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PSK 31 Mode Information

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[What is PSK31 ?]     [PSK Articles]      [PSK HookUp]      [PSK Software ]

[PSK The Real World]     [PSK Limiting Factors]     [PSK Links]

What is PSK 31 ?

Translated literally, it's an acronym for "Phase Shift Keying, 31 Baud". PSK31 is a form of modulation (or "mode") that offers a new and higher level of performance in conversational communications (keyboard-to-keyboard) that we "hams" (amateur radio operators) can enjoy.  And it's been made instantly usable by all of us, due in part to the proliferation of the personal computer, and in part to the superb and generous efforts of some very talented ham/programmers.

In the short time that PSK31 has been in use, its popularity has grown by leaps and bounds.  It may in time replace or at least greatly supplant RTTY and other modes for person-to-person communications. It's fun, easy, and well worth the effort to get set up, which is not very much at all.

It should come as no surprise that the PC is transforming the way we operate.  Think about it, in your little PC you've got one of the most powerful tools for digital signal processing, spectrum analysis, database, logging, and much more.

So this page is devoted not only to PSK31, but also to the large and growing array of ways that the PC can help your enjoyment of this already super hobby. The best way I could think of to help is to list MY favorite tools for these jobs, in the form of links and descriptions.  Incredibly enough most of them are absolutely free for the taking!!! 

To get started just click on one of the buttons to the left. I'll be adding more links and information over time as my own usage broadens. 

PSK31 Description

    PSK31 is a new digital mode:
  • designed by Peter G3PLX
  • that betters SLOWBPSK, an idea and implementation of Pawel SP9VRC
  • based on the RTTY mode of operation,
  • useful for live keyboard to keyboard QSO
  • that works at 31.25 bauds,
  • that uses varicode character coding what gives 50wpm,
  • easy to use and monitor,
  • that give very good copy under low Eb/No numbers and is thus suitable for QRP,
  • that instead of using FSK or on/off keying uses BPSK or QPSK with a Viterbi decoder,
  • that is available for free for many platforms, including Windows (c) with SoundBlaster type Soundcard,
  • and uses advanced DSP and narrow band (31 Hz!!) techniques.
    PSK31 is not a digital mode that
  • will make Pactor, Pactor-2, Clover-II or Gtor obsolete,
  • offers error free links,
  • can be used to transmit files or acces mailboxes...
You can see also how much spectra they use. These images have been obtained with EvmSpec.
You can hear these modes here: Note that these files will be correctly decoded if feeded on the DSP board or SoundBlaster, that's why they are so lengthy.Note the preamble at the start and end of the transmission. If you only want to know how they sound, you can get the ADPCM compressed version (I haven't tested if they decode correctly).
  • PSK31 in bpsk mode calling CQ. Compressed here.
  • PSK31 in qpsk mode calling CQ. Compressed here.

PSK Articles

    The articles presented below are a good introduction to the features of PSK31, at the bits and bytes level. They also discuss the analog characteristics of what makes this mode so highly desirable.  Also, you will find a lot of other information at the places listed under "Other Links".

"Bux Bitz and Bytes" by K4ABT A newly written, original paper by "Buck" Rogers K4ABT.  It's very informative, maybe all you'll need to get going.
"PSK31: A new radio-teletype mode with a traditional philosophy"
(PDF format, get FREE reader here).
An informative 10-page article by Peter Martinez, G3PLX. Peter has been a leader in the definition of, programming for, and evangelizing about PSK31.
"Novel Robust, Narrow-band PSK Modes for HF Digital Communications" Interesting web page document by Johan Forrer.
"Welcome To PSK31 de wm2u" A helpful web page with lots of links.
"PSK31 Fundamentals" Another good article by Peter Martinez, G3PLX with addendum by NB6Z.

PSK HookUp

 The good news is that it's really easy to hook up your hf or vhf rig to your PC. The bad news is that it's also really easy to have problems. They can include over/under driving the rig, induced hum, digital artifacts from the sound card, impedance mismatches, and so on.

      I have found these documents to be useful in determining how best to connect things, and I'll be adding more as time progresses. At the present time, there are a couple of commercial interface units; many prefer to "roll their own" but at least now you don't have to.

K4ABTs Packet Radio Page This is one of the best PSK31 information sites I've ever seen.  Not only does it have page after page of great original material on setting up and using PSK31, Buck also sells components, connectors, interface boxes and the like, all at very reasonable prices.  It's a MUST-SEE!!!
N1RCT's PTT Help Page Dick, N1RCT's good advice on solving PTT issues.
WM2U's PSK31 page A good overview of different methods of hooking it up.  Approaches include direct, transformer, and transistor isolated. Lots of other good info as well.
"Sound Card Interfacing for RTTY,  PSK31, and SSTV" from Bill Holbert, W5BBR. Many good approaches, well documented with simple schematics.
"Adjusting Filters for PSK31" By Dick Stevens, N1RCT Screen shots of what happens when you do (and don't) get it right. Very clear, helps comprehension.
"Bad Vibes ... Illustrations of a RTTY Problem" More good info and pictures from Dick, N1RCT.
WM2U's new Hookup Page Ernie is collecting info from many sources, this page will probably end up being the center of attention for users of many different rig types.
RIGblaster VERY professional looking, connects your rig and PC for PSK31 and many other modes. They now have a variety of interfaces at different prices.  Top-drawer design, reasonably priced.  I use one of the original units with my "main" rig, and it's been a godsend. Easy to install, easy to use, and it WORKS!
Sound Card Interface by Clint Hurd, KK7UQ Clint has done a really nice job of designing a professional looking yet simple-to-build interface.  He has also done quite a bit of homework on documenting and presenting a variety of info on the growing set of interfacing options, commercial and otherwise. Even if you're already set-up, you should still visit this site...
MFJ's Soundcard to Rig interface It was only a matter of time before MFJ got into the fray.  Their box *looks* ok, but the feedback that I got was that it's very hard to set up.  Judge for yourself...

PSK Software

    The list of PSK31 capable software shown below (in no particular order) is by no means a full representation of the available crop.  It's just what I've used, and have demonstrated to myself to "get the job done".

WinPSKse by KA1DT This is an adaptation of AE4JY's fine WinPSK program (yes, the DLL version), expertly crafted by Dave Knight, KA1DT.  He's incorporated the ability to display and read TWO PSK31 signals at the same time, in an easy to read and interpret presentation. This has a much improved user interface, plus other goodies. For example, it has an amazing new simultaneous spectrum/waterfall display. You have to see it to appreciate it!
Intercom This is a DOS program, decodes/encodes many modes, uses sound card in PC.  Freeware.
MixW CW, BPSK FSK31 RTTY PACKET(w/TNC), MFSK THROB MT63 HELLSCRIBER, FAX and SSTV transmit/receive for Windows. Also receives Pactor. Shareware.
RCKRtty RCKRtty is a RTTY, PSK31, Amtor, Pactor and CW program for Windows 95/98 and Windows NT.  I have used this for RTTY, and it was easy and reliable. Now includes support for PSK31.  Shareware.
PSK31SBW The original (updated) program by Peter Martinez, G3PLX. Similar to a portion of Logger (and others), simple to use, currently lacks the spectrum display.  Requires Windows and a SB compatible sound card.  You can get an improved "front end" interface (PSKGNR), click here. Freeware.
WinPSK by AE4JY
New DLL-based version 2.0
Quite popular, and really amazing. This one can turn a "cacophony" of noise into a mouse-selectable buffet of QSOs to copy and join. Very strong DSP, and (I'm told) a really professional job of programming. The DSP is now embedded in a DLL, and source code to the application is readily available.  Perfect for those who want to "roll their own", our thanks go to Moe for all his fine work.
"ZAKANAKA" by Bob Furzer, K4CY Zakanaka finally appears to have stabilized to an actual release version. Some folks really love this program I don't personally use it.  I'm told it can be used with or without Logger, also available on the same site.
DigiPan: A freeware program for PSK31 This software by KH6TY, Howard (Skip) Teller and Nick Fedoseev, UT2UZ, (the author of MIXW32) has really taken hold in the PSK31 crowd, mostly due to its ease of use. There's also a family of inexpensive PSK31 transceiver kits that make full use of DigiPan's panoramic capabilities through the use of a 4000 (more or less) Hz wideband IF from Small Wonder Labs (great writeup in QST).
Windows HAM radio software by the DXsoft group RTTY/PSK31/ ("TrueTTY") send and receive/decode software, uses the PC sound card.  I've not tried it, but I've gotten email from those who use and admire this software. They also have an associated logging program ("AALog").
WinWarbler by AA6YQ WinWarbler utilizes both AE4JY's PSKCORE DLL and JE3HHT's MMTTY engine, along with support for an external RTTY modem (KAM, PK232, etc),  to offer simultaneous decoding of three PSK transmissions or two RTTY transmissions from a single, intuitive user interface. Other features include an integral ADIF mini-log, automatic archiving, 25-second replay, macros with access to all functionality, and a GPS interface. WinWarbler automatically interoperates with other members of the freeware DXLab Suite, including Commander for transceiver control and DXKeeper for full-function logging, including QSL card/label generation and a real-time interface to eQSL.cc.
MMTTY by JE3HHT MMTTY is an excellent RTTY sound card program that requires Windows 95 or 98 and a Sound Blaster compatible sound card.
DX4Win Version 5.0 A nice commercial logging program that now contains PSK31 capability.
Multi-Mode for Macintosh MultiMode allows you to decode and transmit morse code, RTTY, FAX, SSTV, PACKET, ACARS, PSK31, ALE, and many other modes on your Macintosh, without any extra hardware!
PacTerm 98 and PKTerm 99 with PSK-31 by Creative Services Software PacTerm '98 and PKTerm '99 are now available. I've not used them, so can't comment.
W1SQLPSK Interesting new approach to user-interface for PSK31 operations. Decode up to 20 stations at a time, using a horizontally oriented layout.  Cool idea, it works too.

G-PSK31 for Linux users

The Linux GTK+ PSK31 Terminal Program by EA5UD

PSK The Real World

   You might be tempted to conclude from the recent advertisements by the Big Three (Kenwood, Yaesu and Icom) that the latest DSP filtration schemes are ideal for PSK31, but that has NOT yet been borne out by my observations. To understand what all the fuss is about, click here

First of all I'd like to say "Thank you" to those hams, manufacturers and others who have taken the time to re-think the design and use of ham gear in the context of PSK31. I am pleased to report that there has been some improvement in areas that I have previously been critical.  Here are a few examples of new (and some old) ways that you have made things better:

    1. I have received various emails from hams who have found that by "lying" to their radio about the installed filters, have been able to use a narrow (cw) filter in the SSB modes.  If you've been frustrated, this is a very good thing to try.  Good examples include the Icom 706, 756 (not Pro or ProII) and any other rig where you can tell it via a menu what filter is what.

    2. I have heard from folks who say that TenTec rigs, such as the Omni 6 Plus, Jupiter, etc. allow PBT and narrow filters in SSB mode, so they obviously have their act together. From what I've seen, it looks like the really cool K2 (Elecraft) also has this ability.

    3. Users of older rigs, such as the Kenwood 440, 450, and basically any radio that has IF-shift (or the equivalent) in combination with selectable filters for SSB mode have already found that they are super for PSK31.

So...in a nutshell, there are several ways of getting proper receive filtration for the rapidly expanding PSK31 mode.  As the bands get more crowded, and the opportunity for QRMing is greater, you're going to need every advantage these select rigs can provide! If you don't understand what I'm referring to, please be sure to read the ramblings provided below.

A hopeful note: I had been reporting (as late as December 8 of 2001) that the new Icom Pro II was not well suited for the needs of the PSK operator, and that I had difficulty getting anyone at Icom to listen to my input. Thankfully, I was subsequently contacted by a senior individual of Icom America, and after hearing (and reading) my ramblings, assured me that Icom corporate was very aware of the issues I have been presenting.  Now, this is no guarantee that they will act on this, but at least I've been heard. Stay tuned and check back here for further developments.

"Old rigs for new..."

(2/16/2001) I recently visited the local HRO (Ham Radio Outlet) to have a close-in look at how well the most recent HF rigs would do for PSK31.  I went with a VERY specific goal in mind, to see whether the rigs could help in a situation that I'm seeing more and more frequently.

Here's the scenario: you've "parked" your rig at 14.070 (as we often do), with the intention of doing some broad-band reception. You begin a QSO at an audio tone of 2000 Hz. While you're operating a very strong Pactor signal appears at an audio tone of 1500 Hz, 500 Hz wide, causing your AGC to kick in big time, and the weak station that you've been working disappears. OK, now what...

Ideally, one would like to be able to shape the IF bandpass to somehow eliminate the interfering station, and that's what I went to HRO to see how to do. The results were quite surprising, not very good I'm afraid. (Yes, I looked long and hard at the "big guns": the Icom 756 Pro and the Yaesu MK5, as well as several other very new offerings, such as the Kenwood TS2000.)

    1. The High Cut/Low Cut fallacy
    The first thing I tried (naturally) was to use the low cut knob that's present on virtually all of the new rigs.  My thought was to raise the low cut threshold to be above the interfering station at 1500 hz. Imagine my surprise when I discovered that the low cut could not be set to be any higher than mid-IF, approximately 1200 hz. That didn't help.  This is true for ALL of the rigs that have this feature, which (sadly) includes all of the new high-priced radios. The high-cut stopped mid-range too, and thus I'd have the same problem trying to fix a problem that was below the center of the IF.

    2. Filter, what filter?
    Next I went to see if maybe I could use a narrow filter, and move its center up to the 2000 hz location to get rid of anything that's on both sides of the QSO. Once again, I ran into a couple of brick walls.  First of all, many of the newer radios do not permit you to use the narrow filters with the SSB modes.  Second, even those that do often either don't have any facility to do the IF shift, or limit the shift excursion so you can't put the center on that high (or low) station.

    3. Notch filter? Fuhgettaboutit!
    So, I thought maybe I could use the notch filter to notch out the interfering station. Well, that too was a bust, since I couldn't see any way to vary the width of the notch, and they were all too narrow to have much effect on the 500 hz wide Pactor station.

    4. Yeah, but they say you can set the "width" and "center"...
    Nice try.  Too bad that you can't set the width and center in SSB mode (such as in the Kenwood 2000), it's only for CW. You're forced into the High Cut/Low Cut mode in SSB mode, see above.

There's some hope...
Believe it or not, I did find ONE newer radio that appeared to be just the ticket. The funny part of it is that it's also one of the least expensive radios on the market.  It's the ICOM 718, into which you can install a nice narrow 250 hz filter. Upon reading the manual, it seems you are permitted (with a single one-time menu setting) to use this filter in the SSB mode. In addition, the radio has a very nice "old-fashioned" IF-Shift control.  "Voila!"  Now, you can select the narrow filter and slide it to whereever you need to for your QSO.  I plan to bring one of these radios home soon to confirm that it actually is as effective as it promises to be.

Users of other modern radios, don't give up...you may find that by LYING to your radio, you can fake it into using a narrow CW filter in SSB mode. More about this here...

Why is this all true?
From my cursory examination, it seems that the HF rig manufacturers are still designing radios that pay little if any serious attention to PSK31 and other broad-banded AFSK-style modes.  They assume (wrongly) that any operating we want to do is CENTERED IN THE PASSBAND, which is clearly not the case for PSK31.  In fact it's just the opposite; we park the rig and tune with the PC. Sadly, it's probably about two lines of code in the new radio's firmware that stops the Low and High cut limits at the center point.  If they just opened it up to allow the low-cut to be moved up to the high end, and the high-cut similarly to be moved down to the low end, the problem would be solved. I just hope they're listening...

Don't throw out those old radios!!!
Lastly, don't assume that since this is a new operating mode that your old radio just won't cut it. The irony to all of this is that your old Kenwood 440, 450, etc. may turn out to be the best PSK31 rig you can find. They have IF shift, and you can install a nice narrow filter, a winning combination.  I personally use an OLD Drake TR-7 with an external synthesized VFO (for stability) and it's the best PSK31 rig I've ever had. So, why is it so good? Imagine a weak PSK in the middle of the strong boys.  Click in a narrow filter, say 300hz, and use the IF shift to isolate the desired signal.  The effect is truly spectacular.  The station comes up dramatically, the AGC relaxes, and copy improves; it's as if the nearbly stations just disappear. You've got to see it on the waterfall to appreciate how cool it looks and works.

(March, 2001) I received this interesting email from Steve Jackson, KZ1X/4, in response to the above commentary:

    "The rig that bypasses all these problems is the TenTec Omni VI+. I have one, with all the factory filters. You can use any filter you want to, at any time. No Japanese microprocessor trying to make the radio idiot proof!  Just push the button to select one or more real, multipole, hi-Q filters in each IF.   (InRad has filters that are supposedly better.  Haven't tried 'em.) The PBT then puts the filter 'center' wherever in the passband you want it, after you've selected the filter; or, you can bypass all the filtering and just use the PBT.

    All audio and control I/O are on the back panel, on individual RCA jacks.  Don't need to interface with the mic plug.

    Full duty cycle at 100% power, no fan, and at any SWR and phase angle. No auto power cutback. Manual notch is narrow and deep enough to allow me to have a PSK QSO 1 kHz away from an automated PACTOR station, even without the filter! RX specs for close-in IMD (less than standard 20 kHz), etc, are second only to the Elecraft K2, according to the ARRL lab.

    Yes, it's a weird duck, and lots of people just don't "get" TenTec.  I'm no cultist. I have JA rigs, too. But when I want to get serious, the power switch on the Omni is what's on."

Thanks Steve!

(March, 2002) I got this nice message from Wiley Sanders,KF6IIU:

    "I'm succesfully using a Yaesu FT-101 with PSK31. There are three "unique" features using this rig in this mode:
    - The rig has separate tuned circuits for generating the L.O. transmit and receive frequencies.
    - The SSB bandwidth is fixed at 2.5 kHz.
    - The AGC cannot be disabled and has a very slow time constant.
    - The PTT current is 110ma at 13.5V, beyond most interface's current-sinking capabilities.

    The workaround for the TX/RX offset is to call CQ and then tune in a replying station with the Clarifier (RIT). You can get within a couple dozen Hz this way. The FT-101 is still not that stable, though, so you have to lock the transmitting freq or you will drift around. (This is easy in Digipan, don't know about other software.) Plus, you must depend on the patience of the other op! Fortunately most ops are willing to tune a few Hz to accomodate my not-quite-steady signal.

    For bandwidth/ACG issues, there is sometimes no alternative but to put the audio frequency at 900 Hz in the middle of the FT-101's CW passband and manually switch back and forth between receive-CW and transmit-USB. When I forget to switch, that explains why sometimes I don't come back to you right away!

    The PTT current workaround is to use the FT-101's VOX. It works fine for me. I used straight cables with ferrite chokes for several weeks until I decided to splurge and order a professionally made interface.

    Other observations - a lot of ops are still overdriving their rigs. Probably 20% of the signals I "see" have a 2nd, 3rd, or more set of "railroad tracks". I doubt most people monitor their transmitted signal. If you can rig a 2nd receiver to hear your own signal, tune in and zero beat your transmitted signal. If you hear *any* clicks or bumps, your signal probably isn't clean (assuming you are not overloading the receiver too much.)

    Last weekend, one op was cranking out a HORRIBLE 60-Hz-harmonic signal that splattered over 3 khz of the 10 meter band. Obviously he wasn't monitoring his signal. I am sure the cause of his problem was the same problem I had when I first connected my Tigertronics SL-1 interface - my laptop computer was not grounded and it introduced a horrible ground loop. It is a Compaq 1700XL and it was floating at 18VAC above ground! Laptop power supplies are TOTAL CRAP; beware. Grounding the computer to the rig solved the problem.

    PSK31 rocks! See you on the air."

Thank YOU Wiley!

PSK Limiting Factors

Weak Link #1: Your soundcard
  1. Your soundcard is also used by Windows and other applications. Here's the scenario: you're in the middle of transmitting, and your soundcard is generating the tones for your rig. Then, you click on a menu or some other application, and Windows decides that you need to hear a sound (a click, whir, buzz, tuba, whatever). Guess where that sound goes? Yep, it's "on the air". Just try to explain to your QSO buddy why his rig just suddenly growled like a lion, or said "You've got mail".  The best solution would be to use multiple cards, and dedicate one to your Windows sounds, and use the other for your radio. The current crop of software, though, makes this really hard, and I've even heard of one case where Windows itself makes it impossible.
  2. Your soundcard uses real-time wave generation. Thus, it's dependent on the cpu to make it do its thing.  So, if you suddenly have a burst of disk activity, your network card comes alive with email, or any other processor intensive action takes place, guess what stops working momentarily? That's right, your sound card. It will show up as a click or other weird glitch in the audio stream, and, depending on how severe or frequent the processor overload is, it could happen with maddening regularity, and last for seconds.  That's a great QSO buster too.
  3. Your soundcard was never designed for super-clean output. At this point I've tried about a half dozen soundcards, and they ALL show some kind of digital artifacts in the output, ranging from a high-frequency (from an audio point of view) ripple on the surface of the wave, to strange in-signal period variations.  Every card is different, and you'll never see information about this in the specs. There doesn't even seem to be much correlation between price and quality from this aspect.
  4. Your soundcard is a toy. Please don't be offended, but really now. What did you spend for the soundcard? $20, $30 maybe? You really can't expect such an inexpensive device to give you good linearity, clean hum-free signals, rf-shielding, stable DC levels, freedom from transients, wide dynamic range, etc. It's amazing they work as well as they do, considering how really cost-reduced they are.
  5. Your soundcard has the wrong levels. I've yet to see a soundcard that doesn't need external level-setting hardware. For input you can try the microphone input, but that's too sensitive. Then you try the line input, but your speaker's got to be at ear-splitting levels to get useful display and accurate copy.  I've also found that the "Volume" controls on the typical PC are not even used by most of the software that is available, for reasons I don't really understand. The same applies to output for your rig's mic input, you've almost certainly got to reduce the levels and isolate the lines.  The good news here is that there are some good products now that can help, like RigBlaster and others.  Well worth the money!
  6. Your soundcard uses real-time detection. Thus, just like with sound output, it's dependent on the cpu to make it do its thing.  So, if you suddenly have a burst of cpu usage, your soundcard goes "deaf" for a moment. This shows up as lost characters and, depending on how severe or frequent the processor overload is, it could really mess up your incoming copy.

Weak Link #2: The PC itself

  1. Your PC can't keep up. Sure, in general, your machine does fine for typing, paint programs, and lots of other non-time-critical things, but they were not made to take care of events that are "here and then gone".  This is particularly true at the application layer, where (unless you plan to totally hog the machine) you're at the mercy of the Windows task swapper. I don't care if you've got a SuperWhizBangPentium1000 machine, you'll run into this sooner or later.  The net effect is either lost characters, or glitches in the output stream. I even had a problem where the video driver itself was too slow (on a 400 Mhz K6 machine) and made a glitch in the audio output whenever the screen was refreshed.
  2. Your PC wasn't made for controlling external devices So, you've got to play games with using the RTS/DTS lines in your RS232 port to simply key your rig.  What a pain.  Particularly if you, like I, have all these beautiful molded connectors everywhere.  You'll either have to cut into one, or make some kind of jury rigging to get to the lines.  Then, just to be safe, you better drive a relay or opto-isolator, or you're bound to have some nasty ground loops or rf feedback.
  3. Your PC display runs out of room. Imagine this: you're running Logger, the volume control applet, and your Kachina all on the same screen. Problem is, you can't see all of them at the same time. So, you're switching back and forth, and give up in disgust. This is so typical of the PC it's laughable. And, if you're anything like me, you're no longer running your screen at 1600 X 1200, because, frankly, your eyes can't handle it..

Weak Link #3: Your rig

  1. Wideband reception is a myth. There's some really great reasons to want to use PSK31 in a broad banded way.  The problem is that there are some even more compelling reasons NOT to.  Like when that KW packet stations fires up 1kc away from your QSO and makes your AGC go crazy. I defy you to copy clean PSK31 or anything else for that matter.  The problem is that the current design for radios don't let us effectively "notch" out one or more strong stations at the IF stage (most notch filters are MUCH too narrow), therefore the AGC kicks in.  So, we cut back the bandwidth, but it's getting to the point where even my 250 hertz crystal filter isn't narrow enough to get rid of the inter-modal interference.
     
  2. Your rig wasn't designed to accommodate flexible digital modes. OK, you've got several crystal filters, but does your rig let you click them in when you're in SSB mode?  The answer for many users of older ICOM gear, and maybe others, is "NO". So you put up with the problems mentioned in #1 above, and try to find ways to work around the strong interfering stations. Or here's another scenario that trips up even the newest of radios, such as the Icom Pro and Pro II, and the Kenwood TS2000. You've got a desired PSK station at an audio frequency of 1700 hz, and an interfering station at 1300 hz that's 500 hz wide. OK, so you try to bring up the low-cut DSP filter, but it (incredibly) tops out at 1000 hz, leaving the interfering station intact and strong as ever. You're stuck, and the only way to get this guy is to turn the tuning knob on your rig (ackk!!!).

    One possible fix (believe it or not) is that several of the rigs that lack DSP are able to be lied-to, thus making them much more suitable for PSK31.  What you do is go into the appropriate menu, and tell them that that slick 300hz CW filter you installed is really a 1.9kHz SSB filter. THEN it will let you select that narrow filter in sideband mode, and with any luck you can slide the IF shift up or down to make it do its magic without having to touch the tuning knob. Rigs that I've successfully fooled this way include the Icom 706 (all current models), 746 (non-pro) and 756 (non-pro and non-pro-II). "What a world, what a world..."
     
  3. Your rig doesn't really support AFSK input. Sure, you've been running packet for years, and that uses AFSK, so "where's the beef"?  The problem is now that you're using the rear connector on your rig to bring in the audio, and you don't have that handy PTT output from your TNC to key the rig, you're finding all kinds of difficulties. Things like that fact that your VOX doesn't detect rear panel audio, so you try to use PTT via software commands from the PC, but the rig doesn't mute the microphone (so you've got to unplug it). You then decide that's no good, so then you bring the audio into the mic connector, but then you find that you've got to set the level of your audio high enough to trip the VOX, but not so high that you drive your rig into the ALC area, then sadly you find that there's no overlap of the two ranges. These may not SOUND like big problems, but I've heard plenty of complaints from fellow hams about these very issues.  (A good solution to this, the one I use, is to get yourself a RigBlaster and call it a day.  By the way, I get NO commission, it's just a fine product.)

PSK Links

 

Copyright 2001-2010 All Right Reserved E-mail Problems to Shannon Davis KB9WNM