[Asterisk-Dev] Re: How to measure delay in meetme?

[Clive Nicolson]

On Mon, 29 Aug 2005, Steve Edwards wrote:

> On Mon, 29 Aug 2005, Tony Mountifield wrote:
> 
> > I've never found problems with delay when only Zap channels are involved;
> 
> Personally, I don't think anybody would notice in a real conversation, but 
> you can notice it if you have a separate phone to each ear or if you 
> listen on one handset and tap the table with the other.

Get a dual channel oscilloscope, a audio signal generator, a small speaker 
and a microphone. Set the generator to a frequency lower that the delay you 
think you are hearing. Feed the signal to the speaker and one channel of 
the scope (trigger of this signal), adjust the level so you can hear it. 
Connect the microphone to the other scope's other channel and place the 
microphone near the speaker. Adjust the gain on that channel so that you 
can compare the 2 undelayed signals.

Now place the speaker near the mouth piece of one phone and the microphone 
near the ear piece of other phone. Establish a call between these phones.

You should be able to measure the delay over that path on the scope!

Borrow the scope and signal generator and get the speaker and microphone 
from Tandies (your local electronics store).

Clive