04-06-2012, 06:12 PM
Thanks David and Al, I am lacking in text books having given most of my collection away when I went to work in Canada some years ago, the low inductance primary as used in Davids set is fully covered in the Radiotron Designers Handbook which is available as a PDF....
http://paleoelectronics.com/RDH4/
The high inductance primary is not to hard to understand, nevertheless I would still be interested in the low inductance primary function as it seems that set makers favoured this approach in later years and I am wondering why or if it was due the the advancement of valve technology eg: higher Gm valves the high inductance primary being a positive reactance would afford a certain amount of regeneration thus helping to compensate for the low L/C ratio at the bottom end of the bands, my reasoning is that that's fine with the with the lower Gm valves of long ago with higher Gm valves I could see why this would be detrimental eg: it might go into oscillation with a high inductance primary even if it was designed to self resonate outside the band as they were designed to do.
All interesting stuff, ultimately I need the info so I can construct the coils for my Regenerodyne receiver project for the best transfer of signal.
Lawrence.
http://paleoelectronics.com/RDH4/
The high inductance primary is not to hard to understand, nevertheless I would still be interested in the low inductance primary function as it seems that set makers favoured this approach in later years and I am wondering why or if it was due the the advancement of valve technology eg: higher Gm valves the high inductance primary being a positive reactance would afford a certain amount of regeneration thus helping to compensate for the low L/C ratio at the bottom end of the bands, my reasoning is that that's fine with the with the lower Gm valves of long ago with higher Gm valves I could see why this would be detrimental eg: it might go into oscillation with a high inductance primary even if it was designed to self resonate outside the band as they were designed to do.
All interesting stuff, ultimately I need the info so I can construct the coils for my Regenerodyne receiver project for the best transfer of signal.
Lawrence.
