My junky small radios get AM just fine. My more expensive receivers don't -
the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

Thanks

In article .net,
J Antero wrote:
My junky small radios get AM just fine. My more expensive receivers don't -
the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

Terk AM-1000 "AM Advantage" loop antenna
Intensitronics Select-A-Tenna

My junky small radios get AM just fine. My more expensive receivers don't -
the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

In most receivers, the AM tuner doesn't use the wire antenna. A wire
a few feet long is too short to act as an effective antenna for AM
signals, which have a wavelength that's far longer than that. No
matter what fiddling you do with the wire, it won't help the
receiver's AM signal receptivity significantly.

Rather, the receiver probably has an internal "loopstick" - a ferrite
rod which is wound with multiple turns of very fine wire. These
antennas are rather directional - they may work better if the whole
radio is rotated 90 degrees or so (if that's practical).

External AM antennas can be used to improve the signal strength. One
approach is to use an "antenna booster", which usually consists of a
multi-turn wire coil a foot or two across, inductively coupled to the
receiver's own loopstick. A similar inductive-coupling method can be
used to couple a long-wire antenna (tens of feet of wire, with a
ground connection) to the receiver. In both cases, there can be
advantages to "tuning" the external antenna/loop with a capacitor, so
that its resonant frequency matches the AM station you're trying to
receive.

Some sites with ideas for homebrewing:

http://www.mindspring.com/~loop_antenna/
http://www.abc.net.au/reception/radio/am_antenna.htm

A commercial product built along these lines:

http://www.grove-ent.com/ANT21.html

You might want to try knocking together one of the "two-foot loop"
designs listed on the Mindspring site. The 365 pF tuning capacitor
can be salvaged from a scrapped old-style AM radio (table radios have
full-sized caps, while cheap mechanically-tuned AM portable radios
have small "plastic variable" caps which will work). Everything else
(wood and wire) can be purchased at your local hardware store, or
salvaged (scrap wood, old telephone wire, etc.).

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"J Antero" wrote in message
link.net...
My junky small radios get AM just fine. My more expensive receivers
don't - the reception is weak and has static.

**Yep. Ironically, expensive receivers tend to use poor quality AM sections.


The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

**You need to advise us of your specific problems and location. Are you, for
instance, located in a high rise building? How far away is the nearest
window (preferably facing AM transmission towers). Etc.


--
Trevor Wilson
www.rageaudio.com.au

In article , (Dave Platt) wrote:
My junky small radios get AM just fine. My more expensive receivers don't -
the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

In most receivers, the AM tuner doesn't use the wire antenna. A wire
a few feet long is too short to act as an effective antenna for AM
signals, which have a wavelength that's far longer than that. No
matter what fiddling you do with the wire, it won't help the
receiver's AM signal receptivity significantly.

Rather, the receiver probably has an internal "loopstick" - a ferrite
rod which is wound with multiple turns of very fine wire. These
antennas are rather directional - they may work better if the whole
radio is rotated 90 degrees or so (if that's practical).

External AM antennas can be used to improve the signal strength. One

On many quality all band shortwave radios, an external antenna is the only source.
Many front ends are tunned and have a fundamental impedance which
requires a matching antenna. I have a FRG-7 radio, that, if I wanted to
get really good reception, a wire of over 200 feet, a quarter wave, would work really well.
If it was vertical with a good ground plane, the ultimate.

Ferrite loops work very well considering their size.

greg

On Tue, 28 Mar 2006 19:03:05 +0000, J Antero wrote:

My junky small radios get AM just fine. My more expensive receivers don't
- the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

I assume you are referring to stereo receivers of the hi-fi ilk.
The AM sections in these units tend to be an afterthought.

That said, I have had good luck with an outdoor loop several
feet on a side. They are directional, so I have two, at right angles,
with a switch.

The loops should have two sides vertical and the other two horizontal.
They don't *have* to be outdoors, but you want them far away from
computers and monitors.

--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

On Tue, 28 Mar 2006 19:03:05 GMT, "J Antero"
wrote:

My junky small radios get AM just fine. My more expensive receivers don't -
the reception is weak and has static.

The receiver antennas are just wires, several feet long and I've tried a
number of configurations to improve things, with no success. Any
suggestions for an inexpensive indoor AM antenna?

Unfortunately the AM section of "quality" receivers is often just
there to fill the spec sheet. It may just be that your junky radio
has a considerably better AM receiver.

"Laurence Payne" lpayneNOSPAM@dslDOTpipexDOTcom wrote in message
...

Unfortunately the AM section of "quality" receivers is often just
there to fill the spec sheet. It may just be that your junky radio
has a considerably better AM receiver.

Also, there is a tradeoff between sensitivity/selectivity and audio fidelity
(bandwidth).

In article , "mc" wrote:
"Laurence Payne" lpayneNOSPAM@dslDOTpipexDOTcom wrote in message
.. .

Unfortunately the AM section of "quality" receivers is often just
there to fill the spec sheet. It may just be that your junky radio
has a considerably better AM receiver.

Also, there is a tradeoff between sensitivity/selectivity and audio fidelity
(bandwidth).

There is obviously a big difference between communication receivers and
hi-stereo receivers. He never cited what types.

greg

In article , (GregS) wrote:
In article , "mc"
wrote:
"Laurence Payne" lpayneNOSPAM@dslDOTpipexDOTcom wrote in message
. ..

Unfortunately the AM section of "quality" receivers is often just
there to fill the spec sheet. It may just be that your junky radio
has a considerably better AM receiver.

Also, there is a tradeoff between sensitivity/selectivity and audio fidelity
(bandwidth).

There is obviously a big difference between communication receivers and
hi-stereo receivers. He never cited what types.

Most all Hi-Fi types come with ferrite antennas. If its taken off, a short wire antenna
is just not going to work well.

greg

On Thu, 30 Mar 2006 17:44:26 +0000, GregS wrote:

In article , (GregS) wrote:
In article , "mc"
wrote:
"Laurence Payne" lpayneNOSPAM@dslDOTpipexDOTcom wrote in message
...

Unfortunately the AM section of "quality" receivers is often just
there to fill the spec sheet. It may just be that your junky radio
has a considerably better AM receiver.

Also, there is a tradeoff between sensitivity/selectivity and audio fidelity
(bandwidth).

There is obviously a big difference between communication receivers and
hi-stereo receivers. He never cited what types.

Most all Hi-Fi types come with ferrite antennas. If its taken off, a short wire antenna
is just not going to work well.

Receivers in the last ten years or so tend to use small external loop
antennas, not ferrites. This is also true for the Denon tu 680 nab
"supertuner". The inductance of these loops may be part of the RF
tuned circuit.

--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

I thought I'd post a few comments about this receiver.

This is one of the first hi-fi a/v receivers with the AM and FM
HD Radio from Ibiquity. The list price is $1800 but I was
able to mail order one for about $1100.

There is one local station broadcasting in HA AM, KEX 1190.
The HD signal is not broadcast at night. Rush and Laura
don't really need the sound boost, but the elimination of
background noise is welcome. Now and then there is aliasing
distortion which goes away when I cycle power on the Yamaha.

Quite a few FM stations broadcast in HD FM. The virtual
elimination of background noise on KBPS All Classical 89.9
is welcome. It would be nice if the heavy copmpression
applied to the analog signal were removed from the digital
version.

Digital FM is supposed to allow for 8 (eight) programs at
once. Most of the Portland HD FM stations only have one
HA audio stream at present.

Contrary to recent comments in Slashdot, I have not noticed
a delay between the analog and digital signals on either AM
or FM.

--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665