According to Terks website, and product brochure, the Terk AM
Advantage antenna is "omnidirectional". Is that true? I thought

all

loop antennas were very directional. It IS a loop isn't it? It
looks like a loop, it's a big circle.

According to Terks website, and product brochure, the Terk AM
Advantage antenna is "omnidirectional". Is that true? I thought all
loop antennas were very directional. It IS a loop isn't it? It
looks like a loop, it's a big circle.

Thanks, but what about my question regarding "auto disconnect" of the
internal ferrite bar? When I turn the loop to null a strong, local
station (I don't hear ANYTHING)doesn't that suggest that the internal
antenna has been defeated in some way?

--- In loopantennas@..., Jim Dunstan <jimdunstan@r...>
wrote:

At 10:38 PM 8/9/04 +0000, you wrote:

OK, I hooked the loop (a cheap, simple little plastic thing that
comes with an am/fm hifi receiver for the am part) up 1 wire to "am
antenna" and 1 wire to "ground". I tuned to a strong local

station.

When I rotated the loop for strong signal it sounded about like the
internal ferrite bar. But, when I rotated to null the station

signal

I got nothing. Does this indicate that something automatically
disconnects the internal ferrite bar when I have the loop hooked
up?

Okay .... I thought you were using a tuned loop. The loop you

describe

will be an inferior antenna to your built in ferrite rod antenna.

It is

designed for receivers with relatively high gain and no internal

antenna

(HiFi receiver). It will work fine for the purpose of picking up

strong

local signals. A tuned loop is another thing all together. They

have

multi turns and are tuned with a capacitor so they come to

resonance. When

the do come to resonance they create a strong electromagnetic field

at a

very narrow frequency bandwidth. This field can then be coupled to

your

receiver by either bringing a receiver with a ferrite rod antenna

into its

vicinity or if doesn't have a built in antenna you couple using a

wire turn

or two as a link. The loop you have would make an excellent link

to a

tuned loop antenna. It is in fact exactly what I use for my Hi Fi

set.

My set has the same small plastic loop (8 1/2" dia es 3 turns) I

use it to

couple to my tuned loop. The Hi Fi set works just fine with the

plastic

loop when receiving local AM stations. However if I want to pick

up

stations in say Duluth (about 160 miles away) I bring the plastic

loop

close to my tuned loop, which I tune to the same frequency. The

difference

in reception is like night and day. The signal increases at least

20 to 30 DB.

Jim Dunstan
Thunder Bay, ON

At 10:38 PM 8/9/04 +0000, you wrote:

OK, I hooked the loop (a cheap, simple little plastic thing that
comes with an am/fm hifi receiver for the am part) up 1 wire to "am
antenna" and 1 wire to "ground".? I tuned to a strong local station.?
When I rotated the loop for strong signal it sounded about like the
internal ferrite bar.? But, when I rotated to null the station signal
I got nothing.? Does this indicate that something automatically
disconnects the internal ferrite bar when I have the loop hooked up?????????????

Okay .... I thought you were using a tuned loop.? The loop you describe will be an inferior antenna to your built in ferrite rod antenna.? It is designed for receivers with relatively high gain and no internal antenna (HiFi receiver).? It will work fine for the purpose of picking up strong local signals.? A tuned loop is another thing all together.? They have multi turns and are tuned with a capacitor so they come to resonance.? When the do come to resonance they create a strong electromagnetic field at a very narrow frequency bandwidth.? This field can then be coupled to your receiver by either bringing a receiver with a ferrite rod antenna into its vicinity or if doesn't have a built in antenna you couple using a wire turn or two as a link.? The loop you have would make an excellent link to a tuned loop antenna.? It is in fact exactly what I use for my Hi Fi set.

My set has the same small plastic loop (8 1/2" dia es 3 turns)? I use it to couple to my tuned loop.? The Hi Fi set works just fine with the plastic loop when receiving local AM stations.? However if I want to pick up stations in say Duluth (about 160 miles away) I bring the plastic loop close to my tuned loop, which I tune to the same frequency.? The difference in reception is like night and day.? The signal increases at least 20 to 30 DB.

Jim Dunstan
Thunder Bay, ON

At 09:51 AM 8/8/2004, you wrote:

I have been looking for a decent medium-wave AM loop antenna. I have
found a Terk AM-1000 AM Advantage Antenna for $31.70 plus shipping. My
questions are:

1) Can I find a better antenna than the Terk AM-1000 for about $30?

Probably not unless you are willing to build it. If that is the
case you could likely build a much better antenna but it will be
larger.

2) Can I find a better price on the Terk AM-1000?

I did a Froogle search and best price was $29.99



If you want a commercial product this may well be the best deal
on a price/performance basis!

73

Phil

-------------------------------------------------------------------------
Phil Lefever KB?NES Twin Cities Repeater Club
kb0nes@... Burnsville,MN

OK, I hooked the loop (a cheap, simple little plastic thing that
comes with an am/fm hifi receiver for the am part) up 1 wire to "am
antenna" and 1 wire to "ground". I tuned to a strong local station.
When I rotated the loop for strong signal it sounded about like the
internal ferrite bar. But, when I rotated to null the station signal
I got nothing. Does this indicate that something automatically
disconnects the internal ferrite bar when I have the loop hooked up?


--- In loopantennas@..., Jim Dunstan <jimdunstan@r...>
wrote:

At 04:01 PM 8/7/04 +0000, you wrote:

I just bought a Sangean PRD-2 radio. It works great on the

internal

AM antenna. Just for experimentation, I want to hook up an

external

loop antenna. It has 2 terminals on the back. One marked "am
antenna" and the one next to it marked "ground". My question is,
where do the 2 wire leads from the antenna go? I assume the ground
is for a ground wire and not the antenna. Do the 2 wire leads from
the antenna both go to the terminal marked "am
antenna"? What?

The radio more than likely uses a ferrite rod antenna/front end
inductor. If it has a terminal for the AM receiver it will in all

likely

hood be connected to a wire link wound around the ferrite rod. In

this

case you have 2 choices for coupling to a tuned loop.

1. Simply ignore the connectors and making a physical connection

between

the loop and the radio. Tune the radio to the frequency of your

choice,

then tune the loop to the same frequency and orient the loop and

radio for

best reception.

2. If your loop has a pair of wires coming out (usually from a

coupling

link) then simply connect one wire to the 'AM Antenna' connector

and the

other to the one marked 'ground'. If the wire from the loop is a

coax type

wire, then connect the centre conductor to the 'AM Antenna'

connector and

the shield to the 'Ground' connector.

Experiment with both methods.

Jim Dunstan
Thunder Bay, ON

1) Can I find a better antenna than the Terk AM-1000 for about $30?

Find no. Build yes.

2) Can I find a better price on the Terk AM-1000?

Probably not. What is your source? I had assumed the model was
discontinued.

开云体育

At 04:01 PM 8/7/04 +0000, you wrote:

I just bought a Sangean PRD-2 radio.? It works great on the internal
AM antenna.? Just for experimentation, I want to hook up an external
loop antenna.? It has 2 terminals on the back.? One marked "am
antenna" and the one next to it marked "ground".? My question is,
where do the 2 wire leads from the antenna go?? I assume the ground
is for a ground wire and not the antenna.? Do the 2 wire leads from
the antenna both go to the terminal marked "am antenna"?? What??????????????????????????????????

?
The radio more than likely uses a ferrite rod antenna/front end inductor.? If it has a terminal for the AM receiver it will in all likely hood be connected to a wire link wound around the ferrite rod.? In this case you have 2 choices for coupling to a tuned loop.

1.? Simply ignore the connectors and making a physical connection between the loop and the radio.? Tune the radio to the frequency of your choice, then tune the loop to the same frequency and orient the loop and radio for best reception.

2.? If your loop has a pair of wires coming out (usually from a coupling link) then simply connect one wire to the 'AM Antenna' connector and the other to the one marked 'ground'.? If the wire from the loop is a coax type wire, then connect the centre conductor to the 'AM Antenna' connector and the shield to the 'Ground' connector.

Experiment with both methods.

???????????????

Jim Dunstan
Thunder Bay, ON

RR,

AM/MW Loop Antennas: Your best 'connection' may be NO Connection.

Use the AM/MW Loop Antenna "Inductively Coupled" to the
Radio's built-in AM/MW Ferrite Rod Antenna.

IMHO: Most of the time Inductive Coupling works better
than a direct connection to many radios that have built-in
AM/MW Ferrite Rod Antennas.

READ: About Inductive Coupling with a Loop Antenna and
a 'portable' AM/MW Radio


READ: Improved AM/BCB Radio Reception = Think MW Loop Antenna


READ: Passive and Active AM/MW Loop Antennas


iane ~ RHF
.
.
= = = In loopantennas@...,
= = = "realrussian" <realrussian@y...> wrote:

I just bought a Sangean PRD-2 radio. It works great on the

internal

AM antenna. Just for experimentation, I want to hook up an

external

loop antenna. It has 2 terminals on the back. One marked "am
antenna" and the one next to it marked "ground". My question is,
where do the 2 wire leads from the antenna go? I assume the

ground

is for a ground wire and not the antenna. Do the 2 wire leads

from

the antenna both go to the terminal marked "am antenna"?
What ?

.

开云体育

The only dumb questions are those that don't get asked.

Two ways to go:

(1) Antenna screw to a really long wire strung outside. Ground
screw to a cold water pipe in your house.

(2) Antenna screw to the signal end of a loop antenna like we
describe on this group, ground screw to the ground connection. Be
aware that loop antennas are tuned devices, they will have to be
adjusted to the same frequency to which the radio is tuned to be
effective.

开云体育

From experience I would connect inner to AM Antenna and outer to ground.
Whether the internal loopstick will cause problems I do not know. Orientation of receiver will help here.
Is the external loop amplified?
Other method is to wind 2 or 3 turns onto internal ferrite aerial and connect external loop or wire antenna to one end and ground wire to the other
As with all unknowns-try it and see. If it works then tell others about it
If not then research on WEB
regards
dave G8SZX.

loopantennas@... wrote:

hi all , am parting out a technics st-s1 tuner to build a tunable
loop. every thing but the variable cap is available. all switches
knobs andface panel are good the tuner was working yesterday. any
takers?
question regarding the variable cap. there are 3 screws on the
top and a trimmer.where should the wires of the loop be connected?
thanks in advance johnkelsall

I just bought a Sangean PRD-2 radio. It works great on the internal
AM antenna. Just for experimentation, I want to hook up an external
loop antenna. It has 2 terminals on the back. One marked "am
antenna" and the one next to it marked "ground". My question is,
where do the 2 wire leads from the antenna go? I assume the ground
is for a ground wire and not the antenna. Do the 2 wire leads from
the antenna both go to the terminal marked "am antenna"? What?

Greeting folks.
I am currently attempting to build a Loran-C (centered at 100kHz)
receiver and am having some difficulty with the antenna. Though I
have been frequently informed it is difficult to not pick up this
signal, I seem to be quite accomplished at it. My only attempts to
pick up the signal consist of hooking the leads of various AM
antennas to the 50 ohm input of a spectrum analyzer via a matching
network for 100kHz. Any recommendations as to how I should
build/purchase an antenna for this frequency and how I should test
it? Also, does anyone happen to know what the polarization of the
Loran-C signal is?
Thanks,
Matt

I have built a couple of loops on styrofoam - they work great.

At 11:33 AM 7/27/04 -0600, you wrote:

Hi,

I got given some poly square plastic stuff and thought hmm I could use this
in a loop somehow and this popped into my mind I am thinking 15 inches on
the outside with wood and the lengths on the inside holding it together that
poly square plastic stuff is 1/2 inch square. So that would make the loop
14.5in square not huge but decent I figure. I was thinking of bringing the
coupling loop in about an inch or two from that so the coupling loop would
be 13.5in or so to 12.5in not sure which is better. was going to make the
"plate" to hold the cap out of lexan and the "plate" for the connections
back to the receiver. question is how many turns of wire for the AM BCB I am
sure there is a calc for this but I haven't seen it and I wanted to share my
design. Also the rest wood be made from wood the longer pieces.


Scott
KC7WDG

My second post. I took a look at your construction schematic. U are using 4 pegs sandwiched between 2 frames. My construction is similar but different. If you look at your schematic cross section (from the side) ... I have just one frame and the pegs are mounted with 1 screw each to only one frame. The other end of the peg is free. The frame I use is simply a plywood sheet (a plexiglass sheet and pegs would be classy). I mount my capacitor in the center on the opposite side of the sheet from the winding. I screw one end of a 12" peg on the same side of the sheet as the winding. I then slide my coupling coil (8" dia. 3 turns) along this peg for optimum coupling.

I mount the whole thing vertically on a 8" square block which acts as a base. I glued a sheet of velvet material on the bottom to avoid scratching the HiFi set.

For normal listening on the HiFi I just slide the pickup hoop right in the loop .... nothing critical. When I am dxing with another receiver I find the coupling adjustment is invaluable.


Jim Dunstan
Thunder Bay, ON

At 11:33 AM 7/27/04 -0600, you wrote:

Hi,

I got given some poly square plastic stuff and thought hmm I could use this
in a loop somehow and this popped into my mind I am thinking 15 inches on
the outside with wood and the lengths on the inside holding it together that
poly square plastic stuff is 1/2 inch square. So that would make the loop
14.5in square not huge but decent I figure. I was thinking of bringing the
coupling loop in about an inch or two from that so the coupling loop would
be 13.5in or so to 12.5in not sure which is better. was going to make the
"plate" to hold the cap out of lexan and the "plate" for the connections
back to the receiver. question is how many turns of wire for the AM BCB I am
sure there is a calc for this but I haven't seen it and I wanted to share my
design. Also the rest wood be made from wood the longer pieces.


Scott
KC7WDG

I have a BCB loop constructed on a plywood rectangle 10 1/2" x 14". I placed a 2" peg at each corner. I wound 16 turns of Radio Shack hook up wire around the pegs.

The plywood sheet is mounted vertically on a wood block which acts as a base. I mounted a 365pfd capacitor in the center of the sheet on the side opposite the windings. My Hi-Fi set came with a BCB antenna which consisted of a small plastic hoop about 8" in dia. with 3 turns of wire on it. I use this small loop as the pickup loop for my tuned loop. I attached this 8" hoop to the sheet the centre of my tuned loop. The 8" hoop has a twisted pair about 2' long terminated in spade lugs.

Under normal BCB receiving conditions I have the tuned loop sitting on top of my HI Fi set with the twisted pair connected to the antenna input on the receiver. When I tune the loop to the received station the difference in reception increases a quantum leap.

When I attempt DX reception with this tuned loop and a portable receiver out in the garden (minimize the local noise) I find that the placement of the pickup loop inside the tuned loop provides too much coupling. At first I dismounted the 8" loop and moved it farther and closer by hand to find the optimum coupling which is a balance between best selectivity/signal strength. I soon got tired and mounted one end of a 12" dowel to the plywood sheet and just hung the 8" pickup coil on this 'peg'. I could shuttle it from inside the loop to about 10" away from the loop. What I find is that under certain conditions ... eg separating close stations .... the pickup loop works best hanging on the peg up to 8" away from the tuned loop! I find that the placement of the pickup loop is almost as critical as the tuning of the main loop itself.

One of the advantages of making the tuned loop relatively small is that it is portable. I would not be able to put a 4' loop on the table out in the garden hi. Another thing you might want to experiment with is using your tuned loop with a longwire antenna and ground. I have a longwire available out in the garden and I connected it to one side of the tuning capacitor. A ground wire was connected to the other side. The reception increases a second quantum leap. Again adjust the tuning and coupling for best reception ..... you will be amazed at the daytime reception with this setup. I say daytime because night time reception is completely different with all kinds of different stations coming in on skip. All my BCB DXing is daytime.

So back to your questions:

your loop will be about 13.5x12.5 ..... mine is 10.5x14 and it uses 16 turns.
your pickup loop mounted inside the loop ...... mine is variable and some conditions works best at up 8" away from the loop!

Jim Dunstan
Thunder Bay, ON