Attenuator: Serebriakova 13-40dB

created @ 2013/1/1

before i log the process here, 3 weeks passed,  half to one hour per day, almost spend on mechanical design.

3dB/10dB    20dB-var   10dB  (13dB-40dB)                 RL > 20dB     (usage: single stage amplifier testing)

Step 1 select the box

Aluminum die - casting  box is very cute and suitable for this project.

Dimension: 9cmx3.6cmx3cm

step2 create drill mask

first , make a suitable double side PCB board, then mark the drill position.  and dril a dia:3mm hole as the mask for accurate drill.

step3 drill

use the drill  mask drill the box.

step 4 solder

the dirll  mask then use as the PCB shield box panel which will suitable to put into die-cast box.

step 5 done and testing

3dB/10dB    20dB-var   10dB  (13dB-40dB)                 RL > 20dB     (usage: single stage amplifier testing)

DC checking

Use a 4 1/2 digital DVM, a 50R load, a battery to check the DC resistance and the DC attenuation. this ensure all of them connected properly and given a low Frequency attenuation reference.

battery ->  attenuator   -> 50R load

Attenuation=20*log(Vout/Vin)

input           config                          output         attenuation

1.330V     3dB+0dB+10dB        0.2815V       13.48dB

1.3496V   3dB+max+10dB        27.59mV      33.79dB

                        20.3dB max

1.339V    10dB+0dB+10dB       0.1204V       20.92dB

13.41V    10dB+max+10dB      11.92mV       41.02dB

                        20.1dB max

1.3588V   10dB+mid+10dB      28.31mV       33.62dB

1.3588V   3dB+mid+10dB        55.57mV       27.77dB

AC testing  (pending)