Yup! I've seen those odd one pronged plugs. Heck, there is a conversion for the ARC-1 circa 1963 by Lee Pfafenberg (SP?) and it is a voltage quadrupler / doubler arrangement with no isolation. Somewhat intimidating.
Even this WWII Espey morale radio I have is built with a hot chassis. They went to great efforts to keep everything above chassis. What's really weird is that "ground" binding post on a big fiber washer and the phone jack all electically above the case. 73 de KA4JVY Mark --- Mike Dorworth K4XM <[EMAIL PROTECTED]> wrote: > The problem still was that if plugged into the hot side of the line with the > remaining good fuse, the primary, switch etc was HOT to ground all the way > back to the wall plug, Lot of good chances to get stung, a well grounded > chassis the opposite of what you would want.. Remember the old isolation > trainsformers?, Really old radio books called for a SINGLE pronged plug for > AC-DC stuff, relying on the chassis ground to make it work, which has a set > of pitfalls all of it's own, your ground has 110 volts potential to the > power company ground, hopfully the sub surface ground was connected to the > power ground or "Curtains again!" Mike > > > ----- Original Message ----- > From: George Pritchard <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Thursday, February 27, 2003 1:16 PM > Subject: RE: [AMRadio] Series capacitor equalizing resistors - now Johnson > Power Plugs > > > > Since they didn't have polarized outlets in the old days, the plug could > go > > in either way. They had to fuse both sides for safety, and mandate the > > chassis to be grounded. Of course these days, the polarized three pronger > > guy is the best replacement ac line cord, with a fuse in the hot line only > > mounted on the rear chassis. > > George AB2KC > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] Behalf Of Mark Foltarz > > Sent: Thursday, February 27, 2003 12:59 PM > > To: [email protected] > > Subject: Re: [AMRadio] Series capacitor equalizing resistors - now > > Johnson Power Plugs > > > > > > Mike, > > > > You are absolutely correct about those fused line plugs. > > > > But I got to thinking about the philosophy behind those things. > > > > Way back when, proper installation of radio gear was specified as > > including a > > ground - both RF and electrical. If the operator made the installation > > correctly, the chassis was always cold. > > > > I think the engineers of that time believed that the operator was going > to > > be > > responsible and install that chassis connection to a real electrical > ground. > > > > Just a thought. Was operator forethought and responsibility part of > > correctly > > using those plugs or were they just plain dangerous? > > > > Yours, > > > > de KA4JVY > > Mark > > > > > > > > > > --- Mike Dorworth K4XM <[EMAIL PROTECTED]> wrote: > > > Hi folks, just a little about the fused line plugs. You don't see them > > > anymore because of their killing ability, which is very good. All you > need > > > is the fuse in the cold side of the line blown and of course the hot > stuff > > > goes in through and all the way back to the open fuse meaning the entire > > > thing is full of juice waiting for a finger, might have been alright if > > they > > > were polarized which there were not and of course the sockets were not > > > either.. RIP with those literally.. 73 Mike K4XM > > > ----- Original Message ----- > > > From: Mark Foltarz <[EMAIL PROTECTED]> > > > To: <[email protected]> > > > Sent: Wednesday, February 26, 2003 3:57 PM > > > Subject: Re: [AMRadio] Series capacitor equalizing resistors > > > > > > > > > > Wayne, > > > > > > > > The other oddity of that period was of course the fused plugs that > > > Heathkit, > > > > Johnson and other manufacturers used. > > > > > > > > Come to think of it, do you suppose the cord on that particular > AT-1 > > is > > > not > > > > original? I forgot if you described the schematic as specifically not > > > having a > > > > fuse anywhere including the line cord. > > > > > > > > Yours, > > > > > > > > de KA4JVY > > > > Mark > > > > > > > > > > > > --- Sara & Wayne Steiner <[EMAIL PROTECTED]> wrote: > > > > > Mark > > > > > > > > > > The AT-1 manual says 450v, however mine runs about 460v. So , yes > you > > > are > > > > > right, the series combo has a rating of 700v which is substantially > > more > > > > > than what it sees. > > > > > As I mentioned earlier, the AT-1 has no fuse (mine will soon have > > one ). > > > My > > > > > AT-1 was a $5.00 flea market item which came without the power xfmr. > > The > > > > > corner of the chassis where the xfmr was mounted was covered with > > black > > > crap > > > > > where the xfmr obviously had a melt down probably due to a failed > > filter > > > > > caps and no fuse protection! > > > > > > > > > > 73 > > > > > Wayne, N0TE > > > > > > > > > > _______________________________________________ > > > > > AMRadio mailing list > > > > > [email protected] > > > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > > > > > __________________________________________________ > > > > Do you Yahoo!? > > > > Yahoo! Tax Center - forms, calculators, tips, more > > > > http://taxes.yahoo.com/ > > > > _______________________________________________ > > > > AMRadio mailing list > > > > [email protected] > > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > > > > > > --- > > > Outgoing mail is certified Virus Free. > > > Checked by AVG anti-virus system (http://www.grisoft.com). > > > Version: 6.0.455 / Virus Database: 255 - Release Date: 02/13/2003 > > > > > > _______________________________________________ > > > AMRadio mailing list > > > [email protected] > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > __________________________________________________ > > Do you Yahoo!? > > Yahoo! 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