[Amps] grid resonance

[Ian White GM3SEK]

R L Measures wrote:
>> But that resonance belongs to the whole circuit, involving the
>> anode and
>> cathode and all their associated components. There are too many
>> unknowns
>> in that loop to understand what the frequency of the observed dip
>> might
>> be telling us about reverse feed-through from the anode back to the
>> cathode.
>
>It tells me that the grounded grid is no  longer acting as a perfectly 
>wondrous shield between the anode and the cathode.

Sorry, wondrousness is not a valid SI unit. I thought the intention of a 
measurement was to quantify something.

>>> I must admit that I've never had a lot of use for GDO
>>
>> Me neither, because it's so difficult to understand what a dip
>> actually
>> means, except in the very simplest cases.
>
>The dip means that the entire circuit has a resonance at that 
>frequency.
>>
>> The GDO is deceptively simple instrument. The trick is to tell when it
>> stops being simple, and starts being deceptive.
>
>Can a dipmeter indicate resonance when there is none?

Probably not - but the instrument never tells you what that dip MEANS, 
and with a dipmeter the interpretation is always open to question.



-- 
73 from Ian GM3SEK