Hi every one,
still working from time to time on this build.
I just mailed with Volker about wiring the Gain switch.
On the PCB are 2 connections labeled RG1 and RG2, these are
Ra and Rb in the Gain PDF "Widerstandstabelle für die Wahl der Verstärkung".
In a nutshell:
RG1 = Ra
RG2 = Rb
Wiring the 2 pol Gain switch, e.g.:
20db Gain -> Ra = 31623Ohm, Rb = 47000Ohm (Calculated Values, page 1)
Ra = 31623Ohm ~ 33kOhm parallel with 820kOhm
=> 1/(1/33kOhm + 1/820kOhm) = 31723Ohm (Resistor Error ~0.3%) (Page 2)
So, Ra has to be made out of 2 Resistors in parallel at the first row of the switch!?
(20db@ Row #1: 33k || 820k, Row#2: 47k)
A'm I right Volker?
ROCK-ON!
still working from time to time on this build.
I just mailed with Volker about wiring the Gain switch.
On the PCB are 2 connections labeled RG1 and RG2, these are
Ra and Rb in the Gain PDF "Widerstandstabelle für die Wahl der Verstärkung".
In a nutshell:
RG1 = Ra
RG2 = Rb
Wiring the 2 pol Gain switch, e.g.:
20db Gain -> Ra = 31623Ohm, Rb = 47000Ohm (Calculated Values, page 1)
Ra = 31623Ohm ~ 33kOhm parallel with 820kOhm
=> 1/(1/33kOhm + 1/820kOhm) = 31723Ohm (Resistor Error ~0.3%) (Page 2)
So, Ra has to be made out of 2 Resistors in parallel at the first row of the switch!?
(20db@ Row #1: 33k || 820k, Row#2: 47k)
A'm I right Volker?
ROCK-ON!