a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

Building a good receiver of any kind is complex, if you really want
good specs. Very few people have been able to accomplish this at home.
Just for calibration, you will require the proper instruments and
skills.

A good FM receiver with the proper antenna will do it, as long as the
antenna can see over the horizon, and within your distance range there
are no other stations at the same frequency. There are also the
physical limitations to consider as well.

Since the range of an FM station is about 120 to 140 miles at the very
best with a good antenna, there may be allowance for other stations to
broadcast within a 150 mile radius. If there are other stations, these
may be difficult to tune out.

You would be best off with an antenna that is cut to the frequency you
want to recieve, it will have to be able to see over the horizon
enough to see the transmitter site, have the proper directivity, and
be very well impedance matched to the receiver.

All the high end FM tuners are designed to be able to use an external
antenna, using a 75 ohm coax type hookup.

Have you considered calling this station to see if they are on the
net, satellite service, or on your local cable TV service? Many of
these small stations are on the net, and broadcast streamed
programming. This way you can use your computer to listen to them. '


Jerry Greenberg

--

(Alan Horowitz) wrote in message ...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

(Alan Horowitz) wrote in message ...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.
....

Exactly what will make it "hi-performance"? I'd like to get this
nailed down early here. That is, it would really help to know answers
to things like:

What distortion performance do you want to get? (Will you be able to
deliver a clean enough signal from the antenna to get to the desired
performance level?)

What will the level of the desired signal be at the receiver antenna
terminals?

What will the strongest unwanted signals be: level and relative
frequency?

What resources do you have available for design, construction and
testing?

Will this receiver be in a fixed location, or do you want it to be
easily portable? How much power can it draw?

Others may well think of questions to add, before we go off into the
weeds with unproductive answers.

Cheers,
Tom

You need to look at your particular situation. It sounds like you are out
in the desert. Is this the case? Are there other strong FM stations
nearby? Any others close in frequency?

Sensitivity is relatively easy to come by. The "best" audiophile receivers
are more about selectivity, which sounds like it might not be an issue in
your case. There is a similar issue with antennas. Directionality is there
more to combat multipath then it is to get gain. Is the terrain flat? If
you are between a lot of buildings then nothing you do at the receiver will
make up for what you don't do at the antenna.

You are right about needing to get your antenna high, but for a single,
point to point circuit, there is such a thing as high enough. More won't
help. But less will hurt dramatically.

The other big problem is getting the signal from the antenna to the radio.
At FM frequencies, line losses are significant, as is noise pickup. If the
signal is marginal, then you need to get an amplifier at the antenna. If
what reaches the receiver is mostly noise then no amount of sensitivity at
the receiver is going to help.

At any given frequency there is only a certain amount of sensitivity that
you can use. At FM broadcast frequencies, that amount of sensitivity is
easily obtainable these days. You can probably do "better" in terms of
sensitivity by building something, but you wouldn't hear the station any
better ... in fact, probably worse by having too much of a good thing.

...

"Alan Horowitz" wrote in message
...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

Thought I posted a reply yesterday, but it doesn't appear to have made
it.

Before we head off into the weeds with all sorts of opinions, how
about some clarification? I'd be interested in answers to several
questions, and suspect others will add more.

o What sort of distortion levels and signal to noise ratio are you
wanting to achieve?

o What level of desired signal will you be able to deliver to the
receiver's input terminals? Will it be strong enough, and free enough
from multipath, to make the desired distortion and SNR practical?

o What levels and relative frequencies will strong potentially
interfering signals be? -- Let's hope there's nothing significant on
an adjacent channel, and nothing really big on alternate channels
(+/-400kHz).

o How skilled are you in RF and digital construction, and what tools
do you have available for design, construction and turn-on/alignment?

o Do you want the receiver to be portable and battery-powered, or can
it be relatively large and line/mains powered?

(o Why would you not just buy a good FM tuner, and perhaps just build
a preselector if alternate-channel stations were a problem?)

Cheers,
Tom


(Alan Horowitz) wrote in message ...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

(Alan Horowitz) wrote in message ...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

Low noise masthead amplifier

For about the last 15 years I have been listening to NPR at 89.5 MHz while
riding my bike for an hour or two on nice days. There are several locations
where many radios don't receive and lose the station and sometimes capture
another close station. I've been buying used portables at garage sales for
$10.00 or less and comparing their performance. So far I haven't found any
of the Walkmans or Sports radios that are acceptable and to date the best
has been a Sony ICF-34, much better than my Grundig Yacht Boy 400, but I
can't risk it to try my Sony 2010. I've built and/or modified many radios
and often thought about trying to make a better 89.5 radio but I don't think
there's anyway I can beat the commercial jobs especially when I can get them
for $10.00 or less. Generally I prefer not to use headphones and instead
fasten the portable to my handlebars so I can hear the radio and local
sounds. The radios take a pretty good beating but few have failed from the
vibration or minor crashes.
In the past I've lived in somewhat remote locations where I couldn't get the
stations I wanted and the best solution was a good antenna with directivity
and gain as high up as you can get it! But I can't do that on my bike.
However if you come up with a good home brew solution please let me know.
73
Hank WD5JFR
"Alan Horowitz" wrote in message
...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

The rest of the gain budget is.

Let the discussions begin. For example, what approach do the known
"name" receivers (Kloss Model One, GE Super Radio) use? can a
homebrewer do better?
Which commercial house builds the best resonant chambers for the 108
Mhz frequency? Can be be done easily at home? how about the
demodulation and audio portions?

"Alan Horowitz" wrote in message
...
a city I visit frequently -or more precisely, it's exurban outskirts -
has only one mellow-Jazz FM-broadcast station, the only one for many
hundreds of miles.

thus I have decided to build my own single-station hi-performance
receiver to get the one station.

I know enough to know that ideally, the bulk of the gain,
directionality, selectivity should be at the antenna itself. Or even
more to the point, tower height. At least ideally. And
hi-performance single FM channel yagi's are easily spec'd from a
number of antenna houses. So that issue is not being placed on this
table.

I lived in the Albany, NY area for many years, back when there were not too
many local FM stations there (that is, the 1970's and early 1980's). I used
an audiophile FM tuner board and a roof-mount Yagi FM antenna. Most of the
local stations were southwest of my home. In any other direction but the
southwest, I regularly pulled in stations up to 120 miles away. More distant
stations were hit and miss, depending on tropospheric bending, etc. If your
area is not saturated with local stations, you should have no trouble with a
similar arrangement.