hat
Ou gen konprann sikwi sa a pou kapab detèmine li byen. Epi ou bezwen yon osiloskop, nan kou! Pwosesis la kòmanse pa prereglaj tout ajisteman nan pwen mitan yo, k ap aplike yon ekipman pou pouvwa +/- 15V, ak yon vag sinis odyo nan 1kHz nan tou de chanèl, nan yon nivo nan 1V pik-a-lè blokis yo. Mete R5 ak R23 pou egzakteman pp 4.5V nan rezilta yo nan filtè yo pas ki ba, jan yo note sa nan dyagram nan. Lè sa a, ajiste L4 ak R44 repetitively pandan y ap gade nan pwodiksyon an nan U9A, akor bobin an pou siyal maksimòm ak trimpot a pou egzakteman pp 4.4V. Lè sa a ou aplike siyal la 1kHz nan yon sèl D 'nan tablo a, epi ou kout lòt D' a tè. Avèk osiloskop la nan pwodiksyon an nan U11A, ou ta dwe wè yon klasik siyal de-ton. Koulye a, ou ajiste R60, R61 ak R62 repetitively pou pi bon Santralizasyon tè, simetri ak linear. Sa a se pi fasil fè lè l sèvi avèk yon sijè ki abòde chanèl doub ak mete lòt kanal la sou siyal la D 'miltiplikatè a analòg (pwodiksyon nan U6A), supèrpozisyon de tras yo. Apre ajiste benefis la nan kanal yo sijè ki abòde, modulation siyal la de-ton ta dwe jisteman ranpli 1kHz sinis vag nan.
eng
You have to understand this circuit to be able to calibrate it properly. And you need an oscilloscope, of course! The process starts by presetting all adjustments to their mid points, applying a +/-15V power supply, and an audio sine wave of 1kHz to both channels, at a level of 1V peak-to-peak. Set R5 and R23 for exactly 4.5V p-p at the outputs of the low pass filters, as noted in the diagram. Then you adjust L4 and R44 repetitively while looking at the output of U9A, tuning the coil for maximum signal and the trimpot for exactly 4.4V p-p. Then you apply the 1kHz signal to only one input of the board, and you short the other input to ground. With the oscilloscope at the output of U11A, you should see a classic two-tone signal. Now you adjust R60, R61 and R62 repetitively for best ground centering, symmetry and linearity. This is easiest to do by using a dual channel scope and putting the other channel on the input signal to the analog multiplier (output of U6A), superimposing the two traces. After adjusting the gain of the scope channels, the modulated two-tone signal should precisely fill the 1kHz sine wave.