The AM Forum
March 28, 2024, 07:55:09 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: halpern , end fire and broadside antenna  (Read 2632 times)
0 Members and 1 Guest are viewing this topic.
ve3bkd
Member

Offline Offline

Posts: 30


« 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.


* thumbnail_20170820_202748_HDR.jpg (232.56 KB, 1280x720 - viewed 412 times.)
Logged
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8308



WWW
« 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.
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
ve3bkd
Member

Offline Offline

Posts: 30


« 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
Logged
Steve - K4HX
Administrator
Member

Offline Offline

Posts: 2722



« 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.
Logged
ve3bkd
Member

Offline Offline

Posts: 30


« 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.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.059 seconds with 18 queries.