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Keith · 11th Jan 2007, 6:35 pm

Peter,

Just an update on the S-27. By judicious fiddling I've discovered that the frequency range and stability of oscillation is very dependent on the proximity of the feedback winding to the tuned winding. For range 3 these need to be virtually co-located. I have now got the coil almost right - just a bit more tweaking required. Unfortunately, it's currently wound on a modern clear plastic former as that was the only 3/8" diameter I could find. Hopefully I will come across something that looks a bit more like bakelite in the future. Now I need to tackle the input and mixer coils so that I can get the tracking in - 1/4" formers should be easier to find!

Thanks again for all your help,

Keith

11th Jan 2007, 6:35 pm	#16
Keith Heptode Join Date: Jan 2003 Location: Tewkesbury, Gloucestershire, UK. Posts: 693	Re: Hallicrafters S27 coil info required Peter, Just an update on the S-27. By judicious fiddling I've discovered that the frequency range and stability of oscillation is very dependent on the proximity of the feedback winding to the tuned winding. For range 3 these need to be virtually co-located. I have now got the coil almost right - just a bit more tweaking required. Unfortunately, it's currently wound on a modern clear plastic former as that was the only 3/8" diameter I could find. Hopefully I will come across something that looks a bit more like bakelite in the future. Now I need to tackle the input and mixer coils so that I can get the tracking in - 1/4" formers should be easier to find! Thanks again for all your help, Keith