EMRFD Message Archive 11927

Message	Date	From	Subject
11927	2015-12-03 19:39:28	mdinolfo2001	Seeking copy of Dome Dec 1946 "Electonics" article on phase shift ne
I am trying to locate a copy of the Dome article on phase shift networks (R. B. Dome; Dec 1946 "Electronics" magazine- "Wide Band Phase Shift Networks").  Can anyone provide me with a copy (.pdf, or otherwise)?  I don't think I'm asking anyone to violate any copyright laws, because my request is strictly related to research, and I won't be publishing the article, or posting it on-line anywhere (but correct me if I'm wrong on this!)  I'm asking because I'm trying to gain insight into the design process for determination of the RC values in legacy audio phase shift networks such as the B&W 2Q4-350 and the Millen 75012.  I already have some subsequent relevant publications (Weaver April 1954 IRE, Weibach May 1973, the Howard/Faries June 1955 Leland Stanford submittal paper, various GE Hamnews publications, QST Dec 1964 ON4HW Technical Correspondence) but I am hoping that the original Dome paper might finally enable me to grasp the design process and tradeoffs for these (different) published configurations.  The second order networks in EMRFD figs. 9.45 & 9.46 are scaled derivatives of the 2Q4-350, and I am trying to determine relative merits (re: phase shift performance) of cutoff frequencies and component ratios between the 2Q4-350, the Millen 75012, and the ON4HW designs. In the Millen 75012 and the ON4HW designs, the capacitor ratio within each (I or Q) phase shift network is 2.0, whereas in the 2Q4-350 it is 1.581.  The RC cutoff frequencies within each of the four 2Q4-350 networks is 480.7, 480.6, 1872.4, and 1869.3 hz, but the RC cutoff frequencies in the other two networks appear (to me) to be somewhat more arbitrary.  If anyone can provide a copy, please respond to me off-list.  I have not been able to locate a copy of this article on the 'net.  Thanks! Mike Dinolfo N4MWP (mdinolfo@erols.com)
11929	2015-12-04 08:40:58	Ray Anderson	Seeking copy of Dome Dec 1946 "Electonics" article on phase shift ne
Mike-   You can download a .pdf copy at the following location:   http://www.dtic.mil/dtic/tr/fulltext/u2/769585.pdf   -Ray WB6TPU   2 Seeking copy of Dome Dec 1946 "Electonics" article on phase shift ne Thu Dec 3, 2015 7:39 pm (PST) . Posted by: mdinolfo2001 I am trying to locate a copy of the Dome article on phase shift networks (R. B. Dome; Dec 1946 "Electronics" magazine- "Wide Band Phase Shift Networks"). Can anyone provide me with a copy (.pdf, or otherwise)? I don't think I'm asking anyone to violate any copyright laws, because my request is strictly related to research, and I won't be publishing the article, or posting it on-line anywhere (but correct me if I'm wrong on this!) I'm asking because I'm trying to gain insight into the design process for determination of the RC values in legacy audio phase shift networks such as the B&W 2Q4-350 and the Millen 75012. I already have some subsequent relevant publications (Weaver April 1954 IRE, Weibach May 1973, the Howard/Faries June 1955 Leland Stanford submittal paper, various GE Hamnews publications, QST Dec 1964 ON4HW Technical Correspondence) but I am hoping that the original Dome paper might finally enable me to grasp the design process and tradeoffs for these (different) published configurations. The second order networks in EMRFD figs. 9.45 & 9.46 are scaled derivatives of the 2Q4-350, and I am trying to determine relative merits (re: phase shift performance) of cutoff frequencies and component ratios between the 2Q4-350, the Millen 75012, and the ON4HW designs. In the Millen 75012 and the ON4HW designs, the capacitor ratio within each (I or Q) phase shift network is 2.0, whereas in the 2Q4-350 it is 1.581. The RC cutoff frequencies within each of the four 2Q4-350 networks is 480.7, 480.6, 1872.4, and 1869.3 hz, but the RC cutoff frequencies in the other two networks appear (to me) to be somewhat more arbitrary. If anyone can provide a copy, please respond to me off-list. I have not been able to locate a copy of this article on the 'net. Thanks! Mike Dinolfo N4MWP (mdinolfo@erols.com) This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
11930	2015-12-04 09:12:20	Mike	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
Thanks, but:  This link is not to the actual Dome article- it is a link to a Weibach-authored 1973 paper (which I already have).  The Weibach 1973 paper actually cites the Dome paper in the references.  I am looking for a copy of the original Dome article that appeared in the 1946 issue of "Electronics" magazine. Mike N4MWP
11931	2015-12-04 12:57:29	Will	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
Have you tried asking at a local library.  They can probably get a copy from another Library that has it, Library of Congress? Cheers, Will
11932	2015-12-04 13:33:23	Ronan McAllister	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
I was googling and though I didn't find the complete set of 12 months worth of Electronics here, I thought this may be an interesting resource (I am not certain of copyright / legal issues).  http://www.americanradiohistory.com/index.htm
11933	2015-12-04 14:09:51	Chris Howard w0ep	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
My sister-in-law at the university library over yonder says they have that issue in the stacks.
11934	2015-12-04 14:12:22	Mike	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
Wow, what a great resource!  Thank you!  I was not aware of this site.  But as you pointed out, although it's got most issues of Electronics magazine, it does not have the December 1946 issue that I'm looking for.    So my search continues. Mike N4MWP
11935	2015-12-04 14:18:23	Mike	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
The interlibrary loan (ILL) program might work.  I originally discounted this, because it does not allow for loans of periodicals- but then I discovered that they do handle limited photocopying of a few pages of periodicals.  So I will check out my local (Fairfax VA) library to see if they can assist.  Of course, in the meantime, if anyone has a copy of the Dome article that they can share, please feel free to contact me. Thanks for all the suggestions from group members.  I'll let you all know how it goes. Mike N4MWP
11939	2015-12-05 08:03:29	Chris Howard w0ep	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
I stopped by the library while in town this morning. They are open 24x7 for finals week. I found the article. Unfortunately, they have some kind of goofy copy-card system that I don't want to sign up for. So I took some pictures with the cell phone. Maybe it will hold until you can find a better source. http://www.w0ep.us/DOME_1946/Page1.jpg http://www.w0ep.us/DOME_1946/Page2.jpg http://www.w0ep.us/DOME_1946/Page3.jpg http://www.w0ep.us/DOME_1946/Page4.jpg http://www.w0ep.us/DOME_1946/Page3Zoom.jpg
11941	2015-12-05 08:53:05	Mike	Re: Seeking copy of Dome Dec 1946 "Electonics" article on phase shif
Chris: Thanks so much! I am quite impressed with your cell phone photography skills- these images are actually quite readable, and it might be all that I need. I also spent some time on-line last night and submitted an interlibrary loan request to my local library, so they might also provide a photocopy of the article, but I suspect that your photos will be sufficient for my needs in any event. I am particularly surprised that the equations and calculations came out so clear! 73 Mike N4MWP