09-08-2012, 07:42 PM
(09-08-2012, 07:22 PM)tiv48 Wrote: I wounder if anyone has a simple circuit for testing magic eyes.
i can test them on my taylor 45d but they dont glow.
what i envisage is box with say 4 valve holders one for each of the common eyes
this is to save on any complex switching.
i think it will need app 180 volt ht 6.3 volt for heaters and a varible 0 to -20 volts for the controle grid.
has any one built such a device?
rob t
Nope, not built one but I am guessing you are on the right lines ie: anode voltages same as what you would typicaly find in a receiver and grid voltage to simulate typical min and max AGC swing, I would have thought that most characteristics for octal valves would be similar (ish) I do not know about B9A etc, sounds like a good project to do, maybe a switched output to a test point for setting up purposes, just kicking a few ideas around.
Lawrence.
