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Total 18 documents matching your query.

1. Topband: RDF (score: 1)
Author: Pete Smith <n4zr@contesting.com>
Date: Tue, 11 Nov 2003 17:30:54 -0500
I have been hunting for more information on RDF, which Tom Rauch defined the other day as "the difference between average gain and gain in the desired direction and angle." I get the concept, but als
/archives//html/Topband/2003-11/msg00076.html (7,157 bytes)

2. Topband: RDF (score: 1)
Author: Bill Tippett <btippett@alum.mit.edu>
Date: Tue, 11 Nov 2003 22:51:42 -0500
It is available using EZNEC 3.0 which calculates Average Gain over the entire 3D pattern. When choosing 3D Plot, "Average Gain" appears in the box at the bottom of the summary screen as "Average Gain
/archives//html/Topband/2003-11/msg00078.html (7,711 bytes)

3. RE: Topband: RDF (score: 1)
Author: "Charles Hutton" <charlesh3@msn.com>
Date: Tue, 11 Nov 2003 19:51:41 -0800
Try this: http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/RDFMe tric.htm . Chuck I have been hunting for more information on RDF, which Tom Rauch defined the other day as "the
/archives//html/Topband/2003-11/msg00079.html (8,377 bytes)

4. RE: Topband: RDF (score: 1)
Author: Eric Scace K3NA <eric@k3na.org>
Date: Tue, 11 Nov 2003 23:44:18 -0500
Please double check that EZNEC 3.0 does the averaging correctly. There are two common errors: 1) calculating an arithmetic average of the dBi number, not of power. 2) calculating an average of an equ
/archives//html/Topband/2003-11/msg00081.html (9,159 bytes)

5. Re: Topband: RDF (score: 1)
Author: "Guy Olinger, K2AV" <olinger@bellsouth.net>
Date: Wed, 12 Nov 2003 00:01:06 -0500
In EZNEC 3.0, on your chosen antenna, set the plot type to 3D. Then select FF Plot. At the bottom of the main EZNEC window (not the plot window) it will give the average gain. Use real ground and spe
/archives//html/Topband/2003-11/msg00082.html (8,569 bytes)

6. Re: Topband: RDF (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 12 Nov 2003 08:47:18 -0500
Later Windows versions of Eznec, as others have explained, calculates average gain of an antenna when you do a 3d pattern plot. This "average gain" is the radiation (or reception) efficiency of the
/archives//html/Topband/2003-11/msg00085.html (10,675 bytes)

7. Re: Topband: RDF (score: 1)
Author: "Ford Peterson" <ford@cmgate.com>
Date: Wed, 12 Nov 2003 11:31:48 -0600
I've been doing NEC2 modeling using Nec2Go for some time. www.nec2go.com I like the software for many reasons. Most nobably, the ability to define antenna elements, spacing, transmission line paramet
/archives//html/Topband/2003-11/msg00088.html (7,631 bytes)

8. Re: Topband: RDF (score: 1)
Author: Earl W Cunningham <k6se@juno.com>
Date: Wed, 12 Nov 2003 14:20:24 -0800
The method of using EZNEC to calculate RDF is new to me and looks like a useful tool for evaluating receive antennas. I modeled Pennant antennas in various configurations to see how their RDFs compar
/archives//html/Topband/2003-11/msg00090.html (8,140 bytes)

9. Re: Topband: RDF (score: 1)
Author: Earl W Cunningham <k6se@juno.com>
Date: Wed, 12 Nov 2003 14:52:46 -0800
As a matter of interest, here's the RDFs I came up with for full-size verticals: Single vertical = 4.82 dB 2 endfire verticals, 135' spacing, 90 degree phasing = 7.82 dB Conventional 4-square = 10.09
/archives//html/Topband/2003-11/msg00091.html (7,201 bytes)

10. Re: Topband: RDF (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 12 Nov 2003 20:17:11 -0500
As a point of interest, a regular 4-square has "poor" receiving because phase is wrong at 90 and 180. The directivity (and receiving ability and TX gain) actually goes up with more phase delay, espe
/archives//html/Topband/2003-11/msg00093.html (8,185 bytes)

11. Re: Topband: RDF (score: 1)
Author: Earl W Cunningham <k6se@juno.com>
Date: Wed, 12 Nov 2003 19:28:13 -0800
"...The same is true for a 2 element vertical with 90deg spacing and 90 degree phase, the shift is not nearly optimum." == But 90 degree phasing with equal current distribution is relatively easy to
/archives//html/Topband/2003-11/msg00096.html (7,790 bytes)

12. Topband: RDF (score: 1)
Author: W7lr@aol.com
Date: Sun, 18 Sep 2011 12:33:14 -0400 (EDT)
The common slogan in topband is that you can't have too many antennas. My new slogan at age 90 is that you can have too many (time for repairs, maintenance, observing which rx antenna is best, etc) -
/archives//html/Topband/2011-09/msg00093.html (7,646 bytes)

13. Topband: RDF (score: 1)
Author: David Cole <g3rcq@yahoo.co.uk>
Date: Fri, 25 Jan 2013 21:27:04 +0000 (GMT)
How do I calculate RDF I am currently modelling the Shared Apex Loop antenna recently described in QEX and QST , Not to be confused with the following months article on phased K9AYs - I have an 8 dir
/archives//html/Topband/2013-01/msg00204.html (7,223 bytes)

14. Re: Topband: RDF (score: 1)
Author: "James Wolf" <jbwolf@comcast.net>
Date: Sat, 26 Jan 2013 06:59:02 -0500
David, As I recall, you take the average gain and subtract it from the maximum gain. Or Use 4NEC2, it calculates it for you. Jim, KR9U How do I calculate RDF I am currently modelling the Shared Apex
/archives//html/Topband/2013-01/msg00205.html (7,761 bytes)

15. Re: Topband: RDF (score: 1)
Author: "Luis Mansutti IV3PRK" <luisprk@tin.it>
Date: Sat, 26 Jan 2013 12:25:01 +0100
Very interesting question Dave...I was just wondering why I never saw any comments on this "new" receiving antenna design. It has been published by KB7GF on QST Oct.2012 and on QEX Sept/Oct. 2012. It
/archives//html/Topband/2013-01/msg00206.html (8,858 bytes)

16. Re: Topband: RDF (score: 1)
Author: "Steve Flood" <kk7uv@bresnan.net>
Date: Sat, 26 Jan 2013 09:44:41 -0700
A fairly similar design, although quite a bit larger dimension, appeared about 10-12 years ago on the hardcoredx website. It was 6 triangle loops arranged on a mast. Each loop 30 feet tall and 20 fe
/archives//html/Topband/2013-01/msg00210.html (8,048 bytes)

17. Topband: RDF (score: 1)
Author: "Mike(W5UC) & Kathy (K5MWH)" <w5uc@suddenlink.net>
Date: Sat, 30 Nov 2013 14:47:58 -0600
Recently, I have been intrigued by the antenna parameter RDF. Please, can someone tell me, by how much can RDF change(dB) before the difference in performance of the antenna will be noticeable to the
/archives//html/Topband/2013-11/msg00366.html (6,346 bytes)

18. Topband: RDF (score: 1)
Author: "Mike(W5UC) & Kathy (K5MWH)" <w5uc@suddenlink.net>
Date: Sun, 01 Dec 2013 07:06:45 -0600
I received a number of replies to my question about RDF. Many thanks to all. The consensus was that 2 dB difference is the magic number. Thanks again for your interest, and I look forward to seeing a
/archives//html/Topband/2013-12/msg00000.html (5,920 bytes)

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