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Author Topic: Phasing sloping dipoles with DXE Switch?  (Read 2351 times)

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Phasing sloping dipoles with DXE Switch?
« on: May 30, 2008, 05:55:13 AM »

I have the 8 position DX Engineering switch - which is one of the best pieces of ham gear I've ever owned. I used it to phase 2 DX Engineering 40M verticals (60 radials each) using the Christman phasing method. That arrangement worked as well or better than using a phasing box manufactured specifically for this purpose.

Anyway, there will be no more ground mounted verticals for me - but I do have a pair of NE - SW facing sloping dipoles phased using the K1WA style - which is just 2 3/8 wl 50 ohm coax stubs. I'm getting the 12 db F/B and 4 db gain that I expected. I'm just using an Ameritron RCS-4 for this - and it seems OK. I expect that the DXE switch would make this even better.

I'm wondering if I might try to phase these two dipoles using the Christman method - so I can get end fire as well as broadside patterns?

Do you think this is do-able given that I am NOT phasing verticals - but what are essentially sloping half wave vertical dipoles?

Rich
KY6R
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KG22RG

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Re: Phasing sloping dipoles with DXE Switch?
« Reply #1 on: May 29, 2021, 02:10:16 PM »

Nice thread, I love experimenting and building cool antennas. I have built a 2 vertical phased array using the Christman method and it works great. It’s all home brewed and only the radio is commercially bought. Here is a video I posted to demonstrate the powerful ability to tune in wanted stations while rejecting/nulling out QRM. The front to back ratio is 30db on average on both transmit and receive. The ability to electrically.

Thanks for the post and 73
KG2RG
https://youtu.be/vL42hVeieZA
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KM1H

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Re: Phasing sloping dipoles with DXE Switch?
« Reply #2 on: May 29, 2021, 03:33:44 PM »

Ive used the Christman method since the 80's on 160-40 on RX and TX to start and then on TX only once I got involved with Beverages for RX. It was easy with the TS-930, 940, and 950SD to make near instantaneous switching. The phasing lines back then were built using a home brew noise bridge.  I never could understand the benefits of the method using the dummy load to dump power and poor VSWR bandwidth....except it made the seller happy.

I dont understand why the DXE switch is any better than others.

Carl
« Last Edit: May 29, 2021, 03:38:06 PM by KM1H »
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KX2T

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Re: Phasing sloping dipoles with DXE Switch?
« Reply #3 on: May 29, 2021, 04:52:54 PM »

I used for many years either with two dipoles/inverted vee's or two verticals phased with a very simple either 90 or 70 degree phasing line between the two going from a Tee connector fed to both antennas from a switchbox, either a simple relay or an antenna switch box such as an RCS10 but I never had an antenna switch that gave me and open when not in use which would make use of the 3/8 wave coax fed that would make the unused antenna a reflector such as the 5 sloping array that  in the old ARRL antenna handbook. As far as matching I would feed each antenna with 1/2 wave electrical coax then use a 1/4 wave 75 ohm stub feeding the relay box then 50 ohm but going threw the antenna switch which is used for other antennas makes for a problem. With the phased vee's I would get a minimum of 15db F/B on local stations but anywhere from 20 to 25db F/B on further contacts and DX.
If I were you try it and always try and think out of the box cause I remember the big station telling be I could not phase 4-5 element beams closer than 3/4 wave apart on a tower in a stack and I used a pair of 4 element 20's 1/2 wave apart that would tear up on 20m. Never say Never! 
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