There is a lot of history on this tube and I wanted to share it with people other than those in the forum I posted this content on originally, especially since according to Brent on AudioTubes.com, 99% of the tubes with the 7308 rating with Bugle Boy logo AND Holland are fakes. However, you can see below he says there are many aspects that point to this as one of the few real ones ever seen online.
4/3/2015 – AudioTubes.com verified it is the first one they have seen since starting the site.
I reached out to Brent from http://www.audiotubes.com/6dj8.htm as I wanted to find out if they would agree or disagree with my findings. This is what he has to say in regards to this tube.
Thanks to Brent for letting me know more about the tube and reconfirming that this is a real 7308 Bugle Boy!
This tube has one of those Tektronix stickers on it that you can’t pull off. However the logo is obvious from the start in this picture you can see the logo barely showing at the bottom of the Tektronix sticker and the 7308 sticker, but I have more.
Tube Specs from Original Ebay Ad:
***** Tested on our new proprietary tester , the E3444 Triplett/Westmore 501 :
It’s a Triplett 3444 / Westmore 501 that has been enhanced.
This tester uses regulated power sources for the bias, plate, & screen voltages, as well as modified operating & testing procedures.
Filament voltage is also controlled.
Tubes are tested in accordance with the manufacturer’s specifications; measurements closely align with a laboratory tester built to rigorously measure vacuum tube characteristics.
Tubes can be accurately matched for gm & plate current at the manufacturer’s specified test points or at other specified test points.
***** This tester was prepared by Mr. Paul Hart of Falls Church , Virginia. *****
Industry Bogey transconductance = 12,500/12,500 µmhos &
Industry Bogey plate current = 15/15 mA
10,600/11,400 µmhos ~ 11.0/12.0 mA
*Note: You really need to look at the pictures after this first one in full size to see the logos, funny enough the erased batch code is obvious even when zoomed out.
(Now here you can see the VR batch code proving it is a 7308 tube indeed!)
Now here is where I am testing the mentioned/pictured above tube in my 82A tube tester! It shows no shorts and reads roughly 77/100 for something made in 1963 that is pretty good! Also being the only one known to exist at this point!!