An isolation transformer is more than a 1:1 ratio. Typically they have different construction to minimize capacitive coupling. The isolation transformers designed for medical facilities seem to have some of the best characteristics.
-----Original Message----- From: Nigel Gunn G8IFF/W8IFF <[email protected]> To: [email protected] Cc: Drakelist <[email protected]>; TC Dailey <[email protected]> Sent: Tue, Feb 1, 2011 6:16 pm Subject: Re: [Drakelist] Test equipment and getting started You don't make one, you go buy it. It's just a 1:1 mains in/mains out power transformer. You probably need something rated for a couple of KVA. They're not cheap. Run the transformer from a GFCI protected power outlet. On 01-Feb-11 23:06, Jim Larsen - AL7FS wrote: > While we are on test equipment topics... > > I have been combing the internet for a building article on isolation > transformers and Ground Fault Circuit Interrupters > (GFCI). I cannot believe that I cannot find any. It is not even in the ARRL > Handbooks I looked at. > > I want to start working on boatanchor rigs, not to mention my TR4-CW, but > everybody says ALWAYS use an isolation > transformer and GFCI. Nobody says How to do that. It is assumed that all hams > know what an isolation transformer is or > how to build one. Somehow I missed that in my 46 years as a ham. Go figure. > > Google and Bing have failed me. Can any of you help? A URL? A PDF? A .doc > file? > > Thank you. > > 73, Jim > > Jim Larsen, AL7FS > Anchorage Alaska > 907-345-3190 > http://www.AL7FS.us/ > > > On 2/1/2011 8:18 AM, TC Dailey wrote: > > * test gear on MY bench is my trusty Variac. > I run mine through an isolation xfmr, > a single 117vac outlet. AND plug-in bridge rectifier > * Number two is an ANALOG type VTVM - > * Number three is my old Kenwood TS-430S (used as a receiver) > * Soldering iron AND a soldering GUN - > * HP-606A (great signal generator) was analog of course, so I > made a minibox with a .1 cap in series with the gozinta and the > gozouta - with a pickup loop for a counter - it's easy to zero up that > way. > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > -- Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032 Amateur Radio G8IFF W8IFF (was KC8NHF 9H3GN), e-mail [email protected] www http://www.ngunn.net Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pigs QRP Club International #385, Dayton ARA #2128, AMSAT-NA LM-1691, AMSAT-UK 0182, MKARS, ALC, GCARES, XWARN, EAA382. _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
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