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-   -   zepp antenna matchinig method (https://www.radiobanter.com/antenna/74769-zepp-antenna-matchinig-method.html)

larry July 18th 05 12:54 AM

zepp antenna matchinig method
 
Greetings

I am looking for a schematic diagram of a zepp antenna, including the 1/4
matching line and and matchiing method of 50 ohm coax cable...

Are there any website which would show this?...

Larry ve3fxq



W9DMK July 18th 05 03:05 AM

On Sun, 17 Jul 2005 19:54:10 -0400, "larry" wrote:

Greetings

I am looking for a schematic diagram of a zepp antenna, including the 1/4
matching line and and matchiing method of 50 ohm coax cable...

Are there any website which would show this?...

Larry ve3fxq



Dear Larry,

There's nothing to show - it's too simple for a picture. You just take
a 1/2 wavelength of horizontal antenna and you end-feed it from one
side of a piece of balanced line 1/4 wavelength long. You then link
couple that to the final tank coil and do your matching with the
swinging link and the tank circuit. No equations, no schematics or
pictures - just do it!


Bob, W9DMK, Dahlgren, VA
Replace "nobody" with my callsign for e-mail
w9dmkatcrosslinkdotnet
http://www.qsl.net/w9dmk
http://zaffora/f2o.org/W9DMK/W9dmk.html


Cecil Moore July 18th 05 10:31 PM

larry wrote:
I am looking for a schematic diagram of a zepp antenna, including the 1/4
matching line and and matchiing method of 50 ohm coax cable...


Larry, the Zepp was *never* designed to match 50 ohms. It was
designed to be used with tube final rigs which contained
built-in antenna tuners of one sort or another. Moral: A Zepp,
when used with 50 ohm transmitter, is going to require an
antenna tuner unless you are extremely lucky on one frequency.
--
73, Cecil http://www.qsl.net/w5dxp


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W9DMK July 19th 05 04:02 AM

On Mon, 18 Jul 2005 02:05:56 GMT, (Robert
Lay) wrote:

On Sun, 17 Jul 2005 19:54:10 -0400, "larry" wrote:

Greetings

I am looking for a schematic diagram of a zepp antenna, including the 1/4
matching line and and matchiing method of 50 ohm coax cable...

Are there any website which would show this?...

Larry ve3fxq



Dear Larry,

There's nothing to show - it's too simple for a picture. You just take
a 1/2 wavelength of horizontal antenna and you end-feed it from one
side of a piece of balanced line 1/4 wavelength long. You then link
couple that to the final tank coil and do your matching with the
swinging link and the tank circuit. No equations, no schematics or
pictures - just do it!


Bob, W9DMK, Dahlgren, VA


Perhaps, to do it justice, I should explain that my one and only
experience with a Zepp antenna was in a situation in which the 1/4
wave balanced line section was open wire feeders with about 6" spacing
and the transmitter used a pair of plate modulated, push pull 10's as
the final - link coupled, as I already mentioned. In those days no one
had a clue as to load impedances or conjugate matching. We had an RF
ammeter in the transmission line and we tuned everything for maximum
reading on that meter. Those were the days.

Bob, W9DMK, Dahlgren, VA
Replace "nobody" with my callsign for e-mail
w9dmkatcrosslinkdotnet
http://www.qsl.net/w9dmk
http://zaffora/f2o.org/W9DMK/W9dmk.html


BKR July 19th 05 04:49 AM

There is no problem matching up a zep for a modern transciever.
Think of it as a J-pole with the long end bent over horizontally.
Short the bottom of the quarter wavelength section, and find a point
above that to match to 50 Ohms as seen on an antenna analyzer or bridge.

Should be easy.



larry wrote:

Greetings

I am looking for a schematic diagram of a zepp antenna, including the 1/4
matching line and and matchiing method of 50 ohm coax cable...

Are there any website which would show this?...

Larry ve3fxq




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