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Hitch Hikers Guide to the Off Centre Fed Dipole (aka the Windom) Part1 with Rick DJ0IP
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- เผยแพร่เมื่อ 17 พ.ค. 2023
- Rick DJ0IP gave a very detailed and interesting presentation on the Off Centre Fed Dipole. He examines why the OCFD has a mixed response amongst amateurs and looks at parts of the build of this antenna which can create problems associated with Common Mode Current on the feedline.
He takes a special look at the Balun and misconceptions and misunderstandings on how it performs and mistakes in its builds
He provided a detailed handout which is available on request from DDARS by emailing g6ldinfo@gmail.com.
This is Part 1- Part 2 which will focus on putting the theory into practice will be broadcast live on Wednesday June 7th 7.30pm(1830z) on Zoom 842 5221 3056 and then released on this channel in the following days
EXCELLENT presentation!
1:05:50 I'm fiddling around trying to get 40 and 30 working on an OCFDP. This is good information to have. Thanks.
Excellent, I can't wait for part 2.
This is a great opportunity to publicly thank Rick for his tireless efforts in helping me understand and build the OCFD.
Countless emails and DM's and nothing but class!
The epitome of an Elmer, 73!
TNX Leslie.
Thank you Rick for this very interesting talk about OCFD antennas and especially the appropriate baluns and chokes to use for best performance. Looking forward to part 2!
HI Richard- Rick was delighted you found it interesting :)
Super, Rick speaks common sense about technical issues without the all the flannel and showboating.
Couldnt agree more with you ! Nick G4IWO
TNX Steve.
Superb! Really enjoyed this lecture come lesson or briefing. Can’t wait for part 2.
I have built a flagpole antenna, which is an OFCD doublet mounted vertically with no radials. Mainly to use on 40 and oddly 60 meters, and only 20 feet. It does work great on 40 but does not on 60.
Fantastic!
JUST WANTED TO PUBLICLY THANK YOU RICK, FOR THIS PRESENTATION. GOT A LITTLE BLEARY EYED WITH THESE OLD EYES, BUT GREAT JOB OM.
I passed on your nice comments to Rick . I think both his presentations have been top class, Nick G4IWO
Never had an issue with mine. Rule number one is Never over think a dipole.
Seems to me the problem is not with any particular antenna, but with the frequencies that have been allocated to the amateur radio community. I’m sure there is a lot of historical precedence and real-world reasons why it isn’t so today, but why weren’t the allocations granted by the FCC originally designed to match the resonances of one very good multi-band antenna. It seems they got pretty close in many cases, but missed the actual mark.
First of all, the ham band allocations were not granted by the FCC. They were granted by the International Telecommunications Union (ITU).
Second, the original Windom from 1928 was designed as a mono-band antenna, not a multiband antenna.
It was first fed with coax about 1959, shortly after the 15m band had been allocated. It was originally only used on 80 and 40m.
The 4-band version was launched about 1970 (80/40/20/10m).
So we had our band allocations, LONG before the OCFD was introduced as a multi-band antenna.
73 - de DJ0IP
Ham radio did evolve with bands being harmonically related. 80/40/20/10 -- but other bands were added as time went on, the WARC bands.
Is there a link to the slides with ‘live’ links to the reference materials?
Yes very detailed slides and an accompanying commentary are all available on Rick's website at www.dj0ip.com
Who are those tiny, tiny people in the very small window in the upper right? Your opening screen was on way too long. Lets see some antennas, or long wires that are off center fed. I'm 4 minutes in and you're putting me to sleep. Just my honest opinion as I think the subject is great, but the presentation missed its mark.
You missed your opportunity by not being patient enough OM. You can't learn technology in 4 minutes.