[ARC5] No Doubt Dumb Tube Question

[Glen Zook]

It is still different!  The tube has an indirectly heated cathode even if the cathode and one side of the heater do share a common connection.  The electron flow is NOT from the heater like in a directly heated (filament) rectifier.  The electron flow IS from the cathode.
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: "WA5CAB at cs.com" <WA5CAB at cs.com>
To: arc5 at mailman.qth.net 
Sent: Monday, June 17, 2013 1:47 PM
Subject: Re: [ARC5] No Doubt Dumb Tube Question
 

I did not take the time to go and look up the 5AR4 but although the 
standard tube basing diagram is drawn showing a separate heater and cathode, the 
latter is shown as being internally connected to pin 8 along with one side of 
the heater.  So in the practical (electrical) sense it is directly heated 
just like the 5R4.