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Title: MB-150 and MB-40 origins Post by: Opcom on December 29, 2011, 01:45:10 AM Does anyone know what genius invented and documented these little wonders? Its said that the (ham-made) design originally appeared in an earlier QST but no luck so far finding it. It has to be in or before 1953.
Maybe the trick is not the 'feature' of the article, hard to believe.. Probably an amplifier article or perhaps a tuner. It would be interesting to try LTSpice to work it out, maybe tedious but I'd like to try something. Title: Re: MB-150 and MB-40 origins Post by: W7TFO on December 29, 2011, 02:22:43 AM They be from National, I have the original data sheets on both if you need copies.
73DG Title: Re: MB-150 and MB-40 origins Post by: Opcom on December 29, 2011, 02:39:12 AM Copies would be gratefully received the ones I have are not great.
I'm just curious where the idea first showed up and was thoroughly discussed, basically to have a list of cap values and coil inductances and winding data. Title: Re: MB-150 and MB-40 origins Post by: Steve - K4HX on December 29, 2011, 03:10:56 AM Manual/data sheets for the MB-40SL here.
http://www.amwindow.org/tech/pdf/mb40sl.pdf Title: Re: MB-150 and MB-40 origins Post by: vincent on December 29, 2011, 03:27:02 AM MB-40L
http://amfone.net/Amforum/index.php?topic=18076.0 Title: Re: MB-150 and MB-40 origins Post by: KC2ZFA on December 29, 2011, 07:45:44 AM Vernon Chambers appears to have promoted the use of multiband tuners in grid/plate tank circuits but I don't know if he is the inventor of such tuners.
Title: Re: MB-150 and MB-40 origins Post by: Steve - K4HX on December 29, 2011, 10:15:47 AM Yes, he had an article on the topic in the July 1954 QST. And the very famous Three-Control Six-Band 813 Transmitter series of articles (first one in Jan 54) used a multiband tuner. Given the popularity of this HB project, National may have decided to produce the MB-40 and 150. Or maybe they planned to produced them all along and just used the article to prime the pump. ;)
Title: Re: MB-150 and MB-40 origins Post by: Opcom on December 29, 2011, 12:56:35 PM 100% on target! thanks!
Title: Re: MB-150 and MB-40 origins Post by: KL7OF on December 29, 2011, 08:19:06 PM They work very well for me ...I have one working as a grid tuner in my PP 250th rig....I believe there was a 100 watt rig project in an old Calif handbook that used the MB 150 in the output.... AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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