[HAM] Tone Generator

[Hugh]

I think the purpose of the shunt resistor for measurement is more to 
simulate the load that the rest of the organ, i.e. the matching 
transformer and resistance wires, puts on the TG. Wouldn't this load 
affect the output? I would think that it would but I don't know the 
impedance of the matching transformer. If it's low, then it could 
have a huge effect on the actual levels produced by the TG, but I 
understand the logic of not using any loading resistor in order to 
have a baseline reference that is easily repeatable across different 
measurement apparati. Like you mentioned, with different crossovers, 
drivers, box resonance etc. of Leslies, there are many variables that 
will affect the final perceived loudness that there really is no absolute.

Hugh


>My own view about measuring the TG output levels  with a shunt resistor
>such as a 10 ohms (  or Carsten Myer's preferred 27 ohms )  is that this
>produces inaccurate false readings because the TG notes  are loaded down
>and their output levels are lowered. I much prefer to measure the TG
>directly without loading it down with any shunt resistor so that I can
>get the true accurate  output voltage levels. The chart and the output
>curve graph of the unloaded TG readings can then be used as a reference
>and they  can be  used for comparison purposes with other measured  TG
>output level charts and output curve graphs. When people measure TG's
>with a shunt resistor then the only way that these readings can be used
>as a reference is if another person uses resistor  with the exact same
>ohms value reading because each resistor has a different tolerance and
>when it comes to very low ohms values such as 10 ohms or 27 ohms  the
>tolerance would be extremely important because of the way that the
>shunt resistor affects the output voltage reading of the TG notes.
>
>All the best.
>Kon