Path: csiph.com!aioe.org!eternal-september.org!feeder.eternal-september.org!cs.uu.nl!news0.firedrake.org!news.xcski.com!ncf.ca!not-for-mail From: Michael Black Newsgroups: sci.electronics.misc Subject: Re: Building a valve radio Date: Wed, 17 Jun 2015 19:29:50 -0400 Organization: National Capital Freenet, Ottawa, Ontario, Canada Lines: 38 Sender: et472@bas11-montrealak-1177756662.dsl.bell.ca Message-ID: References: NNTP-Posting-Host: bas11-montrealak-1177756662.dsl.bell.ca Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Trace: theodyn.ncf.ca 1434583654 25567 70.51.35.246 (17 Jun 2015 23:27:34 GMT) X-Complaints-To: complaints@ncf.ca NNTP-Posting-Date: 17 Jun 2015 23:27:34 GMT In-Reply-To: User-Agent: Alpine 2.02 (LNX 1266 2009-07-14) Xref: aioe.org sci.electronics.misc:4640 On Sat, 13 Jun 2015, Tom Gardner wrote: > On 13/06/15 09:01, Justin Thyme wrote: >> Dave M wrote: >>> Are you looking to build [a valve radio] from a kit or completely from >>> scratch? >> >> From scratch. > > Interestingly you could consider scratch-building the valves > themselves. > I don't think that was ever a common thing for the home builder. Maybe in the very early days, when tubes were just getting started, but I don't think even then. It's just not something I've read about. Eventually some did make their own tubes, I remember an article in QST about 1964 or 65 about an Argentinian who did. I've seen much more about making one's own components. Roll your own capacitors out of wax paper and tin foil. Make electrolytics with beer bottles and some mixture. Make variable capacitors, in the early days they'd be "book" capacitors, pieces of wood that closed like a book, increasing capacitance, but in more recent decades people have made variable capacitors for special purposes. SOme did make their own resistors, if it was early enough, I've seen descriptions. Quartz crystals seemed to be something made before commercial grinding took off (for a long period, crystals weren't very common, then crowded bands and restrictions made them a necessity). Michael > I can probably find a 1930s book showing how to make a car. It > starts by showing how to make the tools necessary to make the > car - e.g. the engine block from a solid lump of metal. > >