antenna trimming?
in [Repair]
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From: David Brodbeck on 1 Dec 2009 17:16 Dave Plowman (News) wrote: > I've not researched it so was only a guess. But I've not noticed quality > radios without a trimmer having inferior MW reception than before. With the number of stations in the band these days, I find weak signal performance is rarely the limiting factor. Usually the problem is selectivity. This discussion reminds me that my old Mercedes had a momentary contact built into the power antenna switch that would let you adjust the antenna length up and down from the dashboard. It was kind of cute but never seemed to make much difference in reception. (Yet another example of Germans inventing a problem so that they could solve it, I think.) The radio itself was an old Blaupunkt and was a magnificent piece of electronics, though. Vastly overengineered. Automatic three-stage scan, direct frequency entry, and an alarm clock!
From: Dave Plowman (News) on 1 Dec 2009 19:16 In article <SI2dnbh4Vus5CIjWnZ2dnUVZ_rGdnZ2d(a)speakeasy.net>, David Brodbeck <gull(a)gull.us> wrote: > This discussion reminds me that my old Mercedes had a momentary contact > built into the power antenna switch that would let you adjust the > antenna length up and down from the dashboard. It was kind of cute but > never seemed to make much difference in reception. (Yet another > example of Germans inventing a problem so that they could solve it, I > think.) The radio itself was an old Blaupunkt and was a magnificent > piece of electronics, though. Vastly overengineered. Automatic > three-stage scan, direct frequency entry, and an alarm clock! Germany of course had (has) no MW radio transmissions of their own - the frequencies were removed from them after WW2. Which is why they had such a lead in FM in the early days. So it might be their radio installations were also better at receiving distant MW broadcasts. But the other reason to stop the aerial going fully up was high speed travel on the autobahn. -- *Can atheists get insurance for acts of God? * Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: mm on 1 Dec 2009 22:18 On Tue, 01 Dec 2009 14:16:01 -0800, David Brodbeck <gull(a)gull.us> wrote: >Dave Plowman (News) wrote: >> I've not researched it so was only a guess. But I've not noticed quality >> radios without a trimmer having inferior MW reception than before. > >With the number of stations in the band these days, I find weak signal >performance is rarely the limiting factor. Usually the problem is >selectivity. > >This discussion reminds me that my old Mercedes had a momentary contact >built into the power antenna switch that would let you adjust the >antenna length up and down from the dashboard. It was kind of cute but > never seemed to make much difference in reception. (Yet another >example of Germans inventing a problem so that they could solve it, I >think.) The radio itself was an old Blaupunkt and was a magnificent >piece of electronics, though. Vastly overengineered. Automatic >three-stage scan, direct frequency entry, and an alarm clock! A good accessory. When I'm driving I like to set my alarm clock to wake me up every 15 minutes.
From: Jeff Liebermann on 2 Dec 2009 02:15 On Tue, 01 Dec 2009 14:12:18 -0800, David Brodbeck <gull(a)gull.us> wrote: >Michael A. Terrell wrote: >> RG/62, 93 ohm coax. The same as what IBM used for their early >> computer networks. > >I've got some 93 ohm coax lying around from when I used some to make a >matching section. Never knew what the original application was for it. > Very interesting. RG-62/u was used for Arcnet networking, <http://en.wikipedia.org/wiki/Arcnet> and IBM 3270 terminal systems: <http://en.wikipedia.org/wiki/3270> -- Jeff Liebermann jeffl(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
From: Jeff Liebermann on 2 Dec 2009 12:19
On Wed, 02 Dec 2009 10:11:04 -0500, Meat Plow <meat(a)petitmorte.net> wrote: >On Tue, 01 Dec 2009 23:15:32 -0800, Jeff Liebermann ><jeffl(a)cruzio.com>wrote: > >>On Tue, 01 Dec 2009 14:12:18 -0800, David Brodbeck <gull(a)gull.us> >>wrote: >> >>>Michael A. Terrell wrote: >>>> RG/62, 93 ohm coax. The same as what IBM used for their early >>>> computer networks. >>> >>>I've got some 93 ohm coax lying around from when I used some to make a >>>matching section. Never knew what the original application was for it. >>> Very interesting. >> >>RG-62/u was used for Arcnet networking, >><http://en.wikipedia.org/wiki/Arcnet> >>and IBM 3270 terminal systems: >><http://en.wikipedia.org/wiki/3270> > >Ahh, I love the smell of LANtastic over RG62A/U and TCNS in the >morning. You might want to ease up on whatever you're sniffing. Arcnet and 3270 used BNC connectors. What's a TCNS? My favorite gizmo was the passive hub. Huge amounts of cash for a mysterious sealed box with 3 or more BNC connectors. I eventually dissected one and was rather disappointed to find only a few resistors. I'm still not certain that AM/FM car antenna coax cable is RG-62/u. I haven't found a suitable car antenna to compare with the boxes and boxes of RG-62/u I have left over from ripping out Arcnet systems (Lantastic) and replacing them RG-58a/u (Ethernet and Novell). -- Jeff Liebermann jeffl(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |