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 Post subject: Antennas for AM DX and SWL
PostPosted: Feb Thu 24, 2011 10:56 pm 
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Location: Lillooet Canada
I use 2 radios daily. My main receiver is the Eton E1 and then I also have a Panasonic RF-4800.

Living in an urban environment and with lots of electronics in the house, I have a severe interference problem that varies from day to day, it seems to depend on what my neighbors are doing as well.

I was going to treat myself to a magnetic loop antenna next month, when I turn 65. The antenna I am considering is the Shielded Active Broadband Magnetic "Moebius Loop" , model: RF PRO-1A made by Pixel Technologies,

My previous research had pointed me to a Welbrook, but recently I have seen excellent reviews on this Pixel loop.

Anyone have any experience with either antenna?


Frank


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PostPosted: Feb Fri 25, 2011 12:26 am 
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Location: Freeport, LI, New York 11520
Tough question....

What may work for me may not work for you. After doing all the research you can do when you have a choice, you may want to try both types.

That's the fun part, albeit the more expensive way, of antenna farming even if it's the indoor variety.

Then, you could build you own as well.

Good luck on the project and keep us posted.

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 Post subject:
PostPosted: Feb Fri 25, 2011 3:32 am 
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Location: Southern NH, 03076
The first thing to do is ID and tame all the noise sources in your house. Be prepared to spend some money on ferrite toroids and aluminum foil.

I question many of those "commercial" indoor antennas. Its so easy to scam an unknowing person with a fancy ad loaded with hi tech words and a fancy price. Hey for all that money it has to work....right.

Carl


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 Post subject:
PostPosted: Mar Tue 08, 2011 11:13 pm 
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Location: Dallas Tx.
Make sure you have a good solid uncorroded mains ground and rod.
Then invest in a eight dollar Radio Shack outlet tester. Check all outlets. One with a missing or poor ground can overload the whole house wiring with noise.


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 Post subject:
PostPosted: Mar Wed 09, 2011 3:02 am 
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Location: Palmerston North, New Zealand
I'm with Burnt Fingers on this one. If the noise is coming from within your house, then throwing dollars at a fancy antenna ain't going to do diddley.

Fid the source of the noises, then throw as much wire as you can out the window and attach a good earth to the radio. Even skinny transformer wire will do if you want it to be invisible.

Cost to performance ratio compared to a Wellbrook, Pixel or any fancy-shmancy? Infinite!:)

The US CB band is booming in here, and all I have is 60feet of wire! (Not that I want to listen to those blabbermouths, but the reception is interesting. Listened to T88ME this morning who is up in Palau - I couldn't make out the Japanese guy he was talking to though!)

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 Post subject:
PostPosted: Mar Wed 09, 2011 6:02 pm 
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I appreciate all the replies, good information, but my question still remains, does anyone have any experience with high end magnetic loop antennas?

A lot of of my interference comes from my neighbors and I have no control over it. Not 100% sure what they are doing but I have my suspicions that it involves indoor hydroponic gardening.

frank


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 Post subject:
PostPosted: Mar Thu 10, 2011 6:37 pm 
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Location: Southern NH, 03076
Ah, hydroponic gardening especially with high intensity lighting is a popular Vancouver pastime :lol:

A loop will only be able to reject interference from its null direction as it is ineffective in other directions. Its better than a random wire but dont expect miracles.....those only occur after you sample some of the neighbors product:wink:

Carl


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 Post subject:
PostPosted: Mar Thu 10, 2011 7:50 pm 
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Location: Freeport, LI, New York 11520
And remember....

The antenna will have to be as high as it can get.... :wink:

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 Post subject:
PostPosted: Mar Thu 10, 2011 9:14 pm 
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I am on a 7200 square foot corner city lot with "side yard" setbacks of only 5 feet. So my shack is on the second floor on the neighbors side, his walls only 10 feet from mine. So you can see the problem, anything from plasma tv's, routers, dimmers, high intensity lights used for "recreational gardening" and associated amateur poor wiring practices, to fluorescent lights and all kinds of wall warts that can be used anytime of day, just 10 feet away from my radios. I have been using a "snake in the grass" with limited success as I can't get away from the interference. I guess its the price we pay for living in a tolerant society. :D

I know a magnetic loop is not a cure-all, but it has to be better than what I currently have by a wide margin. My CCrane Twin Coil Ferrite antenna does a great job on AM, but I really want to improve my SW reception.

Frank


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 Post subject:
PostPosted: Mar Fri 11, 2011 7:44 am 
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Understood, but even so, wire outside is going to pick up more signal than any amount of loops inside where the interference is.

Have you got a roof or a roof space under ceramic tiles? There's a good spot for your antenna.

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 Post subject:
PostPosted: Mar Sat 12, 2011 4:45 pm 
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Location: Bel Air, Maryland
As testimony to the fact that almost any outdoor AM antenna beats almost any indoor AM antenna, listen to any AM station on your car radio sometimes and compare the reception to an indoor AM radio. The outdoor antenna-based AM car radio will always beat the indoor AM radio in reception.


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 Post subject:
PostPosted: Mar Sun 13, 2011 12:25 am 
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Location: Southern NH, 03076
Thats not a very good comparison. A good car radio has higher sensitivity to start with. Its benefit....with the engine off....is possibly being far enough away from house noise sources.

Take the cheap home radio outside and compare and unless you are in a steel cave the cheap home radio will still be inferior.

Carl


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 Post subject:
PostPosted: Apr Fri 01, 2011 8:33 pm 
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Location: Lillooet Canada
I ordered the Pixel Technologies Magnetic Loop RF PRO 1A today.

I will let you know how it works out for me. Initially I will try it indoors, but I intend to install it outdoors on a rotor as soon as we move in 3 months or so. That will give me a good comparison between indoor/outdoor use. The advantage of a magnetic loop of course, is that it only amplifies the magnetic wave portion of the radio signal. Should cut down a lot on my indoor interference problems I have currently.

Frank


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 Post subject:
PostPosted: Apr Sun 03, 2011 6:14 pm 
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Location: West Salem, OH
I solved my interference problems by locating my outdoor antenna as far away from my house and neighbor's house as I could. It is a random wire up as high as I could get it. I used a homebrew 9:1 balun (actually unun) and a ground rod at the antenna as well as one at the house. I fed the whole mess with RG-6 CATV coax which is very low loss and has great shielding. Yes I know it is 75 ohm but the minor mis-match for a receiver is minimal. Signal levels are somewhat down from just a regular antenna but the s/n ratio is much higher. It all but eliminated my noise problems here and I did have noise levels from an S5 up to an S20 prior to this!

Bill


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 Post subject:
PostPosted: Apr Sun 03, 2011 9:13 pm 
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Bill said:
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It is a random wire up as high as I could get it. I used a homebrew 9:1 balun (actually unun) and a ground rod at the antenna as well as one at the house.


I don't remember you sneaking round to my house and copying my antenna......... :D :D

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