New to Digital Modes and have a few questions.

Discussion in 'Working Different Modes' started by KD8HJR, Sep 12, 2011.

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  1. W0BTU

    W0BTU Ham Member QRZ Page

    Even easier to connect than those are audio transformers from an old 56k modem. That's what I used to break the ground loop.
  2. G0GQK

    G0GQK Ham Member QRZ Page

    Most US hams use the expensive boxes but what you need is an opto coupler to connect between the PC and the RIG, these can be bought quite cheaply but I don't know the names used in the US, look on the internet. Do a Google for Digipan and Digipan help pages for doing an installation. I advise new operators to try Digipan first its simple and won't tie you up in knots.
  3. W0BTU

    W0BTU Ham Member QRZ Page

    Why are optocouplers better than 600 ohm audio transformers?
  4. KA9QWC

    KA9QWC Premium Subscriber QRZ Page

    I still use old Kantronics tnc units primarily for vhf packet which is still fairly popular here in northeast Indiana. But been using the Donner interface units for
    several years now on HF and mine were purchased at $40.00, not a bad price and never had any complaints or issues to date. Been using the MixW for
    HF packet but also have Digipan & Hellschreiber software too. Don / KA9QWC
  5. W0BTU

    W0BTU Ham Member QRZ Page

    I thought packet --which is what the TNC was for-- was all but dead.
  6. ND6M

    ND6M Ham Member QRZ Page

    my kantronnics will do Packet, RTTY, SSTV, PSK, all the "TOR" modes,.... ect
  7. K0RGR

    K0RGR Premium Subscriber QRZ Page

    Mass confusion -

    There seems to be a lot of misunderstanding about 'TNC's. I've heard too many people refer to their soundcard interface as a TNC.

    A 'terminal node controller' is an intelligent device that converts a data stream from the 'terminal' into packets and transmits and receives the packets. This goes back to the day when we used 'dumb' terminals, so all the intelligence to make them work had to be external. The TNC is responsible for the handshaking and control of the transmission, as well as for converting the data into audio tones for transmission over the radio. The basic TNC is only used for packet radio. 'Multimode' TNCs do packet, but also do other modes, like PACTOR and RTTY. A few of them have interfaces to support soundcard modes, so you can do PSK31, etc.. TNC's can also operate in 'KISS' mode, which allows the computer to perform all the packetizing and transmission control. Some 'TNC's only do KISS mode.

    A soundcard interface is usually a passive 'dumb' device that simply connects the computer audio to the radio. It can be very simple. Many use a straight cable on the receive side.
    Examples of soundcard interfaces include the RASCAL, and the RIGBLASTER series. You can do nearly all of the popular digi modes with a soundcard interface. PACTOR is the one big exception, but other than for WINLINK, you don't hear a lot of PACTOR these days. PSK31, MT-63, JT-65, Olivia, and many other modes are available.

    Most radios have some form of 'aux' connector on them, providing a convenient place to connect your TNC or soundcard interface. For most of the commercial interfaces, custom cables can be purchased to make the hookup simpler. Most radios these days use a standardized 'aux' port. One key function of the aux port is to provide a constant volume audio output line from the receiver. This lets you hook up your computer without having to worry about setting the volume control on the receiver to the right level all the time. You can turn the audio to your speaker off if you want to, and still have audio to the computer. There is also usually at least one direct input that bypasses the mic circuit. On some radios, to use the aux connector, you need to be in 'Digital' mode (some use 'packet' mode). RTTY mode is usually something else - not for use with a soundcard. Digital mode cuts off the mic circuit in some rigs, and not in others.

    Signalink is highly recommended, but I haven't tried one yet. I've had good luck with the two interfaces I mentioned earlier. BUXCOM RASCAL is the cheapest one, but if you search, you'll find complaints about them on here - I've never had any problem, and I've done business with them several times.

    I'm using FLDIGI for most of my stuff. I keep Digipan around for troubleshooting. I also have Ham Radio Deluxe, which I really like, but I'm not using it right now. FLDIGI is the basis for the NBEMS suit of programs that is gaining popularity for ARES work. There is also a 'WINLINK equivalent' called PSKLink that runs on top of FLDIGI.
  8. KD8HJR

    KD8HJR Ham Member QRZ Page

    Wow, great stuff! Thanks for all the information guys! I haven't had the time to make up a wire yet but I do plan on it so I can listen around. I'm not sure where to listen or what to listen for, but I'm sure I'll come across something sooner or later. Maybe you can throw out a few commonly used freqs used for all this? I'll mainly be using 20 and 15 meters.

    Thanks for all the help!
  9. W0BTU

    W0BTU Ham Member QRZ Page

    You're welcome. :)

    Listen on 14.070. If you don't hear PSK31 there, the band's dead.
  10. W0BTU

    W0BTU Ham Member QRZ Page

    YES!!! :)

    The last thing in the world that I would buy for PSK31 (or any other digital mode now in common use) is a TNC.
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