The AM Forum

Hello all..i'm back to ask once again on another set of tubes..what!!?? again i thank those that helped with the 18/81 query..ok i've reached the end of my cleaning up and catalouging of a fairly large stash of tubes collected for a few decades only once again this reverts back to that Kolster rcvr from which the 81 tube started..in a cigar box at the bottom of the pile i've come across 5 tubes from that rcvr..no normal markings on the glass envelopes except the 81..only markings are on the base of the tubes as such: Cunningham C335-National NY235-Sylvania SY224-Silvertone 224-National NY224..here's whats odd to me..the tube bases in the rcvr ALSO have the same numbers on top where you plug them in..physically they are 5in high by 1.7 at the widest all 5 pin type..they appear to be the same internally with a small mesh screen circular about .75 by .75 inside..sorry no digital camera..can't post photos..comes out of a Kolster International BC rcvr model K70 that does not have the tubing diagram pasted to the interior cabinet..the patent paper is there ok..
    I have 5 tube manuals with no clue as to what these are..eventually i will have a digital camera and this will help for sure..
Thanks all..i know someone out there has seen these and has the scoop              tnks agn 73 de DAVE

Kolster International - aka Kolster Radio
Service info and schematic attached below for the K-70

Tnx Pete..sorry couldn't get back to ya sooner..evidently as the schematic shows..the 1st number etched on the base is disregarded leaving 3 24s and 2 35s..scrounging thru the box of 2 number tubes found the remaining 3 tubes..an 80-47-27..now the only mystery for myself is just where did the 81 tube come from..that's for me to figure out..thank you Pete..never even thought of the Rider series of schematics to check into..I've got two more to figure out left but for now i'm gonna try to research those myself........agn BIG TNX to you Pete!!              73 de DAVE