Using a TNC to decode

[Radiorick]

How many of you gents use one in your shack? I thinking about getting on to tool around in HF. Looking on ebay it may just be cheaper to get a older TNC rather than a lvl4 FSK decoder. Any ideas?

[key2_altfire]

I've had my eye on the TNC-X, it's PIC-based and very affordable. Official site is tnc-x.com

[ka3jjz]

The problem with these old TNCs is that many of them have not been updated for newer modes in years (The M7000 is a classic example). Even the venerable PK232 now has, in their newer versions, a soundcard input, probably in recognition of the many new modes that have come on the air of late.

You're far better off getting a soundcard driven software package than a dedicated TNC. However, for very specific apps such as FAX decoding, a TNC might do a better job due to the additional filtering some of them have.

It does depend on what you are trying to hear. For example, marine stuff can generally be copied with something along the lines of SeaTTY; for all the new ALE stuff that's out there, and coming out, PC-ALE (which is freeware) is a very inexpensive way to get your foot in the door without a lot of cost. You can later step up to software like SkySweeper (which in it's basic form, is still quite powerful, and not that expensive..).

Mike Chace-Ortiz's website has numerous links for just such software - the link for his site is in the Utility Monitoring wiki. Of course, this assumes you have a good desktop radio - you can get by with portables, but only to a point. Weaker stations, or those with interference, will quickly show the portable's limitations. Some of the better PC driven radios (like the RX320 from TenTec) are also quite good for digital decoding.

73s Mike

[Radiorick]

I'm using PDW as on now off the PCR-1000 and have had success. I'll be checking out that site.

[n9mxq]

I you want a nice multimode decoder, try Ham Radio Deluxe Plug your radio into the sound card, open the DM780 program that comes with HRD... It decodes several modes.

[ka3jjz]

While I agree programs like DM780 and MixW are very good, they're generally oriented toward ham ops - stations outside the ham bands (not necessarily MARS related), don't use things like PSK31, Clover or other modes like that - and that's an issue, particularly for newcomers. They think that they can just tune in with any mode and expect it to work. Digital decoding simply doesn't work that way. All they get is gibberish, and quickly lose interest.

I highly recommend folks that are interested in Digital HF DXing join groups like the Utility DXers Forum (Yahoo) - there you can get a very good idea of what modes are being used, and the equipment or software used for decoding.

73s Mike

[kb2vxa]

Why bother with hardware when everything is software driven? Digital radio is as easy as getting on the internet these days, your sound card is your modem.

[jparks29]

Originally Posted by kb2vxa

Why bother with hardware when everything is software driven? Digital radio is as easy as getting on the internet these days, your sound card is your modem.

I agree...

Check out AGWPE.

[k8mcn]

Originally Posted by kb2vxa

Why bother with hardware when everything is software driven? Digital radio is as easy as getting on the internet these days, your sound card is your modem.

totally correct!!!!!!!! You are only limited by what software you use and how much your sound card can decode. Listen and listen and hopefully find lots to decode. most software tells you how to set it up--one mistake i was making, you can run too much volume into the programs---it will tell you that usually...
The reason you need the interfaces (since most people have computers these days) TNC, Rigblaster,etc, is if you want to send (broadcast) in a certain mode, and you must be licensed to legally do that.......

[ka3jjz]

What you all have written is right on the money, but it misses the point - all these neat packages are really geared for ham usage. There are many other modes that aren't common - or even used - by hams on HF, and some of these (like Link11) cannot be decoded.

The only software (within reach of the average listener, anyway) that addresses these modes is SkySweeper. There are several more expensive packages (Hoka Code 300 for example) that cover even more modes and have more technical capabilities. Something like that would undoubtedly overwhelm someone who is new to the hobby. This is why research, and more specifically learning about what is being heard and read on reflectors such as the Utility DXers Forum, is absolutely critical. It will at least slow down the frustration factor.

73s Mike

[n8emr]

A TNC is pretty much useless on HF. If you want to do digital decoding you would be better off with one of the many sound card software packages. A TNC will give you 300baud packet and little more.

[KI6ABZ]

Originally Posted by kb2vxa

Why bother with hardware when everything is software driven? Digital radio is as easy as getting on the internet these days, your sound card is your modem.

Awesome Geek Blog: File transfer over sound card