18-05-2020, 11:52 AM
(This post was last modified: 18-05-2020, 11:55 AM by Mike Watterson.)
I can post you a couple if they don't materialise!
A friend has a couple of very old radios, probably used bright emitters or very early coated triodes. No tubes. One is a 1926 superhet. So one idea is to run the series filaments off 2V lead acid (which lowers gain) and fit the 1p24b in a holder made from car headlamp bases (pull out the 3 blades, fit 4 pins) and a glass globe from small pear shaped bulbs that are large enough for the rod tube. I sprayed the inside of one to simulate "black" and one to simulate "silver" getter deposit.
Triodise them. I've verified at at 1.8V (a near flat 2V Lead Acid) the performance is if anything a little better than the original triodes.
A friend has a couple of very old radios, probably used bright emitters or very early coated triodes. No tubes. One is a 1926 superhet. So one idea is to run the series filaments off 2V lead acid (which lowers gain) and fit the 1p24b in a holder made from car headlamp bases (pull out the 3 blades, fit 4 pins) and a glass globe from small pear shaped bulbs that are large enough for the rod tube. I sprayed the inside of one to simulate "black" and one to simulate "silver" getter deposit.
Triodise them. I've verified at at 1.8V (a near flat 2V Lead Acid) the performance is if anything a little better than the original triodes.
