New and Old Digital Modes

Basic Info

Old modes used an external device (TNC) for processing, new modes use computer’s sound card and a simple interface device (can be more sophisticated if desired).

- Old favorites are still around:

-- CW, the “original” digital mode (want to join FISTS?)

-- RTTY – just check 7040kc or 14080kc (or near these) during contests

-- HF Packet – “NETWORK 105” on 14.105 LSB, still very active (http://ka1fsb.home.att.net/idx105.html )

-- VHF Packet - SEDAN on 145.77 (http://www.ipass.net/teara/packet13.html ) with nodes at Cesar’s Head and Myrtle Beach

-- Put your old TNC back on the air this winter and try it out

Hardware

New modes are mainly limited by your computer’s processing power

- Program does the processing work (like the TNC did); hardware interface keys the radio and handles audio transfer between radio and computer

- Interfaces can be simple kit (http://www.buxcomm.com/catalog/index.php? main_page=product_info&cPath=25&products_id=166&zenid=7099bff1354d661ee169ff 52051330f2 ) or much more complicated (http://www.westmountainradio.com/RIGblaster.htm ) or even USB compatible small units that work with new USB ports and simply plug into your radio’s accessory jack (http://www.tigertronics.com/slusbmain.htm )

- Older radios will still work, just need compatible interface

- The more sophisticated units act as a sound card and free up your computer’s sound card; computer just runs program

SOFTWARE

Many programs, most downloadable for FREE

- PSK-31 is very popular right now

18 Jan 2010 SARA Brief --Works with 2 tones; approx 25 watts max; easy worldwide comm.; can “see” a signal on your computer screen even if you can’t hear it (looks cool on your screen if you have visitors in the shack).

-- Uses “waterfall” display; frequency across top, time rolls down the screen

-- Good signals appear as solid lines down the screen; just roll the cursor over a signal and click to begin decoding (easy to see splatter on a signal, like an op running too much power

-- Common PSK-31 freqs: 3580.150 kHz USB; 7035.150 kHz USB; 10142.150 kHz USB;  * 14070.150 kHz USB* 18100.150 kHz USB; 21080.150 kHz USB; 24920.150 kHz USB; 28120.150 kHz USB

-- Download Digipan for free (http://www.pavane.net/digipan/digipan.htm ) then just hook a patch cord from your radio speaker jack to computer Line in (or MIC) jack and give it a try to just listen (watch?); no interface needed to just watch

Other Modes (Some programs include some/all of these modes; google them for more info like freqs, procedures, techniques, etc.; check for USB/LSB use)

Olivia - http://www.oliviamode.com/gettingstartedolivia.htm ; another weak signal mode

JT65A and WSPR – Started for meteor scatter, now used on HF (very weak signals) (http://educationalradionet.blogspot.com/2009/07/blog-post-8-jt65ahf-weak-signal- mode-by.html ) and (http://wsprnet.org/drupal/wsprnet/map ; worldwide prop check)

MFSK – Uses variety of tones to counter ionospheric distortions

ALE – Automatic Link Establishment – Uses “soundings” to pick workable HF freq (http://hflink.com/ ) and link HF radios together

Programs

Multipsk – includes many modes, free download (http://f6cte.free.fr/index_anglais.htm )

Fldigi – Free, many modes included (http://www.w1hkj.com/ )

Spectran and Argo – Receive only, good for CW, Aeronautical NDBs, QRSS (LOWFERS and 500kc experiment) (http://www.sdrham.com/ ); free download

Other info sources

ARRL Technical Information Service (http://www.arrl.org/tis/tismenu.html )

Past QST Articles; online for ARRL members (shameless plug for ARRL membership)

Google “amateur radio digital modes” ; mode-specific freqs, etc.

18 Jan 2010 SARA Brief 18 Jan 2010 SARA Brief