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Discussion Starter · #8 ·
Channel Master Quantum 1111 VHF Yagi

rochmndx said:
Is anyone interested in modeling/building the old Channel Master Quantum VHF antennas, like the 1110?
I own a never-used Quantum 1111 :) and here's the story of how I got it (sorry about the exaggerations LOL!)

http://www.digitalhome.ca/forum/showpost.php?p=200572&postcount=8

My property has too many tall trees on it so I've never put it up. I've only ever assembled it once for this photo then packed it away again:

 

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Discussion Starter · #12 ·
rochmndx said:
Btw, is anyone willing to draw up their Quantum for me?
I don't know when I'll be able to unearth my CM1111 out of my garage but hopefully in the weeks ahead. I've always wanted to get out the calipers and blueprint it. ;)
 

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Discussion Starter · #16 ·
Autofils, the Crossfires seem to me to be Quantum-style VHF yagi antennas with UHF corner-reflectors in place of the 1111's directors.

I think another change was that the Quantums are golden-anodized, while the newer Crossfires are gray. Anyone ever seen a golden CM Crossfire?

When I blueprint my CM1111 we can hopefully check the spacings and measurements on the Crossfire's biggest model to see if that's what Channel Master did with such an amazing yagi design.
 

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Discussion Starter · #27 ·
If a person doesn't have the basics of electronics down then it all might seem a bit like voodoo, so I'd say an intro course on electronics would be good. Maybe night school, that sort of thing.

If there is already a basis of electronics knowledge then a good purchase would be the ARRL Handbook, which is packed full of antenna design info amongst other things. Here's their home page: http://www.arrl.org/ They offer beginners courses and books too. Here's a good one: http://www.arrl.org/catalog/?item=9078#top
 

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Discussion Starter · #45 ·

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Discussion Starter · #92 ·
As a Linux user I'd want the same thing, but I've not heard about whether Wine runs these antenna modeling apps. Someone needs to try it... ;)
 

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Discussion Starter · #170 ·
Ganging Antennas: Effects on Reception Patterns

I broke it out a terrific discussion from another thread into its own thread in the main OTA Forum so that some of the other folks will see it better:

http://www.digitalhome.ca/forum/showthread.php?t=95148

I've always been a seat-of-the-pants OTA installer (I know what has always worked and what doesn't) and I don't think I'm qualified to get into the theoretical part, but lots of folks here are. :) Feel free to join into that thread.

cheers!
 

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Discussion Starter · #237 ·
A Note To All Antenna Modelers At This Site

I'm copying this here from a recent post by 300ohm as it really hits the nail on the head about the restrictions we need to keep on the quantity and quality of new models posted to the site:
300ohm said:
we have to be very careful about posting too many models here. (Ive only been at this modeling for about a year, and Ive got pretty close to about 1000 or so different models per se. (including infamous 16 bay GHs that no sane person can build) 4nec2 and a fast 'puter makes it all too easy, heh) Keep in mind, regular casual builders read this site and they already find what is posted to be too overwhelming for them and thus become discouraged. This is not my goal, and Im sure its not yours. I would suggest, going on Autofils suggestion, that we not post models unless there is at least a .5 dbi increase in gain somewhere somehow, or at least its a unique design. (Face it, .2 dbi gain is nothing,
Well spoken indeed. For those of you who are fairly new to RF engineering, 4NEC2, and/or antenna modelling, if your data is really on to something bigger than a .5dBi increase then discuss your data here with others so that it can be peer reviewed, and then if it passes muster it will be ready for sharing at large. If it doesn't meet that threshhold but it looks promising then of course discuss it at this site but lets not go public with them until the facts are in. As 300ohm is getting at, many many readers are looking to you folks for the best antennas that they can build.

cheers
 

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Discussion Starter · #240 ·
Its okay to post models with marginal results if the object is education. No problems there.

What we want to dissuade is a lenthy posting run of miniscule changes in models.
 

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Discussion Starter · #281 ·
Also for Linux and Windows users OpenOffice.org's Calc is pretty well a drop-in spreadsheet replacement for Excel (reads, writes, creates, saves to .xls format if you want) as long as Excel macros are not being used. It can do plots and graphical charts with only a small user adjustment in skill set from Excel.
 

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Discussion Starter · #301 ·
Hi Richard and thanks for contributing that idea! Our members have been using a file sharing site for their designs so in your case it would be possible to post NEC files there for you to work with.

Can someone please remind me of which file sharing site is being used?
 

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Discussion Starter · #355 ·
Thanks for that list, Brittany-Guy!

Have you tried 4NEC2 on Linux via Wine? 4NEC2 is the most popular NEC tool here, but I sure wish it had a native Linux port.
 
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