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Author Topic: Receiving Phased Array with Small Electric or Magnetic Active Wideband Elements  (Read 4931 times)

Offline ChrisSmolinski

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I came across this paper, and thought it would be interesting to others here:

Receiving Phased Array with Small Electric or Magnetic Active Wideband Elements. Experimental Performance Evaluation

http://www.lz1aq.signacor.com/docs/phased-array/2-ele_phased_array11.pdf
Chris Smolinski
Westminster, MD
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Offline RobRich

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On a related note, anyone done a basic phased setup with a couple of monopole verticals and a MFJ-1025 or similar entry-level phasing device? I have tossed around the idea, but I already have multiple verticals littering the backyard landscape.
Tampa, FL USA | US Map Grid EL88
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Offline jFarley

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Nice find, Chris!

Back in the day, I cobbled together a two element phased array using a pair of lower Q (~50) resonant loops with a homebrew phasing unit.  I had some pretty good (read encouraging) results, and I have always wanted to follow up this initial venture into phased arrays when time permitted.

I will post more when I find the notebook with details.
Joe Farley, Near Chicago
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Offline refmo

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Thanks for the link!  I will probably be putting up a short 2 vertical phased array for receiving within the next year.

He also has some good info on Small Wideband Magnetic Loops that I have been looking at lately.

http://www.lz1aq.signacor.com/docs/wsml/wideband-active-sm-loop-antenna.htm


central Kentucky
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Offline jFarley

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OIC!

Hey refmo, thanks for posting that link!  I have a copy of that page in my files, and have been impressed with what looks like a pretty good design.
Joe Farley, Near Chicago
SDR-IQ / R8 / R7
Remote Resonant Loops for HF and LF / ALA 1530
Active 60" Whip / PA0RDT
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Offline RobRich

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I will probably be putting up a short 2 vertical phased array for receiving within the next year.

That is on my project list as well, but it gets tossed down to low priority for whatever reasons, such as looking at more antennas in the backyard. ;) If/when I get around to the project, my first attempt will likely use a MFJ-1025 or similar basic "noise canceller" for phasing control, thus my earlier inquiry.
Tampa, FL USA | US Map Grid EL88
Kenwood R-600 + R-2000 | 2x RTL-SDR V3 | Si-Tex 200 | Soft66LC4 | Yaesu FRG-7
Ameco PCL-P | MFJ-784B | MFJ-901B | 2x MFJ-1020B | 2x Timewave DSP-9
148' "Shielded" Loop-on-Ground | 18' End-Fed Vertical | 9' + 31' Verticals

Offline dbs

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Hello Rob,
I just joined the group and your post about phased antennas was one of the first I read.  I now use two 20' verticals fed into a MFJ 1026 phase box for NDB and MW listening.  It works well most of the time after dark but nulling signals during the day is a problem.  I initially tried two amplified loops, same plane and then at 90 degrees to each other but the nulls were never very deep.

The verticals are only about 25' apart at present and when it warms up a little I'll separate them more.  I have to two very strong local stations to use as a daytime standard and when I get the antennas moved apart I'll report back.  Dave

Offline refmo

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Rob:  Have you tried phasing any of your existing verticals??

dbs:  From what I have read on the subject, 20 feet spacing would be difficult to work with.  60 feet would be much better, especially on those low frequencies.
central Kentucky
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Offline dbs

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I didn't plan the location of the antennas it's just that the antenna bases are mounted to chain link fence posts that are about 25' apart.  I was planing on moving one antenna along the fence line another post or two to see if the nulls improve on my day time test stations.  Too cold here to fool around with it now.  Maybe next week.

Offline RobRich

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No phasing work with the existing stuff here. Too many variances in antenna lengths, tunings, etc.

About separation, some say 1/8 WL at the lowest desired freq is the minimum recommendation. However, 1/4 WL is probably a (much) better approach. I have not done any modelling on such a system, though, so YMMV.

If/when done, I am also debating on the verticals to be used. The S9v43 is of particular interest, but I am close enough to the coast to be concerned about wind loading.

Decisions.... ;)
Tampa, FL USA | US Map Grid EL88
Kenwood R-600 + R-2000 | 2x RTL-SDR V3 | Si-Tex 200 | Soft66LC4 | Yaesu FRG-7
Ameco PCL-P | MFJ-784B | MFJ-901B | 2x MFJ-1020B | 2x Timewave DSP-9
148' "Shielded" Loop-on-Ground | 18' End-Fed Vertical | 9' + 31' Verticals

Offline RobRich

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Also, dbs, welcome to the community. :)
Tampa, FL USA | US Map Grid EL88
Kenwood R-600 + R-2000 | 2x RTL-SDR V3 | Si-Tex 200 | Soft66LC4 | Yaesu FRG-7
Ameco PCL-P | MFJ-784B | MFJ-901B | 2x MFJ-1020B | 2x Timewave DSP-9
148' "Shielded" Loop-on-Ground | 18' End-Fed Vertical | 9' + 31' Verticals

Offline dbs

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Thank you.

Offline sdrnerd

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I'm busy building the physical antenna elements and hope to have the kit running next month ;)
Radio's: Perseus, FCDpro+ and Andrus Mk1.5 SDR and others
Antennae: Active delta flag (FLG100LN), Beverage, MiniWhip & OFC dipole
Software: SDR-radio, Studio1, HDSDR, Multipsk, YaDD & YaDD

Regards, Ron

Offline dbs

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I finally moved one vertical antenna along the fence line, they are now 52' apart(ran out of coax).  The null on the local news station stayed about the same, from +10 over S9 to about S2.  The other local station was about +20 over S9 and nulled to about S3 before the move and now after the move with careful nulling it's only S5.  I don't see any other differences after the move so I'm putting the vertical back to its original location.   Dave