As you may already know, I have developed a wholesale interested in coils. I have been trying to increase my personal understanding of coils as used for antennas (as baluns) and as they are used in band-pass-filters (ummm, as well ... coils) and all other things of an inductive nature.
After the normal frenzy of Google searches, I was lead to -- '
20 bucks and a few days later... I wish I could tell that it were true, in short they are all wrong and I would strongly suspect not one of them actually read the book. I found the book to be at best a loosely coupled collection of articles which seems to start in the middle of basic ideas, and seem to trail on and then abruptly end. To the say the book is badly written, I will not say, I'm no English major myself, and I'll leave that to others. What I can and will say is; I did not enjoy it, and I found it to be contradictory, weak and misleading. -- In many cases the author warns the reader of the evils of voltage baluns (probably a true statement), but then extols the superb benefits and divine merits of Ruthroff's work on the same. huh?!
The author constantly refers to the seminal publication of G. Guanella in the Brown Boveri Review in September of 1944 (PDF) but never really takes the time the explain to the modern reader the construction outlined in the article. The article also constantly referred to C. L. Ruthroff August 1959 equally seminal article (PDF) -- I'm sorry, I had missed that one too, as I imagine most modern readers will have (as in 'we were not born yet!?') and my subscription to the BBR is still in the mail. -- I have posted both of the articles above so that you may acquaint yourselves with their genius.
Like the little boy in Hans Christian Andersen's story, 'The Emperor’s New Suit'. I post this rather negative review at great peril to myself, because HAMs are a funny lot (as in not 'ha-ha'), and are very similar to sheep, and do not take kindly to folks having a difference of opinion on something they hold sacrosanct. Flame On QRPers!![Understanding building and using baluns and ununs Understanding building and using baluns and ununs](/uploads/1/2/5/8/125872241/806273378.png)
As to not become the Andy-Rooney-of-HAM-radio with my Casandra like opinions, I will share with you that I did find a few articles (Free PDF) on the web that are very helpful, and go a long way towards really being helpful.
C. Greene w1CG 2002.pdf (PDF) & C. Greene w1CG QRP 4:1.pdf (PDF)
and R. Bertran vk2DQ 2005 OCF dipole.pdf (PDF superd, must read!!)
I also share with you Jim Brown's J. Brown k9YC APR-2008.pdf (PDF), but with a warning. For it also seems to suffers from Current-vs-Voltage confusion affliction -- For the record the Guanella balun is NOT a voltage balun.
73 ki4SGU![Understanding building and using baluns and ununs pdf download Understanding building and using baluns and ununs pdf download](http://2.bp.blogspot.com/-vtJMlSHNAo0/UORw3sEnc5I/AAAAAAAAANo/XdnUr5kHcvg/w1200-h630-p-k-no-nu/balun11.JPG)
After the normal frenzy of Google searches, I was lead to -- '
COMTEK Jerry Sevick W2FMI Series Current Baluns were inspired by the writing of Jerry Sevick, as published in his book ' Understanding, Building, and Using Baluns and Ununs ', also available from DX Engineering. Most commonly, balanced antennas don't use the earth as part of the antenna. So we can use a balun – a balanced to unbalanced device - to one to another.
Understanding, Building, and Using Baluns and Ununs' by Jerry Sevick, W2FMI -- This book is presented (ARRL, eham, and everyone else) to be universally touted as the pinnacle and the state of the art for those seeking a deeper understanding and actually building. I ordered it....20 bucks and a few days later... I wish I could tell that it were true, in short they are all wrong and I would strongly suspect not one of them actually read the book. I found the book to be at best a loosely coupled collection of articles which seems to start in the middle of basic ideas, and seem to trail on and then abruptly end. To the say the book is badly written, I will not say, I'm no English major myself, and I'll leave that to others. What I can and will say is; I did not enjoy it, and I found it to be contradictory, weak and misleading. -- In many cases the author warns the reader of the evils of voltage baluns (probably a true statement), but then extols the superb benefits and divine merits of Ruthroff's work on the same. huh?!
The author constantly refers to the seminal publication of G. Guanella in the Brown Boveri Review in September of 1944 (PDF) but never really takes the time the explain to the modern reader the construction outlined in the article. The article also constantly referred to C. L. Ruthroff August 1959 equally seminal article (PDF) -- I'm sorry, I had missed that one too, as I imagine most modern readers will have (as in 'we were not born yet!?') and my subscription to the BBR is still in the mail. -- I have posted both of the articles above so that you may acquaint yourselves with their genius.
Like the little boy in Hans Christian Andersen's story, 'The Emperor’s New Suit'. I post this rather negative review at great peril to myself, because HAMs are a funny lot (as in not 'ha-ha'), and are very similar to sheep, and do not take kindly to folks having a difference of opinion on something they hold sacrosanct. Flame On QRPers!
![Understanding building and using baluns and ununs Understanding building and using baluns and ununs](/uploads/1/2/5/8/125872241/806273378.png)
As to not become the Andy-Rooney-of-HAM-radio with my Casandra like opinions, I will share with you that I did find a few articles (Free PDF) on the web that are very helpful, and go a long way towards really being helpful.
C. Greene w1CG 2002.pdf (PDF) & C. Greene w1CG QRP 4:1.pdf (PDF)
and R. Bertran vk2DQ 2005 OCF dipole.pdf (PDF superd, must read!!)
I also share with you Jim Brown's J. Brown k9YC APR-2008.pdf (PDF), but with a warning. For it also seems to suffers from Current-vs-Voltage confusion affliction -- For the record the Guanella balun is NOT a voltage balun.
73 ki4SGU
Handout forNKARC9/12/16 Program,Balun Baloneyby D. Core, K8WDA
My little slide show presents only a top level lookat baluns and ununs. For those who are not already bored to tears and desire a deeper understanding, the following reading is recommended. All on the list except for the first item are available for download on the Internet. For easy access, go on line to http://k4co.org/misc/balunbaloneyhandout.htmlwhere this document appears as a web page. Once there, simply click on a title or web address to view or download your copy.
Understanding, Building, and Using Baluns and Ununs by Jerry Sevick, W2FMI, is widely recognized as a definitive source of balun information. It helped me in my quest for answers. I was a little disappointed in the construction details. Specifically, answers to the questions, “Exactly what type of ferrite should I use?” and, “Where do I get it?” Regardless, this book is worth the price. It is published by CQ Communications, Inc, and is available at DX Engineering for around $20.
Baluns: What They Do and How They Do It by Roy Lewallen, W7EL, (author of EZNEC Antenna Software) was published in the ARRL Antenna Compendium, Vol.1 in 1985. Thisis where the terms “current balun” and “voltage balun” became common and provides convincing evidence favoring Guanella’s design. Available at http://www.arrl.org/files/file/History/History of QST Volume 1 - Technology/AntComp1-Lewallen(1).pdf.
A more eloquent explanation (than mine) of common mode vs. differential mode is presented by W8JI inBalun Basics: Common Mode vs. Differential Mode. This appears on DX Engineering’s web site at https://www.dxengineering.com/techarticles/balunsandfeedlinechokes/balun-basics-common-mode-vs-differential-mode.
For you techies, lots of theory and comparisons of transmission line transformers (baluns) may be found in Transmission Line Transformers, 4th Edition by Jerry Sevick, W2FMI. Chapter 12 includes guidance about ferrite tyes and sources. Available at http://www.okdxf.eu/files/Noble Publishing - 2001 - Transmission Line Transformers, 4ed.pdf. This file is over 17Mb, so be patient.
If you have a deep need for “entertainment” and an engineering background, New Method of Impedance Matching in Radio-Frequency Circuits by G. Guanella is were it all started. This paper may be found at http://www.qsl.net/kp4md/guanella.pdf.
For those who desire more knowledge about ferrite cores, specifications and applications, Chapter 2 in A Ham's Guide to RFI, Ferrites, Baluns, and Audio Interfacing by Jim Brown, K9YC, provides interesting and practical insight. On the web at http://audiosystemsgroup.com/RFI-Ham.pdf.
Is homebrewing your thing? See Transmission Line Transformers Handbook for “48 Improved Designs” by Jerry Sevick at http://www.introni.it/pdf/Amidon - Transmission Line Transformers Handbook.pdf
Sources for ferrite cores in small quantities:
Amidon Corp. ($20 min. order) - http://www.amidoncorp.com/ferrite-toroids/
Universal Radio – http://www.universal-radio.com/catalog/misc/amidon.html
Palomar Engineering – http://palomar-engineers.com/ferrite-products/ferrite-cores
eBay (Search for “ferrite core”) – http://www.ebay.com/
-- This document is on line at --