Idea, lets have a "dont laugh at us" antenna club. - Page 1
Forum section: electronics / rf-microwave

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 04:31:59 am
content: I think we could have a lot of fun with antennas if we agreed that they weren't meant to last, could be built out of junk, or stuff like foam core and copper tape, or whatever, stuff you find, just to get the ideas out there and have fun. We test them with stuff we have, not pro gear unless somebody owns it.Idea is low barriers to entry, innovation, fun, mc guyverism.. etc.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: September 18, 2017, 06:11:46 am
content: There's a lot of articles on the net if you're into building antennas..especially if your into SDR / Ham radio and receiving signals.Like these: (A lot of it come from rtl-sdr.com)https://www.rtl-sdr.com/tag/antenna/https://www.rtl-sdr.com/simple-noaameteor-weather-satellite-antenna-137-mhz-v-dipole/https://www.rtl-sdr.com/building-an-active-wideband-antenna-for-your-sdr/http://rfelektronik.se/manuals/Datasheets/DIY%20137MHz%20WX-sat%20V-dipole%20antenna.pdfhttps://turbofuture.com/misc/How-to-Build-Your-Own-Planar-Disk-AntennaAnd some other articles that might be useful:http://www.amateurradio.bz/2m-70cm_vertical_dipole_antenna.htmlhttp://rsgb.org/main/get-started-in-amateur-radio/antennas/your-first-antenna-the-half-wave-dipole/https://www.arrl.org/files/file/Technology/tis/info/pdf/9106023.pdfhttp://www.hamuniverse.com/multidipole.htmlhttp://www.w6nbc.com/articles/2013-1QSTwalkingstick.pdfhttps://nz.pinterest.com/pin/120963939967732741/...And some YT videos from K7AGE:https://youtu.be/HkmD3Sgz7Q0]DIY 2 meter antennahttps://youtu.be/4K5Vj6wtpE0]DIY 10 meter antenna

author: bd139
author_rank: Super Contributor
timestamp: September 18, 2017, 07:09:40 am
content: I suffer from antenna apathy. I can't be bothered to build a nice one. I'm using a random length of blue 7/0.2 wire strung from the curtain rail in the front room to the curtain rail in the back room over door tops. It works pretty well on 40/20 and I can pick up stations 1000 miles away. I am not licensed so I can't transmit and I dread to think what it'd do to a PA stage

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 01:59:35 pm
content: With a "unun" that can work quite well, if your wire is not right next to noise sources, etc. With a unun you likely could make it a decent match by adjusting the length a bit.Quote from: bd139 on September 18, 2017, 07:09:40 am

author: bd139
author_rank: Super Contributor
timestamp: September 18, 2017, 02:30:34 pm
content: It's actually quite noisy as it's running past two LED mains lights. I've got a slightly de-q'ed BPF on the front end of the receiver which helps a lot and have a narrow audio filter after the mixer so that helps quite a bit.Need to read up on ununs. Any good sources?

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 03:46:23 pm
content: Sure, would be very happy to.The noise is a problem sounds like.I'm guessing the lights are not in your control? (you could probably filter out the noise if they are)The schematics below are all useful with toroids you might have laying around, and consider that if you use coax and site the balun or unun at the antenna, and perhaps just the coax runs near the LED lights, but the antenna is elsewhere, right then you will likely reduce the noise.. Split beads of ferrite material are great to have in quantity for reducing noise. If you are able to, I would buy a large quantity of them so you can use them liberally wherever they do the most good. I'm not kidding. 50 or even more is not too much. Some materials do much better than others for noise reduction, but those kinds of magnetics also likely are more expensive. although putting a common mode choke around a single antenna wire seems as if it would not help, in some settings indeed it does help when the interference is higher in frequency than the desired signal So its unlikely to help in your situation. OTOH, putting ferrites around the power cords for these lamps might help a lot by limiting the LED lamp noise between it and its "antenna", its power cord.For your unun..or balun,Popular choices for HF are #2, #6 ferrite and #43 iron powder materials.I personally often use iron powder magnetics because they work better at higher frequencies and require fewer turns.In a pich try cheap RFI beads, they often are made of #43 material and work well.just "adjust to taste", less turns for the higher frequencies or more toroid enclosure of the wire as you would get with a real or simulated binocular core. A binocular core is particularly useful because you can get a lot of mutual inductive coupling with a short wire length which translates into broadband operation and I suspect also higher efficiency. Since your#1 problem is noise, (mine is too - really bad so thats a situation Ive dealt with a lot) you might also want to try galvanic isolation using a simple 1:1 transformer through a toroid attached to your coax from your receiver with the secondary your antenna and the best ground you can find, preferably NOT your AC ground. Because if your situation is like mine the noise is on the AC side. (especially when its been dry)I am going to add some small images here (starting with one and adding some from my other computer in a bit) to give you something to go on to get started.They are all what I would describe as keepers. Designs Ive made many times with success.The first image is a 9:1Unun design that I have been using for years.You should notice an immediate reduction in noise if you can just get the wire out into the clear a bit. I'm currently using #43 material in my current one. Like you I only use it for receiving so its wound on a 50 size core, very small.#43 material probably is not the best for the very lowest frequencies but it works (I dont care since I now have a "Pa0rdt mini whip" active e-field probe for them, made by a ham in the Ukraine- he sells them on ebay.. which works quite well considering my noisy QTH) the fact that I'm using #43 means this approximately 15 meter long piece of copper wire running out to a tree in my backyard - a fairly short, low antenna, for HF, honestly, with the highest point off the ground maybe four meters off the ground, if that.. that antenna also seems to work fairly well for some VHF-FM reception from NYC FM stations (its quiet, which is what I need for music) I also use a homemade biconical antenna (using two plastic rings from a knitting hoop as the means of separating the wires at each end so its biconical) which is coupled to the coax by means of a small 4:1 balun right at the feedpoint. (usually its vertical and hangs from an almost invisible anchor and hook in he ceiling when its being used in vertical mode) It uses a #61 core and only two turns on each side (thats what is commonly used in 75:300 ohm baluns for broadcast TV use) to cut down the noise on the feedline which is absolutely necessary.The biconical was "cut" for use above around 136 MHz but I also use it for FM reception a lot of the time (when my oher antenna isnt working well) and there again a balun/unun makes a huge difference. the reason I've found baluns and ununs to be essential is because all of my receivers are SDRs, and so the same computer (desktop) and its monitor are always there producing noise.Ive tried everything to reduce the noise and whats worked the best is extensive use of ferrite common mode chokes on every wire exiting the computer or having anything to do with the SDRs _except_ their common grounds, including coax entering them, and unun/balun at either the antenna (like on the biconical) or where the antenna wire comes into the house (long wire with unun currently).For SWL I also use a real ham antenna tuner now (an MFJ with a huge rotary inductor) which I restored that acts to add some selectivity to the input of the SDR which helps a lot. Before I did that I used a high pass filter with the cutoff around 2 MHz. (AM BCB signals are really strong here)Even if you don't have any of what you consider to be suitable magnetic materials to make one, if you think about it people almost always do. if you have two matching clip on ferrite beads you can use them as you would a binocular core and that works really well. (needs many fewer turns as well) Four identical beads works even better than two.That seems to work extremely well, and is efficient enough for anybody it seems. How efficient?If you have a signal generator you can measure it. You can make two identical baluns or ununs and connect them back to back to one another with a scope and termination at the end to assess how much loss there is in one.Underneath there is a PDF on baluns which has two balun designs in it.You'll notice that you can add a DPDT switch to the design to make a switchableBalun that can be both 1:1 and 1:4. That is extremely useful for antenna experimenters. Google Elecraft switchable balun to see how its constructed in a real world unit. Its easy to make one in just a few minutes. Use a slide DPDT switch as they use fairly simple construction so likely have less loss. Then you will find you will always find one or he other to be better and it varies. So the 1:4 switching works. The Elecraft balun is meant for field day or QRP operation. You can make a similar switchable Unun - with switchable imedance transformations.I'll add the schematic for that in a few minutes, have to switch to my main computer.http://vk6ysf.com/unun_9-1_image02.png(also attached at the bottom for posterity)The reason why this gives you such an improvement over just having a piece of wire is he decoupling/transformer effect more than simply the impedance transformation.With a balun you get something similar, but you are using a two element antenna that makes an effort to have both sides somewhat equivalent and working against one another.It also will smooth out the response of an antenna substantially.The number of turns should vary depending on the material you are using and the frequency desired and the length of one leg of the winding should be substantially less than a quarter wavelength

author: bd139
author_rank: Super Contributor
timestamp: September 18, 2017, 04:21:47 pm
content: Thanks for the extensive reply. Much appreciated. I'm actually going to sit and read it in detail later when the kids are in bed as it'll take a few minutes to read and process effectively as well as do some background reading. I can build a superhet with one eye shut but antennas are still mystical to me. I have an ARRL handbook and W1FB antenna notebook sitting here so will use them as reference as I read your post.I have a ton of 43, 6 and 2 material toroids around (37/50 size) that I won in an eBay lot so there's bits lying around which is good.I'm not actually using a ground at the moment as I found it made no difference to the noise at all or signal strength. The rig is entirely floating and battery powered. I tested with the earth on my bench supply initially and then tried knocking a 2 foot long anchor peg into the back lawn and that made no difference. I am a complete antenna idiot at the moment.Incidentally here's a picture of the current antenna when it is put away(many thanks again!)

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 05:15:44 pm
content: just by itself a unun would do wonders with your wire there IF you can add some semblance of a ground for it to use as its opposite half.. Without a ground it has nothing to work 'against'That right there is likely the reason why the performance has been noisy.You said in one of your posts that you tried a ground but that it didn't help. that doesn't sound right to me. thats very unusual. Try using another length of wire as a counterpoise.Here is a fancy counterpoise that can be rigged up.. maybe you can try something called anartificial ground. Ive never done it, but maybe you could try that?Here are some possibilities. maybe you thought that whatever was a ground - wasn't, for example, a water connection that was made with plastic - not metal pipe. Somewhere between the main pipe and your apartment? If so, maybe you can make your connection to the real cold water pipe.Laptops work better for receiving than desktops, because they produce less noise. So, you have a potentially great setup because you have freed yourself from the AC power by using your laptop with its battery. Its just missing that little tiny bit.Below at the bottom there is a crappy picture of an ugly little quick and dirty unun you can make right now, it sounds like.The antenna is the red alligator clip. The ground is the green alligator clip.Wire it like the first drawing I uploaded.Lets say you have hydronic heating. And a cast iron radiator. Use that as your ground. You should be able to get your wire out away from other things too.here is a hypothetical apartment situation. Multiunit building, shared back area used for garbage dumpster, parking and maybe there is one tree back there. If you ask neighbors if they would mind if you ran a shortwave antenna to the tree in your shared back yard, they likely wont mind. make it very thin and dark colored and put an insulator on the far end to make it look like a well made shortwave antennashouldlook like. Also, make it clearly visible that its temporary and removable somehow. (without making it look like its saying "steal me", hopefully your apartment buildings back yard is not frequented by thieves. If it is, losing some small thing might be good if it serves as a warning to you to be more security conscious there.)Unless you live in one of those cities where landlords want even model tenants to move in and out every few years (a really horrible way to live) to keep rents high, and going higher, you shouldn't have a problem.Look up "end fed antenna" for suggestions as to what lengths would be best for whatever space you have. If you plan on getting your ham license and transmitting, you should pick a length that others have had good luck with. there are extensive discussions of this issue on the net.

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 06:23:58 pm
content: If you could take a photo of the lights, maybe the noise might be addressable in some way.Quote from: bd139 onTodayat 08:30:34

author: bd139
author_rank: Super Contributor
timestamp: September 18, 2017, 09:52:57 pm
content: Thanks again for all the info. Have read through it and roughly understand it now. Really appreciate the effort you have put in to replyingI've checked the LED lamps and it's not them that are causing the noise. They are decent quality Philips master ones for a start and I tried them when they were all off. I actually went as far as killing the main breaker to the house. Still noise. I believe this is ambient noise. Unfortunately for me I actually live under the approach path for Heathrow airport so there's a possibility that there's interference from ILS etc. My two analogue scopes can resolve noise just with a looped probe which isn't something that happened when I lived somewhere far far away from the airport a number of years ago. I think this is just something I'm going to have to live with.As for the unun, I've cobbled together enough bits to build one based on your notes. I will approach this at the weekend. Unfortunately lacking in time this week due to a number of appointments.I've looked at earthing options and I've got a 4 foot long metal stake in the shed which I may be able to utilise. I'm on the ground floor (another problem!) so I can drive that into the ground outside and see where I get to with that. I can at least compare that to pipework based ground. The old lady who lives upstairs doesn't seem bothered if I run a long wire to the end of the garden over hers as well when I asked her this evening.. I had a plan B which was to run one very high up from the trees at each end of the property. I'm on the end of the block so I can sneak a thin wire if it's high enough up and no one would even noticeJust as a note I'm not using an SDR or laptop as a receiver (yet). I've built a direct conversion receiver for 40m and am working on a 20/40m dual band superhet transceiver (transmitting into a load only) after a long discussion about "how cheap can you go" with forum member CJay. I'll get my advanced license before I put it on air. In the process of organising foundation first.Thanks again for your help.

author: cdev
author_rank: Super Contributor
timestamp: September 18, 2017, 10:54:58 pm
content: Another option is a "magnetic loop" if you have a variable capacitor lying around. And in the interests of sorting out your reception problem I would suggest that you simply create a "loop" out of a piece of wire that encloses some space which meets at the variable capacitor to make a tuned circuit, and then tap the signal off of that. It turns out that that is a very good antenna for the frequency it resonates on and rejects other frequencies both above and below that frequency. That may tell you something about your noise situation?An approximately meter sized loop, like a big hula hoop size, with around a hundred or hundred and fifty PF capacitance setting is a good starting point. That may well resonate somewhere between 7 and 14 MHz. To go lower than 7 MHz you may need more capacitance and/or a larger loop.Its effectively averygoodpre-selector.I've often thought, "if only I could get this "Q" in a box"... It really helps some receivers.To pick up the signal that the loop is gathering you need a much smaller loop in he same plane the loop is in, connected to the input on your receiver.Adjusting the capacitor up and down you should hear a marked sort of peak in the sound and your s-meter if you have one should rise, when your loop resonates on the frequency you're tuned to.The ideal kind of capacitor to have for this is one of those old AM radio multi-ganged variable capacitors. You go down in frequency wih more capacitance and less capacitance resonates higher. You also can use more wire or multiple turns of the loop to go lower.With many variable capacitors you may need to figure out a way to turn the capacitor without becoming part of the circuit (and detuning it when you remove your hand) A wooden or plastic stick perhaps?Anyway, if you're having problems, its always a morale booster to have it work well, suddenly. Shows you that its possible!Good luck and I hope one of these works!

author: denverpilot
author_rank: Regular Contributor
timestamp: September 19, 2017, 09:33:37 am
content: On the topic of the original post -- a friend once made something like a 40 element Yagi for 144 MHz out of coat hangers and monofilament fishing line to hang between two trees.It tuned up nearly perfectly and in the direction the trees were pointed he wa able to do one FM simplex contact with the thing to someone over 150 miles away with 250 mW.The theoretical gain numbers on the thing were really impressive. And... it worked.He really built it to hang with the elements horizontally polarized for weak signal SSB stuff, but when someone offered to try to converse with him on FM, he took them up on their offer. And it was pretty neat to watch.Could be even more fun to do that at UHF. It was a big pain when the wind came up at VHF, size-wise.

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: September 19, 2017, 10:48:06 am
content: Three suggestions which have worked well for me.1. A demonstration of a 432 MHz 'bobtail' made from some old coathanger wire and wood. Not that well known on UHF but it gives a little gain over a dipole.2. Vertical antenna for 7 - 50 MHz pedestrian mobile. Just 5m of wire held up on a fishing pole held in a backpack. Centre loading coil switched in for 7 MHz. Intended for use while walking in ankle to knee deep salt water the aluminium contact ring provides much improved performance. Used with antenna coupler plugged into transceiver.3. Even cheaper could be the antenna you have when you don't have an antenna. Carry a portable HF transceiver, a wide-range antenna coupler and some clips.Then walk around your neighbourhood looking for metal things to clip on to, load up and (with any luck) get contacts.I'm lucky with miles of beach and some associated structures nearby but those with local flagpoles, fences or gates might find these work also.

author: Bud
author_rank: Super Contributor
timestamp: September 20, 2017, 01:36:19 am
content: Nothing can beat CB crowd stuff.

author: Bud
author_rank: Super Contributor
timestamp: September 20, 2017, 01:38:34 am
content: I am not sure why I am posting this one, does not seem to be anything wrong with the antenna per se

author: cdev
author_rank: Super Contributor
timestamp: September 20, 2017, 01:47:20 am
content: He/she probably likes to drive up to popular mountaintop view-catching areas and catch VHF DX contacts.Quote from: Bud onTodayat 19:38:34

author: cdev
author_rank: Super Contributor
timestamp: September 20, 2017, 01:56:06 am
content: Diana Eng, KC2UHB made a very nice small dualband Yagi which looks ideal for working satellites that rolled up wouldn't look out of place almost anywhere.

author: xrunner
author_rank: Super Contributor
timestamp: September 20, 2017, 02:06:21 am
content: Well it's not off the wall, but it' all home made. It's my HF fan dipole for 10, 12, 15 (3rd harmonic of 40), 17, and 40 meters. Works great!

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: September 20, 2017, 09:17:21 am
content: Some antenna are nothing more than bits of wire with the supports providing all the excitement.Such is the case with kite antennas when it's blustery, the kite isn't very good or you're a beginner at it. For exampleThe unexpected can happen in a public place, when unleashed dogs take exception to your antenna creationOr, without warning, pop-up sprinklersThen there are the times when your signal goes from super-strong to inaudibleOr your mast, pulled by a kite, keels over

author: cdev
author_rank: Super Contributor
timestamp: September 20, 2017, 12:32:02 pm
content: One of hose very long telescoping fiberglass poles would sure be handy for beach DX!Every once in a while I think about getting one for here. (unfortunately nowhere near a nice beach like yours VK3YE) Still, it would be good for experimentation in my approximately 20 x 30 meter small backyard.. (with guying of course), and various antennas, both VHF/UHF and long wire, the advantage being quick setup and take down, but I don't know a good brand/maker, are there any standouts for value? Budget might be $100-150 or so, durability would be key. I don't have any plans to leave it up for extended periods, just for an afternoon here or there. If I had a bit more height (probably a fiberglass pole wouldn't be enough but I can always dream) I could possibly reach the entire NY/NJ/CN tristate area in my fresnel zone. Somebody (commercial operators?) have set up a very tall antenna not far from me (1/2 mile) and appear to be doing exactly that. But they are in a much better location. Closer to the edge of the mountain. I'm on a small hill in a valley back quite a ways from its cliff drop-off. The rich people on that ridge and the one further west both have spectacular views.

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: September 20, 2017, 01:06:38 pm
content: Quote from: cdev on September 20, 2017, 12:32:02 pmMy yard is approx 20 x 4m. In the middle of it is a Spiderbeam 12m pole. It's very robust and I have dipole centre at the 11m level. It is however quite heavy to put up and down so you'd leave it up. I also recommend using clamps with rubber.Whereas a 9m pole is much lighter and better to go up and down more easily. It can't support as heavy an antenna though. More on all this athttp://home.alphalink.com.au/~parkerp/projects/projmast.htm

author: denverpilot
author_rank: Regular Contributor
timestamp: September 27, 2017, 07:35:55 am
content: Quote from: Bud on September 20, 2017, 01:38:34 amDefinitely a VHF contester. I have photos of two of my vehicles decked out similar to that for ARRL June VHF which I haven’t had time to participate in for years now.Dad got smarter when he was doing it and just bought a used Air Force van with a 40’ pneumatic mast. 1984 Ford, got about 8 MPG. But it was a lot easier to use than my lash ups! I donated it to a ham club in New Mexico a while back.Here’s us playing in June of 2011.

author: bd139
author_rank: Super Contributor
timestamp: September 27, 2017, 08:15:02 am
content: That's the sort of antenna my wife would kill me if I had.Quick reply to cdev. Thanks again for the help. Haven't had a chance to do anything with this yet as my back garden was flooded after the neighbour spent months flushing cooking fat down the sink. It has flooded my garden with rice, nappies/diapers (wtf) and various other nasty things from the drain cover in it. It's being washed down at their cost tomorrow!Have ordered some toroids to experiment with baluns and ununs however. Have also increased selectivity at the audio end of things in my RX which has helped internal noise. I've also found an earth fault in my electrical installation while poking around trying to find a ground which is a good thing.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: September 27, 2017, 08:33:46 am
content: Quote from: denverpilot on September 27, 2017, 07:35:55 amWhoa!...what's the gain of those beasties?

author: denverpilot
author_rank: Regular Contributor
timestamp: September 27, 2017, 08:39:10 am
content: Quote from: bjcuizon on September 27, 2017, 08:33:46 amHmmm not sure. A lot.Those were dad's and I think the 6m is an old Cushcraft design, and the other bands were M2 ("M-squared") designs.The M2 antennas are just amazing.That weekend in 2011 we made over 700 contacts on 6m, 2m, and 70cm, mostly SSB with a little CW thrown in for the really weak ones.He passed away in 2013 and the 2011 trip was the last time we contested together. It's a good memory.

author: CJay
author_rank: Super Contributor
timestamp: September 27, 2017, 10:28:01 am
content: After a couple of months planning and neogtiating, my 'shack' goes up tomorrow at the end of a 22 metre long garden.Once it's all wired up and I have finished the thermal insulation there will be a fishing pole supported longwire running back to the furthest point of the house I can find, I'm hoping to be able to suspend roughly 22 metres of wire at approximately 7-8 metres above ground, that'll be the only 'sizeable' antenna I will be able to use (though I reckon I can get away with a 2M/70CM vertical as well) so stand by for pictures of woeful antenna fun.

author: cdev
author_rank: Super Contributor
timestamp: September 27, 2017, 10:43:41 pm
content: Thats just great! I hope it works out for you- 7 or 8 meters high is pretty good..So you will be able to raise your antenna up easily with a telescoping pole..that will be a good way to go..

author: apelly
author_rank: Unknown
timestamp: September 27, 2017, 11:48:24 pm
content: Not to de-rail the topic, but...I am in a temporary house with a small garden and no trees (maybe 3Mx10M, but whatever I decide on will likely have to be in a corner.). I've been putting off setting up a semi-decent antenna.What would you guys recommend for a temporary, easily erected/dismantled HF antenna?I could also do with something functional for VHF/UHF.The main issue I can't get my head around is how to get some height without spending $$$ on something temporary.

author: cdev
author_rank: Super Contributor
timestamp: September 28, 2017, 12:02:52 am
content: Its not the height so much as theangle of radiation.. on HF..A magnetic loop is your only real choice but the cool thing is the performance as far as angle of radiation can end up being quite good even without any real height, (especially if you have some kind of counterpoise right below it which also doesnt have to be super large..also it doesn't have to be heavy to get good performance, just "thick" because of skin effect. So its perfectly fine to get say an octagon made with plastic pipe or even a pool float and wrap it with a spiral of *wide* copper tape - the most important thing is the width of the conductor, and low resistance in the transition to your receiver or transceiver. You can use a coupling loop or a gamma match or some kind of transformer.. Seehttps://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htmfor the definitive document on coupling methods.If you can get a good electrical connection it should tune right up with a reasonable value variable cap and give you good performance. The spiral is to give you the effect of a longer loop in a smaller space.This is kind of what I mean..http://www.hlmagneticloopantennas.com/I've built lots of magnetic loops and they often work extremely well for receiving.

author: apelly
author_rank: Unknown
timestamp: September 28, 2017, 02:04:48 am
content: Quote from: cdev on September 28, 2017, 12:02:52 amThanks for the resources. Also found this:http://adam.curry.com/enc/20150119092647_article-antenna-mag-loop-2.pdfThat's my weekend cut out for me...

author: cdev
author_rank: Super Contributor
timestamp: September 28, 2017, 02:22:35 am
content: When I said "its your only real choice" I was basically saying the first thing that came into my head. There may be other better choices, just to the best of my knowledge this isI thinkthe best thing you could do in that space. Your point about height is a good one.. If you could go straight up and could put out some radials some distance beyond that space and tune it with a tuner at its base or use a unun there you might do better with a vertical.. perhaps.The difference is that antenna would be very visible and this one might not even be noticed, plus you could bring it indoors when you weren't using it.

author: apelly
author_rank: Unknown
timestamp: September 28, 2017, 04:34:19 am
content: Quote from: cdev on September 28, 2017, 02:22:35 amGave me a good clue to be going on with though!Alas, it won't be this weekend. It's going to take a while to get hold of a decent cap.

author: tautech
author_rank: Super Contributor
timestamp: September 28, 2017, 07:14:55 am
content: This thread reminds me when I was setting up a telemetry link for RF control of a mains powered pump some 500 m away when I asked aknowingbuddy about antenna design.He recited this story of his Yagi design and extremely careful antenna construction for UHF TV reception. The best of materials were selected to ensure no dissimilar metals in common contact, stainless fasteners, custom made insulators and all Yagi design parameters met...so he thought.Reception was pitiful for the trouble taken, in fact rat shit were his words.They settled for a spoked bicycle wheel on a pole !

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 28, 2017, 07:19:43 am
content: I got one of my first contacts using ahttps://en.wikipedia.org/wiki/G5RV_antennastrung in the garden... voice from UK to Oz. The other guy had a better antenna.