ANTENTOP- 01- 2017, # 021

Antenna Theory

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Friis Transmission Equation and the Radar Range Equation:

Dear friends, I would like to give to you an interesting and reliable antenna theory. Hours searching in the web gave me lots theoretical information about antennas. Really, at first I did not know what information chose for ANTENTOP.

Now I want to present to you one more very interesting Lecture 06: Friis Transmission Equation and the Radar Range Equation. I believe, you cannot find such info anywhere for free! Very interesting and very useful info for every ham, for every radio- engineer...

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HF- Antenna Practice

The Three L-Antennas:

Dick Reid, KK4OBI

A space saving antenna in the form of an upright L has been around the amateur radio world for a long time... this article is to expand our general knowledge relative to angle-of-bend and off-center-feed (OCF) configurations of the L-Antenna...

12- 19

The WB3GCK Downspout Antenna Revisited:

Craig A La Barge, WB3GCK

A ham friend of mine recently asked me for the details of how I use my rain gutter and downspout as an antenna. I originally did a write-up on it in 1994 (Reference 1). That article found its way into several ham radio publications and newsletters. Most of the original article is still relevant but I have made some changes in the way I feed the "antenna." So, here's an updated description of my Downspout Antenna...

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Stealth Antennas for Amateur Radio:

Charles W Bushell, KC8VWM

This list of Ultra Stealth antenna has been created here in hopes of assisting the radio amateur community who may be otherwise restricted or limited in terms of antenna installation possibilities so they can remain active while serving to address any required need for those individuals who may be seeking just such a solution...

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The GRASSWIRE: Another Approach to Hidden HF Antennas:

Michael J. Toia, K3MT

The article is an AntenTop Magazine variant of Chapter 7 from K3MT book "HF Antenna Topics."

Deed restrictions got you down? Neighbors intimidating your tower plans? Need a really easy, portable HF antenna? Then the Grasswire may be the answer! Virtually invisible, lightweight, and compact (you can carry one in your hip pocket), this antenna works! I've used one in various installations for more than 10 years...

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Indoor Dipole Antenna for 20 Meter:

Credit Line: Forum WWW.CQHAM.RU

Description and pictures of the Indoor Antenna for the 20 Meter were published at ham forum at www.ham.ru . Author of the antenna is unknown to me. However the antenna is work and may be used in tight conditions...

Balcony Dipole Antenna for 20 Meter: Credit Line:

Forum WWW.CQHAM.RU

Description and pictures of the Balcony Dipole Antenna for the 20 Meter were published in ham forum at www.cqham.ru . Author of the antenna is unknown to me. However the antenna is work and may be used in tight conditions...

Inverted V Antenna for 80-, 40-, 30-, 20-, 15- and 10 meter Bands:

Dmitry Belousov, UR4LRG

The I.V. Antenna contains three lengths of wire on each side (the longest length a trap included) and provides operation on seven ham bands- 80-, 40-, 30-, 20-, 15- and 10 meter. The antenna is installed and works at three ham station- UR4LRG, UT5UY and Kharkov club station UR4LZZ...

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Two Helical Antennas for 160 meter Band:

Andre Chichkin, VE3YXO

Helical vertical antenna at its relatively small height may provide a good operation in the Air. It is possible to find the statement at lots ham publications in the internet and in paper magazines. So I decided to make my own helical antenna originally for 160 meter band and prove if the helical antenna works so well. Design of my helical antenna was based on source from internet and magazines that I had at my hand....

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UR0GT Helical Antenna for the 40- meter Band:

Nikolay Kudryavchenko, UR0GT

Nikolay (UR0GT) would like experimented with Helical Antennas for the HF Band. He already made a MMANA model of the Helical HF Antenna for the 40 meter Band. But...did not have time...he lived for us just two files of the antenna...

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Cliff Dweller's Antenna:

K. E. Hughes, W6CIS

Let me say at the outset that such an antenna will not replace a good three- element beam on 20 or 60-foot high doublet on 80; however, considering the space, cost and easy of adjustment, it gives a very good account of itself....

Two Wires Beverage Antenna:

Igor Grigorov, VA3ZNW

Two Wires Beverage Antenna was well known in the former USSR where the antenna was widely used on the HF receiving centers both military and civil ones. The advantages of the Two Wires Beverage Antenna is low compare to one wire Beverage Antenna input impedance that allows reach better matching of the Two Wires Beverage antenna compare to one wire one in the broad band of frequencies, of course compare to one wire Beverage antenna...

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Experimental Window Antenna for the 14- and 21- MHz Band:

Yuri Pankratov, R0CBK

The antenna is very simple for design. It needs to buy just two aluminum tubes in 40 and 10- mm in diameter and two aluminum plates (it is possible use kitchen aluminum foil instead of the plates). Others stuff for antenna may be found in amateur junk box or bought in amateur flea market...

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Practical Balcony Version of an Old Military Car Antenna:

Sergey Sushko, ex UA9LBG

Wide flat dipoles were widely used on the roof of the Soviet Radio Communication Car in 40- 50 years of the 20 century. It was a flat rectangle made of aluminum tubes in 10- 20 mm diameter that has length near 2 meter and wide near 0.75 meter. Inside the rectangle there were installed several aluminum tubes (having diameter 10- 20 mm) in bridge. Their ends were welded to the narrow sides of the rectangle. At my opinion the design looks like Clothes Dryer. So I decided make the antenna at my balcony in way that everyone believes that is the same Clothes Dryer...

55- 56

UHF ANTENNAS

Six Elements Antenna for the 70- cm Band:

Yuriy Skutelis, RN3DEK

There is presented simple six element antenna for the 70- cm Band. Antenna has excellent SWR and F/B ratio. Antenna does not require follow to strictly dimension of the elements. So the antenna may be done ever by ham, who has no large experience in the antenna building...

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Chireix- Mesny Antenna for the 435 MHz:

Nikolay Kudryavchenko, UR0GT

Chireix- Mesny antenna may be used for operation on 435 MHz. Two designs of the antenna are presented here. Both antennas have very wide pass band. So it is not strictly demands to keep the sizes as shown in the drawing. Chireix- Mesny antenna has input impedance 200 Ohm so it is possible match the antenna with 50- Ohm coaxial cable with help of 4:1 transformer...

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UR0GT Chireix- Mesny Antenna for the 1295 MHz:

Nikolay Kudryavchenko, UR0GT

Chireix- Mesny antenna may be used for operation on 1295 MHz. The antenna has wide pass band- 290 MHz at SWR less the 1.5:1. So it is not strictly demand to keep the sizes as shown in the drawing. Antenna has input impedance 200 Ohm so it is possible match the antenna with50- Ohm coaxial cable with help of 4:1 transformer...

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VHF ATU

VHF ATU:

Brett Johnson. Credit Line: Facebook group: The Urban Radio Ham.

Now many of you may think WIRE antennas are the preserve of the HF bands. Well not so. I have a "long" wire here that gets used on 2 m - and for this some form of ATU is handy - here is a simple one I made...

HF ATU

Several Universal ATUs for the Whole Amateur HF Band:

Igor Grigorov, VA3ZNW

It is not difficult to build an Antenna Tuning Unit (ATU) for any amateur HF band. Such device could be done with usual coils and capacitors. However the real problem is making a simple and effective ATU without lots switching and tuning that could work over a broad range of frequencies. Below there are given several different ATU that work effectively over all amateur HF bands from 160-10 meters, easy to do and easy to tune and easy to match antenna with transmitter...

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Classical ATU:

Yuri Ziborov, RZ3GI

The Classical Antenna Tuner (with two capacitors - one for matching with transmitter another one do matching with load and inductors that value depends on frequency between the capacitors) is known by hams and served at the ham shack for decades...

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Simple ATU:

Svoy 3000. Credit Line: cqham.ru

Note from I.G.: I found schematic of the tuner on infinite pages at the ham forum at www.cqham.ru. The design was present by amateur with alliance Svoy- 3000. Of course I have decided make and test the ATU...

History

Sputnik Transmitter

First soviet space apparatus "Sputnik" was launched into an elliptical low Earth orbit on 4 October 1957. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennas. The antennas (two antennas were belonged to each transmitter) were connected to two transmitters. One transmitter was working on 20- MHz another one on 40- MHz. Transmitters turn on and off with help of an relay and transmitted just CW pulses...

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Propagation

Ultra Long Delayed Echoes:

Mike Doig, ZL2BBS

I had an odd experience a few years ago, which, maybe, might count as the longest delayed radio echo on record...

Time Warp on 20 Meter:

Igor Grigorov, VA3ZNW

LDE: what is it: Is it truth or myth? I believe you already have read the article "Ultra Long Delayed Echoes" written by Mike Doig, ZL2BBS. The article was published in K9YA Telegraph # 4, 2017. Yes, it is April article that just may smile you. However, some April articles are not like April articles but... The small notes described what was happened with me and it is not an April joke...