Antenna blues, so far my Sony AN-1 wins!
Jeroen
Picking up my SWL hobby wich I left in ~ 1992.
I have a Phillips D2999PLL and Sony AN-1 which I have kept from back
then. My living situation is far worse (for SWL that is) compared to
back then when living ina quiet suburb. Living in the city centre now
with a supermarket with huge fans on their roof for cooling the
freezers and such, and ofcourse all the equipment from our neighbours.
So I've been reading the forums, sites and newsgroups on my equipment
and found that generally the receiver is well received (*g*), and the
antenna is not! Back then though I've been able to receive quite a
bunch of QSL cards from stations I picked up in the tropical bands. Had
lots and lotsof night of fun!
But, to improve my antenna situation I've been looking around to see
for alternatives. Active antenna's are out of the question for me.
Frick, the quality ones seem to start at 200Euro. As a soon to be daddy
and other expenses coming up I can't afford those...
I've little room for a reasonable 'random wire' either. After some
looking around I decided to give the EMF antenna a try from RF-Systems
in the Netherlands (where I come from as well, accidentally).
After a few days of trying different configurations (indoors, out on
the balcony, horizontal, vertical, north-south, west-east and all
inbetween, 30 degree sloped, earthing to the earthwire in the powerbox
of the appartment, etc) and comparing it to my Sony AN-1, I can savely
say, at best the EMF antenna produces equally to the Sony An-1, but has
never exceeded it. It seems to pickup far more noise and interference
then the AN-1 does.
So the EMF is up for grabs for anyone here who makes a good offer for
it!
I also have to add, I did quite some browsing and reading on the EMF
before I ordered it, and the general tendency was it is an OK antenna.
I guess, in my situation the AN-1 isnt such a bad antenna after all, or
the EMF is for my situation a really bad antenna!
This week I am going to try and build a magnetic loop. At first I saw
many daunting schematics which are too technical for me with my left
hands, but I found this page (http://www.kr1st.com/swlloop.htm) with a
*very* simple version that according to the writer is so simple as it
is for receiving only. Apparently, the transmitting ones need to be far
more technical. Does anyone has any tips regarding building any of
these? My particular interest is the 60meter band.
And, anyone any comments on my EMF/AN-1 comparison? I think I pretty
much tried all configurations, and in reality there isnt much to do
with the EMF, its all prebuild. But I'm open for suggestions!
ve3...
Jeroen wrote:
> Hello All,
>
> Picking up my SWL hobby wich I left in ~ 1992.
>
> I have a Phillips D2999PLL and Sony AN-1
>
> much tried all configurations, and in reality there isnt much to do
> with the EMF, its all prebuild. But I'm open for suggestions!
I used an AN-1 in a concrete apartment for a year and it worked well
after I had made a change to it. Unmodified, it was quiet, didn't hurt
the signals but it didn't seem to have much gain. I added a thin
hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I
recall) and that improved it consiserably. I think that Sony was
worried about generating spurious in high-signal areas like Europe and
used very a conservative amplifier. Adding a length to the whip in
weak-signal areas had no bad effects.
Telamon
"ve3..." <ve3...@hotmail.com> wrote:
The advantage of this small active antenna is you can put it in the
quietest location of you house. Go around with a portable radio to find
a quite spot and mount the AN-1 there.
--
Telamon
Ventura, California
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
Small active loop antennas are pricey but are most likely the best in
town choice.
To get an idea how this type of antenna will work in your location you
could build a passive loop at small cost using just coax cable.
--
Telamon
Ventura, California
Jeroen
Thanks for your replies. Here some reactions from my side:
> I used an AN-1 in a concrete apartment for a year and it worked well
> after I had made a change to it. Unmodified, it was quiet, didn't hurt
> the signals but it didn't seem to have much gain. I added a thin
> hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I
> recall) and that improved it consiserably. I think that Sony was
> worried about generating spurious in high-signal areas like Europe and
> used very a conservative amplifier. Adding a length to the whip in
> weak-signal areas had no bad effects.
I did this as well, I do live in Europe (Holland) and it increased the
noise heavily, making it not really usefull for me.
> Small active loop antennas are pricey but are most likely the best in
> town choice.
Unfortunally, no money for that :\
> To get an idea how this type of antenna will work in your location you
> could build a passive loop at small cost using just coax cable.
This is what I am going to do. Aftre some digging around I will go for
copper tubing however, as on one site I found that on lower frequencies
thicker copper will do better then the thinner one advised in the
article I gave the URL for.
I'm looking forward to building somehting of my own though! And I'll
probably experiment afterwards to improve the results. Can't wait to
see wether it will outperform my AN-1 antenna.... The costs are, like
you said, minimal.
I'll post back when I have done some testing on my to-be magnetic loop
:)
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
You don't have to use copper tubing. You can build the antenna using
just the coax.
If you build a 40 foot loop you would build it like this:
1. Cut a piece of coax 40 feet long.
2. Cut the shield only at 20 feet separate the shield about an inch.
3. Bring the ends of the loop together connecting the shields and center
conductor on one end.
4. Connect the shield of the lead-in coax shield to the shields of the
loop and the remaining free center conductor of the loop to the center
conductor of the lead-in coax.
The loop will be somewhat unbalanced but should work pretty good. You
can improve the balance of the loop by using a BALUN made of enamel
coated wire and a ferrite toroid core. If you use the BALUN you would
have both ends of the loop center conductors connected to a bifilar
winding on the core of a few turns where the other end of the winding is
connected to the lead-in center conductor and common ground made of both
end of the loop shields and the lead-in shield. All this should only
cost under $50 dollars.
--
Telamon
Ventura, California
RHF
VE3 - Did basically the same thing using a
104 Inch CB Whip Antennna with the Sony
Antenna Head mounted on a 21 Foot piece
of Top Rail. ~ RHF
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RHF
Jeroen,
The RF Systems "EMF" Antenna is relatively short at 16 Feet
and is a magnetically coupled Antenna. The signal levels are
thus relatively small compared to a much longer 50-80 Foot
Random Wire Antenna. So -Yes- in this instance you may find
that the Sony AN-1 Active Antenna does as well or better than
the "EMF".
Don't forget that the Sony AN-1 Active Antenna :
* Should be Mounted at least 3-5 Feet above your Roof
-or- at least 15-20 Feet away from your House/Building.
* Can be Mounted inside the Attic.
* Can be Mounted Horizontally and Rotated to Null-Out
the main source of your local Noise to some degree.
{every little bit helps :o}
Alternative - Instead of using the Sony AN-1 Active Antenna's
Short Vertical Whip Antenna Element : Use a One Metre
Diameter Horizontal Loop Antenna Element with one-end
of the Loop connected directly to the Sony's Head Unit and
the other-end of the Loop connected via a 300, 450, 600 or
1K Ohm Resister to the Sony's Head Unit. Try the different
Resisters to determine which gives the best Signal Levels
and overall frequency coverage.
Note - Sometimes the sort of Terminated Horizontal Loop
Antenna Element will provide lower noise levels and better
Radio reception then the simple Vertical Whip Antenna
Element. Usually this type of Terminated Horizontal Loop
Antenna Element is installed in an Attic Area.
iane ~ RHF
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RHF
- Small active loop antennas are pricey but
- are most likely the best in town choice.
-
- To get an idea how this type of antenna will work in your location
you
- could build a passive loop at small cost using just coax cable.
-
- --
- Telamon
- Ventura, California
Telamon - Yes I Agreed - The single-turn Coax Cable {Shielded}
Loop Antenna for basic Shortwave Radio Listening (SWL) is one
of the better choices for ease of construction and utility.
http://www.iri.tudelft.nl/~geurink/images/coupling_loop_schematic.jpg
READ ABOUT - THe Coax Cable {Shielded} Loop Antenna
[GreerTech]
http://groups.google.com/group/rec.radio.shortwave/msg/fa7b1501f08ffebe
http://groups.google.com/group/rec.radio.shortwave/msg/4703fed7472a9e53
http://groups.google.com/group/rec.radio.shortwave/msg/008005ce8c7f5c9c
http://groups.google.com/group/rec.radio.shortwave/msg/37f9f216217d3420
http://groups.google.com/group/rec.radio.shortwave/msg/a76e2b951e35abd9
http://groups.google.com/group/rec.radio.shortwave/msg/7052a8e37790a367
http://groups.google.com/group/rec.radio.shortwave/msg/008005ce8c7f5c9c
http://groups.google.com/group/rec.radio.shortwave/msg/9adc49a6c156fa2b
"Low Noise Receive-Only Coax Cable Loop Antennas for the
160 Meter to 10 Meter Shortwave {High Frequency} Bands"
http://www.greertech.com/hfloop/mymagloop.html
The so called GREER TECH "Coax Loop" Antenna.
The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas
http://groups.google.com/group/rec.radio.shortwave/msg/3ba0aadd03af7bc7
Hula Hoop Loop Antenna and more . . .
http://groups.google.com/group/rec.radio.shortwave/msg/84fc1c535a7e8169
The basic design of the "GreerTech" Coax Cable [Shielded] Loop
Antenna is good and very practical.
GREERTECH => http://www.greertech.com/hfloop/mymagloop.html
LOOP=> http://www.greertech.com/hfloop/mymagloop.html
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1625
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1730
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1539
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/1008
FWIW - 'other' "Shielded-Magnetic" Loop Receiving Antenna
WebPages to Check-Out :
http://www.io.com/~n5fc/loop_ant.html
http://user.netonecom.net/~swordman/Radio/shloopant.htm
http://www.qsl.net/mnqrp/Loop/Mag_Loops.htm
http://beradio.com/news/radio_shieldedloop_am_antenna_2/
http://www.iri.tudelft.nl/~geurink/magnloop.htm
http://www.hard-core-dx.com/nordicdx/antenna/loop/coaxloop.html
ABOUT - Loop Antennas:
http://www.frontiernet.net/~jadale/Loop.htm
- What is a Loop and Why Use It
- Construction Principles
- What Can I Use a Loop For
- Loops Another Look
- Pictures of Home Built PVC loops
- Loop Links
keeping you in the loop when it comes to
shortwave antennas cause . . . iane ~ RHF
.
Shortwave Listener Antennas => http://tinyurl.com/ogvcf
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
SWL Antenna Group => http://tinyurl.com/ogvcf
.
The Shortwave Listener's Blessing :
SWL BLESSING => http://tinyurl.com/s2bjm
May You Never Tire of Listening to the Radio and Always
have Strong Signals and Noise Free Reception ~ RHF {ibid}
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/9233
.
Tous Sont Bienvenus ! - - - Groupe par Radio
d'auditeur d'onde courte pour des Antennes de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Alle Sind Willkommen ! - - - Shortwave Radiozuhörer
Gruppe für SWL Antennen
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Tutti Sono Benvenuti ! - - - Gruppo Radiofonico
dell'ascoltatore di onda corta per le Antenne di SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Todos São Bem-vindos ! - - - Grupo de Rádio
do ouvinte do Shortwave para Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Все Радушны ! - - - Группа оператора
на приеме коротковолнового диапазона
Radio для Aнтенн SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
¡Todos Son Agradables! - - - Grupo de Radio del oyente
de la onda corta para las Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
= = = = = = = = = = Translation = = = = = = = = = =
All are Welcome - - - To Join the Shortwave Listeners
(SWL) Antenna Group on YAHOO !
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
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Jeroen
RHF wrote:
> Alternative - Instead of using the Sony AN-1 Active Antenna's
> Short Vertical Whip Antenna Element : Use a One Metre
> Diameter Horizontal Loop Antenna Element with one-end
> of the Loop connected directly to the Sony's Head Unit and
> the other-end of the Loop connected via a 300, 450, 600 or
> 1K Ohm Resister to the Sony's Head Unit. Try the different
> Resisters to determine which gives the best Signal Levels
> and overall frequency coverage.
This could be an interetsing experiment :) I've already bought
coppertubing and so to make the loop as described on that previous
page, so if that turns to be a failed experiment, I might use it for
this ;)
Just to clarify (I blame my non-native knowledge of English):
So one end of the loop to the element where the whip is normally
attached to, and the other to the unit with the switches? And, do I
connect the loop to the 'inside' connector of the box? Nothing needs to
be connected to the shielding?
I'd love to see a schematic if possible...
RHF
Jeroen,
Where the Whip Antenna Mast screws-on-to the top of
the Mast-Screw of the Sony AN-1 Active Antenna's Head Unit.
1 - Attach one-end of the Loop. (Use a Nut and Washer)
2 - Attach the other-end of the Loop to the Resister.
3 - Attach the free-end of the Resister to the Mast-Screw.
Just a plain simple Wire Horizontal Loop Element.
* You could use Stranded Wire or Litz Wire and Copper Tubing
or even the Outer-Shield of a Coax Cable would be OK too.
* The shape of the Loop could be Round, Square,
Triangle, Diamond, Octagon, etc.
* One Meter Diameter or per Side
* Length of Wire in the Loop about 10-12 Feet.
iane ~ RHF
.
.
. .
Jeroen
RHF wrote:
> Jeroen,
>
> <snip>
Cheers for that, I will give that a try after I trtied building the
magnetic loop!
Jeroen
Jeroen
I'm impressed! I was really wondering how it would work against the
An-1, and sofar it seems to work at least equal as good, and then you
have to add in the benefits of it being directional. Naturally, having
to 'tune in' all the time makes it a bit less practical.
I also got it to start tuning from about 4400KHz (hurray).
I found a cheap ~ 15$ building package for an antenna amplifier
(unfortunally 10-140MHz, not covering my fav. the 60 meter) which might
be a good experiment to further boost the performance of this hobby
project.
If anyone knows of idiotproof schematics (I have about zero knowledge
of building electronics) that would also include the 60 meter band,
that would be awesome.
m II
> If anyone knows of idiotproof schematics (I have about zero knowledge
> of building electronics) that would also include the 60 meter band,
> that would be awesome.
>
There should be something of use here:
god luck in your new project.
mike
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
Who is Kr1sts? How did you build it?
--
Telamon
Ventura, California
Jeroen
> Who is Kr1sts? How did you build it?
http://www.kr1st.com/swlloop.htm
Mostly according to this article. It was really easy to build. Hardest
was to find a proper capacitor wich I eventually found in my
girlfriends alarmclock (lol).
I'm going to skip the amplifier, after some research I learned that
it'll only amplify the whole sound, and adda bit of noise to it as
well, so it won't do me much good.
Instead I'm going to build another loop, geared towards the 60 meter in
specific. It will be a multiple turn loop made of a 1/10 wavelenght
copper tube. More information can be found here:
http://home.datacomm.ch/hb9abx/loop80m-e.htm
I'll start by using the capacitor they advise there, a 10-125pF so 3.9
to 10 MHz will be covered, including my fav. the 60 meters and an
amateurband I regurarly listen to.
I'm really enthousiastic in magn.loops after this first experiment, and
might have a AN-1 for sale in a not too long time from now. I heard (on
this newsgroup) one fetched 200$ a week or so ago on eBay?!? That'll be
great and allows me to build 4 more magnetic loops! ;)
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
The first link is a manually tuned loop and the second is a motorized
version of the same. A tuned loop will be quieter than a broadband loop
design I posted earlier.
The drawback with the tuned loop is you have to tune it along with the
radio complicating the operation of tuning in a station.
Looking at the first link I think the design would work better if there
was more separation between the pickup loop and the tuned loop. I would
attach the pickup loop on the other side of the PVC pipe.
The second suggestion is to use a series 50 ohm resistor from the coax
center conductor to the pickup loop. This may not do much other than
sharpen the peak of the tuning response.
--
Telamon
Ventura, California
Jeroen
Telamon wrote:
> The first link is a manually tuned loop and the second is a motorized
> version of the same. A tuned loop will be quieter than a broadband loop
> design I posted earlier.
I posted the second link as it offers more information about the
circumvence of the loop, and the possibility about making the loop
multiple turns, and how the distance between those tunrs affect the
range the loops works best for. Those are all info not present in the
first.
> The drawback with the tuned loop is you have to tune it along with the
> radio complicating the operation of tuning in a station.
I have it in the livingroom becuase of that, haha. It's indeed a bit
less practical. The overall bandwidth thats tuned into is about 100Khz.
So its doable to browse the 60 meter band for example.
> Looking at the first link I think the design would work better if there
> was more separation between the pickup loop and the tuned loop. I would
> attach the pickup loop on the other side of the PVC pipe.
Hmm that is interesting, and something I want to experiemnt with. In
the testing phase, with simply holding an antenna of a portable close
to the loop, I found that the closer, the better...
> The second suggestion is to use a series 50 ohm resistor from the coax
> center conductor to the pickup loop. This may not do much other than
> sharpen the peak of the tuning response.
>From a SWL in the Netehrlands I've understood that the whole point of
using the coupling loop is to make the input into the antenna 50 ohm.
Why would adding a 50 ohm resistor improve things further?
Thanks for your help, learning so much about antenna's doing all this
building, experiementing and asking around! :)
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
The pickup loop will look like a short on the end of the coax at some
frequencies and the resistor will cause the impedance to be a minimum of
50 ohms.
You don't want the two loops to actually touch each other and mounting
the pickup on the other side of the PVC pipe is an easy way to
accomplish that.
--
Telamon
Ventura, California
Jeroen
Telamon wrote:
> You don't want the two loops to actually touch each other and mounting
> the pickup on the other side of the PVC pipe is an easy way to
> accomplish that.
Yes, but why not allow them to touch eachother? What's the reason for
it?
Just hoping to get a (physics) reason for why they shouldnt be too
close togheter, jst to further udnerstand the nature of the thing
better :) I havent came acros any descriptions that said they shouldnt
be too close, so I'm really curious.
Thanks,
Jeroen
Telamon
"Jeroen" <jer...@peatfreak.com> wrote:
Two things referring to the link <http://www.kr1st.com/swlloop.htm>
1. The tuned loop and pickup loop are supposed to couple magnetically.
The tuned loop is bare copper and it looks like the pickup is made of
bare wire so if they touch they will have a direct circuit connection.
If you use magnet wire for the pickup you are counting on a thin layer
of enamel paint to insulate one from the other, which can easily be
abraded.
2. One parameter controlling Magnetic coupling between the loops is
distance. You already know this and the loop will tune a little sharper
if the pickup loop does not load it as much as when the loops are
physically together.
--
Telamon
Ventura, California
Jeroen
wouldve been a joke ;) ). I'll experiment with the distance here and
see what differences it makes.
I also noted that different setups can affect different type of
stations in different ways again. What can benefit stations hidden in
static (tropical dx) can worse reception of SSB stations that are
strong, and ofcourse, the other way around.
Fun stuff, making your own antenna for sure!