Longwire antenna question

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svenmarbles

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So I am pretty limited on space, and lack the ability to place antennas outdoors. The extent of what I'm able to do is limited to the confines of an indoor spare room. That being said, I've been using a 40 foot piece of speaker wire indoors, strung up sort of haphazardly.

My question is, what would the ideal configuration of this wire be? Does it need to be outstretched as much as possible end to end? What it it were wound? Could I coil it round a couple of posts (nails in the wall) about 5 or 6 feet apart? Could I wrap it around the perimeter of the walls at ceiling height? Would it be better to wrap it vertically along one wall from floor to ceiling? What is the best thing to do? I also have somewhat of an access to the attic (only about 2 feet high). I've heard this is a good place to place an antenna. Should I pop open the attic door, string a weight to one end of the wire and toss it across as far as I can?

Also,.. This 40ft wire was split down the middle, so I have 2 sets of this wire. Might it be a good idea to braid them together and make it an 80 foot length?
 

w2xq

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The configuration probably won't make much of a difference, depending upon the type of radio and the building construction. For example, too long of a wire may overload a portable radio's front end. A steel-framed building impedes reception. Without knowing the rest of the story, I recommend experimenting.

There are similar threads here in RR. Use search atop the page and explore. HTH a bit.
 

svenmarbles

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I've got a Sony ICF-2010, and although it's a portable the front end is very good and doesn't overload easily.

So I got impatient after typing this message and did something that might have been sort of silly, but I'll let you guys tell me what you think.. So I did combine both pieces of wire into an 80ft length.. With some creative household engineering I was able to run most of the length outside through a small gap in the window jam/frame (leaving enough inside to get to the desk traced around the door jam). After that I went over to the balcony and lowered some twine to the ground. I then went downstairs and tied the twine to the end of the wire. Went back upstairs and hoised the twine carrying the other end of the wire. So now having the wire run out of the window and having it located onto my balcony. I then got an apple and drilled a hole through it, fed the end of the wire through and tied it to secure it. Then I took the whole thing like a grappling hook and flung it over the roof. End result is I now have about 70 feet of wire draped over the top of the roof. Eventually the apple will bio-degrade and I'll probably have to repeat this so I realize it's not permanent. Speaker wire is cheap :p
 

ridgescan

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Ah yes-a shortwave nut after my own heart-cannot wait to hear what results you get when nightfall hits there and propagation is favorable.
Love the apple thing LOL
 

SCPD

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Try using a tennis ball instead of an apple. I've done this several times, up over the roof, up in a tree, and the neighbors don't have a clue as to what your doing.
 

SCPD

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So I am pretty limited on space, and lack the ability to place antennas outdoors. The extent of what I'm able to do is limited to the confines of an indoor spare room. That being said, I've been using a 40 foot piece of speaker wire indoors, strung up sort of haphazardly.
Okay just for clarification this is called a random wire. A longwire antenna is a specific type and configuration and as the name implies, it's very long -- (a few hundred meters.)

My question is, what would the ideal configuration of this wire be? Does it need to be outstretched as much as possible end to end? What it it were wound? Could I coil it round a couple of posts (nails in the wall) about 5 or 6 feet apart? Could I wrap it around the perimeter of the walls at ceiling height? Would it be better to wrap it vertically along one wall from floor to ceiling?
Yes, bad idea, bad idea, good idea, and no effect -- in that order.

I also have somewhat of an access to the attic (only about 2 feet high). I've heard this is a good place to place an antenna. Should I pop open the attic door, string a weight to one end of the wire and toss it across as far as I can?Also,.. This 40ft wire was split down the middle, so I have 2 sets of this wire. Might it be a good idea to braid them together and make it an 80 foot length?
Yes and yes -- length is good. Just pray that it doesn't get caught up on anything.

What is the best thing to do?
No way to know, as you haven't given us enough information.

First off, what radio are you using? How are you connecting the wire to the radio?

Are you in a rural area? What are you trying to listen to specifically?

For a cheap alternative, watch this video: http://www.youtube.com/watch?v=LGMRgmHCEzM
 
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svenmarbles

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Okay just for clarification this is called a random wire. A longwire antenna is a specific type and configuration and as the name implies, it's very long -- (a few hundred meters.)



Yes, bad idea, bad idea, good idea, and no effect -- in that order.



Yes and yes -- length is good. Just pray that it doesn't get caught up on anything.



No way to know, as you haven't given us enough information.

First off, what radio are you using? How are you connecting the wire to the radio?

Are you in a rural area? What are you trying to listen to specifically?

For a cheap alternative, watch this video: Grundig S350DL W/Slinky Antenna - YouTube
Alright here's all of the details.

I'm in a south suburban area of Chicago. Urban but not super urban. It's a Sony ICF-2010. I've got the wire attached to the whip. I'm trying to listen to everything. Broadcast, numbers, Russian buzzer, Hams, pirate.
 

SCPD

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Okay so don't spend a whole lot of money on this... but your best bet is to just use your 80ft speaker wire up in the attic. As close to the roof as possible and away from any outdoor lights, etc. Obviously, steer clear of any electrical wiring.

For the connection to your radio, you don't want to clip it to the whip. If you look at the side of your radio, there are two 1/8" jacks for connecting external antennas. The one that says AM is the jack you want.

You can go to R/S and pick up a package of 1/8" mono connectors seen here:

1/8 Mono Phone Plug (2-Pack) : Phone Plugs | RadioShack.com

Just solder the speaker wire to the center conductor of the connector. If you don't have access to a soldering iron then you can probably just crimp the wire against the connector. Before you do the final connection, I would unscrew the connector cover and put the bare connector in the radio. Experiment with how you're going to attach the wire to the center pin. You should immediately hear a jump in noise level when the wire touches the center pin.

Obviously, start with the time signals -- WWV on 5/10/15/20/25 Mhz. This will give you a good indication of signal strength for the given conditions and time of day.

Keep the antenna wire away from any source of EMI such as speakers, TVs, lights, etc.
 

svenmarbles

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Okay so don't spend a whole lot of money on this... but your best bet is to just use your 80ft speaker wire up in the attic. As close to the roof as possible and away from any outdoor lights, etc. Obviously, steer clear of any electrical wiring.

For the connection to your radio, you don't want to clip it to the whip. If you look at the side of your radio, there are two 1/8" jacks for connecting external antennas. The one that says AM is the jack you want.

You can go to R/S and pick up a package of 1/8" mono connectors seen here:

1/8 Mono Phone Plug (2-Pack) : Phone Plugs | RadioShack.com

Just solder the speaker wire to the center conductor of the connector. If you don't have access to a soldering iron then you can probably just crimp the wire against the connector. Before you do the final connection, I would unscrew the connector cover and put the bare connector in the radio. Experiment with how you're going to attach the wire to the center pin. You should immediately hear a jump in noise level when the wire touches the center pin.

Obviously, start with the time signals -- WWV on 5/10/15/20/25 Mhz. This will give you a good indication of signal strength for the given conditions and time of day.

Keep the antenna wire away from any source of EMI such as speakers, TVs, lights, etc.

I followed your advice and I'm glad I did. Performance has increased 10x. I bought the 1/8th inch mono plugs and attached my 80ft random wire (strung over the top of the roof). I can now get WWV strong on 5 10 15 20 and 25 simultaneously. That has never been achievable before. Also when I roll through the 20 meter ham band on the wide filter, I can hear just about a hundred hams chattering away. Then I set it to USB and dial one in, I can pull them in loud and clear like a com receiver.

I'm home with a power outage after some severe storms rolled through last night, so I'm going to put it through it's paces tonight after dark and literally no RF noise since my entire neighborhood is blacked out :p
 

SCPD

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I followed your advice and I'm glad I did. Performance has increased 10x. I bought the 1/8th inch mono plugs and attached my 80ft random wire (strung over the top of the roof). I can now get WWV strong on 5 10 15 20 and 25 simultaneously. That has never been achievable before. Also when I roll through the 20 meter ham band on the wide filter, I can hear just about a hundred hams chattering away. Then I set it to USB and dial one in, I can pull them in loud and clear like a com receiver.
Great! Yeah I think what probably helped you the most was getting the wire on top of the roof. Being outside can make a pretty drastic difference. The side input is the best way to connect a wire as it's matched for that purposed. Clipping it to the antenna helps but the radio expects only a short whip and not the longer wire so the matching gets messed up.

I'm home with a power outage after some severe storms rolled through last night, so I'm going to put it through it's paces tonight after dark and literally no RF noise since my entire neighborhood is blacked out :p
These are the best times... maximize your listening during the outage. You can probably tune down to your lowest frequencies and hear perfectly clear. I've had this happen during the winter and it's a lot of fun.
 

SCPD

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Also don't forget about the CB frequencies. They can be rather interesting to listen to at times! :D
 
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