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                           Avionics-List Digest Archive
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                     Total Messages Posted Tue 02/25/03: 2
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Today's Message Index:
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     1. 08:20 AM - Unswitched Audio Inputs  (MikeEasley@aol.com)
     2. 08:42 AM - Re: Unswitched Audio Inputs  (HornetBall@aol.com)
 
 
 
________________________________  Message 1  _____________________________________


Time: 08:20:13 AM PST US
From: MikeEasley@aol.com
Subject: Avionics-List: Unswitched Audio Inputs

--> Avionics-List message posted by: MikeEasley@aol.com

I am wiring my own panel with a UPSAT SL15M audio panel with 2 unswitched
audio inputs.=A0 I have an AOA, EDM900, TruTrak Autopilot, and a Davtron that
all need to be connected to an unswitched audio input.=A0 PS Engineering said,
"Use a dropping resistor from 100 to 460 ohms on each feed and hook two up to
each input".=A0 UPSAT said, "It can't be done, pick two".=A0 TruTrak said, "Just
hook all 4 up, it won't hurt a thing".=A0 Anyone else care to cast a vote!!!

Thanks,

Mike Easley
Colorado Springs
Lancair ES






________________________________  Message 2  _____________________________________


Time: 08:42:22 AM PST US
From: HornetBall@aol.com
Subject: Re: Avionics-List: Unswitched Audio Inputs

--> Avionics-List message posted by: HornetBall@aol.com

In a message dated 2/25/03 10:21:08 AM Central Standard Time, 
MikeEasley@aol.com writes:

> I am wiring my own panel with a UPSAT SL15M audio panel with 2 unswitched
> audio inputs.=A0 I have an AOA, EDM900, TruTrak Autopilot, and a Davtron 
> that
> all need to be connected to an unswitched audio input.=A0 PS Engineering 
> said,
> "Use a dropping resistor from 100 to 460 ohms on each feed and hook two up 
> to
> each input".=A0 UPSAT said, "It can't be done, pick two".=A0 TruTrak said, 
> "Just
> hook all 4 up, it won't hurt a thing".=A0 Anyone else care to cast a 
> vote!!!
> 
> Thanks,
> 
> Mike Easley
> Colorado Springs
> Lancair ES
> 

PS Engineering designed the SL-15 and they're right.  Actually, both PS 
Engineering and Tru Trak are right.  The PS Engineering solution is more 
elegant and allows you to tailor the volume of the various audio sources by 
adjusting resistor values.  You'll need this because the power coming from 
the various sources won't be the same.  At headset levels, there's no need 
for amplifier protection.  UPSAT was just doing a CYA (after all, it's their 
warranty you'll be claiming on if something gets messed up).