Hi Jim,

I spoke with you earlier today about this.
I have 3 aux audio inputs that I want to run through my PM-3000
intercom. The problem is the PM-3000 does not support any unswitched
aux inputs. I had tried running them through the entertainment input
but this results in the audio only playing through one speaker (stereo
system). If I run them to both the left and right inputs this
permenently shorts the left and right sides and I end up with a mono
entertainment system. Can I run these on the same line as the com radio
input? Is there something available to to make this work or do I need
to buy an audio panel?


Thanks,
Danny

Danny ...

Sorry, but I stay as far away from stereo systems as I possibly can...

Here's the canned answer:

******************************

Stereo In The Aircraft

RST does not produce any stereo intercoms, audio panels, headsets, or other
devices that reproduce stereo music. If you are absolutely determined to
have stereo in your aircraft, you might just as well stop reading now,
because anything we have to say isn't going to change your mind.

We made a conscious business and engineering decision not to produce any
product for stereo. There are good aviation and engineering reasons for
this.

First, a little background music or listening to the ballgame in a cockpit
environment isn't all that bad. Sometimes flying is miles and miles of
nothing but miles and miles. On the other hand, I know from my own love of
music that when there is a particularly good cut playing on my home stereo
and I have the headphones on (try "Sweet Sir Galahad" by Baez or "Minstrel
Of The Dawn" by Lightfoot at somewhere slightly below the threshold of pain
in the 'phones to see what I mean) that I get totally lost within the music
and the world just sort of blurs away. Just about the LAST thing I want in
an airplane is a pilot that has zoned out on music and is just holding the
controls to have something to do with their hands. That's item #1.

Second, stereo is expensive. Yes, I understand that FLYING is expensive,
too, but to go to the expense of specially-designed headphones, intercoms,
audio panels, and all the rest of it seems to us to be on the other side of
reasonable. Our company thrust has, and always will be, to make flying
affordable for everybody. That's point #2.

Now to the engineering stuff. Suppose you try and take your stereo headset
and fly in somebody else's airplane that is "regular airplane". Will your
stereo headset work without the trick little switch on the cable to convert
it to a monophonic headset? No, you will hear one ear of the conversation
only. And what did that little switch do? It put both earphones in
parallel, which cut the impedance of the headset in half. Properly
designed, this MIGHT not be noticeable to the aircraft radio, or it might.
Since airplane radios weren't designed to figure out whether or not you were
messing around with a stereo headset, the manufacturer didn't worry about
making sure his radio would drive that low of an impedance.

Even worse, if somebody else takes his standard aircraft headset and puts it
into your stereo airplane jack, it will short out one of the channels.
Depending on the design of the intercom, the best you can hope for is that
one stereo channel will be dead in everybody's headphones. Second worst is
that the short on that channel will blow out the amplifier for that channel.
In a really lousy design, that short will cause the whole intercom/audio
panel to fail, leaving you without any headphone audio at all.

Given all these reasons, RST has decided not to produce any stereo
equipment. While it probably won't sway your decision for stereo in your
airplane, we thought you should at least consider these problems.

Jim

**************************************************
"Danny" > wrote in message
oups.com...
> Hi Jim,
>
> I spoke with you earlier today about this.
> I have 3 aux audio inputs that I want to run through my PM-3000
> intercom. The problem is the PM-3000 does not support any unswitched
> aux inputs. I had tried running them through the entertainment input
> but this results in the audio only playing through one speaker (stereo
> system). If I run them to both the left and right inputs this
> permenently shorts the left and right sides and I end up with a mono
> entertainment system. Can I run these on the same line as the com radio
> input? Is there something available to to make this work or do I need
> to buy an audio panel?
>
>
> Thanks,
> Danny
>

"Danny" > wrote in message
oups.com...
> Hi Jim,
>
> I spoke with you earlier today about this.
> I have 3 aux audio inputs that I want to run through my PM-3000
> intercom.> Thanks,
> Danny
>

I stay as far away from stereo in the aircraft as I can, so I'm sorry I
don't have an answer for you.

HEre's my "canned" answer::

******************************

Stereo In The Aircraft

RST does not produce any stereo intercoms, audio panels, headsets, or other
devices that reproduce stereo music. If you are absolutely determined to
have stereo in your aircraft, you might just as well stop reading now,
because anything we have to say isn't going to change your mind.

We made a conscious business and engineering decision not to produce any
product for stereo. There are good aviation and engineering reasons for
this.

First, a little background music or listening to the ballgame in a cockpit
environment isn't all that bad. Sometimes flying is miles and miles of
nothing but miles and miles. On the other hand, I know from my own love of
music that when there is a particularly good cut playing on my home stereo
and I have the headphones on (try "Sweet Sir Galahad" by Baez or "Minstrel
Of The Dawn" by Lightfoot at somewhere slightly below the threshold of pain
in the 'phones to see what I mean) that I get totally lost within the music
and the world just sort of blurs away. Just about the LAST thing I want in
an airplane is a pilot that has zoned out on music and is just holding the
controls to have something to do with their hands. That's item #1.

Second, stereo is expensive. Yes, I understand that FLYING is expensive,
too, but to go to the expense of specially-designed headphones, intercoms,
audio panels, and all the rest of it seems to us to be on the other side of
reasonable. Our company thrust has, and always will be, to make flying
affordable for everybody. That's point #2.

Now to the engineering stuff. Suppose you try and take your stereo headset
and fly in somebody else's airplane that is "regular airplane". Will your
stereo headset work without the trick little switch on the cable to convert
it to a monophonic headset? No, you will hear one ear of the conversation
only. And what did that little switch do? It put both earphones in
parallel, which cut the impedance of the headset in half. Properly
designed, this MIGHT not be noticeable to the aircraft radio, or it might.
Since airplane radios weren't designed to figure out whether or not you were
messing around with a stereo headset, the manufacturer didn't worry about
making sure his radio would drive that low of an impedance.

Even worse, if somebody else takes his standard aircraft headset and puts it
into your stereo airplane jack, it will short out one of the channels.
Depending on the design of the intercom, the best you can hope for is that
one stereo channel will be dead in everybody's headphones. Second worst is
that the short on that channel will blow out the amplifier for that channel.
In a really lousy design, that short will cause the whole intercom/audio
panel to fail, leaving you without any headphone audio at all.

Given all these reasons, RST has decided not to produce any stereo
equipment. While it probably won't sway your decision for stereo in your
airplane, we thought you should at least consider these problems.

Jim

**************************************************

Hi Jim,
Thanks for taking the time to answer. I respect your opinions so OK, I
can live without stereo and install a PM-1000 that I have but what is
the best way to interface the aux audio input into a system that does
not provide for any other inputs other than COM from the radio and a
music input. I know I can use the music input but this gets muted
anytime someone speaks.

Danny

Danny
RST Engineering wrote:
> "Danny" > wrote in message
> oups.com...
> > Hi Jim,
> >
> > I spoke with you earlier today about this.
> > I have 3 aux audio inputs that I want to run through my PM-3000
> > intercom.> Thanks,
> > Danny
> >
>
> I stay as far away from stereo in the aircraft as I can, so I'm sorry I
> don't have an answer for you.
>
> HEre's my "canned" answer::
>
> ******************************
>
> Stereo In The Aircraft
>
> RST does not produce any stereo intercoms, audio panels, headsets, or other
> devices that reproduce stereo music. If you are absolutely determined to
> have stereo in your aircraft, you might just as well stop reading now,
> because anything we have to say isn't going to change your mind.
>
> We made a conscious business and engineering decision not to produce any
> product for stereo. There are good aviation and engineering reasons for
> this.
>
> First, a little background music or listening to the ballgame in a cockpit
> environment isn't all that bad. Sometimes flying is miles and miles of
> nothing but miles and miles. On the other hand, I know from my own love of
> music that when there is a particularly good cut playing on my home stereo
> and I have the headphones on (try "Sweet Sir Galahad" by Baez or "Minstrel
> Of The Dawn" by Lightfoot at somewhere slightly below the threshold of pain
> in the 'phones to see what I mean) that I get totally lost within the music
> and the world just sort of blurs away. Just about the LAST thing I want in
> an airplane is a pilot that has zoned out on music and is just holding the
> controls to have something to do with their hands. That's item #1.
>
> Second, stereo is expensive. Yes, I understand that FLYING is expensive,
> too, but to go to the expense of specially-designed headphones, intercoms,
> audio panels, and all the rest of it seems to us to be on the other side of
> reasonable. Our company thrust has, and always will be, to make flying
> affordable for everybody. That's point #2.
>
> Now to the engineering stuff. Suppose you try and take your stereo headset
> and fly in somebody else's airplane that is "regular airplane". Will your
> stereo headset work without the trick little switch on the cable to convert
> it to a monophonic headset? No, you will hear one ear of the conversation
> only. And what did that little switch do? It put both earphones in
> parallel, which cut the impedance of the headset in half. Properly
> designed, this MIGHT not be noticeable to the aircraft radio, or it might.
> Since airplane radios weren't designed to figure out whether or not you were
> messing around with a stereo headset, the manufacturer didn't worry about
> making sure his radio would drive that low of an impedance.
>
> Even worse, if somebody else takes his standard aircraft headset and puts it
> into your stereo airplane jack, it will short out one of the channels.
> Depending on the design of the intercom, the best you can hope for is that
> one stereo channel will be dead in everybody's headphones. Second worst is
> that the short on that channel will blow out the amplifier for that channel.
> In a really lousy design, that short will cause the whole intercom/audio
> panel to fail, leaving you without any headphone audio at all.
>
> Given all these reasons, RST has decided not to produce any stereo
> equipment. While it probably won't sway your decision for stereo in your
> airplane, we thought you should at least consider these problems.
>
> Jim
>
> **************************************************

"E Pluribus Unum" (backside of the dollar bill; "Out Of Many, One")

The basic idea is to take each output, terminate it in a resistor of the
impedance it "wants" to see (generally a 560 ohm resistor to simulate a
standard 600 ohm load), the run all the outputs through an isolation
resistor to a summing amplifier, possibly through a switch to turn each one
on or off as desired, and then the output of the summing amplifier into the
COM input of the intercom. I'm very surprised, though, that the intercom
doesn't have an "aux" input other than the music input.

I can't describe a summing amplifier in words without pictures. Anybody got
a lead on a binaries group where I can post a picture of what I'm talking
about?

Or, go to www.rstengineering.com/kitplanes and look at U101 in the August
2002 article for an idea of what I'm talking about.

Jim





"Danny" > wrote in message
oups.com...
> Hi Jim,
> Thanks for taking the time to answer. I respect your opinions so OK, I
> can live without stereo and install a PM-1000 that I have but what is
> the best way to interface the aux audio input into a system that does
> not provide for any other inputs other than COM from the radio and a
> music input. I know I can use the music input but this gets muted
> anytime someone speaks.

Jim,
Many thanks for pointing me in the right direction.
Danny

RST Engineering wrote:
> "E Pluribus Unum" (backside of the dollar bill; "Out Of Many, One")
>
> The basic idea is to take each output, terminate it in a resistor of the
> impedance it "wants" to see (generally a 560 ohm resistor to simulate a
> standard 600 ohm load), the run all the outputs through an isolation
> resistor to a summing amplifier, possibly through a switch to turn each one
> on or off as desired, and then the output of the summing amplifier into the
> COM input of the intercom. I'm very surprised, though, that the intercom
> doesn't have an "aux" input other than the music input.
>
> I can't describe a summing amplifier in words without pictures. Anybody got
> a lead on a binaries group where I can post a picture of what I'm talking
> about?
>
> Or, go to www.rstengineering.com/kitplanes and look at U101 in the August
> 2002 article for an idea of what I'm talking about.
>
> Jim
>
>
>
>
>
> "Danny" > wrote in message
> oups.com...
> > Hi Jim,
> > Thanks for taking the time to answer. I respect your opinions so OK, I
> > can live without stereo and install a PM-1000 that I have but what is
> > the best way to interface the aux audio input into a system that does
> > not provide for any other inputs other than COM from the radio and a
> > music input. I know I can use the music input but this gets muted
> > anytime someone speaks.

No such group on my newsreader.

Jim



"T o d d P a t t i s t" > wrote in message
...
> "RST Engineering" > wrote:
>
>> Anybody got
>>a lead on a binaries group where I can post a picture of what I'm talking
>>about?
>
> I suggest alt.binaries.pictures.aviation. It's reasonable
> to post an aviation related picture there as an adjunct to
> any discussion in the rec. aviation hierarchy.

Jim,

My service provider, cableone.net, has alt.binaries.pictures.aviation with a
total of 23,644 postings.

Wayne
HP-14 N990 "6F"
http://www.soaridaho.com/Schreder/HP-14/N990/N990.html
Amateur Radio W7ADK

"RST Engineering" > wrote in message
...
> No such group on my newsreader.
>
> Jim
>
>
>
> "T o d d P a t t i s t" > wrote in message
> ...
>> "RST Engineering" > wrote:
>>
>>> Anybody got
>>>a lead on a binaries group where I can post a picture of what I'm talking
>>>about?
>>
>> I suggest alt.binaries.pictures.aviation. It's reasonable
>> to post an aviation related picture there as an adjunct to
>> any discussion in the rec. aviation hierarchy.
>
>

("RST Engineering" wrote)
> I can't describe a summing amplifier in words without pictures. Anybody
> got a lead on a binaries group where I can post a picture of what I'm
> talking about?
>
> Or, go to www.rstengineering.com/kitplanes and look at U101 in the August
> 2002 article for an idea of what I'm talking about.


If they're JPEG's, sent them to me as e-mail attachments and I'll set them
up to a link.

Type up any info you want to go along with the attached photos.

1. (Easy on the text length - there's a limit. Amount???)
2.
3.
4.
etc.
etc.

This is what photos will look like on Yahoo:
http://makeashorterlink.com/?W26821A3D
(Wait for it...)


Montblack-at
vi
si
[.]
com

Jim is using Wildblue satellite for the ISP; I have no idea who they sub out
their newsgroup server to. I have TONS of alt.binary.photo.sexthissexthat
sites, but no aviation.

Jim



"T o d d P a t t i s t" > wrote in message
...
> It looks like Jim is using sisna.com, perhaps they don't
> carry the binaries? I know a lot of ISPs are dropping
> usenet and/or dropping the alt.binaries hierarchy.

make that alt.binary.picture.

Jim



"RST Engineering" > wrote in message
...
> Jim is using Wildblue satellite for the ISP; I have no idea who they sub
> out their newsgroup server to. I have TONS of
> alt.binary.photo.sexthissexthat sites, but no aviation.
>
> Jim
>
>
>
> "T o d d P a t t i s t" > wrote in message
> ...
>> It looks like Jim is using sisna.com, perhaps they don't
>> carry the binaries? I know a lot of ISPs are dropping
>> usenet and/or dropping the alt.binaries hierarchy.
>
>

RST Engineering wrote:

> make that alt.binary.picture.
>
> Jim
>
Make it

alt.binaries.pictures.aviation

My newsreader when you click on "subscribe to newsgroup"
it has a search box and if you type in aviation it will list all groups on
the server with aviation anywhere in the name. I don't know what your
running for a reader but it probably has something similiar. (I'm running
Linux so I'm sure you probably don't have the same reader!)
John

PS My house just got rocked by a lightning/thunder blast it actually shook!

"UltraJohn" > wrote in message
nk.net...
> RST Engineering wrote:
>
>> make that alt.binary.picture.
>>
>> Jim
>>
> Make it
>
> alt.binaries.pictures.aviation
>
> My newsreader when you click on "subscribe to newsgroup"
> it has a search box and if you type in aviation it will list all groups
> on
> the server with aviation anywhere in the name. I don't know what your
> running for a reader but it probably has something similiar. (I'm running
> Linux so I'm sure you probably don't have the same reader!)
> John
>
> PS My house just got rocked by a lightning/thunder blast it actually
> shook!

Hope everything is okay on the electrical storm.

I'm Jim's wife and I rarely jump in but I just checked and we do not have
alt.binaries.pictures.aviation. Jim is almost as good at newsreaders as he
is at copper tape antennas, BTW. He taught me how to use one (okay, I
looked over his shoulder and taught myself).

We had our choice, WildBlue with less comprehensive newsgroups, or dial-up
with better newsgroups. We were dying on dial-up. Cable or DSL are not
available out here in the boonies. Unless we want to pay the big bucks for
SuperNews or such (which Jim can do with my blessing if he so desires) we
get what we get. I read some groups on news.readfreenews.net to fill in the
slack. I've heard that the NRTC WildBlue customers get better newsgroups
than the regular WildBlue customers, who get fewer newsgroups from Sisna.
That's better than HughesNet with no newsgroups.

But that's it. We don't have it. So don't pick on my sweetie who just
provided me with broadband at home ;-)

I will now resume lurking.

Awwww, wanna come on upstairs and console me (snort, wheeze)?

Jim



> But that's it. We don't have it. So don't pick on my sweetie who just
> provided me with broadband at home ;-)

Hey, I don't care if it is "June, June, June!" Take it off-group you two.
:-)

Darn lovesick kids! [...rolling up the garden hose]

Montblack
"Hi Gail"


("RST Engineering" wrote)
> Awwww, wanna come on upstairs and console me (snort, wheeze)?

>> But that's it. We don't have it. So don't pick on my sweetie who just
>> provided me with broadband at home ;-)

"RST Engineering" > wrote in message
...
> Awwww, wanna come on upstairs and console me (snort, wheeze)?
>
> Jim

Either upstairs or consoling - make up your mind. You know you can't handle
bof of 'em.

Rich S.

"Montblack" > wrote in message
...
> Hey, I don't care if it is "June, June, June!" Take it off-group you two.
> :-)
>
> Darn lovesick kids! [...rolling up the garden hose]
>
> Montblack
> "Hi Gail"

Hi Montblack, Hi Rich! Hi Everyone who I don't type to so very often but
who I don't forget. Thanks for offering to help upload the pic Montblack,
and to both of you for keeping my honey from saying things publically that
he may live to regret ;-)

Now, back to lurking and I mean it this time, lol.