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Can you make a AM antenna out of speaker wire?

J

jras20

I am thinking of getting a 100' of speaker wire and run it all around my attic for my AM antenna. Something happened to my other antenna and it is not working very well. any more.
 
jras20 said:
I am thinking of getting a 100' of speaker wire and run it all around my attic for my AM antenna. Something happened to my other antenna and it is not working very well. any more.
Click to expand...

You could. But it depends on the speaker wire. The cheaper wires have copper wire for the positive polarization and aluminum wire for the negative, in which case you'll have to strip the aluminum wire off and use the copper. But it still does a fantastic job at a fraction of the cost......
 
You can make an AM antenna out of damn near anything conductive. Copper, aluminum, steel wire... Remember, the transmitting towers are not made of copper.
 
That reminds me of a funny story. My buddy was a ham radio operator and was living in an apartment while he was waiting for his new house to be ready. He ran a wire out of his balcony and "loaded" the chain link fence so that he could broadcast. It worked well until one of the neighbors walked his dog who relieved himself on the fence! Talk about a hot dog.
 
If you're concerned about the conductivity of copper vs. aluminum, consider that TV antennas are made of aluminum (lighter weight), and that silver wire of a given gauge is even more conductive than copper. I don't think there would be much difference in propagation velocity. I can't say what the galvanic effect would be of twisting the wires together. I really can't imagine why aluminum wouldn't work just about as well, though.
 
I'm no expert on this....just my basic (if crude) knowledge........
 
The AM antenna that comes with many Sony radios, including the XDR-F1HD uses aluminum wire, although it seems most higher end AM antennas use copper magnet wire. While I know the conductivity of copper is better than aluminum it seems most antennas have always used aluminum, probably because its lighter and it doesn't oxidize as bad as copper does. Plus copper is so darn expensive these days. But you shouldn't have a problem using speaker wire for an AM antenna. I use speaker wire to add an extension onto my AM antenna, including the RCA plugs so I can swap antennas easily.
 
Y'know, for years, I have wanted to build a nice AM loop, but---

(1) My knack of building is near zilch,
(2) I know nothing about capacitors, where to put them, or even where to get them,
(3) I'm not even sure if it would work better than the Select-a-Tenna I have.

Seemingly, every design is too complicated for me. Not only that, I don't even DX AM much anymore, outside of daytime in remote areas.

Also, my Superadios have never seemed to "respond" to any AM antennas that connect to terminals. I have the Sony as well, but it's only in 10 kHz steps.

I like the Select-a-tenna because it can work on any AM radio, just by placing it nearby. No wires needed (altho' mine has a 1/8" jack to connect, just in case).

I just wish there was a simple way to do it.

cd
 
Speaker Wire ? Use the aluminum side or the copper side if such be.


I don't have a list of metals here now and 'conductivity'. Aluminum is better than steel.(Iron)


Copper has gotten soooooooooooooooo expensive.



I'm trying to adapt myself from using copper with everything and simply soldering things together.


I'd guess there is a plug for everything whatever that might be. Like RG6 Coax. Aluminum shield. Crimp connectors to it.

Steel Fence Wire. (or Aluminum) I guess popular in farm areas. How to connect together ? I think there is a tool that connects sections together. --but protect from oxidation ?


ya know...like 3000 feet of an antenna horizontal for just a receive antenna ? Galvanized Steel? Every time something segments it ? I'd guess 'steel' and welding knowledge would come in handy.


It's hard to find electrical solder anymore.
 
As an apartment dweller, I use AM loops like the Terk Advantage and a home untuned loop I once used on the Sony HD tuner. I am getting "at least OK" results on both AM and the low portion of the SW on a new ICOM R75. I may considering in buying the Pixel big loop in the future once I save enough money for it.
 
Twisting together the Cu and Al wires may cause rapid oxidation where it is twisted, due to the galvanic effect. This is the distillation of skimming some links on the internet. This is particularly true when the contact is exposed to water, and particulary salt spray on ocean coasts. It was actually an article about mixing Cu and Al in chimney flashing that was the most serious example.
 
The speaker wire that I've seen is copper. One conductor is tinned. The other is not. I've not seen speaker wire with an aluminum conductor.
One sure test is to apply solder to the silver wire. If it sticks, it's tinned copper. If not, it's probably aluminum.
 
Let's see I've used window screens, copper electrical wire, copper pipe, gutters, wrapped a wire (insulated) around a telephone wire, aluminum chairs, just about anything metal for an AM antenna. At a studio transmitter location I used a piece of wire plugged into the back of an amp for an air monitor. RF goes wherever it wants to!
 
Kelly Watts said:
Let's see I've used window screens, copper electrical wire, copper pipe, gutters, wrapped a wire (insulated) around a telephone wire, aluminum chairs, just about anything metal for an AM antenna. At a studio transmitter location I used a piece of wire plugged into the back of an amp for an air monitor. RF goes wherever it wants to!
Click to expand...

Hehe... I've used various things for an AM antenna as well. :) Among those are chain-link fences, barbed-wire fences, telephone poles (with the ground wire running down the pole), etc. Interesting thing... a barbed wire fence across the street from my house is the ONLY thing I've found that enhances longwave reception on my Tecsun radios (PL-380 and PL-606). Pretty much everything else has no effect at all, and the telephone pole ground wire only desenses my radio's front end pretty bad (it's untuned of course) due to the strong mediumwave locals.

Speaking of that telephone pole groundwire... combining it with the Select-A-Tenna can give a whole lotta gain!!! Just to give you an idea of how much gain that utility pole groundwire and Select-A-Tenna combination gives...
I'm 7.3 miles SE of 50kW (night) 760 KFMB, and with that combination they have an extremely strong signal on my Tecsun PL-380 on the fundamental, 2nd harmonic and 4th harmonic (pictured, of course other harmonics are strong as well.) For comparison, I had to be within a few meters of the center tower for 590 KTIE San Bernardino (when I was visiting the area recently) to get comparable signals on the fundamental, 2nd harmonic and 4th harmonic. BTW in the comparisons, the 2nd harmonic was indicating stronger for KFMB, but the 4th was indicating stronger for KTIE. The radio will not tune either stations' 3rd harmonic.
Another example... I'm about 300 miles west of 50kW 1580 KMIK Tempe, AZ, which is easily my strongest nighttime signal that's not usually heard at all in the daytime (except occasionally in winter when I have heard it overpower 50kW KBLA Santa Monica). They don't have the blowtorch level signal that KFMB does, but they still can overload my radio's audio stage with a very strong signal. (The photo was taken at night without flash, so you'll only be able to see the radio's display. I've had people look at me funny for taking photos with flash next to a utility pole. ;) :D ) To get the same signal, I had to be 90 feet from the SW tower of 5kW 1290 KKDD San Bernardino, CA.

Has anyone else found an antenna that gives as much or more gain than a utility pole groundwire? Also anyone know if there's a way to build a tuned antenna with that much gain that will enable me to dig out the 5 µV/m or weaker signals (I hear that's what a class A station's groundwave is protected to) on the first-adjacents (+/- 10 kHz) to those massively strong locals in the same direction? :) For example, well right now it'd be impossible due to their local running IBOC, but if there was no IBOC, what antenna would my friends in Arcadia, CA, need to be able to hear 1100 KFNX Cave Creek, AZ with an armchair-copy signal at solar noon on the summer solstice? They're about 1 km west of 50kW 1110 KDIS Pasadena, CA. KFNX is N of Phoenix - according to radio-locator their 150µV/m barely makes it west of the CA/AZ state line.
 
tfcwings said:
Also anyone know if there's a way to build a tuned antenna with that much gain that will enable me to dig out the 5 µV/m or weaker signals (I hear that's what a class A station's groundwave is protected to) on the first-adjacents (+/- 10 kHz) to those massively strong locals in the same direction?
Click to expand...


Please refer to the clip from the applicable regulation on this subject from 47 CFR quoted below.

The FCC requires millivolts per meter (mV/m) of the field intensities of Class A AM broadcast stations to be protected from interference, not microvolts per meter (µV/m).

A millivolt (mV) is 1000 times greater than a microvolt (µV).
_________________

§ 73.182 Engineering standards of allocation.

(a) Sections 73.21 to 73.37, inclusive, govern allocation of facilities
in the AM broadcast band 535-1705 kHz. § 73.21 establishes three
classes of channels in this band, namely, clear, regional and local.
The classes and power of AM broadcast stations which will be assigned
to the various channels are set forth in § 73.21. The classifications
of the AM broadcast stations are as follows:

(1) Class A stations operate on clear channels with powers no less than
10kW nor greater than 50 kW. These stations are designed to render
primary and secondary service over an extended area, with their primary
services areas protected from objectionable interference from other
stations on the same and adjacent channels. Their secondary service
areas are protected from objectionable interference from co-channel
stations. For purposes of protection, Class A stations may be divided
into two groups, those located in any of the contiguous 48 States and
those located in Alaska in accordance with § 73.25.

(i) The mainland U.S. Class A stations are those assigned to the
channels allocated by § 73.25. The power of these stations shall be 50
kW. The Class A stations in this group are afforded protection as
follows:

(A) Daytime. To the 0.1 mV/m groundwave contour from stations on the
same channel, and to the 0.5 mV/m groundwave contour from stations on
adjacent channels.

(B) Nighttime. To the 0.5 mV/m-50% skywave contour from stations on the
same channels.
 
tfcwings said:
Has anyone else found an antenna that gives as much or more gain than a utility pole groundwire?
Click to expand...

grounding the radio to utility ground? not a bad idea. but i bet a bare wire laying in wet sand on a beach is gonna be a lot quieter..

as for longwave, you can do select-a style and just use more wire. unwound a 9V/1A wallwart myself and wrapped it around an IKEA futon frame. so about 3 by 7 feet by 40 turns. it definitely pulls all the european stations on west coast of atlantic ocean.
 
carmen said:
tfcwings said:
Has anyone else found an antenna that gives as much or more gain than a utility pole groundwire?
Click to expand...

grounding the radio to utility ground? not a bad idea. but i bet a bare wire laying in wet sand on a beach is gonna be a lot quieter..

as for longwave, you can do select-a style and just use more wire. unwound a 9V/1A wallwart myself and wrapped it around an IKEA futon frame. so about 3 by 7 feet by 40 turns. it definitely pulls all the european stations on west coast of atlantic ocean.
Click to expand...

Well, considering I'd have to lay out upwards of 16-18 plus miles of wire just to get TO the beach, it'd probably be a TON more sensitive, and maybe it'd be quieter than grounding to utility ground.... BUT when you consider that the length of wire would have to go right through metro San Diego (ok, maybe bypassing downtown by a couple miles) and not far from a few stations' transmitter sites (with field intensities approaching, if not exceeding several hundred to a few thousand millivolts/meter), one of which uses IBOC, I suspect that wouldn't work too well in my location. ;)

Also, from what I can tell, the Pacific Oocean is quite a bit wider than the Atlantic Ocean. ;)
 
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