Hi, I am wondering if anyone has any information on 4033X's parameters?
Previous links with datasheets appear to be removed a long time ago.
On radiomuseum (without sources), it states that it requires 4V filament, but stated the 6V tube, 4033L as "Normally replaceable-slightly different"
I note that online tube sellers commonly label 4033X together with NT37, which was stated to use 6V (http://www.r-type.org/pdfs/cv1220.pdf)
Any ideas if 4V on radiomuseum is a mistake, or could the 4033X be one of those tubes that are usable on both listed voltages?
Previous links with datasheets appear to be removed a long time ago.
On radiomuseum (without sources), it states that it requires 4V filament, but stated the 6V tube, 4033L as "Normally replaceable-slightly different"
I note that online tube sellers commonly label 4033X together with NT37, which was stated to use 6V (http://www.r-type.org/pdfs/cv1220.pdf)
Any ideas if 4V on radiomuseum is a mistake, or could the 4033X be one of those tubes that are usable on both listed voltages?