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As of early 2008, I am also active on IRLP (node 3348) and Asterisk (multiple nodes)!
I discovered Echolink in the Summer of 2006, and have been experimenting with it ever since.
I have three registered node numbers:
Background
My Echolink adventure began when I was traveling through Austin, Texas and scanning local 440 MHz FM repeaters. I stumbled
upon a QSO between a local ham in Austin and a guy in the UK! Once I figured out WHAT I was listening to, I wanted
to figure out HOW it worked!
The audio quality was excellent, and all repeater functions worked normally (squelch tail, courtesy tone, etc). The
two guys chatted as though they were both in the same town. Of course, the fellow's accent and G3 callsign gave it
away.
The more I listened to that repeater, the more excited I became! Using DTMF sequences, these local hams were able to extend the
range of their repeater from the Austin metro area to anywhere on earth via Echolink! The DTMF control is very similar
to an Autopatch, and allows you to connect to a specific node number, random node, disconnect the link, etc.
I was excited about all of the possibilities! What a great way to stay in touch while traveling! As long as there
is an Echolink-enabled repeater where you're going, you can connect via your HT or mobile to those
back home (or anywhere else!).
Echolink vs. IRLP?
To be honest, I proceeded with caution, as I'd been discouraged before (with IRLP). IRLP is a similar
system, but not nearly as friendly to install, or operate. For example, IRLP only runs on the Linux operating
system and requires that you BUY a proprietary commercial interface - no homebrewing is allowed!
Also, IRLP is only for linking repeaters together - no home users are allowed. This is a big drawback for the
casual operator. However, the number of registered stations on Echolink is about 300,000 compared to about
3000 on IRLP, so don't worry about it.. hi hi
IRLP is not helpful to you if the person you want to talk to is not in range of an IRLP node! With Echolink,
you can connect as a home user without a repeater!
Echolink's home user mode can be useful for many situations. For example, many OMs are in assisted living centers
and cannot install antennas of any kind. Maybe you live in a subdivision with an out-of-control Homes Association
(complete with Antenna Police!) and are also precluded from installing antennas?
Perhaps you're out of town on business, and don't know which repeaters will be in range, etc? Stay in touch
by using Echolink in your hotel room, coffee shop, etc using the Internet.
Echolink will work with dial-up, cable, DSL, Wi-Fi, whatever!
I have learned that IRLP is different from Echolink in other ways. For example, random connects are quite common
on Echolink. There is even a list of DTMF commands for "Connect to random repeater or link", "Connect to random conference",
"Connect to random user" and so on. Generally speaking, IRLP node owners do not support such activity.
IRLP does a very good job of connecting two machines together, and is very robust and effective using the
Linux operating system. I would recommend getting started with Echolink first, then add IRLP and/or Asterisk
to the station down the road.
Getting Started with Echolink
The Echolink software runs on the Windows platform, and can be operated a couple of different ways. Note that
the Echolink software package is exactly the same in all cases.
* Using the normal 'user' mode, you simply sit at your PC and talk into a computer microphone.
* Via repeater. Many repeaters offer Echolink! The access is controlled by the repeater owner, so you may
be required to join a club, etc for access.
* Set up your own RF-linked node, or simplex link. This is how I operate 99% of the time. I connect a radio in my shack
via homebrew interface to my PC. The interface is basically a PSK31-type sound card interface with a
few extra features. This allows me to take Echolink with me where ever I go! I routinely operate while out walking my
dog, and have worked stations in Australia, Japan, and all over the US this way.
Asterisk
I heard about the Asterisk VOIP system in early 2008, and spent quite some time trying to find
out everything I could about it. I became active on Asterisk in September 2008.
In late 2008, Asterisk can now operate IRLP and Echolink by way of channel drivers! This should
eliminate the need to install IRLP, and Echolink software along with Asterisk if you want to
operate all three VOIP systems.
Asterisk is built on an open-source PBX telephone system, but the folks from
AllStar Link
have designed a specific Amateur Radio application. The capabilities of Asterisk surpass anything I've
dreamed of in a Ham Radio VOIP system. For example, one PC running Asterisk can control up to 8 separate
radio links or repeaters!
The easiest way to get started with Asterisk is to download the ISO on the Allstar web site, and burn an
Installation CD .
NOTE: The installer will repartition your hard drive and install CentOS 5.1 (Linux) and
Asterisk. The installer does not ask which hard drive to install CentOS to (Most Linux
Installs will!), and the software will be installed to the first hard drive. I lost my Windows XP drive this way!
I hope to QSO with you on Asterisk soon!
Homebrew Echolink / Digital Modes Interface
Below is a picture of my homebrew interface. Scroll down for a schematic and connector diagram. As stated above,
it is a PSK31-type radio to sound card interface with the addition of COR/COS capability. The COS signal allows
the PC to detect when the squelch is opened on the link radio. Note that this interface is also compatible with
many other digital applications including SSTV, Voice Keyer, off-air recording, etc.
The interface fully isolates the PC from the radio, using audio transformers and an opto-coupler for the PTT line. The
COR/COS line is buffered using a second IC.
Prototype Echolink/Digital modes interface.
This page has the latest info on my Echolink station. See the left side of the page for
other operating modes and projects.
If this is not visable, click here to reload web page.
Read more about
Asterisk below.
K0KN 267895
K0KN/L 309554
K0KN/R 307578
K0KN Universal Interface Schematic Connector Pinout
K0KN-L Node Hardware
The Phoenix is capable of 40 watts output, but I want it to run nice and cool, so it's set at 20 watts out. The fan currently
runs all of the time, but I plan to build a fan control circuit in the near future. The UHF receiver is always listening for
commands, which allows control of the link even while it's transmitting.
The antenna I'm currently using is a 5/8 wave dual-band omni at approximately 30 feet. Coverage has been quite good considering
the modest antenna and power output. Mobile coverage extends to about 10 miles, depending on terrain. HT coverage is limited to
about 2 miles with rubber duck antenna.
The link utilizes a dedicated homebrew sound card / radio interface. Because this unit
is dedicated to the link node, it does not need to be as easily adjustable or
versatile as the prototype unit.
This dedicated unit uses internal pots for the audio level adjustments, and
does not have the EFJ mic preamp or DSR switch.
Now the prototype unit is available for use with other radios and modes. I've built
three of these interfaces, as one is installed at my repeater, K0KN/r. All units
are interchangeable, so I can substitute interfaces in the event of a failure.
Please
email me
with your results also!
73 and good luck!
Kyle
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