R-301 tube info needed

[oldfarmall]

Hello-

I recently purchased an old Gambles cattle electric fence controller. Has a transformer and two vacuum tubes.

The tube that I believe is bad has R-301 stamped on it, plus what I believe is a date code of 5-40 for May 1940. The tag on the fencer says approved by industrial commission of Wisconsin February 23,1939. So I believe this fencer is from 1940 or 1941.

I cannot find any info online about the R-301 tube. I think it may be a rectifier tube, but not sure? I found R-301A tubes online but not sure if it is equivalent.

The other tube that may still be good is T-302. I believe this tube emits a light to show unit is operating, as that tube is directly underneath a magnifying lens on the outer case of the fencer.

Can anyone provide info on this R-301 tube and if a replacement is available? There are no markings anywhere of a brand name on the tube.

 

[oldvinyl]

Try a Google search for “R-301 vacuum tube equivalent”.
Also search for “R-301 tube data sheet” and “R-301A tube data sheet”. Compare the plate voltage and heater current.

If none of that makes sense, reply here. I can look it up tomorrow.

There are R-301A for sale on eBay. Look for a seller that provides test results showing that the tube is good. Maybe get a couple spare if that fixes it.