Boonton 59LFcoils free download

File name 59LFcoils.pdf

file:///C|/Documents%20and%20Settings/Kenneth%20Grimm/Desktop/FOR%20BAMA/59LF-coil-construction/email.txt Hi Ken, I am forwarding the email from Alan Douglas with his measurements of the original 59LF coils, along with a picture he sent. I also attached the final configuration of my coils. My main coil values came out very close to Alan's measurements, but I ended up putting the coils together, with the trim caps before measuring the final values of all the coils. Regards, -Joe ------------------------------ Hi Joe, Thanks for sharing the excellent photos. If you could provide a table of the inductance values, I think that the photos plus the values might make a nice addition to the 59LF collection. Thanks again, > To: Joe Sousa > From: Alan Douglas > Subject: Re: 59LF Megacycle Meter > X-Rcpt-To: > > Hi, > Photo enclosed. This is as far as I can open the coil forms without > unsoldering the wires. Coils are universal-wound on ferrite slugs 7/8" > diameter, maybe an inch long. They're held on with wax and I can't count turns. Inductances (1 kHz) as follows, in microHenries: > > pins 1-2 pins 3-4 pins 3-5 > > A: 59, 5000, 22. > > B: 5.5, 900, 2.2 > > C: 2.8, 200, 11.6 > > D: 1.9, 27, * > > * = can't read because of 1k resistor in series. > > I presume you have the schematic, but pin 3 is the cold end of the coil, > hot end to pin 4, tap to pin 5. Feedback winding is 1 and 2. > > A .1-.25MHz, B .25-.55, C .55-1.5, D 1.5-4.5. > > The basic coil forms are by Na-Ald (Alden), standard stuff in the 1930s > and 40s. > > Alan www.PhilbrickArchive.org A free repository of materials from GAP/R, George A. Philbrick /Researches. Operational Amplifier Pioneer. file:///C|/Documents%20and%20Settings/Kenneth%20Grimm/Desktop/FOR%20BAMA/59LF-coil-construction/email.txt12/19/2008 10:19:50 PM