Electronics > RF, Microwave, Ham Radio

Best long-wire antenna for SW radio that is inconspicuous

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edy:
I have a question about what kind of a reliable cheap wire I can use for a backyard long-wire RECEPTION ONLY antenna that is inconspicuous enough that neighbours and my wife don't complain too much about it. I have about 12m or almost 40 ft to work with if I go diagonal, or two 30 ft sections if I make a 90-degree dipole, and would be clipped on to my Tecsun SW radio or plugged into the ext. antenna input (or into my laptop's SDR dongle).

One end of the wire would be going to my upstairs 2nd floor bedroom window and in to my radio, and the other end would be at the diagonal part of my backyard (opposite corner fence post) perhaps 5-6 ft off the ground, and likely pass through the branches of a tree along the way which is in that corner. Distance from bedroom window to fence is roughly 40 ft at ground horizontally, but with the diagonal rise it may add another few feet.

The wire should be thin enough that I can slip it through my window which I would then shut on it, and not too obvious to see, yet strong enough that it won't easily break. In the past I've used telephone wire strands (solid copper insulated) but I feel they are not flexible enough and would tend to snap if I tensioned them, and I can't always see the break because the insulation keeps it together on the outside even though inside conductor may have separated. I've also used braided insulated wire, not sure what gauge but I'm sure it was pretty cheap 30 AWG spools available of 50 ft. I don't need the wire to be tensioned, I expect it to sag anyways a bit.

Do you recommend insulated vs. non-insulated? What gauge would you recommend? I've seen copper, there is also just bare steel wire spools that I've seen (solid, not braided) but I believe they are shorter sections so I'd have to connect several together (how would that affect the antenna reception).

The other question is do I make an "L" like a dipole and send out two wires at right-angles... If I do, I can get about 30 ft on each wire, with 90-degree between them. How do I then connect it up at my radio? Do I just tap the middle of the wire and clip to my external radio antenna, or do I cut it and feed it into the ext antenna jack (which has 2 terminals). Any ideas, suggestions would be helpful. I'll see if I can upload a satellite photo at some point so you can see.

Any advice would be appreciated to get my hobby back up to some level since the house move without upsetting off my family too much.  :-DD

Ian.M:
Get a decent diameter polyester hollow braid and thread insulated extra-flexible wire + Dyneema kite line (for tensile strength) through it using a very long fid, then 'milk' the braid down onto the core and call it a clothesline!

Insulated multistrand CCS wire could also work if it passes the S.O's clothesline 'sniff' test. 

Put the block and tackle to let it down / tension it at the far end so your lead-in can be fixed. 

There are commercially available 'shut in the window' feedtroughs used for satellite systems, but you might do better to use a fairly short length of copper foil sandwiched between two wider pieces of Kapton tape, joined to the end of your exterior lead-in.

edy:
Thanks for the suggestions. I've attached some potential options (single and dipole) that may be feasible but if you have any other ideas, please let me know. These are running "in the air" but I could run it along the house and fence to make it look less obvious, which I assume will degrade performance with all the bends and such.

I've included a 3D and top-down view with relevant measurements and angles.

I wanted a rude username:
"Honey, let's plant a tree."

geggi1:
If you make a square loop you will get a loger antenna.
Make some fiberglass poles like the thin ones used flr electic fences.
Put the poles on top of your fence and also on top of your house on the side facing you back yard.
Put a thin stainless wire on top of the poles and feed the center down to your window.
Call it a bird repellant to prevent the birds flying over your back deck and dropping  ;)
For feed-line you can use two parallel RG59 taped together so that they have the exact same length. The screens on the coaxses have to be connected together a at the ends. The two coaxes are connected to the opposite ends of the loop.
The feed-line will work as a 150 ohm ladder line.

I have this kind of setup at my cabin. The antenna is very god at RX and TX. On RX its very quiet with low noise levels.

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