¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. TekScopes
  2. Messages
Single Messages Topics Expanded Polls

Re: Rescuing 500s from tube snatchers/scavengers - how much is it worth

 

Good, clean data on the 5687/6900 is available here:



Having been thru many 100s of 5687s, as seen here:



and here:



I can say that the Tung-Sol 5687 is the NOS part to use to replace the 6900. But even so they have to be tested, see the reject rate in the Excel spreadsheet.

As nearly as I can tell the Raytheon-branded 5687 was a Tung-Sol part

Bill

Which 500 series was the 6900 used in? (I believe 6900 a twin medium mu triode.) 6AX7/12AX7 was high mu.
Bendix was (their gone) an interesting company, involved in the aerospace industrial military supply. (A common name during WWII and the 50's, and 60s.
The 6900 was a "hardened" tube.. made to withstand high g, shock, vibration, and was supposed to be more reliable. (well ... for at least the brief time a launched missile lasted.)
Unless one is planning on launching one's class A, audio amp, into low earth orbit... one doesn't need Bendix 6900s.
Join [email protected] to automatically receive all group messages.