Now that I've sorted out the original circuit problem with my Halson Model 606 eye tube circuit...The green glow is weak on the 6E5, so I assume I need a new one. I have a 6U5 and it glows great, but the signal deflection is not as great. Is there any thing I can do to the circuit to increase the deflection on the 6U5?

:Now that I've sorted out the original circuit problem with my Halson Model 606 eye tube circuit...The green glow is weak on the 6E5, so I assume I need a new one. I have a 6U5 and it glows great, but the signal deflection is not as great. Is there any thing I can do to the circuit to increase the deflection on the 6U5?
:

If the grid of the eye tube is connected to the secondary of the 1st IF, you can try moving the connection to the secondary of the 2nd IF. This might cause operational problems. Otherwise, you need a 6E5.
Johnnysan-

The negative voltage on the AVC line is the control voltage to the grid of the 6E5. The 6U5 needs more negative voltage to close the eye. The option is to make a voltage doubler for the original 6E5 to make the target brighter. Here is a link from NA about this and other options.

http://www.nostalgiaair.org/references/articles/TheFlash/Flash04.htm

This is the link showing how the high voltage option works. This puts a higher voltage on the weak 6E5 target. ( Pin 4 )

http://www.antiqueradios.com/chrs/journal/eyetube.html

Hi Brian,
If you look on eBay you will notice that 6U5 is a much more valuable tube thatn the more sensitive 6E5. You may want to consider purchase of a 6E5 and selling your 6U5 and pocketing a little change.

Best Regards,

Bill