I just finished reading this. I should have just said "don't get me started." I didn't.
I started out in this industry as a hobbyist listening to AM radio...used to get, in Southern California, KOA in Denver, KOB in Albuquerque, sometimes WLS in Chicago, occasionally WWL in New Orleans....
On 11/10/04 15:50 ET, mr2channel said...
I would say that not all tuners are created equal,
Right. When I started in HiFi in 1970, I got the impression that once manufacturers could put high fidelity FM tuners into their products, they decided to only spend about a buck twenty on an AM tuner. After all, there is no way it can be hifi (in this modern profit-driven world)! Unless you buy one that actually pushes its AM reception, the AM section is likely to be crap.
and that car tuners would be better, since they
are used more often than the one that is in most
A/V components,
OEM car tuners are better because they are designed to be used all across the country (see the section on distance below). I recently drove from northern Arizona to Los Angeles around four in the morning, and I was clearly receiving a station in Norman, OK while in Arizona. After that I switched to a San Francisco station.
Most car HiFi radios have poor AM sections, just like home HiFi. Same principle.
and as far as a clock radio goes,
I would also say you have a better chance of the
tuner also being better, since it is most often
used to wake up to.
This seems like a nice wish. You can wake up to FM and it sounds better, so there is no reason for a clock radio to have a good AM section. After all, loud static will wake you up, right?
Are you saying you have found this to be true, or are you theorizing?
RG-6 is fine, but you have to remember that AM
is Amplitude Modulated NOT Frequency Modulated,
so since the earth is not flat you will lose your
ablity to pick up the station sooner than with
Frequency Modulation (FM).
Unfortunately, pure bunk.
RG-6 is fine if your AM antenna has a 75 ohm output. RG-6 will work well with amplitude modulated signals. Analog TV signals have AM picture and FM sound.
It is not the type of modulation, but the frequency, that determines the possible reception distance. At AM frequencies, there is a "ground wave" that hugs the earth, so reception is possible beyond where the curvature of the earth would eliminate it. FM, at 100 mHz, is line-of -sight. Transmitters on mountains can send FM signals (100 mHz signals, that is) more than a hundred miles, but 100 mHz. transmitters at ground level are limited to around 100 miles.
AM signals go along the ground, attenuating as they spread. They also are radiated up into the air, and actually bounce off the ionosphere before returning to earth. There is a distance between where the ground wave is too weak and where the ionospheric bounce returns the signal to earth; in this range you cannot receive an AM (oops, I mean 1 mHz) signal. The ionosphere is calmer when the sun is not shining on it, making a better reflecting "surface," so 1 mHz reception is much better at night.
The "loop" antenna
for AM reception is the only way I am aware of
to receive AM reception, but the size and direction
of the loop will affect reception, as well as
the quality of the tuner.
Yeah, the old 1948 RCA consoloe I had as a teenager had a loop. About 12" wide, 30" high, and 2" thick. You had to orient it for best reception of each station...which is a drawback to this day with any AM reception (1 mHz, really).
I once had an early 1930s Philco radio (it had a tube in it with a label saying that it had been installed as a replacement in 1935). This radio took one ground wire and one wire tossed out the window, or as long as you could get it. It did not work with a loop. Lops are not the only possible antenna type for 1 mHz recetpion.
I know Terk make a
specific AM antenna a while back, it seemed to
be OK as far as performance but I would say it
was not suited for use in an attic, and definitely
is not an outdoors unit.
It is the best AM antenna I have seen, and that is saying a lot since I have hated Terk for looking good but performing like junk since day One.
In fact, I have one. You rotate it for best orientation each time you change stations, and there is a tuning knob that can peak the signal or "unpeak" an interfering signal. It is awesome but it does not lend itself to use in a customer's home unless they want ONE AM station or they are willing to mess with it all the time.
This antenna does not even need to be connected: just place it near the radio's AM antenna and its internal resonating coil/capacitor system will aid the radio.
I would contact Weingard, an antenna manufacturer,
as they have in my opinion made some of the
best FM antennas as well as off air NTSC and ATSC
antennas. Oh yeah don't forget that ground wire...
I don't think Winegard has anything to offer for AM, although you are RIGHT ON about their other products.
Basically,an AM antenna needs two wires, similar to an FM one, but the frequency difference makes the rest of it dissimilar. You should use the loop that comes with the reciever, remembering you have to orient it to maximize a station you are listening for or minimize an interfering station.
When you use the loop, the AM section of the radio is matched to a type of circuit it wants to see. You can then augment this by connecting one terminal to GROUND. I mean the earth, planet, dirt, wet sand, wormtown, whatever, not the closest electrical ground. Amplitude Modulation is exactly the type of signal put out by motors and fluorescent fixtures, so going to ground without going to the electrical fixture ground will be quieter.
Then, put up a wire connected to the other AM antenna terminal. A long one. In fact, "long wire" is a technical name for a type of AM (oops, 1 mHz) antenna (google "long wire antenna")! Basically, run it out the window, up to the chimney, out to the tree, across to the neighbor's house...the longer it is, the better. Longer means more signal pickup, which means the fluorescent noise will fade more into the background. Longer also means less directional for some reason, so you don't have to worry about reorienting your sixty to one hundred foot antenna.
Oh, yeah, and don't forget to keep this NOT connected to the ground.
