Those are interesting recollections Martin. I remember listening
to FM public service stuff from around 35 44 MHZ using a tunable
receiver back in the 60's and 70's. Car phones could be heard
all over the place even some long distance ones around 35 MHZ and
of course the local ones around 152 MHZ. You could often hear
PD's FD's and snow plows on the low band VHF frequencies, many
were using repeaters and you could often hear both sides of the
QSO when they were using simplex as well. When my daughter was
in high school, they used a MARTI unit on 152. something VHF to
remote their football games from the stadium to the fm station
studio at the high school. It was funny because you could hear
the remote station on 152 mhz far better than you could hear
their commercial FM station around the area. It was also great
because when the Fm station took breaks for whatever reason, they
left the mic open at the game and you could often hear the
commentators talking about different plays and how stupid the
players were who made a bad play. Will never forget one guy
talking about the half time program when he said something like,
"Now the cheer leaders are down on the field doing their tricks,"
which made them sound like, well, like they were hookers! Jim
WA6EKS
----- Original Message -----
From: "Martin G. McCormick" <[log in to unmask]
To: [log in to unmask]
Date sent: Tue, 31 Mar 2015 21:55:47 -0500
Subject: Re: 25.909 fm?
When the bands are full of Sporadic E or F2, no telling
what you will hear between 25.9 and about 26.5 MHZ.
When I got my first general coverage receiver that would
tune all the way to 34 MHZ, actually 37 MHZ if you counted the
images at the high end of the dial, it was early 1966 and I
discovered broadcast links rather quickly. As many of you have
probably noticed, narrow-band FM must be slope-detected if your
receiver does not have an FM detector. The audio is best when
slightly mis-tuned.
These frequencies aren't used nearly as much as they
used to be due to the fact that VHF high-band has many
allocations for IFB's and remote broadcast units as does the
450-MHZ band and 900 MHZ range. None of those frequencies have
the
problems of skip encountered in the 25-26 MHZ range.
For hams and SWL's, skip is wonderful. You can sit in
your house in Oklahoma or Arkansas as I did in the late 60's and
early seventies and joyfully waste a whole Saturday afternoon
listening to a live broadcast from the Montana State Fair,
countless mobile news reports of fires, accidents and you name
it from towns up and down both coasts.
There used to be several radio and television
engineering nets. One was around Chicago and another seemed to
be in Northern California.
They put booming signals in to middle America and they
consisted of station and transmitter engineers shooting trouble
on their microwave and related links.
Back in the sixties, some of those engineering networks
could control parts of their network remotely with tone signals.
One would say, "I'm going to turn on the beam gate."
You'd hear a pager-like signal and maybe something like, "Is
that better now?"
There would be a reply and they'd leave it alone or try
something else if it didn't fix the problem.
A number of those remote pickup units or IFB's were and
maybe still are AM. I remember a remote broadcast from such a
system in 1967 or 1968. The transmitters were essentially
CB-like rigs licensed to operate in the 26.something range. The
audio was good but the music was played back at the station and
the DJ doing the broadcast would key down a few seconds before
the song or commercial ended so the guy running the board could
smoothly cut over to him.
I was in Hot Springs, Arkansas at the time and the
remote broadcast was clear as a bell from Santa Barbara,
California.
Nowadays, there is so much illegal free-band activity in
English and Spanish in AM, SSB and even FM that a station
engineer would almost have to be a fool to try to use one of
those frequencies for an on-air link but they are probably okay
for an IFB feed if you don't mind getting your ears blown up by
a pirate station somewhere.
Definitely give those frequencies a listen periodically
as there is still a dwindling but interesting batch of signals
to be heard.
73 Martin WB5AGZ
Dave Marthouse writes:
That station is probably an IFB cue channel. IFB or interrupted
feedback is a channel that is setup to provide a signal from a
broadcast
studio to a reporter in the field who sends live feeds back to
the
station. In addition to the broadcast you may hear interuptions
with
instructions from the stations master control engineer to the
talent in
the field.
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