Outdoor AM radio to solve reception problems

[Mitchell Gossman]

I live in a house with metal siding, sort of the mother of all Faraday
cages, so AM reception is terrible for any station whose transmitter
is more than 10 miles away. Reception from car radios is acceptable to
excellent. There seems to be something about car radios - perhaps they
have special circuitry to reduce or eliminate antenna directionality.

So what I am going to do is build a little "doghouse" to place outside
containing: 1) A car radio featuring an IR remote (available for $120
or so), 2) a 110 VAC -> 12 VDC transformer, 3) one of those X10 800
Mhz audio/video beamers, and 4) a Radio Shack infrared remote extender
(converts IR to an RF signal then back to IR). Then I can wirelessly
receive the AM signal inside and change frequencies. So what I'm
wondering is:

1) Anyone with a better idea for the overall problem?
2) Is there a better idea for the radio receiver? Even my excellent CC
radio suffers in its extreme directionality.
3) What is the deal with car radios with their superior AM reception
and lack of directionality? Why are they superior in these respects?

Mitch Gossman
mvgossman at astoundnospam . net.

[Laurence Payne]

>I live in a house with metal siding, sort of the mother of all Faraday
>cages, so AM reception is terrible for any station whose transmitter
>is more than 10 miles away. Reception from car radios is acceptable to
>excellent. There seems to be something about car radios - perhaps they
>have special circuitry to reduce or eliminate antenna directionality.
>
>So what I am going to do is build a little "doghouse" to place outside
>containing: 1) A car radio featuring an IR remote (available for $120
>or so), 2) a 110 VAC -> 12 VDC transformer, 3) one of those X10 800
>Mhz audio/video beamers, and 4) a Radio Shack infrared remote extender
>(converts IR to an RF signal then back to IR). Then I can wirelessly
>receive the AM signal inside and change frequencies. So what I'm
>wondering is:
>
>1) Anyone with a better idea for the overall problem?

Would just mounting an outside antenna and feeding a cable into the
house be too simple?

[Mitchell Gossman]

I have tried different AM antennas just as you describe, such as a
TERK combo antenna (too direction and minimal improvement), a long
wire (same deal), and even the Super-Select-A-Tenna behemoth
inductively coupled. Nothing seems to improve the signal. But
actually, my solution does not get too expensive, the components are
reasonably cheap.

I gusss I assumed that car radios did not use the FM whip antenna just
as portable radios do not, and instead use ferrite core wire-wound
antennas. I thought perhaps the car radios had two orthogonally
mounted core antennas and electronically selected the best one.

But is there anyone who denies that AM antenna sections in car radios
are innately superior somehow, in performance, compared to any
high-end home system or portable radio, including even the CC Radio?

Specifically what kind of external antenna would you suggest? Having a
car radio in the house near a window would certainly be more
convenient than my doghouse solution.

Mitch

"Richard Crowley" > wrote in message >...
> Mitchell Gossman wrote ...
> > I live in a house with metal siding, sort of the mother of all Faraday
> > cages, so AM reception is terrible for any station whose transmitter
> > is more than 10 miles away. Reception from car radios is acceptable to
> > excellent. There seems to be something about car radios - perhaps they
> > have special circuitry to reduce or eliminate antenna directionality.
> >
> > So what I am going to do is build a little "doghouse" to place outside
> > containing: 1) A car radio featuring an IR remote (available for $120
> > or so), 2) a 110 VAC -> 12 VDC transformer, 3) one of those X10 800
> > Mhz audio/video beamers, and 4) a Radio Shack infrared remote extender
> > (converts IR to an RF signal then back to IR). Then I can wirelessly
> > receive the AM signal inside and change frequencies. So what I'm
> > wondering is:
> >
> > 1) Anyone with a better idea for the overall problem?
>
> Your solution seems extravagantly over the top. You could put up a
> very decent external antenna, conduct it inside your Faraday house,
> and connect and/or couple it into your existing AM antenna without
> any active components. And for a fraction of your proposed budget.
>
> > 2) Is there a better idea for the radio receiver? Even my excellent
> > CC radio suffers in its extreme directionality.
>
> Any radio (good or bad) will seem more directional inside your
> Faraday cage because you are trying to use it at the lower end
> of its effective dynamic range.
>
> > 3) What is the deal with car radios with their superior AM reception
> > and lack of directionality? Why are they superior in these respects?
>
> All the car radios I've ever seen use vertical whip antennas which
> are essentially omnidirectional. In addition, they virtually all have
> better circuits than most "home" receivers/tuners. It has been
> this way for many decades. No great magic there.

[Laurence Payne]

>But is there anyone who denies that AM antenna sections in car radios
>are innately superior somehow, in performance, compared to any
>high-end home system or portable radio, including even the CC Radio?

The AM section on many "hi-fi" receivers can indeed be included for
appearance' sake, and be crap.

Car radios may well take AM more seriously, and will be designed
particularly with interference-rejection in mind.

[Mitchell Gossman]

Laurence Payne > wrote in message >...
> >I live in a house with metal siding, sort of the mother of all Faraday
> >cages, so AM reception is terrible for any station whose transmitter
> >is more than 10 miles away. Reception from car radios is acceptable to
> >excellent. There seems to be something about car radios - perhaps they
> >have special circuitry to reduce or eliminate antenna directionality.
> >
> >So what I am going to do is build a little "doghouse" to place outside
> >containing: 1) A car radio featuring an IR remote (available for $120
> >or so), 2) a 110 VAC -> 12 VDC transformer, 3) one of those X10 800
> >Mhz audio/video beamers, and 4) a Radio Shack infrared remote extender
> >(converts IR to an RF signal then back to IR). Then I can wirelessly
> >receive the AM signal inside and change frequencies. So what I'm
> >wondering is:
> >
> >1) Anyone with a better idea for the overall problem?
>
> Would just mounting an outside antenna and feeding a cable into the
> house be too simple?


I just might be able to do that if experiments show that putting the
radio in the house and the whip antenna outside the house works. I
learned something here, namely that the whip antenna serves both FM
and AM. As someone privately emailed me, what better Faraday cage than
a car, so putting a ferrite core antenna in the car wouldn't work any
better than it would in my house. Plus the whip is non-direectional,
an important feature in a turning car.

MVG

[Laurence Payne]

>I just might be able to do that if experiments show that putting the
>radio in the house and the whip antenna outside the house works. I
>learned something here, namely that the whip antenna serves both FM
>and AM. As someone privately emailed me, what better Faraday cage than
>a car, so putting a ferrite core antenna in the car wouldn't work any
>better than it would in my house. Plus the whip is non-direectional,
>an important feature in a turning car.


Even if a radio does have an internal ferrite rod aerial for AM, there
will normally also be a connection for an external AM aerial.

In the old days, it was just along wire strung across the loft space,
or wrapped round the garden.