Introduction
Internet
linking is one of today's fastest growing facets of Ham Radio, marrying
the world of Radio Frequency to the Internet. iLINK and ECHOLINK are internet
gateway programs that allow you to communicate with other Hams around the
world using "internet propagation". You can talk to other hams using the microphone
and speakers on your pc while connected to the Internet, or you can access
the system using your HT or FM-mobile radio through a radio link that
is interfaced to an Internet computer ! All you need to
access iLINK or EchoLink from your computer is the appropriate software.
Click here iLINK homepage to download iLINK. Click here EchoLink homepage
to download EchoLink.
To set up a radio link, you will need the "LINKS" Sysop version of
the iLINK software (also available from the iLINK site above) or if using
EchoLink software, to configure it for SYSOP Mode. You will also need a
board to interface the internet
computer to a link radio. While experimenting with the linking programs,
the monotonous task of hand wiring an interface board due to the lack
of a readily available printed circuit board was realized. Hence, the
VA3TO Linking interface boards were designed and made available at a reasonable
price to make it easier for other hams to set up a link and promote the
ultra cool world of iLINK and ECHOLINK.
Board description
Our Version 1.0 Board was the first pcb based Linking interface made widely available
to amateurs around the world. Then came Version 2.0 which built on the
success of our first offering with on-board connectors and other new features
and enhancements. Our latest board, Version 2.1, continues the trend with further features
and enhancements that offer more reliable linking and greater versatility.
Features:
- High quality components for reliable operation. The double sided PTH pc board
is professionally designed and manufactured with gold plating, silkscreen
(white part designator text) and soldermask (green anti-solder coating).
- Functional and esthetically appealing layout with the LED indicators arranged across the front edge and all board
mounted connectors arranged across the back. Holes are located on each corner for easy chassis
mounting.
- Passive Sound-Card operation for digital modes like PSK-31, SSTV, RTTY, WSJT, WEFAX ect.
No configuration changes are required when changing modes.
Software for these modes available at various Ham Radio related sites on the Internet.
- Plug-and-Go operation. No special configuration is required. Get out of the box and
on the air in minimal time. Just run the software for the mode of your choice !
- All audio and control I/O brought out to 3.5mm (1/8") jacks. 12-15vdc power is supplied
through a 2.1mm barrel type jack. RS-232 I/O via standard DB-9 female connector.
- COS or VOX RX Control. COS greatly reduces drop-out and "falsing"
that is sometimes experienced when using VOX RX Control. (Requires COS signal from radio).
- An "Auxiliary Control Relay" ! This relay is turned on and off using the
DTMF C and D keys on your remote radio. Use it to trigger or control anything
you like, from a weather radio to the lights in your shack. Route audio or power
through the relay !
- 5 LED indicators display the status of Power, PTT, Aux Relay,
Valid DTMF, and Active Data. The LEDs can be fly-wired to the front of
any size enclosure that will accommodate the board
- A 4 minute Time-Out-Timer (TOT) is implemented to disable the PTT line
to the transmitter in case of computer lock-up or other problems that could
otherwise result in a fatal failure of the transmitter, should the keydown
condition go unnoticed for an extended period of time. The TOT can be disabled
when not desired.
- Interrupt driven serial I/O with true RS-232 levels using a MAX232 IC for reliable communications.
- Trimpots for easier RX and TX audio level adjustments.
- A high-pass filter in the TX audio to mic input
line to reduce hum and other noise.
- Overdesigned power supply section using a TO-220 type 7805 regulator
for cool, lightly loaded operation.
- Two additional PIC port pins brought out to pads for possible
future use.
- A larger prototyping area for the experimenter / future
mods.
- Available as a full board level kit, partial kit or assembled and tested.
- Very well documented and supported ! All information is available in PDF
format on this web site at a click of the mouse.