Cobwebb antenna calculator software

Cobwebb multiband folded dipole resource detail the. Now head over to calculate and type in the freq box 7. As such, the source of the name of the antenna has been found. My version is made up of a homebrew center hub and 5 fishing poles. Experiments with a homemade cobwebb type antenna loughton. The main category is cobwebb antenna projects that is about cobwebb antenna projects. I was astonished that a cobweb isnt as bad as i thought it was, certainly in software modelling. The antenna is resonant on the bands it has been designed for, and to my delight i also find that it is resonant on 6m. The fibreglass poles have arrived for the cobweb antenna, these i suspect are fibreglass fishing poles but ideal for what i want and more to the point once i had removed the plastic ends with copious amounts of boiling water fit the metal sleeves perfectly. Mfj1838, 1500w, 406m, super heavy duty cobweb antenna. Slim jim j pole antenna calculator radios, hf radio, ham radio antenna. Transmitter power gets converted to rf, not to heating the ground, coax, or matching network components.

My design is based on the wellknown cobwebb antenna using standard speaker cable, however only one gamma matched dipole will be constructed for 11 m band use. G3tpw cobwebb antenna for 14, 18, 21, 24 and 28 mhz bands. You should consider a multiband vertical on that 7th floor roof, if roof is large enough to lay out several quarterwave radials. The list will grow with your help so lets start and share the knowledge. Here are my notes which should hopefully help anybody else heading down the same path. Its a great dx antenna in a very small footprint package which covers 5 bands from 1020m without any need to use an antenna tuner. The antenna complimented my lowband horizontal dipole nicely and gave me the most useful hf bands 2010m without needing an atu.

The most important design point about the cobwebb is that it is a completely horizontally. The cobweb antenna meets the requirement nicely it comprises 5 parallel dipoles bent into a square shape and mounted on a support structure made of fibreglass poles. Oct 22, 2012 last summer i built myself a cobwebb antenna and was fairly pleased with the results. After a few more weeks of not getting on the air i managed to man handle the portable hexbeam up to about 4 above ground level note. Antenna calculator for hf antennas ham radio secrets. Design and adjustement is easy, as with the capacitor you can tune the resonance by some mhz with no effort.

Antenna, ve3sqb ham radio antenna design software programs. All antenna lengths in the information below are in feet and are the results based on the standard formula of 468 fmhz total length in feet. Baofeng uv5r programming with chirp software or keypad. The cobwebb is 5 separate full size dipole antennas, each bent into a square. Here is my setup for connecting to the mfj 259b analyzer that i have. About 5 band cobwebb antenna the resource is currently listed in in a single category. The design is the same as the low power cobweb antenna only. Stations received at s34 were up to s9 on the cobwebb. This link is listed in our web site directory since thursday apr 12 2007, and till today cobwebb multiband folded dipole has been followed for a total of 7942 times. Reading a lot of enthusiastic stories on the cobwebb antenna originally by stephen webb, hence the webb and considering its dimensions i thought it would make a good compromise for my situation. About cobwebb multiband folded dipole the resource is currently listed in in 2 categories.

Software modelling your vertical antenna ground radials with. By using relays, a single feed line could be switched to 1 of 3 elements or to all for an omni position. The design is the same as the low power cobweb antenna only using other materials to handle the load. Computer modelling of this arrangement shows that one result of bending the dipoles is that the antenna is close to being. Winter is rolling in here to western nebraska now, and to my surprise, i was finally able to hear north and south dakota qsoing during the a. Cobweb antena is the best omnidirectional antenna for 6m, 10m, 12m, 15m, 17m, and 20m hf bands. Dx engineering 80 meter self supporting heavy duty vertical antennas, model dxe7580fsva2, are high performance vertical antennas specifically designed for the 7580 meter band. Anyone i hear on 804020171512and 10 meters ssb so far, i can qso with, and also compliments me on my signal and audio.

This antenna has superstrong large diameter fibergalss and heavyduty 14 gauge stranded hard copper wire. As an added bonus, the antenna is also resonant on 6m each dipole leg is made from twin cable and fed with 50ohm coax. This link is listed in our web site directory since thursday feb 28 2008, and till today the cobwebb antenna has been followed for a total of 4589 times. This link is listed in our web site directory since thursday feb 28 2008, and till today cobwebb revealed has been followed for a total of 12765 times. The antenna shown in the photo at the beginning of this thread is installed on a simple pole at 32 but if you look at the photo shown below, i have also used it a heights as low as 15. Another good choice might be the cobweb antenna, which is small, horizontal, omnidirectional, without nulls. This is a nosolder product and ready for mounting onto your cobweb metalwork and spreaders. It is made by srw commuications ltd steve webb, astrid house, swinton, malton, n. Where i was getting up to s6 of noise from the wire antenna, the cobweb was showing me a paltry s23.

Cobwebb antenna projects category is a curation of web resources on, towertalk. Here is a handy chart for determing 14 wave verticals, 12 wave dipoles, and full wave loop lengths. Dec 29, 2012 regular contacts are made using this antenna with places like japan, australia, alaska, hawaii,south america, russia, italy and many, many more places using this particular design. Its multiband, omnidirectional and doesnt need to be located on a mahoosivetall mast to get decent performance. The other antenna was made by antenna specialist who are still in business and may still produce the super scanner. G3tpw cobwebb antenna for the 14, 18, 21, 24 and 28 mhz bands the main advantages of the cobwebb over other 5 band 14 to 28 mhz antennas are that it is small, lightweight, strong made from fibre glass, only requires a single support, needs no rotator, gives full size dipole performance on all 5 hf bands. The result is a much neater looking antenna on top of my push up mast. Cobweb ham radio antenna 6 feet off the ground youtube. Their length is 7ft which provides the correct length for arranging the twin speaker. A noticeable improvement over the 4020 meter trap dipole. This clip illustrates my progress from start to finish building a homebrew single wire cobweb antenna for the five amateur bands. As the whole idea is to reduce weight on this new antenna i have to come up with better solutions than home brew breadboards etc. A cobwebb homebrew build by dave 2e0ddhm0mbd loughton. My cobweb singlewire antenna build by tony breathnach ei5em.

G3tpw cobwebb antenna for the 14, 18, 21, 24 and 28 mhz bands. Yet even though the antenna takes up little physical space, the actual antenna elements on this design, are still actually full sized antenna elements anyways. Here is a simple antenna calculator for two popular forms of ham radio hf wire antennas. Feeding the antenna can be done at the director or at the reflector. If your main interest is dx, the 80 meter doublet is not a good dx antenna. G3tpw cobwebb antenna for the 14, 18, 21, 24 and 28 mhz bands the main advantages of the cobwebb over other 5 band 14 to 28 mhz antennas are that it is small, lightweight, strong made from fibre glass, only requires a single support, needs no rotator. Our software, consultancy and ongoing support make business processes easier and more enjoyable. The antenna was the brainchild of the articles author, c.

This antenna beams into three quadrants without the use of a rotator. Checking with antenna analyzer reveals resonance on 1020m bands, as well as 6m, 4m, 2m and 70 cms bands, as well as other nonamateur bands. If you have no particular preference within a given ham radio band, then simply enter its center frequency i. What i realised quite quickly was that the cobwebb was much quieter than the wire and exhibited much better signal reception. Describe your experience with the mcr666 7 band cobweb antenna from 4 to 20 meters and tell us why you give it the rating you did required. Mfj hf cobweb wire dipole antennas mfj1835 free shipping.

The cobwebb is a five band 14 to 28mhz compact array of dipoles, bent into a square, almost omnidirectional and with unity gain. Com 0200 utc wed our program is also simulcast on famous. So i had an email from jake asking why hes not getting out too well on 20m. Aug 10, 2016 cobwebb plan click for a larger image. Over the past 15 or 20 years i have heard many good reports from users of the g3tpw cobwebb antenna. G3tpw cobwebb antenna for the 14, 18, 21, 24 and 28 mhz bands all the other small multiband commercial antennas that are available are less than.

The cobweb is a multiband hf aerial 20 through 10m of compact size and is almost omnidirectional. Aug 08, 2016 dx engineering 80 meter self supporting heavy duty vertical antennas, model dxe7580fsva2, are high performance vertical antennas specifically designed for the 7580 meter band. Cobwebb discussion, 4band cola antenna 20171510m, cobweb antenna construction details. However, the name cobweb came from his wife who said that the antenna looked like a cobweb. Sep 07, 2016 i built a cobwebb 5band antenna for hf. As this is the g3txq variant, i refer to mine from now on as a cobweb. Housed it in a grey pvc junction box and mounted a silverplated so239 on one end for the lmr400 feedline. This antenna is built with pvc pipe as the spreaders, simple lampcord wire. The weather here is still miserable, there is snow on the ground and it is very cold, so getting outside to play antennas is a bit of a no no at the.

Hf dipole antenna this antenna software will help you design a simple wire dipole. The actual field test, cobwebb antenna with the ft450 hf radio work well in blindspot, in addition to cobwebb antenna does not require the land to build a complex network system, set up. Apr 24, 2015 the 5 bander cobweb antenna is a high quality designed antenna with products from europe. It has had 100% accuracy in the past 6 years since implementation. G3txq hexbeam, gm3vlb delta, g3tpw cobwebb, moxon, vk2abq etc. Marcus jenkins is a freelance software engineer specialising in lbs, navigation, mapping and mobile.

The addon kit is intended for the current users of the original 5 band mfj1835 as well as the current mfj1836 6 band cobweb. You can buy a complete cobwebb antenna, which can be purchased online from the web pages of steve webb g3tpw, the designer. Note peters plot of the dipole takes account of the effect of ground reflections which which fill in the theoretical nulls off the end of a dipole. Heres the antenna pattern when compared to a dipole. Introduction the cobwebb is a five band 14 to 28mhz compact array of dipoles, bent into a square, almost omnidirectional and with unity gain. I cant think of an instance where cobwebb barcode has failed. The cobwebb or cobweb aerial is an hf aerial for 20m10m and only 7ft square. It is strongly made using fibre glass rods and comes pretuned, but is easily adjusted to ones own frequency ofread more. After the success of my first cobweb antenna i decided to build a rigid version for my home qth, the design this time is based on one by g3txq. Well, here it is, a few months after throwing the antenna up on a 25 foot pushup mast and i am still happy with it. This hardware kit comprises a mast to boom clamp, a spreader clamp plate, central 1 inch diameter tubes, insulating fittings for the spreader arms and the necessary nuts and bolts pictured. The cobweb is a 5band antenna that is really suited for space retricted qths.

So nine useful amateur bands on one antenna is not too bad note the cobwebb is omnidirectional, so no rotator required, and no tuner required on all bands. Unfollow cobweb antenna to stop getting updates on your ebay feed. I built it from g3txqs tutorial posted on his website and used a pair of ft24061 toroids wound with rg316 teflon coax. I have a 200 ohm carbon resistor across the leads where you connect the antenna wires, then connect the core and shield of the 50 ohm coax to their respective wires. This design permits the cobweb to be mounted at any height up a typical. Blue cobwebb red dipole so as you can see above, the cobwebb has more signal strength over a large majority of the antenna pattern when compared to a dipole. The dipole was 1db better broadside on but the cobwebb, being omni directional was 4db better than the dipole when the dipole was endon to the direction of the signal. Jan 26, 2014 a checkup on my homebrew cobweb after the terrible storms recently, all seems well and still going strong after 3 years. The cobwebb is a popular antenna due to its small size its a 5band hf aerial, under 8ft square, and is ideal for the small qth. Cobweb antenna and balun construction by amateur radio g3txq. Click the view tab and ensure that the source is at the bottom of the antenna. It looked like just the ticket so i copied the design and low and behold after a few evening work i finished it off. About the cobwebb antenna the resource is currently listed in in 2 categories. His cobweb is about door height and hes a lowpowered station.

Antenna calculator and design software electroschematics. The cobwebb is an omnidirectional antenna and therefore it doesnt have any nulls in the pattern. Other useful information would include your experience with similar products, infomation on a product that you would purchase instead of this one, and so on. The 5 bander cobweb antenna is a high quality designed antenna with products from europe. Ultra light cobweb antenna is a very low cost multiband antena system. The cobwebb ticked the most boxes for me due to its 5band capabilities, reasonable size and not too tricky to build as its an omnidirectional antenna, i wouldnt have to faff about with a rotator. The basic design is the similar to my portable version but this one uses a 1. About cobwebb revealed the resource is currently listed in in a single category. This link is listed in our web site directory since wednesday dec 26 2012, and till today 5 band cobwebb antenna has been followed for a total of 2712 times. Spacing is the distance from the boom to the gammamatch.

This video i will be assembling both the mfj1836 6 band cobweb antenna with the additional 3040m addon kit. Cobwebb discussion, 4band cola antenna 20171510m, cobweb. See more ideas about ham radio antenna, ham radio and ham radio operator. Last summer i built myself a cobwebb antenna and was fairly pleased with the results. Experiments with a homemade cobwebb type antenna posted on monday, july 8th, 20 by g4ddp over the years i have experimented with quite a few wire antennas at home increasingly to minimise the effect of the increasing noise level from the likes of plasma tvs, switch mode power supplies, plt and adsl routers but fighting a losing battle on hf. I built a portable version of a cobweb antenna, it is based on a design by stephen webb g3tpw and my adaptation of the idea is to make it so that it can be collapsed easily and when required reassembled and mounted hopefully on a telescopic pole. Note the spelling of cobwebb vs cobweb the original g3tpw was designed by steve webb, hence the spelling.

Mfj hf cobweb wire dipole antennas cover multiple bands and are suitable for many restricted space applications. This was our first contact on 20 meter ssb using the homebrew cobweb antenna. The cobwebb is a full size half wave dipole on each of the 5 amateur bands, 14, 18, 21, 24 and 28 mhz. We compare it to a 806 meter ocf, to a 20 meter delta loop, and to a. The table below shows the swr bandwidth with the antenna about 15ft high. Way more information than you ever wanted on how to fell a tree. The original frame made out of breadboards and aluminium plating. The coax jumpers made the other 2 unactive elements.