A way to calibrate the Expat VU meter mod?

[jwhmca]

I'm using a meter I bought off ebay nessei tr-35

It doesn't seem to track right.

7db gain reduction on the meter = about 10db reduction on any other meter

Is there a way to adjust it other than the zero set?

 

[SSLtech]

The problem has to be with the meter.

Most Nissei's aren't even AC meters... is yours AC  or DC?

The rectifier adds a nonlinearity, plus the nissei movements aren't very linear to begin with...

If you use a proper VU meter, the readings should be perfect... If that's the case, then the problem is that your meter is too far from linear.

 

[jwhmca]

Part No. TR-35

Professional, high Class

dB : -20~+5dB

0dB=1.228V+/-10%, calibalated

DCR= 650Ω, If=450uA

Lamp : White LED x1pcs ,10~20mA (has no resistor inside)

Led Lamp voltage : 2.2~2.6V

So, you need the resistor :270Ω 1/4W ,if VDC=5V

390Ω 1/4W ,if VAC/DC=6.3V

1000Ω 1/2W ,if VAC/DC=12.6V