Corporation, would probably turn over in their graves if they knew (or somehow were to find out) what has happened today to the proud firm they started over nine decades ago.