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halpern , end fire and broadside antenna




 
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Author Topic: halpern , end fire and broadside antenna  (Read 405 times)
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ve3bkd
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« on: August 20, 2017, 11:06:18 PM »

hello friend's .
A good ham friend of my , SILENTKEY . JOHN ,VE3POS.
I like to share this with you.
any help on how this antenna works .
thanks.


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Opcom
Patrick J. / KD5OEI
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« Reply #1 on: August 21, 2017, 01:09:34 AM »

I'll take a stab at it.

The antenna's direction of radiation can be changed by activating the relay's 12VDC coil. which switches in the 180 degree phasing line. The 12VDC and RF go along the co-ax together. At each end they are separated so the TX signal and 12V do not interfere.
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Radio Candelstein - Flagship Station of the NRK Radio Network.
ve3bkd
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« Reply #2 on: August 23, 2017, 06:10:26 PM »

thanks ,Opcom.
i see what you mean on the relay
i have never seen this antenna in any books ,etc.
he build it so he could used it on 80 meter context,  he was invited and promises a spot for him , but they changed it on him and put him on 17 meter on the last minutes , some cry slapbacket wanted 80 meters, so he never got to used it , even at his property lot to small for it .
i just wounder if it is horizontal polarizes or vertical and what gain it maybe have.
thanks
peter
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Steve - K4HX
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« Reply #3 on: August 23, 2017, 07:51:49 PM »

Yes, it appears to be an attempt to have broadside and end-fire verticals. I don't think it will work in the broadside mode (phasing line switched in) because the coax phasing line is probably not the correct length. 102 feet would only provide a 180 degree phase shift when the coax is terminated in 50 Ohms. I don't think the feed point impedance is 50 Ohms, so the phase shift is probably off.

The 62 foot horizontal extensions off each end probably aren't needed. Do a search on the half-square antenna for how the broadside approach would work without the 62 foot horizontal sections.
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ve3bkd
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« Reply #4 on: August 23, 2017, 08:41:47 PM »

hi,steve.
thanks for moving the post to tech.
I am not so tech on antenna ,I just find it cool .
but to me it seems like a 3/4 wave antenna radiating horizontal and vertical at the same time!!.
so I think your probably right on impedance at the feed point  with the un switch relay.
I am not sure how the phasing works. or if it is correct .
maybe he was going to used it with an automatic antenna tunner build in radio.
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