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Antenna Question
#antennas
#v3
I was offered a complete V3 from a kind ham. I have a dilemma now that I have a rig.
I have a half wave dipole and I live in an apartment. My landlord said I could hang it outside and run coax in to our apartment, however I live in a bad place where copper wire is going to get gone. Seeing as I will only be putting out 10 watts I was thinking about just hanging it inside as I wont be pummeling us with radiation constantly. However it doesn't seem that? we have many long enough straight line distances to string the dipole up.? My question is this, what will happen if it bends at all? I am going to try and make it straight across from one room to the other with minimal deflection but again, I am in a small space and I dont want my nice dipole stolen. Chris KF4FTR |
Too bad you live in a place where wire will be stolen.?
The big issue I has when I used my deck railing to support a stealth antenna was all the noise from the electronics in my house. A Gell cell battery charger and the power supply for my cable modem were the worse sources of loud nose that overpower all by the strongest received signals. I got rid of the Gell cell charging arrangement and was able to fold an aluminum "mini muffin" pan around the cable modem power supply. Then I experiment with the best ground location. That turned out to be the ground at the connect where the CATV cable attached to the modem.? So an antenna in your apartment may compromise your receiving ability.? I was able to just use lengths of speaker wire. Fairly thin, maybe 22 or 24 gauge, with the two wires connected in parallel for each length of the antenna. Would it be possible to run an antenna with thin wire that would look like it wasn't worth the time and effort to steal be a possibility? Of course, calling attending to something that may be in your apartment could be another issue. In my case I just wanted the antenna to be somewhat stealth, so no complaints from neighbors about imaginary TV signal issues, and the low cost of the speaker wire was nice, also. But I didn't have to worry about the antenna being stolen.? I'm sure there will be many suggestions on antenna solutions, here. Tom, wb6b |
Depends how aggressive you want to be. Organize a high voltage to the dipole (both legs unless balun-isolated), switchable instead of the rig while not in use. A few kV should do enough damage to deter any unwary adventurous thief. Even ordinary mains gives a nasty shock if thief should be barefoot, particularly ZL's 220V. :)?
... and some bending can be tolerated - but will detune the dipole. If you compensate with a Tuner, be aware that it will only make the rig happy - it will NOT restore efficiency. 73 de ZL2DEX |
Andy_501
¿ªÔÆÌåÓýIf you have a balcony you might be able to get away with using
HAMstick radiators (ie a different one for each band). I used to
use a modified CB mag mount antenna on 15 M back when solar prop
was a bit better and was able to work many missionary stations in
South America from Canada with that. The metal guard rail on
balcony served as ground plane. It was one of those 3 section CB
antennas with a base section radiator, then a carbon
composite/center loading device, then top radiator. I removed top
radiator and replaced it with a full replacement uncut 60" VHF
stainless whip. AA-30 showed resonant mid 15 M band so worked well
for me. I suspect one could change the feedpoing radiator mount to
a threaded one that would accept the hamsticks so one could have
access to more bands as well. Over time I have collected the
complete set from 80 thru to 10 M as well as a cut down CB
fiberglas whip to work on 6 M. I use them for HF mobile don't see
why it would not work on a mag mount on a balcony rail also.
Probably have to stick to 40, 30, 20, 17, 15, 12 &10 M because
ground plane restricted by rail length I used a manual MFJ ant
tuner also with them.? They arent super expensive either and one
could likelyhave good success with just a 40/30/20 & 10 to
begin with as 40 would likely serve for 15M as it is 3rd multiple
of 40 M freqs. I think MFJ sells the sets and elements now. On 2020-03-11 12:47 a.m., Christopher
Miller wrote:
I was offered a complete V3 from a kind ham. I have a dilemma now that I have a rig. |
Use a steel wire rather than copper.?
a half wave end fed? would be 64-65 feet for 7mhz and higher frequencies. 33 feet if you want 14mhz and above.?if you are up high enough you might let it drape down. Need a 49:1 unun to connect it to coax.? If you can put one end on the roof and one hang down you can run a vertical dipole.? The amount of radiation that the uBITX puts out would not be enough to harm although there is enough voltage you wouldn't want to touch the antenna while transmitting. There is about 60v of rf on the wire as measured by my old oscilloscope.I imagine that the receive quality inside would be severely diminished due to noise.? -- 73 Dave |
Mark - N7EKU
Hi,
Just use very thin wire for outside.? That will probably deter theft.? I've even used a single strand from an old ethernet cable (there are 8 strands inside).? You can solder pieces together if it is too short.? Or you can buy some 26 or 28 AWG magnet wire which is hard to see and low priced for the length.? Also, you can get copper coated steel wire.? Maybe it won't get stolen if you put a tag in it indicating it is not copper wire but just steel with a copper coating? Best of luck, Mark |
Chris
many options exist for low cost, homemade antennas.? yes cheap thin wire as others suggest.? an effective small antenna takes some effort so be patient, especially in this time of solar flux.? a company makes an antenna called buddi-pole: homemade versions of this antenna are encouraged check the web for plans.? note a ubitx can be taken to a park - so perhaps acquire a medium sized gel cell battery and a portable antenna.? do find other hams who live nearby with similar passion for portable/low power operating.? an end-fed half wave antenna can be homemade - it just requires a toroid and a fixed capacitor (recipes on the web).? here in US a little enterprise called QRPGuys has portable antenna stuff.? enjoy the ride and be patient learning - welcome to world-wide ubitx community.? Curt wb8yyy |
Chris,
I also would recommend a half wave end fed. The QRP Guys is the perfect comb for your uBitx, all you need is some cheap wire. I have found cheap rolls of speaker wire at the local thrift shops for cheap, you can also take it portable also as was mentioned. I use this same antenna for all my portable outings, but at home use a home made dipole up about 20 feet. Joel N6ALT |
Unfortunately I would have to bribe the maintenance guy to climb up and then drill a hole in the wall, which is possible. But the coax being tacked up will draw attention. You guys don¡¯t have to apologize but we live in a building that for some reason brings drug addicts around and I don¡¯t believe it¡¯s going to be worth it.? I am on the 3rd floor so I have that.? I¡¯ll see what I can do to keep it straight. Chris? |
Jack, W8TEE
One of my club members has a similar situation and he strung a 20M dipole down a hallway and held it in place with thumbtacks. He admits it's not the best setup, but the only one he can manage and he does regularly make contacts. Perhaps the end-fed mentioned earlier would be a way to go. Jack, W8TEE
On Wednesday, March 11, 2020, 11:42:38 AM EDT, Christopher Miller <djmalak2k6@...> wrote:
Unfortunately I would have to bribe the maintenance guy to climb up and then drill a hole in the wall, which is possible. But the coax being tacked up will draw attention. You guys don¡¯t have to apologize but we live in a building that for some reason brings drug addicts around and I don¡¯t believe it¡¯s going to be worth it.? I am on the 3rd floor so I have that.? I¡¯ll see what I can do to keep it straight. Chris?
-- Jack, W8TEE |
Keeping the wire straight is not? all that important. You would think it would be critical but you will be able to work stations with one end of a dipole laying on the ground, not suggesting it but like most have done it.?
Personally I would keep the wire out of reach of anyone touching it.? There are a lot of alternatives. Hang it from your balcony door frame and run each side of a dipole out each side of your balcony. Should be able to get 32' feet and the ends be off the ground. Learn to make your own antennas You will be surprised at how easy it is to build an effective radiating element.? -- 73 Dave |
Chris,
All is not lost if you can run an antenna inside unless you live in a faraday cage. Stow the half wave dipole until your living situation changes to a more opportunistic location or use it for portable outings. Assumption is your apartment is on ground floor since don't indicate otherwise. Tacking a wire at the top of a wall and the edge of the ceiling or across the ceiling would be good. With a long drill you may be able to drill a small hole through the headers above doorways to continue your run of wire without having to bend it down through the doorway and up to the ceiling on the opposite side of the doorway.You may be able to build a balanced dipole for the higher bands, e.g. 10m, 12m, and 15m. It depends where your station is placed regarding your antenna feed. The close it is to the end of an endfed the better. Be sure to use an unun balun and ATU for endfed antennas. 18 awg to 22 awg has worked well for my ranch, single floor duplex. Not my primary antenna but I had to try it. It does work. Not optimally but surprisingly at times. If you have access to the attic or a crawl space you may gain another foot or two of height. Of course, if your apartment is located in a multi-floor building the higher your apartment above ground the better. Another option is building a magnetic loop. It can be mounted on a short pole or camera tripod inside your apartment, preferably near an open window. You need to know how the walls of your apartment are constructed. My apartment walls have solid foam insulation with aluminum foil on both faces. No RF will penetrate the walls. Therefore my antenna needed to be at the top of the wall or higher. Whatever your selection is may work some of the time. It will never be ideal. Sometimes you will be surprised from the contact if it is a DX QSO. You may only be able to work NVIS contacts but you will be able to work. Until you change your living condition you may have to take your equipment mobile/portable for ideal antenna deployment. Best 72, KB8AMZ, Terry |
Mark - N7EKU
Hi Chris,
Of course you can run it inside and zigzaging is no big deal.? Just try to keep the angles less than 90 degrees. But, listening would be a lot more pleasant with the antenna outside; farther away from all the electronic noise makers inside the apartment.? An option would be an endfed antenna.? It could start at a window or balcony and the end could just be tossed over a tree.? MyAntennas makes some good ones, or you can check out AA5TB's website and make your own.? With the antenna starting on the 3rd floor and the end up in a tree somewere, there would be little chance I think for theives to get at it. 73, Mark |
Maybe a tuner with included an artificial ground. At HF I think you could use the cheapest green steel wire for gardening. Il 11/mar/2020 21:10, "Mark - N7EKU" <n7eku@...> ha scritto: Hi Chris, |
?You can use small gauge electric fence wire. Sold at feed stores such as "Tractor Supply". ?While not as good as copper, aluminum or copperweld, it can work well enough. I forget the price but if comes in very long spools. ?I know a ham that loaded a former electric fence for an antenna. ?Hamsticks are an option, but there is another make, Lake, I think, that HRO sold. ?I have a set of 5 that I bought from them, with a set of bayonet mounts, one stud and 5 that thread onto the whip base. 80, 40, 20, 15 and 10 ?The 10 can be adjusted for 12. ?I also have a 6 meter Hamstick, and I bought a magnet mount that has 4 large magnets. Tricky to get onto the roof of a vehicle, a bit trickier to remove. I need to get it off the roof of the house and clean up the magnets. I used it on two different vehicles, and put it on the metal roof on the house with the 6 meter antenna. ?Note, for 6, you can adjust a 5 foot CB whip for 6. Great if you want to work 6 mobile, as a 1/4 wave whip would be about 56 inches. ?BTW, I worked a couple of Mexican hams on 6, that were around the West Coast of Mexico. ?Plus several eastern states. ?I am around 30 miles from Ft Stockton TX, and had some nice openings on 6. ?When I first got the mobile whip set, I set one up on 20, I think it was, at night up in WA, and worked Sweden, Russia and Finland that night. ?In another place, I set up a 75 meter dipole, with ends going around trees so the ends were pointing at each other. Small lot in a mobile home park. Did what I could to be on the air. ?Improvise as you can. ?Use small cheap wire for dipole.? ?Don't need much with QRP rigs. ?They also sell a small tuner kit for an end fed QRP antenna. I have the kit, but have yet to build it. ?I plan a 40 meter dipole, with, maybe, 20 meter legs. Can use some stranded copper I have, if I don't need to use it to repair my 160/75 dipole. ?One end of the 160 was fastened with poly rope that broke, and a helpful person pulled the wire out of the insulator up on a high pole. Trying to figure out how to get that part down, to redo it. ?Main thing is, figure out what you can do, and DO it. ?Wayne WA2YNE ?73 On Wed, Mar 11, 2020, 4:04 PM iz oos <and2oosiz2@...> wrote:
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Ok, so the sky¡¯s opened and a choir of angles sang.? My apartment manager and the head maintenance guy came over to view the splendor of the UBITx. They both were impressed that I got wwv at 10 MHz. They wanted to know what it meant.... I simply said it means the radio is calibrated and working. They looked disappointed but then the magic happened. They want to install a long wire or dipole on my roof. I told them I wasn¡¯t going 40 feet up but my maintenance guy who has cb experience wants to do it.? So I now have a bitx with a 20 meter dipole at 40 feet. This should be fun. KF4FTR |
That's great! Long life to CBers and SWL! Il 13/mar/2020 20:32, "Christopher Miller" <djmalak2k6@...> ha scritto:
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