[Amps] Audio/RF compression

[Jim Thomson]

Date: Wed, 11 Jan 2017 13:04:03 -0800
From: Jim Brown <jim at audiosystemsgroup.com>
To: amps at contesting.com
Subject: Re: [Amps] Audio/RF compression


On Wed,1/11/2017 12:07 PM, Manfred Mornhinweg wrote:
> in addition to various circuitry that performs audio processing at 
> varying levels of versatility, quality, and cost, we should not forget 
> the possibility to do it in software.

Yes, certainly a possibility. But have you looked at latency? This may 
or may not be a problem.

Another question though. What's your ham call? How much operating do you 
do? What sort of operating do you do? DXing? Contesting? Casual 
rag-chewing? CW, SSB, RTTY, etc? What bands?

73, Jim K9YC

##  100 msecs or more is ok....even with vox.   Problem starts when you are trying to
monitor urself with headphones on.   A few msecs is fine... but when it gets up to 7-8-9-10 msecs,
the audio will sound screwed up in the headphones..... since u will  hear urself twice,  once through
bone conduction in real time..then again... but delayed, through the headphones.   Phasing problem. 

##  on some digital gear, the delay is fixed..and short, like 3 msecs. 
On some of my other digital gear, like the 6 band  compressor  and digital eq,
the delay is programmable from 1 msec to 3000 msecs.   But that is used for stuff like
outdoor sound  re- enforcement, where a 2nd bank of speakers is located  towards the back of the venue.
Takes 1 sec for sound to travel 1100’.   The fronts are fired 1st.....then the rears are delayed.   If sitting 
at the back of the venue, the two sounds should arrive at the same time.   But this is one off stuff. 
My  JPS   digital noise redux box has a  135 msec delay in it.   Its  bypassed on TX for that reason. 
I see a similar 130 msec delay when using my cell phone to phone myself on the hone phone. 

##  Some of the internet HF receivers I have used have a 15 sec delay.   Fine for testing +monitoring yourself,
after the fact.   

##  If the free  VE3  software works..... go for it.  It has every feature you could need.

Jim   VE7RF