| Interfacing |
Interfacing PC to Transceiver
Interfacing your radio to your PC can be as simple as direct connection or isolated (more complicated)
to help RF immunity/isolation. Basically you need 3 connections, audio output to PC Line In (or
Mic in), microphone input to PC speaker or Line Out and PTT line to PC com port. You can either "homebrew" or
purchase a ready made unit (see below). If you are already QRV on other digi-modes - RTTY, PSK31
etc - then you are ready to go with JT6M !!
If not and you build/buy your interface, it will open up those other digi-modes - you then just
need the software !!! |
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Receive Interface
This can simply be just a connection from your transceiver speaker output to PC sound card Line Input. (Sound card mic.input can also be used in certain
cases.) This is probably the easiest to make. It will also give you receive facilities straight away - so get it hooked up now and tune to
50.230MHz.... |
| Isolated methods usually involve a transformer
(passive) or more active using opto couplers and amplifier stages/drivers. Using a transformer
from an old transistor radio output stage may be sufficient. Use the 8 ohm secondary connected
to your transceiver output (speaker) and the primary to the sound card Line In. Many modern
transceivers have auxiliary outputs (and inputs) which may be more suitable. Remember that
if you use your transceiver speaker output, the audio level to you PC will vary as you adjust
the AF Gain control to suit listening conditions. Using auxiliary audio output usually gives
a fixed audio level. Check your rigs manual. |
Transmit Interface
Basically, you need to connect your sound card output - either Line Out
or Speaker Output to your transceiver microphone or AF input. This can be direct (not recommended), attenuated and/or isolated. Again, a transformer may be used
as can other isolation methods. Auxiliary inputs on your transceiver again can be used. |
PTT switching
Connection between your transceivers PTT line and the PC Serial COM port is
necessary for automatic switching between TX and RX although it is possible to use the manual method. |
| Recent PC and laptop trends favour the exclusion
of the Serial Port in favour of USB (Universal Serial Bus) ports only. In this case you will
need to use a USB to Serial port converter. Fortunately interface manufacturers have recognised
this trend and now can supply USB interfaces. WSJT uses either RTS or DTR control lines (or
both) from a PC's RS232 com port - Ver.3/4.x.x only - see Setup
page ( Ver.5.x.x. just has setting for Com Port No.)
This should be interfaced using at least a transistor or better still opto coupler. DO NOT connect
directly from Com port to PTT line. |
Tigertronics Signalink USB Sound
card/Interface |
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