They're "acetate" discs, 16" OD for a 15 minute transcription (33 1/3rpm) in broadcast service, (12" & less was used for domestic recordings). Some went up to 17.5" OD
Recordings were not great at less than 6" diameter hence the big diameters. Used a cellulose lacquer on the aluminium platter which produced swarf that was the basis for truly excellent "bombs" when packed into small bags & ignited with various fuse wires, usually under unsuspecting colleagues' desks. Every heavy metal '50's AM broadcast tx in amateur service should have a Presto or Beardsley recording lathe for log-keeping. Another BA angle: Here's http://cgb-1.com/pod/20090929.jpg a Jap seaman on a WWII navy ship preparing to record enemy CW for subsequent authentication of the fist. Nige VK3DZ On Thu, Jan 21, 2010 at 7:10 AM, CL in NC <mjca...@yahoo.com> wrote: > I have several test circuits I salvaged before they hit the dumpster. These > were built in the late 50's, early 60's. They were in homebuilt Bud type > miniboxes, and the constructor, Fritz, W4NTO said the aluminum came from old > records. They melted the plastic off the disk and a shiny aluminum platter > of the perfect minibox thickness remained. The aluminum was high qualtiy and > even to this day, the inside of the chassis are as bright as chrome, not one > hint of corrosion. The outsides were painted. > > So that old cracked and scatched Caruso 78 might have a gold mine of aluminum > under its useless surface. > > Charlie, W4MEC in NC > > > > > Please consider the environment before printing this e-mail. The information contained in this email and any attachment is confidential and may contain legally privileged or copyright material. It is intended only for the use of the addressee(s). If you are not the intended recipient of this email, you are not permitted to disseminate, distribute or copy this email or any attachments. If you have received this message in error, please notify the sender immediately and delete this email from your system. The ABC does not represent or warrant that this transmission is secure or virus free. Before opening any attachment you should check for viruses. The ABC's liability is limited to resupplying any email and attachments. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
