[arm-allstar] PTT Delay idea

[David McGough]

Wow, yes, agreed, something is wrong. Those SMM2167 boards are designed
for and work well with mic level input. The URI output is way, way higher
than needed.

How are you coupling the URI to the SMM2167 board?

73, David KB4FXC



On Sun, 6 Oct 2019 john at qso.com wrote:

> It's a DMK URI. The output is already at 995 on the output menu. I know
> something's not right. I have 2 URI's, both seem to act identically.
> 
> -----Original Message-----
> From: David McGough <kb4fxc at inttek.net> 
> Sent: Sunday, October 6, 2019 8:01 PM
> To: John Griffith via ARM-allstar <arm-allstar at hamvoip.org>
> Cc: john at qso.com
> Subject: Re: [arm-allstar] PTT Delay idea
> 
> 
> John,
> 
> What is your audio input source? Can you turn the input level up some before
> the SMM2167--that's probably the simplest solution??
> 
> 
> 73, David KB4FXC
> 
> On Sun, 6 Oct 2019, "John Griffith via ARM-allstar" wrote:
> 
> > I've been trying to integrate one of these SSM2167 boards into my repeater
> > now.
> > I can't figure out how to completely defeat the noise gate however. On low
> > level transmissions off the network, the audio cuts out. 
> > I need to defeat the noise gate while maintaining the gain. Also I need to
> > find a schematic of the little red board itself, not just the chip so I
> > know how to tailor it to my needs. I found that 50K resistor for R1 works
> > for the compression ratio I need, and I've tried all different values for
> R2
> > including the no more than the recommended 5K (1mV) threshold, but I can't
> > detect a difference in the noise gate.  Any documentation would be great
> and
> > appreciated.
> > 
> > John
> > N7OKN
> > n7okn.com
> > 
> > 
> > 
> > >John,
> > 
> > > We are using that board in our radio-less nodes that are about to be
> > >released. You really need some kind of limiting/compression when you just
> > >hook a mic to the CM1xx chip. It works very well. Anyone that is building
> > >their own radio-less node should be aware of this. You either need to
> > >reduce the level such that peaks do not clip or use some kind of
> > >compression.
> > >
> > >
> > >*73 Doug*
> > >
> > >*WA3DSP*
> > >
> > >*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
> > >
> > >On Tue, Mar 5, 2019 at 1:52 PM "John Griffith via ARM-allstar" <
> > >arm-allstar at hamvoip.org> wrote:
> > >
> > > Perfect. Looks like from the documentation, that increasing the value of
> > > the  AVG capacitor increases the recovery time without affecting the
> fixed
> > > 30 ms attack time. That's actually what I was looking for. I think I'll
> > > order one and a project box to put it in. Impressive that that chip will
> > > amplify signals all the way to 1MHz.
> > >
> > > In the meantime, is there a way within the programming of app_rpt to
> send
> > > a short tone or noise burst then the PTT signal on every key-up?
> > >
> > > -----Original Message-----
> > > From: David McGough <kb4fxc at inttek.net>
> > > Sent: Tuesday, March 5, 2019 11:02 AM
> > > To: john at qso.com
> > > Cc: arm-allstar at hamvoip.org
> > > Subject: RE: [arm-allstar] PTT Delay idea
> > >
> > >
> > > Okay....I think this board (or a similar one) will solve your ALC
> issues.
> > > I haven't measured the actual dynamics of this board, with the supplied
> > > component values.  These values could be adjusted to allow wide
> > > modification of all the various parameters, or course.  I would guess
> the
> > > attack is under 1mS and release maybe 100mS. I know on a radioless node,
> > > with a electret mic attached and without this board, you can easily
> > > pop-your-P's, even with the levels set low. With this board, no
> spattering
> > > at all!!!
> > >
> > > Here is a datasheet for the SSM2167 chip:
> > >
> > >
> > >
> >
> https://www.analog.com/media/en/technical-documentation/data-sheets/ssm2167.
> > pdf
> > >
> > >
> > > 73, David KB4FXC
> > 
> > 
> > _______________________________________________
> > 
> > ARM-allstar mailing list
> > ARM-allstar at hamvoip.org
> > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> > 
> > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> > 
> 
> 
> 
>