Ultimate AM Atenna

[MuZak]

In case anyone is interested..

...in the 14 inch tuned loop, here's how to build it.

For those of you who find the so called "ultimate" almost adequate,
but want a considerable boost... and find it a good compromise
size-wise, here are the details, nice and simple/quick 'n dirty:

Get a 14 inch embroidery hoop... I have a spare or 2 if anyone
wants one.
(feel free to PM)

Get a plaque base (like the one Paul used for the ultimate).
I also got a small wood box at the same craft store to house
the tuning cap.

Get the tuning cap from MTM.
They sell them alone for 15 bux. Might be a bit more now.
I got mine a couple of yrs ago.
http://www.mtmscientific.com/

A short length of dowel makes it a bit easier to mount the hoop.
I used a round one.

26 guage magnet wire... got mine from Rat Shack.

Get a 2 position screw-terminal block like Paul used.

The hoop has 2 sections... inner and outer, which seperate.

You mount the outer to the dowel top with a brass screw.
Drive the screw through it into the dowel.
(be careful since the hoop can break easily)
Another screw thru the base into dowel bottom.
Use brass screws... brass is non-inductive.

Wind 13 or 14 turns of wire around the inner section of the hoop,
leaving a pair of tails several inches long.

Twist them together.
Make sure they're long enough to reach wherever you locate
the tuning cap.

You want the coil winding to be fairly tight with the wire laying close
together... touching.

I used double stick tape in the outside of the inner ring to make
it easier to wind,
You lay the wire into the tape, where it stays put while you continue
to wind the rest.
Keeps it staying put while you assemble the rest too.

Then, optionally add a coupling loop, for use with receivers with
AM ant terminals... otherwise it can only be used placed near
the loopstick of a radio or receiver.

One turn for the pickup loop.
You'll want to wind the main loop... (or primary winding) off
to one side of the hoop.
Wind the pickup (or secondary) off to the other side.
Better to not have them touch.
It actually improves voltage transfer to have them seperated
a bit.

Leave adequate tails twisted together as above.

Insert the inner hoop (with the windings) carefully into the
outer ring.... with the wire tails pointing downward towards
the base.

Mount terminals on the plaque base as Paul did for the ultimate.

Then, mount the cap... (or house it in the small wood box
attached to the base as I did)

Next is to solder the tails from the main loop to the cap.
Solder either end to the solder terminal on the cap.
Don't forget to remove 1/4 inch or so of the enamel.
Use steel wool and acetone.

Either solder the other end to the chassis of the cap, or
put a screw in the threaded hole in the cap, on rear of its chassis.
If you go that route, be VERY careful not to let the screw
interfere with the workings of the cap!!!
Just look into the side of the cap as you thread the screw in
and you'll see how far is to far.

The size is 6-32 for the screw.. use a jam nut to keep it from
going in to far and for attaching a spade too.

Get spades sold as "telephone spades" from Radio shack.
Cat #64-3070.
Strip the enamel and solder one on.
Put the spade between the nut and cap chassis.
Those spades are recommended for your "lead in" cabling too.

After trimming to length, strip/solder the 2 twisted wires
comming from the 1 turn pickup loop to each of 2 spades.
Connect them to your terminal block.

Notes:
I said 13 or 14 turns above.
I found 13 best... 14 shifted the tuning range up a tad to
high on the caps rotation.
Try 14 first... before making the solder connection.
You can remove wire, but you can't add it once its cut off.
Or.. take the chance and go with 13 right off.
Its only magnet wire :arrow:

Stain if ya like....

Its a lot easier than it sounds! ara:

Its about the same size as the ultimate..
14" in width, and 14 vertical plus the height of the dowel
you choose and plaque base.

Works fairly well...
Waaaaaaaaay better than the "ultimate"!!!!! :thmbsp: :yes:

Good luck!

 

[Paul C]

MuZak, you are correct, the "Ultimate" (Carver's name for it, not mine) does not work with a radio or receiver that already has a ferrite rod loop antenna. That ferrite rod antenna would supply much more signal to the RF section than an untuned loop, so it is not surprising that the "Ultimate" loop did not help on these receivers.

Most stereo tuners and receivers have no built in antenna at all, and the "Ultimate" actually works very well for those tuners/receivers. However, in the past week, with my Onkyo TX-866 receiver and the "Ultimate" I have listened to these stations from here in Louisiana: WOAI 1200 San Antonio (about 500 miles), WSB 750 Atlanta (about 500 miles), KMOX 1120 St. Louis, MO (about 740 miles), WLW 700 Cinncinatti (820 miles), WLS 890 Chicago (970 miles).

There are some radios, and stations, which even a high-Q tuned loop will not improve over the built in ferrite rod antenna. The more sensitive the radio, the less an external loop will help. But it can help on weaker stations. Also, a tuned loop provides an extra stage of filtering, more selectivity.

For example, I have a Grundig S350DL, which has a PAL socket for external FM antenna, and terminals for external AM or SW antenna. The "Ultimate" untuned loop has no effect whatsoever on this radio. It already has a very good ferrite rod loop built in, and quite a large one, I understand.

The MTM tuned loop will couple quite well with no connection at all, but can also be used with the pickup loop.

When I added the pickup coil to the MTM, just inside of the main loop, I did it similarly to how a lot of "box loops" are constructed.

http://www.mindspring.com/~loop_antenna/amloop2.htm

Signal is so strong coming off the pickup coil as I have it now that for most stations I have to turn the RF Gain all the way down when directly connected to the Grundig. I asked one guy, might have been Bruce Carter, about using two turns on the pickup loop. He stated that it would likely provide too much signal, swamping the receiver.

BTW, the main page of Bruce Carter's loop antenna site has links to a number of good loop projects, a calculator, and other info.

Also, for supplies for building loops, I just received an order from Crystal Radio Supply.

http://www.crystalradiosupply.com/

Prices are reasonable, parts were well packaged, and shipping was quick. What more can you ask for?

They have the exact same tuning capacitor, their number N50, as the MTM's for $9.50. (NOTE: MTM's $15 price includes shipping) Also, a neat mounting bracket for $2.49 is available if you need one. They have wire, too, scroll all the way down on the left. 22 ga is no more expensive than smaller 23 ga or 24 ga wire, $4 for 100'.

MuZak said: Another way, is to add a vernier to the tuning cap shaft. Google vernier to find one. A bit pricey though, but makes it much easier.

Actually, right there at the Crystal Radio Supply site listed above, there is the same tuning capacitor as the N50, but with a 8:1 geared vernier dial, listed as the N50P. It is just $12.95.

http://www.crystalradiosupply.com/home.html?lang=en-us&target=p43.html


Same capacitor as the MTM variable cap and 26 ga wire available from Midnight Science:

http://www.midnightscience.com/catalog5.html

 

[wa2ise]

Most stereo tuners and receivers have no built in antenna at all

Most modern SS AM tuners expect a loop antenna of some specific inductance. I've built a few large loop antennas using spare 75 ohm CATV type coax. How I did it: Using about 20 feet of coax, strip about an inch to separate the shield and center conductor to prepare it to connect to the receiver's AM terminals, the center conductor to "AM" and shield to ground. At the other end, strip the end the same way, though all you'll need here is the center conductor. Temperarly connect a push-pin to the far end center conductor. Now create two turns of about 2 1/2 feet diameter, and be prepared to trial-and-error probe the shield with the push-pin, at the point where the turns of the coax "ends' and the rest of the coax becomes the lead in to the receiver. This loop will be vertical, not horizontal. With it connected to the receiver, tune in a reasonably but not very strong station near 600KHz. Now try various different diameters of the loops, and press the push-pin just far enough to pierce the insulation jacket of the coax, but not short to the center conductor at that point. You should be able to find a spot along the coax where the station seems the loudest. be sure you don't get confused by the orientation of the loop changing, keep it always north south or east west while you do this. Avoid holding it in a null for that station. (later on, once you're done, you could use the null to ignore one station near on the dial of a desired station). Once you find a good spot for the push=pin connection, you can make that connection more permanent by soldering carefully the end's center conductor to the shield. Then test it by tuning up and down the AM band.

Using shielded wire should help reduce noise, as most noise in the AM band tends to be electrostatic and less so magnetic. Radio stations produce equal amounts of electrostatic and magnetic radiation. So better signal to noise, around 3dB or more if you luck out. Be careful in that you don't create too large a loop antenna, as strong local stations can cause intermod crud across the band. That sounds like multiple stations on top of each other. If you get that, try more loops of smaller diameter of coax. That will reduce the signal energy extracted from the "air" and hopefully get it to a level the tuner front end can handle. Or you could try a bigger loop if your first try doesn't cause intermod.

 

[MuZak]

MuZak, you are correct, the "Ultimate" (Carver's name for it, not mine) does not work with a radio or receiver that already has a ferrite rod loop antenna. That ferrite rod antenna would supply much more signal to the RF section than an untuned loop, so it is not surprising that the "Ultimate" loop did not help on these receivers.

Hi Paul!

Plz understand...
My remarks were aimed at no one in particular..
Just intended to inform that it might not be ultimate for everyone's situation.
My anger is aimed exclusively at myself.
Mainly for not just building the MTM right off when I got the plans and caps back in 2004/5!
Instead wasting time fiddling with everything but, and still not having the performance I need as a minimum.
However, its been a HELLuva learning experience!!!
I just badly needed to vent about it, as I'd said.

While I did try the untuned loop (how I'll refer to the "ultimate" from now on)
as well as all my tuned loops with the units mentioned previously,
with built-in ferrites for information's sake...
Its mainly about the receiver I have with NO loopstick or any
other kind of integral AM antenna.

Btw, the "ultimate" loop type IS indeed untuned, in the sense
that the term tuned is intended.
The cap tunes the coil (to a particular freq) in the tuned variety.
It then becomes a high Q resonator.
The untuned type, are only wound for (an approximate) correct
impedance for the receiver to "see".

The reason the untuned type loops don't work with ferrite
equiped units is as follows:
The untuned loop connected to the ANT terms most likely
sucks up all (or most) of the signal the ferrite colleted!
(Current can flow both ways)
OR..
Using both together causes phase cancellations.
A test for whether its the latter, is to turn the untuned loop
90 degrees to the ferrite...
If its a phasing issue, doing that will add signal.

Both may also be occuring.

One way to make the untuned loop useful with a ferrite equipped
unit, is to wrap a wire one or two turns around the ferrite,
then twist the wire and connect it to the loops terminals.
Then, whatever extra energy the loop gathers will be transfered/concentrated
to the ferrite...
and take none away. (most likely)
You may also get some noise nulling by turning the loop relative
to the loopstick.

What I've found works best with ferrite equipped units, is to
have a tuned loop proximity-couple to the ferrite.
Works super!
The degree to which it works well, is STILL dependant on
how big the tuned loop is though!

Remember, it is the area of the coil that determines how
much energy it interacts with.

The integral ferrite will definately add more signal than the
untuned loop...
I'm not certain if its MUCH more.
On the one hand, its much more efficient.
RS 660 was dead on! A good ferrite is much better than an
untuned loop, in any case.
60s/70s technology vs 1930s tech.

The ultimate style is an air core coil...
Basically just a folded long wire, of an impedance roughly correct
for an AM RF section.. With a very slight noise reduction over
a long wire antenna.

The ferrite instead, is a ferrous core coil. (duh) :stupid:
Those are very efficient!
You'll find that in older speaker crossovers, and current ones
in cheap/crummy speakers, use iron core coils.
They're inexpensive to make, and used because they're efficient.
(bang for buck)
They fell out of favor when amps with power output above
60 or 80 watts became common, because iron core inductors
saturate around that power level.
A good example is how a Dyna ST-70, with its limited transformers
compared to say a HK Citation, begins to compress with the
volume up high.
Power saturation is hardly a consideration with a receive antenna.

Thus, the ferrite is very much more efficient than the air core
loop.
Its why RS 660 was right in his suggestion of using one rather
than a (relatively) big untuned loop.

That said, the ferrite is small... has an extremely limited
aperture, hence ability to gather energy.

While its also trimmed (matched) to the receiver its integral to's
RF section which yeilds an additonal advantage...
In the aggregate, its likely only slightly superior to the larger
untuned loop.
Particularly on a sensitive receiver.

Btw, the reason some tuners with an integral ferrite have ext. ant. terminals at all, is that they're intended for use with
a longwire antenna... which puts out soooo much that the ferrite
becomes basically irrelevant.

Most stereo tuners and receivers have no built in antenna at all,

I think I'd use the terms many or some....
"Most stereo tuners", IF they have AM at all, have an integral
ferrite, in my experience.
Particularly those from the early 60's thru the 70's.
During the 80's, AM almost went away, and better tuners were only FM... as were the better ones from the 70s and even 60s to some degree.
The notable exceptions were some of the best of the
Japanese tuners from the 70s/80s
You're very lucky to have tha Onkyo, btw...
I wish I had the time/resources to satisfy what must be my
tuner fetish... (in spite of so little worthwhile on radio now)

and the "Ultimate" actually works very well for those tuners/receivers.

In your low noise environment. (relative to mine)
In a noisy environment, one is actually better off with a low
sensitivity tuner with an untuned loop...
Both pickup EVERY bit of noise, with little to help reject it.

However, in the past week, with my Onkyo TX-866 receiver and the "Ultimate" I have listened to these stations from here in Louisiana: WOAI 1200 San Antonio (about 500 miles), WSB 750 Atlanta (about 500 miles), KMOX 1120 St. Louis, MO (about 740 miles), WLW 700 Cinncinatti (820 miles), WLS 890 Chicago (970 miles).

You're very lucky. Here, there's NO way!
Even with my Yamaha T-85 (which I forgot to mention in previous post)
its just all noise with the untuned loop.
Only the locals come in even on it, in the daytime, and with
S/N where the noise is equal to the signal.
(it has no integral ferrite)

In your situation, this combo works so well for you due mainly
to your tuner's exceptional sensitivity... IN your relatively low
noise environment... all thats needed is a termination thats
of proper impedance...
So much the better that you can turn it.
The "ultimate" yeilds very little (if any) gain.

There are some radios, and stations, which even a high-Q tuned loop will not improve over the built in ferrite rod antenna. The more sensitive the radio, the less an external loop will help. But it can help on weaker stations.

If you have.. and want to listen to a very strong/clean station
to listen to... the whole point it moot. You have what you need.
Its only about situations where, for whichever reason, there's not a strong/clean station that you want to listen to.
With a strong nearby station, even an insensitive radio will work perfectly.
Whether with an integral loopstick or the untuned loop!

Let me offer this example.
Even here.. in this horrible location... there's an AM station
1.6mi away. (per radio-locator)
Its 50k watt daytime.
Its unreal! I can pick it up on my gold fillings and bedsprings.
No.. I don't really have gold fillings.
Even my cheap/crummy RadioShack Ipod lookin thingy..
(it hangs from a string around your neck and its about 5"x3")
gets it like mad!!! Almost overload condition.

Only problem is...
Its exclusively, 24/7, bowel cleansing and invest your millions talk. uke:
(Not nessecarily during the same show)

That station... the untuned loop... no problem!!!
The radios with ferrites and crummy tuners.. slight overload.
The better tuners with ferrites... sounds like FM.

Now...
The tuners with no ferrites.. BUT with the 14" tuned loop connected...
NO difference between the ultimate and the 14"!!!
Rotate the tuning cap and it does zip. Nada.
A hair of overload condition on the sweet spot as you rotate
the cap knob.

An *AM TUNER* needs strong signal to reject everything else!
There's no free lunch.
Well.... a tuned loop pretty much is the exception to that!!

On the other hand.. the 50k watt daytime "local" station 48 mi
(over dead flat terrain) has hiss/noise equal to signal daytime,
with the untuned loop on the better ferrite-less tuners.
Same with the better ferrite equipped tuners.
A tiny tad better with the ferrite equipped tuners, IF you turn
them.
Not something easily achieved with the bigger ones like the
MAC 1900.

Put in the 14" tuned loop...
That 50kw/48mi "local" sounds like FM in daytime.
Same for the other 50kw local at 26mi.

Nighttime..
The 14 incher struggles with the 48mi station.
Barely acceptible at 7-8pm. By 9-10pm, unlistenable.
Absolutely zero signal with the ultimate. No matter how you
turn it.

This result is highly repeatable with all the tuners.
Including the better ferrite equipped units, with the 14" tuned
loop proximity coupled.

Also, a tuned loop provides an extra stage of filtering, more selectivity.

Actually, the antenna has no selectivity.
It just gives your tuner what it needs to achieve optimal selectivity.
A sharp peak @tuned freq, which the tuner needs to reject everything else.

For example, I have a Grundig S350DL, which has a PAL socket for external FM antenna, and terminals for external AM or SW antenna. The "Ultimate" untuned loop has no effect whatsoever on this radio. It already has a very good ferrite rod loop built in, and quite a large one, I understand.

Its ALL about your local RF/EM noise level!!!!!
(and your antenna's ability to help tuner overcome it)

The MTM tuned loop will couple quite well with no connection at all, but can also be used with the pickup loop.

You might want to try moving the MTM closer to and farther from
radios with ferrites..
To give you a sense of the response to proximity of pickup coil
to resonator.

When I added the pickup coil to the MTM, just inside of the main loop, I did it similarly to how a lot of "box loops" are constructed.

Signal is so strong coming off the pickup coil as I have it now that for most stations I have to turn the RF Gain all the way down when directly connected to the Grundig.

I asked one guy, might have been Bruce Carter, about using two turns on the pickup loop. He stated that it would likely provide too much signal, swamping the receiver.

Ok.. whats actually happening there is the reverse... in a certain sense.
While its easier to understand, and therefore explain, that "it swamps the receiver",
its actually the reverse.
The receiver (with its active circuitry) loads the pickup coil..
That in turn loads the resonator.

More turns presents a higher impedance to the receiver.
More voltage that colapses when the receiver tries to load it.

It overloads the resonator.
It also reduces the Q of the resonator.
(The net effect of that is the same as attenuating the RF gain
control, btw)


By contrast, too few turns and the impedance is too low
(stable but very low voltage out).
The ideal impedance has a signal voltage that falls to
about half when connected to the receiver.
One turn normally.. but 2 could be used to advantage..
IF you're finding the output to high and Q to peaky.

My suggestion of experimenting with 2 turns was based on the
assumption/understanding that you've found the MTM to be
more powerful than you need and your radio can handle.
Maybe I misunderstood?

If not however, 2 turns together with a more distant spacing..
ie the 6 inch diameter MTM recommends might work better
in your case. (or somewhere in between)
It may be worth experimenting.

This begs the question though... why has MTM chosen the 6in
diameter pickup???
While I've a feeling its because the thing is SO dang powerful,
its a way of mitigating that for most normal radios.

If I had the time, I'd email them and ask..
Might if I've a free moment later, or you might if you like.

From your descriptions and that of others, I'm realizing its
wicked powerful, which is why I think its what I need!

BTW, the main page of Bruce Carter's loop antenna site has links to a number of good loop projects, a calculator, and other info.
Also, for supplies for building loops, I just received an order from Crystal Radio Supply.
http://www.crystalradiosupply.com/
Prices are reasonable, parts were well packaged, and shipping was quick. What more can you ask for?
They have the exact same tuning capacitor, their number N50, as the MTM's for $9.50. (NOTE: MTM's $15 price includes shipping) Also, a neat mounting bracket for $2.49 is available if you need one. They have wire, too, scroll all the way down on the left. 22 ga is no more expensive than smaller 23 ga or 24 ga wire, $4 for 100'.
Same capacitor and 26 ga wire available from
http://www.midnightscience.com/catalog5.html

Btw (back atcha) thanks sooo much for all that fantastic info!!!
Thats soooooooo helpful for what I need to do now!!!

Incidently, the 14" loop might serve you best.
Its power and Q are a good bit less overwhelming than the MTM.
The size (aperture) is similar to the ultimate.
The design is one where the turns are closely spaced.
That yeilds a lower Q.
An unfortunate byproduct is a bit of stray capacitance...
which is why I'm using 13 turn rather than the mathematically correct 14.
It throws the cap value off a tiny bit.
14 only resulted in the tuning being a bit higher than it should
be on the cap-dial... misses the freq's above 1550 or so too.
You'd want to try both 13 and 14 though, to be sure.

Ironically, the MTM will almost certainly be best for me.
I built the 14 inch as I thought it would be just right, but'
in this horribly noisy environment, it just isn't.

Greg

PS: Sorry for all the errors in this posting.. I just don't have
the time to go back and correct em all.

 

[Paul C]

None of my stereo receivers and tuners (Onkyo TX-866, TX-870, TX-906, T-4500, T-4017, and recently in my hands, TX-850, TX-860, T-4087) have a built in ferrite rod, and all worked well with the Ultimate loop.

I did have an Onkyo T-15 at one time that had a ferrite rod on the back mounted on a ball swivel, but that was before my more recent experiments with loops.

The MTM is a very powerful loop. For most stations I have to turn my Grundig's RF Gain all the way down.

Also I've found for whatever radio/receiver/tuner I use, it must be well away from computers, routers, and TV/VCR/etc gear. They put out a lot of hash, especially computers.

 

[Paul C]

Most modern SS AM tuners expect a loop antenna of some specific inductance. I've built a few large loop antennas using spare 75 ohm CATV type coax. How I did it: Using about 20 feet of coax, strip about an inch to separate the shield and center conductor to prepare it to connect to the receiver's AM terminals, the center conductor to "AM" and shield to ground. At the other end, strip the end the same way, though all you'll need here is the center conductor. Temperarly connect a push-pin to the far end center conductor. Now create two turns of about 2 1/2 feet diameter, and be prepared to trial-and-error probe the shield with the push-pin, at the point where the turns of the coax "ends' and the rest of the coax becomes the lead in to the receiver. This loop will be vertical, not horizontal. With it connected to the receiver, tune in a reasonably but not very strong station near 600KHz. Now try various different diameters of the loops, and press the push-pin just far enough to pierce the insulation jacket of the coax, but not short to the center conductor at that point. You should be able to find a spot along the coax where the station seems the loudest. be sure you don't get confused by the orientation of the loop changing, keep it always north south or east west while you do this. Avoid holding it in a null for that station. (later on, once you're done, you could use the null to ignore one station near on the dial of a desired station). Once you find a good spot for the push=pin connection, you can make that connection more permanent by soldering carefully the end's center conductor to the shield. Then test it by tuning up and down the AM band.

Using shielded wire should help reduce noise, as most noise in the AM band tends to be electrostatic and less so magnetic. Radio stations produce equal amounts of electrostatic and magnetic radiation. So better signal to noise, around 3dB or more if you luck out. Be careful in that you don't create too large a loop antenna, as strong local stations can cause intermod crud across the band. That sounds like multiple stations on top of each other. If you get that, try more loops of smaller diameter of coax. That will reduce the signal energy extracted from the "air" and hopefully get it to a level the tuner front end can handle. Or you could try a bigger loop if your first try doesn't cause intermod.

What would be good loop diameter, number of turns, for SW, 3000 khz-8000 (90 m to 41 m) khz, or 8000 khz - 30 khz (31 m - 11 m)?

 

[MuZak]

The MTM is a very powerful loop. For most stations I have to turn my Grundig's RF Gain all the way down.

Sounds like just the ticket for me!

Also I've found for whatever radio/receiver/tuner I use, it must be well away from computers, routers, and TV/VCR/etc gear. They put out a lot of hash, especially computers.

Definately.
Along with dimmers, flourescents, even nightlights so I hear.
All the "reception tips" you read list an ever growing liteney
of such gadgets.
Even the thermostat (which I learned from you)
(I always thought it was the AC compressor itself)

In addition to all that..
Looking out the fairly large picture window right over
yonder, I count
no less than 6 transmitter towers.
6 if you count the phased array of 4 as one.
2 have cell phone repeaters on them.
My cell phone has 5 bars when near that window!
Thats only the roughly 45 degree view I get from there.
That I can see over the tall tree tops in the other directions,
there's about 8 more.

Once not long ago, while trying to listen to SW with an indoor
50ft long wire late night...
I was absolutely astonished at HOW MANY ppl nuke late nite snacks!!!
Rarely more than a minute or 2 break between microwave generated noise.
Lest one think its one guy with MAJOR munchiez... each oven
has its own sonic signature.

To make matters worse still... I now live in an appartment.
Even if I try to keep things turned off and radios/antennas
far from noise makers.... the neighbors don't.

Having said that though, it wasn't much better in the home I
lived in prior, till recently.
Someone who lives nearby, in a thread on AK, described those
homes as "concrete hurricane bunkers"
Concrete roof tiles, thick concrete everywhere else.
Even there, I could hear my neighbor's fridge.
Homes are about 20ft apart.

I tried SW there too... with a longwire just outside the lanai.
6ft feedline with communications receiver just below where
it
taps in, and 4ft ground rod about 4ft away.
It was only a small bit better than here.
This is just a sucky RF environment!

Even tried taking the radio and loop out to the dock thats
40ft behind the house.
Sitting on it, over water... only a small bit better.
Seems that every improvement you try is only a small bit better.

There was one exception, however...
For 2 weeks after huricane Wilma, nobody for 60 or 75 miles
around had power.
(first few days anyway... then some areas came online)
It was amazing...
AM with a totally black background!! lol.
I'd get 770-WABC in NYC like it was a local.
That with the GE super radio next to the 10inch terk tuned
loop.
Came in readably even without the terk.
Heh...
Was nice while it lasted!
There wasn't much else to do anyway, after dark, than DX.

 

[Paul C]

MuZak said: ...in the 14 inch tuned loop, here's how to build it.

For those of you who find the so called "ultimate" almost adequate,
but want a considerable boost... and find it a good compromise
size-wise, here are the details, nice and simple/quick 'n dirty:

Get a 14 inch embroidery hoop...

My wife and her friend are at a craft show. She found some 18" hoops and called me. I had her pick up three for me, less than $7 each.

 

[wa2ise]

What would be good loop diameter, number of turns, for SW, 3000 khz-8000 (90 m to 41 m) khz, or 8000 khz - 30 khz (31 m - 11 m)?

I think shortwave radio sets are expecting an antenna like a dipole. I don't think a loop would work for these sets. Easiest thing is the "random length" wire", strung up into trees and such. Stay well away from power lines, both for safety and noise reasons.

 

[Paul C]

Hmmmm.... and there are always J-poles... :scratch2:

 

[Laemmle]

I am using the Ultimate on my McIntosh MR-74 tuner here in New York City...and I must say it it truly a wonder!

I am lucky, the 74 has a switch in the rear to utilize the supplied ferrite rod, or an external antenna.

I can not utilize it on my 1900 McIntosh receiver.....it has a fixed rod antenna and the am terminal on the rear is a waste with an external antenna.

That is why I love this particular model of McIntosh tuner.