This antenna requires the use of Tuned Open wire feed line , ladder line , window line , etc.
NOT Coax cable !
It is suggested a 450 – 600 ohm line.
This antenna also requires the use of a matching network “Transmatch” at the transmitter end of the feed line.
WH2T used a 75 meter band Double Extended Zepp Antenna with very good success. He affirmed to have worked all 50 states and several countries with 100 Watts using theantenna on the 75 meter band.
With a good antenna tuner the antenna will work 6 thru 160 meters, but this antenna will only tune the 160 meter band if the open wire feed line is the proper length.
More info on Double Zepp Antennas
The Zepp, short for Zeppelin is any resonant antenna end-fed by ladder line.
A Double Zepp is a center-fed 1/2 wavelength antenna.
The double extended Zepp is a dipole type Antenna consisting of two collinear 0.64 wave length elements fed in phase.
This double extended version provides 3 db gain over a dipole on the band it is designed for and each side or leg is about 5/8 wavelength long.
When measuring the wire it is very important to get each of the two sides as close to the same length as possible.
The formula to determine the length of each side is
599/Freq in Mhz = .64 wavelength.
So to design an antenna for 3.85 Mhz take 599 divided by 3.85 = 155.585 Feet per side or 155′ 7″ each side.
This 75 Meter antenna would be about 311′ 2″ overall length.
With this antenna the feed line should be routed away from the antenna at a right angle for as great a distance as possible. This will prevent current imbalance in the feed line caused by RF pickup from the antenna. A right-angle departure of 1/4 wavelength or greater is suggested.
To avoid problems matching any center fed antenna with high impedance open wire lines, keep the feedline around these lengths.
[The WORST POSSIBLE line lengths are shown in brackets]
160 meter antenna 35-60, 170-195 or 210-235 feet
[Avoid 130, 260 ft]
80 meter antenna 34-40, 90-102 or 160-172 feet
[Avoid 66, 135, 190 ft]
40 meter antenna 42-52, 73-83, 112-123 or 145-155 feet
[Avoid 32, 64, 96, 128 ft]
Some slight trimming or adding of feedline may be necessary to accommodate the higher frequency bands.
Copyright to W2HT
This article was originally available at bloomington.in.us/~wh2t/zepp.html
just a word of thanks, i have had your Dbl Zepp up for almost 3years and at two QTH’s . it WORKS great , i use a dentron super tuner with it and can tune 10 mtrs >>> 160 mtrs .
thanks chuck KC8OYD
OlÃ¡ amigo, eu tenho uma Extended Double.Zepp Antena,para a banda de 40 Metros, hÃ¡ mais de 10 anos, quando mudei de casa em 2001.Estou muito satisfeito com ela, uso um sintonizador da MFJ-969.
Os meus melhores 73de ct1exs/hb9ijb.
I wish I had enough ROOM here at my Tampa Florida QTH for the EDZ Antenna ! Ka7niq
josÃ© & chuck:
How do you connect the zepp antenna to your equipment? Open line or TV line, how long? and what else?
chuck & jose:
Please tell me how do you connect the antenna to your equipment? Open line, TV open line and how long? And what else, balun maybe? Thanks. GermÃ¡n CE3GP.
Need some discussion on determining length of feeder using 450 ohm ladderline and whether or not you use a balun or not for coax from end of ladderline to rig.
A double extended zepp is basically two 5/8 wavelenghts dipole lenghts each side with 1/6 the lenght of the dipoles used as open wire feeder to tune out the reactance.(tuning stub)
The higher the open wire impedance the less the feedline will change under windy conditions. Moving from 150 to 300 to 600 ohm open wire feeder will affect the lenght of the tuning stub.
Then feed it with 50 ohm coax , Use a balun to the antenna, coax is unbalanced , open wire is balanced.
Wheter it is a multiband antenna depends on if u use a tuner , Without a tuner it definately is NOT
A 17mtr DEZ at 18-19mtrs agl shows 10-11dBi gain in MMANA.
this is not a zepp it’s a dublet
zeps have a tuning section
I put a DEZ up using a tower and 2 trees. The apex is up 40 feet and the ends are 25-30 off the ground, feed with about 90 feet of 450 ohm ladder line. The DEZ is well worth the effort to put it up.
Pingback: Simple Ham Radio Antennas–a 10 meter double extended zepp antenna, post #272 « KH6JRM's Amateur Radio Blog
The EDZ is a only one band 3 db gain antenna. According with that, you can cut two wire legs, each one 0,64 lambda . Then, you can connect it to a open wire line fed, 450 ohms. Tipically is a piece of 0,18 lambda.
To connect to 50 ohms coaxial, you should put a 1 to 1 balun, and check the swr. If the system is resonating down your frequency design, you will cut the open wire line fed to find your your frequency design.
Then, you can use this antenna in other band, with a tuner, but is not the same, of course.
If you need a multiband antenna, you can use a Collins table design. An example is 42 meters each side, 30 meters open wire line fed, and transmatch link. You can work correctly 160, 80, 40 and 30 meters succesfully.
73, Jan, LU5YF
Would you please make one our of twinlead for the FM band (88 – 108 Mhz)…receive only? Thanks