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Shadograph question
#1

I have not a whole lot of experience with this, so:

The shadograph I have is the old type from 16 (same used in the 118 ), the one with a rectangular box with coil on top.
It has the original coil, according to Dee the guy from Alabama radio club who repaired vew wound things for me. Mine had some mechanical problems he could not tackle fast so meantime he gave me this one.

It is skewed. The shadow segment is closer to the left when looking at it.
And though reacting to tuning, the reaction is not very strong.

I the beginning the shadow is narrow  like it should be. Then a voltage of about 4.5V develops across it indicating a current of 6mA (it is about 850 ohm and 4K res in parallel. Removing the resistor does not change anything much).
When tuned to the local station with me for an antenna (at half volume it can de-cone the speaker, it is so strong) the voltage goes down by 1V to 1.2V.
I changed the detector tube, the result is the same with voltage overall gone up about 0.5V and the shadowmeter behavior remaining largey the same.

So

1) are my currents across the shadowmeter looking correct?
2) could the weak magnet simply not pull the vane strongly enough if the current change is OK (the change is about 1.5mA)

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.


Messages In This Thread
Shadograph question - by morzh - 11-27-2016, 02:42 PM
RE: Shadograph question - by Ron Ramirez - 11-27-2016, 04:11 PM
RE: Shadograph question - by morzh - 11-27-2016, 04:29 PM
RE: Shadograph question - by morzh - 11-27-2016, 05:12 PM
RE: Shadograph question - by Radioroslyn - 12-01-2016, 07:38 PM
RE: Shadograph question - by Mondial - 12-01-2016, 08:12 PM
RE: Shadograph question - by morzh - 12-01-2016, 11:04 PM



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