Nice description.
I believe that voltage is 3 or 5 V on the computer mic jack.
If you want to get even more crazy, the 3.5MM plugs for cell phones is a 4 
conducter plug with 2 rings and a sleeve.  These are for the phone headsets 
that carry mic audio and audio from the phone.

Pretty much all pro audio line mixers have fantom power these days, even the 
small 2 or 4 input mixers have a 48V switchable fantom power source.
The higher end mixers will have a 48V switch on each channel strip. some 
have switches to apply 48V to groups of 4 XLR inputs on the mixer.  The 
majority have 1 on/off switch for 48V usually located next to the main power 
on/off switch.
Back in the days when the T-rex roamed the earth, and ferns grew aplenty, 
and neanderthals were just a twinkle in someones eye, and when the earth was 
still round and not flat hi hi, pro condenser mics used batteries because 
only a few models of very high end mixers had 48V on the XLR jack.  You 
could and still can get 48V power supplies that can be inserted into the mic 
line to provide the fantom power to the mic.  But, with todays mixers having 
48V as a pretty standard feature, those boxes are far less important.
The old classic Neuman and Telefunkin studio tube mics all used their own 
dedicated power supplies.  Nowadays, they just come as is and you use the 
power supply provided by whatever device you are plugging the mic into 
weather it be a recording interface, mixer or whatever.
So instead of batteries in the condenser mics running down because people 
would leave them on etc, the audio engineers bain is now wireless packs and 
mics being left on and draining the batteries.
Some companies are getting pretty good at intelligent circuitry to put the 
devices into stand by when they aren't being used to save batteries, but 
it's still a fight with gear that doesn't have that option.
Some of the big touring acts like U2 for instance, have 48 wireless packs on 
stage between guitar transmitters and vocal mic transmitters.  Those guys 
don't even mess around, they simply change all the batteries out immediatley 
prior to the show.  The newest wireless tech in the pro audio industry is 
using half the power to accomplish the same job.  In otherwords, packs that 
used to take 2 double A batteries now only require 1.  A high end long range 
FM wireless guitar transmitter say 10 years ago would require 4 double A 
batteries, and the same device now, using totally digital modes needs 1 for 
the same range and same use time.
Thankfully I only have to deal with 4 wireless packs in my band, two headset 
mics and two guitar packs, but even still, I tend to run through double A's 
pretty quickly with at least 8 fresh batteries per show and usually a fresh 
set every 3rd rehearsal or so.


73
Colin, V A6BKX
-----Original Message----- 
From: Martin McCormick
Sent: Wednesday, August 8, 2018 3:39 PM
To: [log in to unmask]
Subject: Computer Microphones and Don't Leave!

Computer Mic's are a little different than your standard
Microphone.  They have 3 connections rather than just 2 but they
are not a balanced line either.  So, what are they?

They are actually an amplified condenser microphone.  If
you have ever accidentally plugged a headset in to the microphone
jack, you will hear a click and nothing else and here is what is
going on.

As you know, a stereo headphone has the sleeve grounded
just like mono headphones but that sleeve breaks on a stereo plug
and there is a second sleeve above the ground sleeve before you
get to the tip.  In a stereo headphone plug, the tip is the left
channel.  The first sleeve is the right channel and the ground is
the rest of the sleeve.

In a computer mic plug, the tip is audio.  What would be
the left channel is the phantom DC supply and the rest of the
sleeve is ground.

When you plug a computer mic in to the Mic jack on the
sound card, the phantom DC supply feeds a few volts at a very
small current in to the second sleeve.  Audio comes out the tip
and ground is just ground.

The phantom DC supply is called that because the current
is so low that if it gets shorted to ground, nothing smokes or
goes wrong.  It just goes away.  In a computer mic, that phantom
current drives a little FET preamp in the microphone, itself, and
the high impedance condenser mic element is turned in to a lower
impedance output which is more like that of a dynamic
microphone.

I think I have even tried a tape recorder mic and had it
work reasonably well but it has been a while since I did that.  I
know that telephone pickup coils will deliver a useful signal to
the microphone input and those devices are 2-wire sources.

I think you can use a dynamic mic on a computer sound
card but you can't use a computer type microphone on a tape
recorder-style dynamic mic input.

Professional mic mixers sometimes even have a phantom
voltage switch on at least one XLR input so you can use a
condenser mic.

When I was an audio-visual technician, our big headache
with condenser mics was a people problem.  They were always
forgetting to take the batteries out of them so they were run
down when next needed.

Martin Wb5agz

Butch Bussen <[log in to unmask]> writes:
> Works for me.  Maybe catch a cubs game.  Are you the Howard who is a
> cubs fan?
>
> I havde no itnerest at all in the digital modes.  I have an irlp node
> here and I can do what they do much easier.  I can dial up reflectors
> all over the world or do a one on one contact, voice over i p of course.
>   I just have no tolerance these days for those blind people who think if
> they do something everyone can, and if I can't I'm some kind of stupid
> jerk.
>
> Thanks. for the note.
> 73
> Butch
> WA0VJR
> Node 3148
> Wallace, ks.
>
>
> On Sat, 4 Aug 2018, Howard, W A 9 Y B W wrote:
>
> > Butch,
> >
> > Don't go away, you contribute a wealth of information to the list.  Just
> > ignore those who are set in there ways and are intolerant of your way of
> > doing things.
> >
> > For example, there is a lot of traffic on this list about the new
> digital
> > modes on the VHF and UHF repeaters these days.  Listening to all the
> > discussion on how to create code plugs for these radios makes my head
> spin.
> > I am not interested in those modes nor have the patients to learn it.  I
> > guess that makes me lazy also.  Let's go out and get a beer together.
> >
> > Howard #3
> >
> > ----- Original Message -----
> > From: "Butch Bussen" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Saturday, August 04, 2018 12:51 PM
> > Subject: Re: Adapter for ham radio microphone
> >
> >
> >> Yep, a lot of traffic on the new list.  I'm tempted to dump it.  And
> >> there are thosse who figure I'm a lazy slob because I don't bown to an
> i
> >> phone like many do.
> >>
> >> I'd have to dig for it.  I bought a head set once at Walmart and it was
> >> made for use with cordless phones or computer.  I came with an adapter,
> >> but I am not sure if it will do exactly what you want.  What microphone
> >> are you wanting to use?  Most Hile stuff uses an xlr I think.  I think
> >> most computers just use an eighth inch standard plug, not sure if it is
> >> stereo or not.  I just haven't done much of that sort of thing.
> >> 73
> >> Butch
> >> WA0VJR
> >> Node 3148
> >> Wallace, ks.
> >>
> >>
> >> On Sat, 4
> >> Aug 2018, Fred C. Adams wrote:
> >>
> >>> Butch, Glad to hear from you
> >>> but surprised as I never seem
> >>> to receive any traffic from
> >>> the old list and I am no
> >>> longer a member of the new
> >>> list.  Maybe I will give Heil
> >>> a call and see if they make
> >>> any adapters.  It would be
> >>> good if we could get some guys
> >>> back on the old list.
> >>>
> >>> Adios,
> >>>
> >>> -----Original Message-----
> >>> From: For blind ham radio
> >>> operators
> >>> [mailto:[log in to unmask]
> >>> ORS.ORG] On Behalf Of Butch
> >>> Bussen
> >>> Sent: Saturday, August 4, 2018
> >>> 11:26 AM
> >>> To:
> >>> [log in to unmask]
> >>> Subject: Re: Adapter for ham
> >>> radio microphone
> >>>
> >>> I gather you want to use a
> >>> regular microphone on your
> >>> computer?  Yes, should work
> >>> with right adapters, although
> >>> these days, I don't know where
> >>> 73
> >>> Butch
> >>> WA0VJR
> >>> Node 3148
> >>> Wallace, ks.
> >>>
> >>>
> >>> you'd get them with radio
> >>> shack gone.  On Sat, 4 Aug
> >>> 2018, Fred C. Adams
> >>> wrote:
> >>>
> >>>> I know that I am on the old
> >>>> list but there is just to
> >>> much
> >>>> traffic on the new list for
> >>> me
> >>>> so I thought I would try the
> >>>> old list.  I do not like
> >>> using
> >>>> a headset and so I am asking
> >>>> if the following even exist.
> >>>> If possible I would like to
> >>>> use a ham radio microphone
> >>>> with my computer and listen
> >>> on
> >>>> my external speakers.
> >>>> Somehow, I would have to
> >>>> connect a UHB connector to
> >>> the
> >>>> SM-8 microphone so I could
> >>>> plug the microphone into the
> >>>> UHB port and even then it
> >>>> might not work.  If anyone
> >>> has
> >>>> any ideas on this I sure
> >>> would
> >>>> appreciate hearing from you.
> >>>> There might not even be
> >>> anyone
> >>>> on the old list to read
> >>> this.
> >>>>
> >>>> Thanks much,
> >>>>
> >>>> FRED C. ADAMS W4HC
> >>>> THE NIGHT IS FAR SPENT AND
> >>>> THE DAY IS AT HAND
> >>>>
> >>>>
> >>>
> >>>
> >
> >
> > ---
> > This email has been checked for viruses by Avast antivirus software.
> > https://www.avast.com/antivirus
> >
> >
>
>