Restricted space and a good HF antenna

[cj5]

I don't know if this is in the right forum, but I am going bonkers with trying to find a decent HF receiving antenna. I realize that the bigger the antenna, the lower you can go in frequency, but I am bound by my landlord's exterior rules, and don't have many options when it comes to setting up large dipoles or outdoor wire antennas. I did try constructing a homemade loop, but failed miserably, partly because I don't know how to tune it, and build it corrrectly.
Does anyone have any recommendations as to what to use? I don't need to transmit, listening only. I am not looking to spend a ton of money either, and by the looks of things, some of these HF antennas can get pretty pricey. Right now I am looking into dropping a wire out my window, but is that all I need? A wire! What else do I need? Any help would be greatly appreciated.

 

[IdleMonitor]

Try the wire out the window. You won't know unless you try.

Don't be surprised at the results but they can be better. But if that works, that's all you'll need.

 

[DaveIN]

You could also try the Degen/Kaito DE31 Active Shortwave loop antenna. I've had some good success with it.

http://www.radiointel.com/review-degende31.htm
http://radios4you.com/antenna-kaito-ka31.html (cheaper on ebay).
http://www.kaitousa.com/KA31.htm

 

[IXNAY]

Restricted

You can try #28 ga enameled wire strung from your window, the other end tossed up into a tree. It is real hard to see, and inexpensive. Also no big deal to put up again if it breaks.
I would use a small antenna tuner, like those made by MFJ, and a ground connection to the tuner. You can buy those used if money is a problem.
Try to make the length around 60ft if possible, but anything over about 15 ft will work.
Great height is not necessary for this antenna to work. You will hear most everything, but
a high, DX antenna will hear abit more. Don't sweat it.

 

[cj5]

You can try #28 ga enameled wire strung from your window, the other end tossed up into a tree.

Yeah, the whole up in the tree bit is not gonna happen. My landlord is a property nazi. She said "if I can see it, or touch it, it's coming down". AS of now I have two speaker stand tripods about 8' high, one holding a discone scanner antenna (works like a charm), and the other using an HF active gain antenna (the LF Engineering LF-900, Grove Ent. sells it), which is worthless in my situation, because there is too much noise all over. I got slick and t-boned the HF antenna out the upstairs window on the tripod, and just pull it in when I'm not listening. But I am not getting the reception I expect. Maybe someone out there knows how to tweak the LF-900 to get better reception.

 

[CapeCodRichie]

Shortwave antennas that are different

Shortwave is cool because you spend a fair amount on the radio but the antenna can be anything. No harm in trying. Due to giant icicles wasting my longwire last winter I attached the wire from the balun directly to my aluminum gutters. Works swell. Also you might try a metal handrail if you have one. Radio waves aren't real fussy. Give it a whirl, use your imagination..................have fun....................

 

[ka3jjz]

We have several topics on the Antennas Wiki that might interest you. There's a section on Coax loops (since you did try them, this might enlighten you a little as to why the one you built didn't work well), AC6V's antennas links, Hard Core DX's antennas page (look at the 'loops', 'hidden' links - and there's one or two others I can't remember right at the moment). The Carpet Loop is a real possibility....
It would be most helpful if we all knew what receiver you were using, and a bit more about your apartment; are you on a top floor? Do you have access to an attic or crawlspace? Are you surrounded by aluminum siding (so many are, these days)? What is the construction - if you know how to tell - of your roof? Is your shack close to an outside window or an outer wall?
It sounds like you don't mind getting a little solder flux under your fingers - Good! If memory serves, there's a homebrew antennas link on AC6V's site; as long as the formula is posted, lengths can be recalculated.
There's even a couple of Yahoo groups devoted to the subject. Joining them will give you access to even more links and places to check out.
It's not always necessary to spend a lot of money on antennas; invest your time in research - it will be time well spent 73s Mike

 

[cj5]

Yes, I'm on top floor. No access, and no crawlspace (basically I am the attic). My roof is old corrugated tin. My shack could be close to a window or outer wall. I don't mind soldering at all, in fact I would like more projects that would involve it. I would really like to learn how to build a really good antenna, but I'm not really knowledgable enough to do so. I researched a lot of the plans/schematics online, but I feel like I'm missing something (in other words, experience builders leave the common sense stuff out, that stuff which us newbs need). But I will spend more time looking around, and have some more patience. Oh, and by the way I am trying to receive on an Icom R-75

 

[ka3jjz]

Be sure to look up the links on the Antennas wiki; they will help you out. Specifically what 'common sense stuff' are you missing? And on what schematic or what antenna? I've been building antennas for condos and apartments for 20 years, and have heard my share of DX....73s Mike
P.S. Be sure to check out those Yahoo groups at the bottom of the Wiki page...their list of links is even better than the ones I have on the Wiki page...

 

[racin06]

I don't know if this is in the right forum, but I am going bonkers with trying to find a decent HF receiving antenna. I realize that the bigger the antenna, the lower you can go in frequency, but I am bound by my landlord's exterior rules, and don't have many options when it comes to setting up large dipoles or outdoor wire antennas. I did try constructing a homemade loop, but failed miserably, partly because I don't know how to tune it, and build it corrrectly.
Does anyone have any recommendations as to what to use? I don't need to transmit, listening only. I am not looking to spend a ton of money either, and by the looks of things, some of these HF antennas can get pretty pricey. Right now I am looking into dropping a wire out my window, but is that all I need? A wire! What else do I need? Any help would be greatly appreciated.

I have very stringent outside antenna restrictions in my subdivision. However, that didn't stop me from building a good indoor antenna. I just built my second coax loop antenna. This baby is 5 ft. x 5 ft. and is square in shape (20 ft. of RG-58 coax cable on the loop taped to 1 in. PVC and a 7 ft. feeder to my antenna tuner. My Icom R-75 loves this antenna! I get very good performance from 1.8 - 21 mhz. I usually place the loop on the floor and behind the drapes, in front of two large windows. I built the antenna based upon the instructions at the following weg site: http://www.greertech.com/hfloop/mymagloop.html

I would highly recommend building one of these coax loop antennas. Total materials cost me about $25.00 and about one hour of my time...that's it. Good luck

 

[cj5]

Well, the common sense stuff is what I need to know, that's what's often left out of instructions. I would like to see some well laid out plans, and step-by-step instructions, as one would see in any good building book, or even a cook book. I would like to build something like this http://www.schmarder.com/radios/misc-stuff/loops.htm, but I guess I just don't know where to begin. I looked through 1/4 of these http://members.fortunecity.com/xe1bef/loop.htm, and just got way too overwhelmed. Thanks very much for the pointers, they are well appreciated. The saga continues...

P.S. Are loops good for single-sideband receiving?

 

[ka3jjz]

Be more specific - again, what 'common sense stuff' are you missing?? This is much too broad a statement to be able to answer accurately.

Those links you have there look very interesting. I'll probably put them on the Wiki (or you can, if you're familiar with HTML coding, you can use Wiki's markup language....). If you have more of these, feel free to add them - that's what the Wiki is for.

Re 'loops and single sideband receiving' - you're mixing apples and oranges. The 2 have no relationship to one another; the recovery of SSB audio has to do with the receiver, not the antenna.

73s Mike

 

[cj5]

OK, sorry about the specifics. When I get done perusing the plans I saw in the aforementioned links, I'll let you know what "common sense" questions I may have. Am I familiar with HTML? LOL, yes I am a web programmer . Sure, I'll put them in. They are some great links, and very comprehensive. So, being that the Icon R-75 has the LSB and USB modes, then I have the ability to listen to SSB effectively with a loop antenna, as well as with a standard whip?

 

[kb2vxa]

Hi CJ,

"My roof is old corrugated tin."

Does that give you any ideas?

"My landlord is a property nazi. She said "if I can see it, or touch it, it's coming down"."

Do you suppose she'll rip the roof off the house?

We hams love antenna tuners so much we say "you can load up the bed springs with one" and have done it. Now get cracking, you'll have what amounts to a Marconi T antenna, one of the oldest designs and was used by early AM broadcast stations. Don't look now, I have a picture of Edwin Armstrong dancing on the one used by WJZ.

 

[ka3jjz]

That's a real good idea, Warren - if he can get to it easily. The tricky part will be bonding a good piece of copper (or using a nut, bolt and star washer arrangement) to the tin without having the 2 different metals eventually form a dielectric over time. If memory serves me, there is a treatment you can buy for this...

Anyhow, I'd suggest that, since we're talking about antennas, that we jump over to the antennas forum. I'll bet there's lots of ideas floating around there...but the above idea certainly merits a look.

73s Mike

 

[cj5]

HAHAHA, oh boy, would my landlord love you guys (sense the sarcasm?). Wow you two just blew me away. And what makes what you mentioned so ingenius is that I have a skylight with direct access to the roof, and my receiver is on my desk right below. KB2VXA, thanks. Now what are the steps I need to take to getting the receiver connected to the roof? Will I have to spot weld the copper to the tin? I sure hope not. AS an alternative, what type of conductive adhesive could i use? The roof is so old that she would never notice a small strip of copper. Is tin a good enough conductor for an antenna. This is great I'm so psyched about this.

 

[ka3jjz]

I'd temper that enthusiasm a bit. The roof may well be able to be loaded as a receive antenna using a tuner, but it's going to pick up every snap, crackle, pop, TV oscillator and anything else that is able to cause noise on HF. While it's likely that it will get you started, you should continue to consider other alternatives, such as those I've already mentioned.

73s Mike

 

[BANDIT]

Attach a wire to that tin roof. You would be supprised at what it can do.

 

[kb2vxa]

Hi Again,

"Now what are the steps I need to take to getting the receiver connected to the roof?"

The steps yoy're looking for are on the ladder.

"Will I have to spot weld the copper to the tin?"

Solder will do, use a gas torch with a soldering tip or really heavy duty electric soldering iron (Hexicon) like I do for soldering sheet metal. NEVER use a slodering gun, the tip cools quickly and sticks to the work, what you need is an iron with a massive heat sink which acts as a resivoir.

"Is tin a good enough conductor for an antenna."

Every metal is a conductor. (;->) We're not concerned how conductive it is, we're not feeding amps through it.

"... but it's going to pick up every snap, crackle, pop, TV oscillator and anything else that is able to cause noise on HF."

Remember the "property Nazi"? The guy can't put up a proper antenna and the metal roof is as good as any wire strung around indoors. Some noise must be tolerated, you guys should be counting your blessings and be glad you don't have to put up with 13.8KV HV feeders a block away in a salt spray environment like I do.

"This is great I'm so psyched about this."

Take it from the antenna pscycho (me) and all the strange yet workable antennas I have used, my motto is "whatever works". OK, now that I have lit a fire under you, JUMP! BTW, during WW2 the GIs used to drive a spike into a tree a few feet off the ground and use it as an antenna. "...oh boy, would my landlord love you guys..." Uh huh.

Tech note:
Electrically, the tree antenna is a gamma fed groundplane.

 

[ka3jjz]

Once again, this really belongs on the Antennas forum....but....
Warren - while I agree that some noise must be tolerated, there are steps you can take to reduce it that don't cost an arm and a leg. There are a few designs on sites that I've mentioned earlier (that evidently no one has read) that show some promise in cutting the noise down. You can't escape it, but there's no reason you need to help it along, either.
I could easily be wrong, but over time, won't a dielectric form at the joint between the copper and tin due to oxidation between the 2 dissimilar metals? There is a compound you can use to inhibit this, but I'll be doggoned if I can remember it....73s Mike