Early stereo FM - thoughts?

[Jeffhs]

Originally Posted by Bob E.

Well, what's important to you, going early, or going built-in multiplex? I have a Harman Kardon FM-100 that is a copper-faced beauty, and it was introduced in 1956. It does not have a built-in multiplex decoding circuit, but they were anticipating it...there are two RCA output jacks, one for mono connection to a pre-amplifier's "Tuner" input, and one that bypasses the de-emphasis circuits for connection to an external demultiplexer. I have a Fisher MPX-100 (from about 1960) that does admirable duty in that regard.



As for stereo stations, here in the SF Bay Area, KPEN is pretty-well known for breaking ground in stereo broadcasting, under the stewardship of local-legend Jim Gabbert. They turned on the first stereo transmission west of the Mississippi in July 1961. You can hear some vintage air-checks at:

http://www.bayarearadio.org/audio/kp...959-1960.shtml

--Bob

I'm looking for information on stations that were transmitting multiplexed FM after 1961; which stations were the first, or at least one of the first in a given area to transmit in stereo. I think the phrase "multiplex ready" in my post is why you asked what was (more) important to me (early FM or early multiplex stereo broadcasts), although your mention of the external multiplex adapters fits into this discussion just as well; after all, there had to be a way to retrofit older monophonic tuners for the new stereo broadcasts when the latter started shortly after the new standards were approved.

I was not aware that KPEN-FM was the first commercial FM station west of the Mississippi River to transmit in full stereo, but living in the northeastern corner of Ohio, which is the easternmost state of the Midwest, I haven't heard any FM stations further west of here than Detroit, Michigan and Toledo, Ohio, as well as the local stations from Cleveland and a lakefront city called Ashtabula (I live roughly midway between these cities, so can hear local FM from both areas using a simple wire antenna, even on my 1961 Zenith MJ1035 which was one of Zenith's first table radios equipped for then-new stereo multiplexed FM, although the multiplex decoder used in this radio was rather crude by today's standards and really does not work well further out than about 15 miles from the stations). I can also hear stereo stations from a smaller city about 60 miles south of here called Akron; a suburb of that city has a rather powerful country-western station on 94.9 MHz that also comes in very well on every one of my FM radios, and I also hear an NPR station near Akron via a translator station on 89.1 MHz.