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Topband: how to set up a Skype receiving beacon

To: Topband <topband@contesting.com>
Subject: Topband: how to set up a Skype receiving beacon
From: Eric Scace K3NA <eric@k3na.org>
Reply-to: eric@k3na.org
Date: Wed, 08 Mar 2006 09:51:21 -0500
List-post: <mailto:topband@contesting.com>
    The K3NA receiving beacon seems pretty popular.  Many 
people have written encouragin email (thanks) and the 
history file at the station shows connections from all over 
Europe, North America, Australia, and Africa.

    When I have been working at the station, it's been 
interesting to suddenly hear a couple of dashes and a 
callsign appear out of the receiver's speaker, and look over 
at the computer to see someone listening to my receiver from 
another continent!

    This was a very easy project, and I would like to 
encourage other topband operators to create a receiving 
beacon at their location.  Step-by-step instructions are 
listed below: 12 steps only!

    A receiving beacon doesn't require fantastic antennas or 
an exotic location.  Many times people want to understand 
how their signal sounds at a typical, average topband QTH.

    And a receiving beacon doesn't interfere with chasing 
DX.  When it's time to chase DX, simply grab the receiver 
and go work the DX.  I usually leave the Skype software 
running, so someone who connects to "K3NA160m" at that time 
will be listening in to my operating.  But you can just 
close the Skype application while operating.  When you have 
finished operating for the moment, just return the receiver 
to the beacon frequency, start Skype, and walk away.

73,
    -- Eric K3NA

=================

How to create a Skype receiving beacon:

1.  Skype configuration:

    a.  Install Skype on the station computer.

    b.  Create a Skype username.  Perhaps we could agree to 
use a common format for beacons of the form "callsign+160m"; 
e.g., K3NA160m, ON4UN160m, or S9SS160m.  (The last two don't 
exist.)

    c.  Under the Tools menu, click Options.

    d.  In the Options dialog, select "Sound devices".  For 
Audio In, choose the soundcard to which you will connect 
your receiver.  Uncheck the box "Let Skype adjust my sound 
device settings".  (Skype has an automatic gain control 
function and a soundcard level control function.  That 
second function, designed for human speech in microphones, 
appears to distort CW signals and noise from receivers. 
Unchecking this box turns off the Skype adjustment of the 
soundcard levels.)

    e.  In the Options dialog, select "Privacy".  Selection 
the option "Allow calls from anyone".  This option allows 
people to listen to your receiver without pre-registering as 
a member of your Skype contact list.

    f.  At the very top of the Skype main display, your 
beacon user name is displayed.  Click on this name to reveal 
a gray box that says "Enter a mesasge here for all your 
friends to see in their Contact list".  Click in this gray 
box and provide some description about your beacon.  A 
useful example:
    "(callsign) 1832.10 kHz  (latitude longitude) (antenna 
description)"
    K3NA 1832.10 kHz
    41Â 34' 45"N  70Â 50' 50"W
    NE beverage

2.  Receiver configuration:

    a.  Tune to 1832.10 kHz.  WA6CDR has suggested using 
1812.30 kHz for beacons which could be used by a station 
transmitting in the JA window.  Both frequencies are 
somewhat arbitrary, but located in the two areas of the band 
accessible to many topband operators for transmission... and 
both frequencies are easy to remember:  18 three two one... 
and one two three.

    b.  Set for CW mode.  On my Orion radio I use 1000 Hz 
bandwidth so that people can hear nearby band activity, but 
you may wish to use something smaller... but still wide 
enough for another operator to hit with his transmitter. 
Just set the receiver for normal CW reception at your 
location (e.g., with a noise blanker if you need it).  Be 
sure to set the CW pitch to 500 Hz or even higher.  Very low 
frequencies are not necessarily transported well by Skype, 
which is designed to carry human speech.

    c.  Connect the receiver output to the soundcard 
microphone input.  Skype only transmits from the mic input 
-- and only mono!  I use the receiver's line ouput signal 
from the back panel -- the line output does not change with 
the front panel AF gain control, so there is one less 
adjustment to worry about.

3.  Soundcard adjustment:
    The goal is to set the soundcard mic input level so that 
the normal antenna noise on a quiet frequency is just above 
the noise floor of the microphone input jack.  Skype's 
internal AGC will take care of the rest.  Too high a setting 
results in a great deal of distortion on the Skype 
connection.  I used this approach:

    a. Start a sound display, recording or editting program 
that allows you to see the sound levels, relative to the 
encoding range of the sound card.  I use Goldwave, but there 
are lots of options.  What you want is a graphical display 
of the mic input's signal level vs time.  Begin recording or 
display...

    b. To use the Windows volume control to set the 
soundcard level, open the volume control application.  On a 
WinXP system, this is found on the Start menu under 
Programs\Accessories\Entertainment\Volume Control.
    Choose Options from the menu, and select properties. 
The properties dialog will open.
    In the Properties dialog, select "Adjust volume for 
recording".  Now make sure the "Mic" box is checked.  Close 
the dialog by clicking "OK".
    Back in the volume control, make sure the Mute box under 
the mic volume control is unchecked.  Click the Advanced 
button and turn off the mic boost.  (If you do not see the 
Advanced button, click the Options menu and select "advanced 
controls".)
    With the receiver on a quiet frequency, adjust the mic 
volume level until the band noise is just visible.  When the 
mic volume is too low, you will see a flat signal that 
represents the floor of the mic input (probably with some DC 
bias).  The receiver noise needs to be above this level.

4.  Finished!  Don't forget to tell us that your beacon exists!

-- end --
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