Magic eye "Old Buzzard" timer

[AB2EZ]

Upon reset, the magic eye is fully open (grid is 12 volts below the cathode)

After a time determined by the 1000uF capacitor and the 270k ohm resistor (RC ~ 270 seconds), the grid rises to a high enough voltage to start to close the eye. Finally, the grid voltage will equal the cathode voltage, and the eye will close as much as the tube allows it to close.

For my unit:

The eye begins to close (the shaded area begins to appear) when the grid rises to 8 volts (i.e. when the grid is at -4 volts relative to the cathode). This occurs at 270 seconds x [ -ln (4/12) ] ~ 270 seconds x 1.11 = 299 seconds ~ 5 minutes

Stu

[flintstone mop]

Ahhh Yes,
A good application for the 6U5???
They were very good recording level indicators for the early reel-to-reels as they would show the peak levels of audio rather than the inaccurate consumer type VU meters.

Fred

[steve_qix]

This is great !  I think an additional feature should be to set off some type of audible alarm......or a small shock which is imparted to the offending operator    (or simply a connection to the T/R system!).   

Regards,

Steve

[Steve - WB3HUZ]

Proper modulation.

[w4bfs]

propermod ....uh reminds me of the first campfire jam in 'Caveman' ....cooda ! ...beefus

[W3FJJ]

Love that Idea Stu!
I want to build one of those, got a few the
eye tubes kicking around, and lord knows I need it!

Chuck

[steve_qix]

Love that Idea Stu!
I want to build one of those, got a few the
eye tubes kicking around, and lord knows I need it!

Chuck

Talk about buzzarding !!!

There's one guy from a bit West of me who literally makes 20 to 30 minute transmissions EVERY TIME !  I was listening a few days ago - the aforementioned operator was on - the other guy to whom he was talking SIGNED OUT, and the first guy proceeded to make ANOTHER 15 minute transmission, ANYWAY !!!  The operator in question is a great guy - just very LONG WINDED 

I myself have prepared (from scratch), COOKED and EATEN an entire meal during one such QSO (I have a BC1004 receiver in the kitchen, so I can listen while doing other things), - I did all that stuff, and got back to the radio room before it was turned back to me!  Now *that's* an old-buzzard transmission 

We have several like that in the New England area.  Probably why the Grey Hair Net started around here (dedicated to rag chew sessions on 160 meters).

Regards,

Steve

[Mike/W8BAC]

I like the idea very much Stewart. I'll have a look at what I have in my tube stash. I know I have at least three nos magic eyes and never considered what I might do with them except to replace an old, worn out tube but I only own one receiver that uses the eye. Good idea!

JJ, Adding an audible reminder to the eye at say 11 minutes would be a neat addition  but it would have to be something vintage like the eye, agreed? Any ideas?

For the old buzzard your talking about Steve, maybe a klaxon followed by a solenoid actuated wire cutter on the B+.

Mike

[N0BST]

6U5s are a bit too valuable for that.  Maybe some 1629s?

Scott Todd