Two friends and I had a great time on Saturday. We had talked about building some new field supplies for our Lansing Iconic two way speakers (or parts thereof) for years, and finally got around to studying the project seriously about three months ago.
I didn't have enough F-820 field supplies to power the Iconics on hand, and my friends have been more or less in the same boat. We decided to build a dozen new ones, to meet our current (sorry) and future needs. I also had three original supplies in bum shape, so I ordered enough parts to bring them back up to spec.
To start the project I disassembled one original supply. The transformer and choke went to Jack Elliano at Electra Print Audio in Las Vegas so that he could quote on new iron built to original specs. The bare chassis went to a metal shop. New sockets, capacitors, wire and other miscellaneous bits were obtained here and there. Jack shipped us a dozen new transformers and chokes that are just beautiful, typical of his work. The lamination sizes are just a bit larger than the originals, as those sizes are now obsolete. The new chassis were designed to reflect the slightly different iron dimensions, and we were relieved when the new trannies dropped right into place. One friend mixed up some enamel that beautifully matches the original Lansing dark blue color and sprayed the chassis and transformers.
On Saturday we built up two new supplies and made needed repairs to two original ones. The new ones tested fine under load, delivering just a few volts lower than the original supplies. This seems to be a good result, as line voltage is probably higher now on average than in the 1940s.
Upon completing the rest of the new supplies, the next phase will be to build new wiring harnesses. All Iconics except the earliest ones supplied 330VDC to the field coils of the 801B high frequency driver and 815 woofer in a series string. The harness connects to the drivers using Amphenol four pin and five pin connectors. These are thankfully still manufactured, as is cloth covered wire that closely matches the original harness wiring. The harness also incorporates signal leads from the dividing network to the drivers.
The pictures show one of our new supplies as well as an original, a circa 1945 Altec era piece. By that time they had shifted to a dark gray finish, though all earlier ones were Lansing blue.
Reply With Quote
