COBWEBB ANTENNA PDF

COBWEB,HF,1/2W,8-BD,6,10,12,15,17,20,30,40M,KW . MFJ Cobweb Antenna turns your space problem into a stack of QSL cards from far away places . Ideal HF Antenna. Efficient. Transmitter power gets converted to RF, not to heating the ground, coax, or matching network components. G3TPW CobWebb Antenna for the 14, 18, 21, 24 and 28 MHz Bands All the other small multi-band commercial antennas that are available are less than.

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Mounting The mounting consist of 2 aluminium plates 0. You have now created a single transmission line with a Characteristic Impedance of 25 Ohms Now wind 8 turns of this twin cable onto a FT toroid to form a 1: Engineering the Doublet Antenna December 31, A complete balun solution is also available: In stockshipped in 1 or two days.

Most purchases from business sellers are protected by the Consumer Contract Regulations which give you the right to cancel the purchase within 14 days after the day you receive the item.

Our 1 priority is you, the radio Operator. Frequently bought together Feedback on our suggestions – Frequently bought together.

I advise you to fit all 5 dipoles and then tune 20m first, then move up, ending with 10m. The mounting consist of 2 aluminium plates 0. See all mcr has no other items for sale. Now bind the two 1: This item will post to United Statesbut the seller hasn’t specified postage options. Estimated delivery dates – opens in a new window or tab include seller’s dispatch time, and will depend on postal service selected. Here’s a SWR plot measured at 25ft above ground. After extensive testing, I have came to the conclusion that there is little difference between using black or white PVC tube the Wickes brand, at least — Therefore, you can choose the best colour to suit your QTH.

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The “scramble-wound” air-cored balun often installed within the terminal box may not provide much choking impedance unless the dimensions and winding style are carefully controlled The use of twin lead makes it a little more difficult to assemble and disassemble the antenna if, as I do, you prefer to store the wires separately The alternative arrangement I used was to combine the impedance transformation and balun functions into a 1: The folded dipole page on this web site looks in depth at the postioning of the shorting link.

Feedback on mcr from others who bought this item. It’s spam or has links There are copyright or trademark issues It’s offensive or has swear words It includes Feedback about the seller Something else Cancel. Seller assumes all responsibility for this listing. Fully assembled, soldered, boxed, sealed and with optional dipole wires which will need pruning for resonance.

Representative APR variable A dipole or a CobWeb has a gain of about 5dB over a dipole in free space. No additional import charges on delivery. We believe in our product and hold ourselves to the highest standards. Trim the four ends to form short pigtails. Add to basket.

The Cobweb is the solution, Great antenna for small places! Get the item you ordered or your money back. Ratings and reviews Write a review.

The weight of the Cobweb is just 4. For a long-term solution, fibreglass tubing is advised.

The turn radius is a very compact 6. A drive-over base and some swaged poles make a nice setup for operating from the car. Why is this review inappropriate?

Customer specific antennas telescope antennas etc. The frequency cobbwebb the SWR minimum can be tuned by changing the length of the dipoles. See all condition definitions – opens in a new window or tab The Cobweb antenna covers the five upper shortwave bands 20, 17, 15, 12 and 10m.

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There are 2 items available.

CobWeb Aerial

None Parcelforce Global Value. Equally the wind surface is rather small, allowing a max.

Easy to set up works well. Quite acceptable for the average transceiver. Balun Construction Some folk have had difficulty visualising the balun construction, so here are more details; click on the thumbnails for higher resolution photographs.

These small sizes and the small packing size of 11 x 11 x cm makes this antenna well suitable for vacations, fielddays, SOTA and other portable activities. Please allow additional time if international delivery xntenna subject to customs processing.

High Quality 5 bander CobWeb Antenna

The mounting arrangement consists of 2 plates — The 1st holding the main crossover poles 1 on top, 1 underneath and the boom, the 2nd supporting the boom and fixing to a mast. It was a experiment into compact multi-band HF aerials for the higher bands and various solutions existed: This means that you can move the position of them quite easily if you need to make changes.

This Cobweb Antenna is using a double 1: Add to Watch list Watching. Please note that the SWR is referenced to the coax connector on the balun box; in practice the SWR bandwidth will be better than that shown because of losses in the feedline. You will need 2x mm lengths of RG or RG for w max which can be linked via a series of short lengths of heat-shrink tubing.

Depending upon your circumstances, you may find this aerial visually more appealing that a 5-band flat-top fan dipole.