if i have a signal that is .4 μV and it is on a 50Ω system how do i express this in dBμV i tried the .4μ/.2236 and then took 20 log of that and it didn't work

 

if i have a signal that is .4 μV and it is on a 50Ω system how do i express this in dBμV i tried the .4μ/.2236 and then took 20 log of that and it didn't work

I don't know where you got the .2236 from.

Db(uv) = 20 log (v1/v2)=20 log(.4/1)=20 log (.25)=-7.95 db(uv)

 

thank you i was getting the .2236 from the square root of .001*50 formula

 

if a microwave transmitter normally requires a +8dBm audio level to driave the input fully. if +10dBm is measured what is the actual voltage level measured assuming a 600ohm system

 

thank you i was getting the .2236 from the square root of .001*50 formula

As long as you're keeping all your calculations in voltage, you don't have to convert to power...the impedance cancels out. (This assumes the same impedance for input and output signals). If you're calculatiing db for POWER, you'd use 10 log (p1/p2).

Eric