开云体育

Gents... I have built my first geomantic (ground-coupled) antenna which I am calling the Geomantic Spiral. It's nothing more than 30' of RG58 coax rolled into a tight, flat spiral and placed on the ground under some bricks on my lanai (patio to you Mainland folk). Performance is _very_ good!!! I have posted a more detailed description and preliminary listening results in my new group at... <http://groups.yahoo.com/group/geomanticantenna> Drop in and check it out. Everyone is welcome. 'Bear' NH7SR (Doing happy Snoopy dance)

Hello all, I uploaded some pics of my 18" loop that had sagging wires. It took a while at 46k bps ! Dave

I bought this kit, also available assembled: http://www.aade.com/lcmeter.htm Very nice, from 1nH to 150mH, and .01pF to 1.5uF. Has an internal reference that it calibrates itself from each time you turn it on. Steve

I just ran across a page with some nice illustrations, photos and plans for MW/LW loops. I hadn't seen this one before. The instructions and illustrations are very good... especially if one has not built a loop before. They answer a lot of the "newbie" questions. Here it is... <http://dspace.dial.pipex.com/town/pipexdsl/r/arar93/mds975/Content/ae rials1.html> Have a look-see. 73, 'Bear' NH7SR

Gents, I have added a new URL to the Links page. It points to an article that describes the advantage of mobius connecting a multiturn loop and also describes counterwound balanced ferrite bar antennas. 73, 'Bear' NH7SR

Just paid a visit to the QRPARCI Forum and found a post pointing to a new page with absolutely excellent instructions for building an HF MagLoop. Even tells you how to solder copper tubing... with photos no less!! Check it out at... <http://qrp.ke9v.net/magloop.html> You won't be disappointed. 73, 'Bear' NH7SR

I am thinking about getting some wood , and build a 4 foot loop, cause my broadband loop has got the winding less than 10 turns. Are there any other projects that I should try out to dramatically improve my AM and LW reception? I will take notes. Adam Ebel Thanks.

This page,new to me,caught my attention because in addition to good info on loop & capacitor constuction, he has used a BBQ spit motor for remote tuning. Hmmm,two of them might allow even a novice to mount something light (hula hoop) on the roof to rotate & remotely tune. Probably would confirm your neighbor's suspicions,too. www.qsl.net/mnqrp/Loop/Mag_Loops.htm

These were posted on the earlier loop group so I thought i'd post them on this one. The RF connector is a 75 ohm cable TV chassis mount. It goes to hookup wire that is wound 10 turns around the internal ferrite antenna in the radio. Makes a convenient way to connect loop antennas to the unit. The 14" box loop antenna is BCB. The poly capacitor is slavaged from a failed tranisitor radio. I suspect that it is about 250 pf because if I have enough turns to pick up 440 KHZ, it won't tune all the way up to 1600. That is what the alligator clip is for. There is a tap midway on the coil that allows tuning the other half of the band. The black windings are the loop and the white is the coupling winding. I'll post another of the big SW & MW "rook" wound loop as soon as I get a picture of it.

Hi There Does anyone have any idears how to make at stealthy SW antenna. My problem is that i live in an apartment, and we are not allowed to have any vissible antennas out side the building. So my question is how to make an antenna that is very "invisible". I have a smal balkon but my wife tells me not to use all the space on it ... :-) Another question : Do i have to use an antenna tuner for my radio, (it?s an SAGEAN ATS909), or is it okay just to plug the antenna directly to the radio ? If yes - do you know any where on the internet where i can find a diagram on how to build it my self ?? Kind Regard from Lui

I have a yamaha reciever, that has an am antenna hookup with an "in" and a ground. It came with a small plastic loop antenna, that doesn't quite seem to get the station I want. So i searched am antennas online to find LOTS of info, and some plans, but they all seem to be to big or overly complex for my needs. what I'm looking for is plans for an antenna for a modern reciever with the antenna hookups I desribed. and not too huge, maybe like 2 feet or so in diameter. It seems to me that most of the stuff I have read deals more with the construction of the frame and stuff, and less about the wiring etc. I will have no problem figuring out a sutible frame design and what I was really looking for was a simple description of the correct windings for a said diameter. Also I'm not sure how to hook it up to the reciever, do I need this "coupling winding"? Or in my case do I just hook up the main windings to the antenna hookup on the reciever. Also, there is no variable resistor on the little plastic loop that came with the reciever, does this mean that I don't need one if I build my own? I thank you for any comments/ suggestions that would help me out. I don't think I will be getting into this as a hobby or anything, I was just hoping to make one that would get the station I want, which is 570 AM, which has somwe interesting stuff on it at night, but it would be cool if the loop worked through the whole band decently also as I thought it might be fun to surf the whole spectrum for some cool talk shows. Thanx again in advance, chris

thanx for the reply, while I was waiting for the reply I ended up making one, maybe you could tell me if I'm on the right path. It is 19" X 19" square with 18 turns on it, both begginning and ending on the same leg. I used stranded 20 guage hook up wire from the Rat Shack, wich didn't come in a long enough spool, so I very carefully soldered the two together end to end and shrink wrapped it, for a very nice splice. Then I ran a coupling turn, that is very very slightly smaller diameter than the main windings, like maybe an 1/8th inch smaller or so. I cut small grooves in the leg ends so the wires would be very symerically spaced, and the 18 winds take up 4 1/4"s on the leg ends. I found a used variable resistor at a local electronics shop. I made a gear reduction box for it and attched a knob to the smaller gear, I'm happy with the results, it works very smoothly. The point I'm at right now is I still have to attach the cap to the frame and wire it. Heres what I'm not sure on. I wire one sidfe of the main winding to the fixed plates and the other side of the main winding to the moving plates via the soldering tabs, right? also how do I hook it to the reciever? Do I just hook one side of the single coupling wind to the antenna connection and the other to the ground? Does the coupling wind have to be hooked to the variable cap at all? Does it have to be twisted together? Do I need some sort of a diode atached to the coupling wind in series for the reciever to recognise the signal? I will include a pic of the cap with the gear drive I made and the loop I made so you can see what I'm talking about. Thanx again, chris

http://www.mindspring.com/~loop_antenna/

When I looked at the end of that cable I only saw 6 wires. Upon taking the white covering back I see 4 twisted pairs. White and 4 colors. No shielding. All insulated. Telephone? I am sorry and will try to be more careful in the future. Just to clear up hopefully one last question-- are you saying to take the insulation off of everything and just have bare wire? Or can I leave the insulation on the little wires and take off the outside covering? --- In loopantennas@..., "Bruce Carter" <brucec@m...> wrote: > > > I have a cable that says > > MPP/CMP/PCC FT6 -- -- 4/24. Six copper wires. Would that work? > > > Any > > easy way to get the covering off? > I find that rolling the wires with the knife on a meat > cutting block spares my fingers from any chance of cuts. > > It is interesting that you have this type of cable. I cannot find a data sheet for that particular type of cable, but it is possible > that it is a shielded type - it has a braided conductor around the > copper conductors. IF that is

First let me apologize for wasting everyone's time here but I am so lost. And thanks for being brave enough to read this. I don't know what any of these technical terms everyone writes of mean. Induction is what happens before they put the dog tags on and the rest of the terms you use are otherworldly to me. My homely problem. I was given a radio receiver with 4 clip inputs in the back that say AM loop and FM loop. With nothing attached, nothing was received. I do live in a fringe area. Trying to help myself, I did a little research on the net yesterday (found you'all then ) and so put a splitter on my TV cable, rigged up a pigtail for the stereo, put the wire in one of the FM inputs, and now receive FM stations I could never hear well in the house before. What luck! Until lightning hits the TV antenna maybe? Then for the AM I hooked up, into one of the AM inputs, various lengths of TV/telephone cables, straight and loopy, but nothing. So, reading from yesterday's net research , I skeptically ran a cable (medium red/gray color covering, no writing on it, 4 wires I twisted together) from one radio AM input to one of the two screws on the room light switch cover. Lo and behold, 2 faint stations, and another one that I could hear with static at the same volume level as the broadcast. But it was the station that I wanted to hear. Looks like my year of luck, no? Then, heady with success I ran another pigtail to the screw of a light switch cover that was on a different electrial circuit. That did noticeably help the static so listening for half an hour might be tolerable now. Question: Can I easily improve on this AM a whole whole lot? Is there an AM antenna to buy that is not super expensive? And easy to use? I have an attic opening right above the radio I could throw something large into, if need be. I see cheap little stereo antennas on Ebay for $10-20. Would one of them work? I have looked at antenna diagrams but after seeing parts I never heard of, and with all the 'tuning' and 'ratios' I had a panic attack. I would be ever so grateful for some advice. Sorry that I am so ignorant and confused as I have lived 68 yrs and never heard of a "loop" until 3 days ago.

Good afternoon, My name is Steve, N4TKP located in Bartow, Florida and I am new to the list. I am interested in building and experimenting with small transmitting loops. I have found alot of information so far and the links here helped me find a couple of tutorials on how to build a basic one. I am planning on building the first one next weekend. I have a question though, where can I find the capacitors I need to take my input power (5 watts for the first and then 100 watts later) and what should I try first, air variable or a vacumn variable? Anyway have a great day and I would appreciate any suggestions or hints that anyone could provide. 73 Steve N4TKP

Hi, I got given some poly square plastic stuff and thought hmm I could use this in a loop somehow and this popped into my mind I am thinking 15 inches on the outside with wood and the lengths on the inside holding it together that poly square plastic stuff is 1/2 inch square. So that would make the loop 14.5in square not huge but decent I figure. I was thinking of bringing the coupling loop in about an inch or two from that so the coupling loop would be 13.5in or so to 12.5in not sure which is better. was going to make the "plate" to hold the cap out of lexan and the "plate" for the connections back to the receiver. question is how many turns of wire for the AM BCB I am sure there is a calc for this but I haven't seen it and I wanted to share my design. Also the rest wood be made from wood the longer pieces. Scott KC7WDG Image of Design Is Here > http://jupiter.walagata.com/w/bh420/15BCBLOOPIDEA.gif Any thoughts or suggestions are certainly welcome as this is an idea I haven't started building yet.

Greeting folks. I am currently attempting to build a Loran-C (centered at 100kHz) receiver and am having some difficulty with the antenna. Though I have been frequently informed it is difficult to not pick up this signal, I seem to be quite accomplished at it. My only attempts to pick up the signal consist of hooking the leads of various AM antennas to the 50 ohm input of a spectrum analyzer via a matching network for 100kHz. Any recommendations as to how I should build/purchase an antenna for this frequency and how I should test it? Also, does anyone happen to know what the polarization of the Loran-C signal is? Thanks, Matt

hi all , am parting out a technics st-s1 tuner to build a tunable loop. every thing but the variable cap is available. all switches knobs andface panel are good the tuner was working yesterday. any takers? question regarding the variable cap. there are 3 screws on the top and a trimmer.where should the wires of the loop be connected? thanks in advance johnkelsall

From experience I would connect inner to AM Antenna and outer to ground. Whether the internal loopstick will cause problems I do not know. Orientation of receiver will help here. Is the external loop amplified? Other method is to wind 2 or 3 turns onto internal ferrite aerial and connect external loop or wire antenna to one end and ground wire to the other As with all unknowns-try it and see. If it works then tell others about it If not then research on WEB regards dave G8SZX. loopantennas@... wrote: