Hi,
I need help with parts values for a 600 ohm input to 150 ohm output t-Pad or commonly called H-Pad. I need 50db pad.
Am I correct in assuming that R1/2 is 1/2 of the R value and if R=299 then R1/2 value is 150 ohms?
Using a calculator available on the internet I come up with R1/2=299, R2=2, R3/2=74
Yes, I realize that Shure has an A15LA available that is a 50db pad but I do not want a U-Pad and the Shure is a U-Pad.
I need help with parts values for a 600 ohm input to 150 ohm output t-Pad or commonly called H-Pad. I need 50db pad.
Am I correct in assuming that R1/2 is 1/2 of the R value and if R=299 then R1/2 value is 150 ohms?
Using a calculator available on the internet I come up with R1/2=299, R2=2, R3/2=74
Yes, I realize that Shure has an A15LA available that is a 50db pad but I do not want a U-Pad and the Shure is a U-Pad.
Attachments
Last edited:
With R2=2R I get something closer to 55.5dB.
Don't forget your output impedance sourcing results in a (close to) 6dB attenuation.
I get roughly R2=3.75 ohms for overall 50dB.
R1/2=298.125
R3/2=73.125
🙂
Don't forget your output impedance sourcing results in a (close to) 6dB attenuation.
I get roughly R2=3.75 ohms for overall 50dB.
R1/2=298.125
R3/2=73.125
🙂
Dug,
I think from your attached thumbnails that you are neglecting the 600 Ohm Input Impedance when you do you calculations. Add a 600 Ohm resistor across the input terminals and repeat calcs.
Cheers,
Ian
I think from your attached thumbnails that you are neglecting the 600 Ohm Input Impedance when you do you calculations. Add a 600 Ohm resistor across the input terminals and repeat calcs.
Cheers,
Ian
That would load the 600 ohm source with 300 ohms (attenuator of 600 ohms and 600 ohms) ...does not make sense.
No, that would make my numbers even higher, more attenuation.
I believe the calculators are ignoring the ~6dB attenuation for the output matching resistors.
Have you looked at my math and used the online calculators and compared the results?
- Status
- Not open for further replies.