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Groups > alt.folklore.computers > #155133

Re: off topic: old house wiring?

From Michael Black <et472@ncf.ca>
Newsgroups alt.folklore.computers
Subject Re: off topic: old house wiring?
Date 2015-12-12 21:42 -0500
Organization National Capital Freenet, Ottawa, Ontario, Canada
Message-ID <alpine.LNX.2.02.1512122138210.32294@darkstar.example.org> (permalink)
References (1 earlier) <scgmjc-32e.ln1@sambook.reistad.name> <707ad635-2d91-4089-a5e6-2c2246fd8a38@googlegroups.com> <dd30soFpud0U1@mid.individual.net> <n4hpoa120od@news6.newsguy.com> <dd3o36F18guU1@mid.individual.net>

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On Sat, 12 Dec 2015, Osmium wrote:

> "Charlie Gibbs" wrote:
>
>> On 2015-12-12, Osmium <r124c4u102@comcast.net> wrote:
>> 
>>> I think the most common was 35W4, 50L6, 12SA7, 12SG7 and12SQ7,
>>> There's some guesswork in there and I think the 12SG7 is wrong,
>>> but a few minutes work doesn't come up with a better guess.
>> 
>> You're looking for 12SK7.  And 35W4 was the rectifier in the
>> later sets using 7-pin miniature tubes; the one used in the
>> octal version you're thinking of was 35Z5.
>> 
>> (The 7-pin miniature version used 12BE6, 12BA6, 12AV6, 50C5,
>> and 35W4.)
>> 
>> https://en.wikipedia.org/wiki/All_American_Five
>
> Thanks, 12SK7 it is. That is strange how my mind messed up the two series and 
> let 35W4 be octal.  Even after reading your post, the 35Z5 refuses to come to 
> my mind, as though I had never heard of it.
>
> The linked article says that the chassis may be connected to one side of the 
> line - I don't think I ever saw that happen in practice on a radio.  I don't 
> even know haw dangerous a 120 V power line really is to a healthy teenager. 
>
I once took a VTVM (voltmeter that had a power supply that ran from the AC 
line) and I just wasn't thinking, so I connected the ground wire to the 
"ground" of an AC/DC tv set (that was common for portable sets, at least 
in the B&W days).  The insulation on that ground wire burned off fast, the 
fuse took longer to go.

Nowadays, the equivalent of those old radios is switching supplies.  The 
initial circuitry is right across the AC line, but it converts it to DC, 
which then powers an AC oscillator at a higher frequency, so the voltage 
can be stepped down with a much smaller transformer (since it can operate 
at hundreds of Hertz rather than 50/60Hertz of the line frequency).  Up 
till that transformer, the circuitry is as unsafe as those old radios.

   Michael

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Thread

off topic:  old house wiring? hancock4@bbs.cpcn.com - 2015-12-09 11:01 -0800
  Re: off topic:  old house wiring? Jon Elson <jmelson@wustl.edu> - 2015-12-09 14:17 -0600
    Re: off topic:  old house wiring? Dan Espen <despen@verizon.net> - 2015-12-09 16:18 -0500
      Re: off topic:  old house wiring? hancock4@bbs.cpcn.com - 2015-12-09 13:38 -0800
        Re: off topic: old house wiring? philo <philo@privacy.net> - 2015-12-09 17:38 -0600
        Re: off topic:  old house wiring? Jon Elson <jmelson@wustl.edu> - 2015-12-10 13:54 -0600
  Re: off topic:  old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-09 21:43 +0100
    Re: off topic:  old house wiring? hancock4@bbs.cpcn.com - 2015-12-09 13:19 -0800
      Re: off topic:  old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-12 10:38 -0600
        Re: off topic:  old house wiring? "gareth" <no.spam@thank.you.invalid> - 2015-12-12 16:53 +0000
        Re: off topic:  old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-12 18:06 +0100
          Re: off topic:  old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-12 11:31 -0600
          Re: off topic:  old house wiring? hancock4@bbs.cpcn.com - 2015-12-12 11:25 -0800
        Re: off topic:  old house wiring? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-12 18:41 +0000
          Re: off topic:  old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-12 17:14 -0600
            Re: off topic:  old house wiring? Bob Eager <news0005@eager.cx> - 2015-12-12 23:31 +0000
            Re: off topic:  old house wiring? Michael Black <et472@ncf.ca> - 2015-12-12 21:42 -0500
    Re: off topic: old house wiring? Peter Flass <peter_flass@yahoo.com> - 2015-12-09 16:22 -0500
      Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-09 13:42 -0800
        Re: off topic: old house wiring? Peter Flass <peter_flass@yahoo.com> - 2015-12-09 17:11 -0500
        Re: off topic: old house wiring? cmadams@cmadams.net (Chris Adams) - 2015-12-09 19:41 -0600
      Re: off topic: old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-10 01:54 +0100
        Re: off topic: old house wiring? Dave Garland <dave.garland@wizinfo.com> - 2015-12-09 22:42 -0600
          Re: off topic: old house wiring? Jon Elson <jmelson@wustl.edu> - 2015-12-14 17:28 -0600
            Re: off topic: old house wiring? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-15 08:19 +0000
              Re: off topic: old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-15 09:48 +0100
              Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-16 09:53 -0800
        Re: off topic: old house wiring? "Ranger" <r5432@gmail.com> - 2015-12-10 17:44 +1100
        Re: off topic: old house wiring? Peter Flass <peter_flass@yahoo.com> - 2015-12-10 15:23 -0500
          Re: off topic: old house wiring? scott@slp53.sl.home (Scott Lurndal) - 2015-12-10 20:49 +0000
          Re: off topic: old house wiring? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-10 23:48 +0000
            Re: off topic: old house wiring? Michael Black <et472@ncf.ca> - 2015-12-10 23:12 -0500
              Re: off topic: old house wiring? mausg@mail.com - 2015-12-11 10:12 +0000
              Re: off topic: old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-11 08:31 -0600
                Re: off topic: old house wiring? "gareth" <no.spam@thank.you.invalid> - 2015-12-11 14:47 +0000
                Re: off topic: old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-11 09:06 -0600
                Re: off topic: old house wiring? "gareth" <no.spam@thank.you.invalid> - 2015-12-11 15:49 +0000
                Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-11 09:37 -0800
            Re: off topic: old house wiring? mausg@mail.com - 2015-12-11 10:08 +0000
              Re: off topic: old house wiring? cmadams@cmadams.net (Chris Adams) - 2015-12-11 08:38 -0600
                Re: off topic: old house wiring? mausg@mail.com - 2015-12-11 16:24 +0000
              Re: off topic: old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-11 15:17 +0100
                Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-11 09:30 -0800
                Re: off topic: old house wiring? Stephen Sprunk <stephen@sprunk.org> - 2015-12-11 12:43 -0600
                Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-11 11:09 -0800
                Re: off topic: old house wiring? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-11 22:56 +0000
                Re: off topic: old house wiring? Michael Black <et472@ncf.ca> - 2015-12-11 14:47 -0500
                Re: off topic: old house wiring? "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-11 15:13 -0600
      Re: off topic: old house wiring? Stephen Sprunk <stephen@sprunk.org> - 2015-12-09 22:39 -0600
        Re: off topic: old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-09 23:12 -0600
          Re: off topic: old house wiring? Stephen Sprunk <stephen@sprunk.org> - 2015-12-10 00:59 -0600
        Re: off topic: old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-10 09:48 +0100
          Re: off topic: old house wiring? Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-10 12:40 +0000
          Re: off topic: old house wiring? Stephen Sprunk <stephen@sprunk.org> - 2015-12-10 11:02 -0600
            Re: off topic: old house wiring? Jon Elson <elson@pico-systems.com> - 2015-12-11 22:01 -0600
              Re: off topic: old house wiring? Stephen Sprunk <stephen@sprunk.org> - 2015-12-12 00:48 -0600
                Re: off topic: old house wiring? Morten Reistad <first@last.name.invalid> - 2015-12-12 11:16 +0100
      Re: off topic: old house wiring? Jon Elson <jmelson@wustl.edu> - 2015-12-14 17:25 -0600
        Re: off topic: old house wiring? hancock4@bbs.cpcn.com - 2015-12-16 09:45 -0800
    Re: off topic:  old house wiring? scott@slp53.sl.home (Scott Lurndal) - 2015-12-10 14:06 +0000
    Re: off topic:  old house wiring? "capek@ieee.org <Peter Capek>" <peter.capek@gmail.com> - 2015-12-12 11:50 -0800
      Re: off topic:  old house wiring? "Osmium" <r124c4u102@comcast.net> - 2015-12-12 16:56 -0600

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