New Seattle AM music station KVI 570

[Jeffhs]

Originally Posted by Sandy G

Another thing was most early FM sets I've found have been VERY insensitive...They seem to be set up to pick up local stations only, to take advantage of FM's higher audio frequency response.

I think Zenith's FM radios from about 1960 to 1970 or so, particularly the MJ1035 and C845 (from 1965 and 1960, respectively), are quite sensitive; Zenith was not one to cut corners on anything they designed, built and marketed, as long as the original Zenith Radio Corporation existed. I have a C845 that can get FM stations from 50-60 miles away using its built in antenna with no trouble at all, and the sound is very good. I live near Lake Erie and can often hear FM stations from Canada (SW Ontario), Detroit, Toledo, Ohio,et al., as well as all Cleveland stations, on this radio when the band opens up.

I have a feeling that the C845 and other high-end Zenith table and console FM sets must have sold like hotcakes in radio fringe areas, because of their excellent sensitivity and selectivity. Both the C845 and MJ1035 have RF amplifiers ahead of the antenna, and both have RF stages on AM and FM. However, the MJ1035 uses two separate RF stages for each frequency band, whereas the C845 uses a single tube (6BJ6) as an RF amp, switched between AM and FM as necessary. Even my Zenith R-70 AM/FM transistor portable, from 1980, will pull in FM stations like crazy under good propagation conditions, even though it does not have an RF stage on AM. The only thing I don't like about it is the lack of an AFC defeat switch.

I think the reason why this set is so good in this regard (excellent FM sensitivity/selectivity) is that it has four IF stages on FM and at least two on AM. It is probably the best transistor AM/FM portable I have seen in years, even though it was built to Zenith's standards by the company's subsidiary in Korea at the time. However, I do think that the R-70 may have been one of the last really good FM portables to bear the Zenith name, as by the mid-1980s the company had gone out of the radio business and left Chicago for good.