How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.

Thanks in advance.

On Thu, 22 Dec 2022 06:55:57 -0800 (PST), David Paste
<pastedavid@gmail.com> wrote:

>How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.

My expectations are: (1) a car radio is designed for use in a car and
(2) the car is likely to be outdoors and not surrounded by electronic
devices.

On 22/12/2022 15:07, Scott wrote:
> On Thu, 22 Dec 2022 06:55:57 -0800 (PST), David Paste
> <pastedavid@gmail.com> wrote:
>
>> How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.
>
> My expectations are: (1) a car radio is designed for use in a car and
> (2) the car is likely to be outdoors and not surrounded by electronic
> devices.

.... or foil backed plasterboard, roof-tiles of a certain (IMS), etc.

--

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I may be contacted via the contact address given on my website:
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On 22/12/2022 16:28, Java Jive wrote:
> On 22/12/2022 15:07, Scott wrote:
>> On Thu, 22 Dec 2022 06:55:57 -0800 (PST), David Paste
>> <pastedavid@gmail.com> wrote:
>>
>>> How come my car car gets much better AM reception than my home
>>> stereo, even though I have a dedicated AM antenna arranged as well as
>>> I can, whilst the car has what I assume is a coil of wire on a
>>> ferrite rod within the metal body of the car itself.
>>
>> My expectations are: (1) a car radio is designed for use in a car and
>> (2) the car is likely to be outdoors and not surrounded by electronic
>> devices.
>
> .... or foil backed plasterboard, roof-tiles of a certain (IMS), etc.

Oops! The missing word is 'type'!

--

Fake news kills!

I may be contacted via the contact address given on my website:
www.macfh.co.uk

On Thu 22/12/2022 15:07, Scott wrote:
> On Thu, 22 Dec 2022 06:55:57 -0800 (PST), David Paste
> <pastedavid@gmail.com> wrote:
>
>> How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.
>
> My expectations are: (1) a car radio is designed for use in a car and
> (2) the car is likely to be outdoors and not surrounded by electronic
> devices.

The car will have an external antenna - may be a rod, a sharks fin, or
in the rear or rear-side window glass (with amplifier in the last two
cases.) Whichever it is, if the car was fitted new with a radio capable
of LW then the aerial system will work with it. Certainly it isn't a
ferrite rod - the radio (metal) case makes a pretty effective Faraday cage!

Per the hi-fi LW, most such units are Japanese designed (may or may not
be built there) and as the Japs never had a LW broadcast frequency
allocation they tend not to pay too much attention to it. Sony tuners
(and especially the multiband communication receiver types) were some of
the best (mine is pretty good) but otherwise you need to get a tuner
designed and preferably built in Europe. Brands such as Telefunken, the
earlier Grundig and Bosch units (now just names,) and Philips are
generally well sensitive. NAD also make very good products, designed in
the UK but built in the Far East - not sure if they ever did a LW tuner?

David Paste <pastedavid@gmail.com> wrote:
> How come my car car gets much better AM reception than my home stereo,
> even though I have a dedicated AM antenna arranged as well as I can,
> whilst the car has what I assume is a coil of wire on a ferrite rod
> within the metal body of the car itself.
>
> Thanks in advance.
You probably don’t have DSL in your car.

If you want good AM reception at home, you’ll need at least a communication
receiver designed for that band, and a specialist aerial.

Stereo systems are notorious for poor AM performance.

--
Spike

On 22 Dec 2022 16:59:08 GMT, Spike <Aero.Spike@mail.invalid> wrote:

>David Paste <pastedavid@gmail.com> wrote:
>> How come my car car gets much better AM reception than my home stereo,
>> even though I have a dedicated AM antenna arranged as well as I can,
>> whilst the car has what I assume is a coil of wire on a ferrite rod
>> within the metal body of the car itself.
>>
>> Thanks in advance.
>
>You probably don’t have DSL in your car.
>
>If you want good AM reception at home, you’ll need at least a communication
>receiver designed for that band, and a specialist aerial.

In the case of long wave, would this need an aerial 750 metres long?
>
>Stereo systems are notorious for poor AM performance.

On 22/12/2022 17:22, Scott wrote:
> In the case of long wave, would this need an aerial 750 metres long?

Sky noise dominates thermal noise at long wave frequencies, so receive
aerials don't need to be very efficient to be dominated by noise coming
from the aerial.

Highly directional aerials are impracticable.

Scott <newsgroups@gefion.myzen.co.uk> wrote:
> On 22 Dec 2022 16:59:08 GMT, Spike <Aero.Spike@mail.invalid> wrote:
>
>> David Paste <pastedavid@gmail.com> wrote:
>>> How come my car car gets much better AM reception than my home stereo,
>>> even though I have a dedicated AM antenna arranged as well as I can,
>>> whilst the car has what I assume is a coil of wire on a ferrite rod
>>> within the metal body of the car itself.
>>>
>>> Thanks in advance.
>>
>> You probably don’t have DSL in your car.
>>
>> If you want good AM reception at home, you’ll need at least a communication
>> receiver designed for that band, and a specialist aerial.

> In the case of long wave, would this need an aerial 750 metres long?

I’d suggest a magnetic antenna rather than an electric one.

--
Spike

On 22/12/2022 16:59, Spike wrote:
> If you want good AM reception at home, you’ll need at least a communication
> receiver designed for that band, and a specialist aerial.

That often does not help when I used to have to usee Medium Wave and
Long Wave, before we got Radio 4 on VHF FM, I often used a
communiications receiver with a synchronous detector but it was still
rubbish reception.

On 22/12/2022 14:55, David Paste wrote:

> How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.

Only portable radios have ferrite rod antennas. Why do you suppose cars
have telescopic aerials (or wire coat hangers if they have been ripped off)?

--
Max Demian

On 22/12/2022 14:55, David Paste wrote:
> How come my car car gets much better AM reception than my home stereo, even though I have a dedicated AM antenna arranged as well as I can, whilst the car has what I assume is a coil of wire on a ferrite rod within the metal body of the car itself.
>
You're lucky you even have AM on your car radio. The facility on my 2021
Peugeot's audio system seemed to vanish after a software upgrade for its
12mth service !

The best non car AM receiver I ever owned is in my loft. A 1978 Trio
Tuner Amp. I suspect if I power it up the electrolytics will go pop !

Scott <newsgroups@gefion.myzen.co.uk> wrote:
> On 22 Dec 2022 16:59:08 GMT, Spike <Aero.Spike@mail.invalid> wrote:
>
> >David Paste <pastedavid@gmail.com> wrote:
> >> How come my car car gets much better AM reception than my home stereo,
> >> even though I have a dedicated AM antenna arranged as well as I can,
> >> whilst the car has what I assume is a coil of wire on a ferrite rod
> >> within the metal body of the car itself.
> >>
> >> Thanks in advance.
> >
> >You probably don?t have DSL in your car.
> >
> >If you want good AM reception at home, you?ll need at least a communication
> >receiver designed for that band, and a specialist aerial.
>
> In the case of long wave, would this need an aerial 750 metres long?

:-) That would be ideal but not necessary! I could hear R4 on 1500
metres on my communications receiver when I was in Oman, that was with
a tens of metres long wire.

We also get pretty good R4 reception on our boat in France using just
an ancient car radio and a tiny (half a metre or so) vertical aerial.

--
Chris Green
·

On Thursday, 22 December 2022 at 16:59:10 UTC, Spike wrote:
> David Paste <paste...@gmail.com> wrote:
> > How come my car car gets much better AM reception than my home stereo,
> > even though I have a dedicated AM antenna arranged as well as I can,
> > whilst the car has what I assume is a coil of wire on a ferrite rod
> > within the metal body of the car itself.
> >
> > Thanks in advance.
> You probably don’t have DSL in your car.
>
> If you want good AM reception at home, you’ll need at least a communication
> receiver designed for that band, and a specialist aerial.
>
> Stereo systems are notorious for poor AM performance.
>
> --
> Spike

Indeed - they don't even do stereo in AM and the bandwidth is at most 9kHz (in Europe)

On 22/12/2022 18:21, Max Demian wrote:
> Only portable radios have ferrite rod antennas. Why do you suppose cars
> have telescopic aerials (or wire coat hangers if they have been ripped off)?

How many cars have telescopic antenna now? I can't remember seeing one
for a long time.

MB <MB@nospam.net> wrote:
> On 22/12/2022 16:59, Spike wrote:

>> If you want good AM reception at home, you’ll need at least a communication
>> receiver designed for that band, and a specialist aerial.

> That often does not help when I used to have to usee Medium Wave and
> Long Wave, before we got Radio 4 on VHF FM, I often used a
> communiications receiver with a synchronous detector but it was still
> rubbish reception.

Once upon a time I wanted to decode the time signal from DCF77, so I fired
up a comms receiver and added a few metres of wire to the aerial input
terminal.

Faint signal buried in the noise.

Wrapped the wire round the bookcase, one end to aerial input, other to
Earth terminal.

DCF77 signal now way over the noise, easily decoded.

Then connected both ends of the loop together after winding ~6 turns round
a random ferrite ring. Wound a separate 3 turns round the same toroid and
fed them into the balanced input on the receiver.

DCF77 signal now even less noise on it.

At these frequencies the choice of aerial is crucial, a random wire just
won’t cut it.

--
Spike

On 22/12/2022 16:59, Spike wrote:
> David Paste <pastedavid@gmail.com> wrote:
>> How come my car car gets much better AM reception than my home stereo,
>> even though I have a dedicated AM antenna arranged as well as I can,
>> whilst the car has what I assume is a coil of wire on a ferrite rod
>> within the metal body of the car itself.
>>
>> Thanks in advance.

Unlikely. Many cars use the screen heater or have a dedicated antenna on
a rear window.

Dave

>
> You probably don’t have DSL in your car.
>
> If you want good AM reception at home, you’ll need at least a communication
> receiver designed for that band, and a specialist aerial.
>
> Stereo systems are notorious for poor AM performance.
>

No most car radios either have an external aerial or use the heated rear
window element or an aerial in one of the many plastic bits of cars.
I also see that if I'm in a taxi and it goes into a densely occupied area,
you get whines and all sorts of crud in with the signal, just like you do
at home. Its often far better to adopt the old frame aerial ideas at home in
the loft orientating it to get minimum crud.
It escapes me as to why they did not start to adopt DRM Am broadcasting
when it first came out, as it was reasonably good and you could hear most
stations during the day.
Brian

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"David Paste" <pastedavid@gmail.com> wrote in message
news:2fcd3391-f311-4496-b21d-89794bf18d6fn@googlegroups.com...
> How come my car car gets much better AM reception than my home stereo,
> even though I have a dedicated AM antenna arranged as well as I can,
> whilst the car has what I assume is a coil of wire on a ferrite rod within
> the metal body of the car itself.
>
> Thanks in advance.

Who remembers the ambit Tune. I had one of those. It could bring long wave
to a spare bit of medium wave.
There seem to be about 5 LW stations these days. I have also noticed a
trend toward lw and mw being on the same band, ie the old 455Khz IF is tuned
through between the lw and mw. This presumably is because its either some
SDR or they use a higher IF frequency.
Brian

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Blind user, so no pictures please
Note this Signature is meaningless.!
"Woody" <harrogate3@ntlworld.com> wrote in message
news:to2279$1dpk8$1@dont-email.me...
> On Thu 22/12/2022 15:07, Scott wrote:
>> On Thu, 22 Dec 2022 06:55:57 -0800 (PST), David Paste
>> <pastedavid@gmail.com> wrote:
>>
>>> How come my car car gets much better AM reception than my home stereo,
>>> even though I have a dedicated AM antenna arranged as well as I can,
>>> whilst the car has what I assume is a coil of wire on a ferrite rod
>>> within the metal body of the car itself.
>>
>> My expectations are: (1) a car radio is designed for use in a car and
>> (2) the car is likely to be outdoors and not surrounded by electronic
>> devices.
>
> The car will have an external antenna - may be a rod, a sharks fin, or in
> the rear or rear-side window glass (with amplifier in the last two cases.)
> Whichever it is, if the car was fitted new with a radio capable of LW then
> the aerial system will work with it. Certainly it isn't a ferrite rod -
> the radio (metal) case makes a pretty effective Faraday cage!
>
> Per the hi-fi LW, most such units are Japanese designed (may or may not be
> built there) and as the Japs never had a LW broadcast frequency allocation
> they tend not to pay too much attention to it. Sony tuners (and especially
> the multiband communication receiver types) were some of the best (mine is
> pretty good) but otherwise you need to get a tuner designed and preferably
> built in Europe. Brands such as Telefunken, the earlier Grundig and Bosch
> units (now just names,) and Philips are generally well sensitive. NAD also
> make very good products, designed in the UK but built in the Far East -
> not sure if they ever did a LW tuner?
>
>

Hence the loop aerial of course.
No you can use shorter aerials if you tune up the first stage of the
receiver with the aerial connected, it becomes part of the tuned circuit.
Brian

--

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"David Woolley" <david@ex.djwhome.demon.invalid> wrote in message
news:to24eh$1e3r6$1@dont-email.me...
> On 22/12/2022 17:22, Scott wrote:
>> In the case of long wave, would this need an aerial 750 metres long?
>
> Sky noise dominates thermal noise at long wave frequencies, so receive
> aerials don't need to be very efficient to be dominated by noise coming
> from the aerial.
>
> Highly directional aerials are impracticable.

Bit of a generalisation. Pioneer hi fis had good AM performance. I'm not
sure how they do it but it has something to do with bandpass tuned IFs I
believe.
Brian

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"Mark Carver" <mark.carver@invalid.invalid> wrote in message
news:k0jlq2F978hU1@mid.individual.net...
> On 22/12/2022 14:55, David Paste wrote:
>> How come my car car gets much better AM reception than my home stereo,
>> even though I have a dedicated AM antenna arranged as well as I can,
>> whilst the car has what I assume is a coil of wire on a ferrite rod
>> within the metal body of the car itself.
>>
> You're lucky you even have AM on your car radio. The facility on my 2021
> Peugeot's audio system seemed to vanish after a software upgrade for its
> 12mth service !
>
> The best non car AM receiver I ever owned is in my loft. A 1978 Trio Tuner
> Amp. I suspect if I power it up the electrolytics will go pop !
>

On 23/12/2022 10:04, Brian Gaff wrote:
> It escapes me as to why they did not start to adopt DRM Am broadcasting
> when it first came out, as it was reasonably good and you could hear most
> stations during the day.

Few DRM receivers on sale, few cars with DRM? How many years would it
take to get enough DRM receivers in use to make it profitable for
commercial stations and the BBC were committed to DAB which has
advantages and lots of receivers in homes and cars.

I would agree with that from an amateur radio viewpoint Brian, which is
what an aerial tuner does!

Trouble is that most tuners with an AM coaxial connection these days
have a high impedance input (possibly resistively loaded for matching)
so any wire connected to the input will do the job.

If the AM aerial connection is 300R (and many still are) then the
internal matching transformer should - in theory - have a centre tap
earth - which is not a lot of good if the mains lead is two core and/or
there is no physical earth screw on the case!

From the OP's point of view, assuming the mains lead is two-core, the
best solution would be to connect a decent thickness wire from a case
screw on the tuner to a nearby earth. That could be a wire through the
wall and to a close earth stake (assuming on ground floor), or to a
convenient metal water pipe. As already noted by others, a decent earth
on a tuner will reduce the mush noticeably.

On Fri 23/12/2022 10:15, Brian Gaff wrote:
> Hence the loop aerial of course.
> No you can use shorter aerials if you tune up the first stage of the
> receiver with the aerial connected, it becomes part of the tuned circuit.
> Brian
>

On 23/12/2022 11:45, Woody wrote:
> If the AM aerial connection is 300R (and many still

Are you sure. 300R is common for VHF, because the indoor aerial was a
300R ribbon, configured as a folded dipole. Mine has a small frame
aerial on a, detachable, external ball and socket joint, and hardwired.

> From the OP's point of view, assuming the mains lead is two-core, the
> best solution would be to connect a decent thickness wire from a case
> screw on the tuner to a nearby earth. That could be a wire through the
> wall and to a close earth stake (assuming on ground floor), or to a
> convenient metal water pipe. As already noted by others, a decent earth
> on a tuner will reduce the mush noticeably.

If there is any conductor connected to this, functional earth, which
could also contact a human, directly or through another conductor, you
must bond it, at mains frequencies, to the safety earth.

A lot of British wiring uses the PME system, which, under fault
conditions, can result in mains earth being significantly different from
stake in the ground earth.

Note the main reason for preferring magnetic aerials is that there is
general belief that most locally generated, near field, interference, is
E field, rather than H field. (VHF aerials are resonant, so use both E
and H fields.) The obvious reason for not using H field aerials on LW,
in a car, is that the transmissions are vertically polarised, which
makes H field aerials directional, which you don't want in something
steerable.

On Fri, 23 Dec 2022 11:45:53 +0000, Woody <harrogate3@ntlworld.com>
wrote:

>I would agree with that from an amateur radio viewpoint Brian, which is
>what an aerial tuner does!
>
>Trouble is that most tuners with an AM coaxial connection these days
>have a high impedance input (possibly resistively loaded for matching)
>so any wire connected to the input will do the job.
>
>If the AM aerial connection is 300R (and many still are) then the
>internal matching transformer should - in theory - have a centre tap
>earth - which is not a lot of good if the mains lead is two core and/or
>there is no physical earth screw on the case!
>
> From the OP's point of view, assuming the mains lead is two-core, the
>best solution would be to connect a decent thickness wire from a case
>screw on the tuner to a nearby earth. That could be a wire through the
>wall and to a close earth stake (assuming on ground floor), or to a
>convenient metal water pipe. As already noted by others, a decent earth
>on a tuner will reduce the mush noticeably.
>
I take it you are not recommending the earth pin of the three pin
plug?