MFSK

By Bob Wexelbaum, W2ILP

 

February 2006                              VOL.  79, NO. 2                                                  CIR 120

 
In my lecture series at GARC, I covered MFSK, another digital mode.  I am again presenting a discussion about  this interesting mode here and including some updated information.

 

MFSK means Multiple Frequency Shift Keying.  We have discussed RTTY, which is a frequency shifting mode that transmits only two frequencies, one for a space and another for a mark.  MFSK differs from RTTY in that it transmits with more than two possible frequency shifts that result in a number of possible audio tones when a receiver with a BFO is used.  MFSK, unlike PSK-31, is not a new mode.  Variations of MFSK have been used commercially since 1937, when it was described in a publication called Electrical Communication by L. Devaux and F. Smets..  Because of its warbling audio, which seems musical to some ears, MFSK had been called Piccolo by the British and Coquelet (Rooster) by the Belgians and French..  Another application that has evolved from MFSK is DTMF, which means Dual Tone Multiple Frequency.  DTMF was developed by Bell Labs for “Touch Tone” telephone dialing.

We have seen how the same hardware interface between a PC and a SSB transceiver can enable Hams to use RTTY and PSK-31.  Now we will see how the same hardware set up can be used with different software for MFSK.  The most popular software for MFSK was developed by Nino Porcino, IZ8BLY, with its parameters suggested by Murray Greenman, ZL1BPU.  The software is called Stream. The coding used is new and not the same as was formerly commercially used for MFSK.  IZ8BLY and ZL1BPU first tested MFSK with Stream on June 18, 2000.  Since then they have been in communication every day on 20 or 17 Meters, using as little as 5 Watts.  The MFSK chosen for hams uses 16 possible tones and is called MFSK-16.  The software also provides MFSK-8 which uses 8 possible tones.  The MFSK-16 mode has the 16 tones spaced so that the tones are only 15.625 Hz apart. The bandwidth is calculated by BW = B + m.s.K = 16 X 15.625 x 1.2 = 315.625 Hz. This results in a total bandwidth of about 316 HZ.  The MFSK-8 mode utilizes the same bandwidth as MFSK-8.  This is not much wider than an RTTY signal and it can fit into a receiver’s CW filter..  A third mode included with the IZ8BLY software is 63PSKF, which is a 63 baud PSK mode like PSK-31, but faster. The advantages provided by MFSK can be realized mathematically from the Information Theory developed by Claude Shannon and from texts which applied it to spread spectrum communication systems.  The spread spectrum texts explain mathematically why even the closely spaced MFSK system may produce more robust solid copy than other systems during multi-path conditions.

MFSK (continued)

 

The MFSK system uses a Forward Error Correcting system technique (FEC), which is a Veiterbi method applied by Phil Karn, KA9Q.  The system accepts typing as fast as 42 WPM and employs a self-synchronizing interleaving method developed by IZ8BLY.  The coding used is a Varicode similar to that used for PSK-31, but it is not the same as the PSK-31 Varicode.  Remember that a Varicode does not have a fixed number of bits per character.  The MFSK code also uses fewer bits for the more frequently used characters.   The originals Piccolo integrating detector is modeled in the sound card by using a Fast Fourier Transform (FFT) routine.  The FFT routine is also able to produce phase information, AFC, and a waterfall tuning display.  It easily separates the 16 tones with 4 Hz wide channels.  No synchronizing information is actually transmitted for signal timing since the timing is intrinsic to the signal itself.  This enables more coded possibilities than the PSK-31 Varicode could.

Although there are advantages to the use of MFSK over other digital modes during certain propagation conditions, it has not become as popular as PSK-31 or RTTY.   Operators have claimed that PSK-31 is easier to use and don’t often try MFSK during propagation conditions and over distances where it might work better.

MFSK is such a robust system that it can perform with perfect copy even with bad QSB, QRM, or noticeable Doppler shift, when it is barely audible.  It is the best mode on 80 and 40 Meters, during times of high noise levels.  Unlike other modes the amplitude of the MFSK RF is not critical and RF amplification need not be linear.  You can not change its bandwidth by over driving the transmitter final amplifier. Is MFSK-16 better than PSK-31?  That depends on propagating conditions at the time and frequency that you want to use it and the distance involved. .  It is up to ham experimenters themselves to compare these modes.

To download the latest Stream V1.1 software that was updated January 31, 2004 go to:-

http://xoomer.virgillo.it/aporcino

This is IZ8BLY’s web site.  You must click on <STREAM> on its home page to get MFSK software, as software for other digital modes is also available there.

Using an SSB transceiver with any waterfall displayed digital mode presents the problem that the strongest signal in the waterfall will control the transceiver’s AGC.  This can suddenly make you lose weaker stations and can only be eliminated in the transceiver itself, if it has a narrow filter that can easily be slewed to the frequency of the desired acquired signal. 

Next you need to know what frequencies can be used for MFSK.  This is now not as straightforward as it could be.  Amateur Radio sub-band frequencies for different modes are supposed to have been spelled out by the IARU and specified for three different zones covering the whole Earth.  This is known as the “Band Plan”.  The entire world is divided into three band plan zones.  The U.S. is in Region 2.  The band plans for regions one and three have been firmed up and accepted, but the band plan for the U.S. remains controversial and is not being accepted by many hams or even by the ARRL at the present time.   At least two petitions have been sent to our FCC and they have not yet been officially acted on.  Both say that sub bands should be determined, not by the names of digital modes, but by the actual bandwidths.  This can promote lots of future experimentation with new and different digital modes and their variations.  Modes that have yet to be officially named can be accommodated.  Avid hams seem to be fighting among themselves in very much the same way that the first ‘Phone operators argued with the CW operators.  There are some CW operators who can not accept any digital modes on their parts of the ham bands without complaining.  There are some old RRTY guys who think that RTTY should be the only digital mode.  Then there are others who are satisfied with PSK-31 and think other digital modes need not be used. The curses of irate hams can be copied during contests for each mode when a frequency is being used by another mode.  You would think that CW and the digital modes are so narrow in bandwidth that the sub-bands could easily be shared…but no!  Hams who devote there time and money to a specific mode or contest are often intolerant of other modes.  Here we see the same old conflict of tradition verses technology.

                                                                                   Page 2

PRESIDENT’S PAGE

BY

KE2LJ

 

           

      We continue to encounter problems with the Bethpage repeater. It all stems from the ongoing activities of repairing the roof on Plant 14. They plan to strip it down to bare concrete, and this caused them to have to remove the 4 towers up there. Our antenna was on a 30’ tower that had to come down. I gave Facilities our Diamond antenna, and they bolted it to the E2C dome wall with the same feed line. So, at this lower altitude, the system doesn’t play as well, and is also subject to lots more noise. But a few weeks ago, it was off the air entirely. Ed (WB2EAV) was able to get up there, and found that the roofers had tripped a circuit breaker. After that was fixed, we were back up OK. Then a few weeks later, the repeater power dropped off considerably, and that’s where we are right now. It sounds great if you are in Bethpage, but you can’t hear it in your car if you are more than a few miles away. At my home, I have a really good antenna at 60’ in the air. The repeater is usually full scale at my shack, but right now it’s barely on the meter and I can hardly hear it. Either the antenna cable is loose, or the finals have blown. Ed has to make another trip to find out. I wish we had easier access to the roof, but that’s not going to happen anytime soon.

Bob (W2ILP) has decided to make it easier for potential applicants to get to his VE sessions. UL has become a little difficult, and might get worse in the future. We made contact with a teacher at Briarcliff College in our old Plant 35. This fellow is a new Ham, and seems very eager to help. I worked with him on the HRU Committee. He offered us a classroom, and we’re taking him up on the offer. All future VE sessions from now on will be at Briarcliff, in a room on the North side of the first floor. I expect that GARC meetings will also be here down the road a ways. The LIDXA has been meeting in Briarcliff for about 2 years. They have a VCR,  DVD player, etc, and it’s an easy place to get to.

At our last meeting I did a little talk on my railroading experiences. We started a little late, and I didn’t cover all the stuff I had. I was thinking of doing the rest in the future, but since the meeting was so under-attended, I believe there is not much interest from most of the members. So, I won’t do anymore of that for awhile. But, as always, we need to come up with some interesting programs for the meetings, and we are out of ideas. If you have any topics you would like to see presented, let me know, and I’ll get somebody to talk on it for us.

Our next Garc meeting is 2/15 at U.L. and our speaker will be Tom Carrubba, KA2D.  His subject will be ARES, and why we should all participate. After sitting through some major hurricanes lately, I think ARES is becoming a very important part of our hobby. It has brought a lot of visibility to Ham Radio at very high levels of our Government. Now if only these same people would read what we are saying about BPL!

Hopefully, you can make the meeting. See you there.  -Pat KE2LJ

 

                                                                                                                                    Page 3

CQ DE WA2LQO DECEMBER 2005

GRUMMAN AMATEUR RADIO CLUB

MINUTES OF GENERAL MEETING -1/18/2006

Karen KC2OPX

The meeting was called to order at 5:50 PM by Pat.

 

TREASURERS REPORT – Ed, WB2EAV          REPEATERS – Gordon, KB2UB

Finances continue to be in good shape.                     Nothing new to report. Gordon ws in Florida.

                                                                                                                                                                                                                                 

VE REPORT – Bob, W2ILP                                  NET REPORT- Zack, WB2PUE

Two applicants passed the Extra exam..                  The Sunday morning 40-Meter Net was doubling.

 Es present were AB2NT,  KB2QFT,                       Due to selective propagation some could hear, but

 KC2HNN, N2SFT and W2ILP                                 some couldn’t.. 

                                                                                     The Thursday evening 2-Meter Net was good.

2006 G. A. R. C. DUES:

For those who have not yet paid their 2006 dues, they are now due. The year that you are paid up  to should be shown on your address label.

Basic membership dues are $20 per year.  Multiple members in the same household pay the family rate of $30.  Retirees living outside of the New York City metropolitan area can pay the associate            member rate of $5.

Send dues checks, payable to GARC (or any other mail) to:

GARC, P.O. Box 664, Bethpage, NY 11714

 

OLD BUSINESS:

Pat passed around pictures showing the antennas at Rocky Point.   Also pictures of the old Motor  Parkway. 

 

NEW BUSINESS:

Pat announced that the Grumman Model Railroad Club was to have a show at the Bethpage HS, on             1/21/06.  At the same date and time at the Long Island Maritime Museum in Patchogue there was to be a

presentation about the old Telefunken radio station.

 

PROGRAM:

Pat showed pictures of a 1928 SX Steam Locomotive in Essex, Connecticut, including inside the fire      box, running gear, the shop, welding tanks and how they hammered out steel by hand.

 

The meeting was adjoined at 6:55 PM.

 

Karen, KC2OPX, our secretary, wants to thank everyone who helped her set up her new radio.             Karen has now successfully signed on to the 2-Mater GARC Net.

 

GARC NETS:

40 Meters: 7.289 MHz at 7:30 AM EST Sundays.

20 Meters: The 20 Meter WAG net has been cancelled because of inactivity.

2 Meters (via repeaters): 146.745 MHz  (-.600)at 8:30 PM EST Thursdays.

                                           145.330 MHz (- .600) at 9:00 PM EST Thursdays.

[Tone for both repeaters is 136.5 Hz]         (ARES/RACES) Mondays

                                                                                                    

MEETINGS

General Meetings of the GARC are held on the third Wednesday of each month, starting at 5:30 PM.   The meetings are usually held at the Underwriters Lab, 1285 Walt Whitman Road,  Melville, NY.  Driving directions and maps can be obtained from http://www.mapquest.com   It is suggested that the GARC Web Site be checked to be certain of meeting location, which may change after this newsletter is distributed. Board meetings are held eight days before the General Meeting and GARC members are invited. to attend, but please call Pat Masterson, KE2LJ, at 516-346-7125 to confirm place and time of meeting.

                                                          

GARC WEB SITE

The web site of the GARC can be found at http://www.qsl.net/wa2lqo/     Webmaster is Pat Masterson KE2LJ.  Pictures of GARC activities, archives of newsletters, roster of members, and other information about the GARC may be found there.

                                                                                                                                                                                                                                                                                                                                                                                                                

Internet Link of the Month for Internerds

 

“SUITSAT” TARGET DATE NOW FEBRUARY 3rd

as received from Stan Rogak, KB2QFT

 

Amateur Radio on the International Space Station (ARISS) has announced another change in the “SuitSat” deployment date, which has been a bit of a moving target.  The latest target date is Friday, February 3rd.

That’s when the International Space Station crew is set to perform the next space walk. According to informed sources, the crew is scheduled to open the hatch for its excursion around 2200 UTC, and SuitSat should be put into orbit within the first hour.

 

Possibly the most unusual Earth satellite ever, SuitSat consists of a surplus Russian Orlan space suit converted into a transmit-only satellite with an FM downlink frequency of 145.990 MHz.  Using the call sign RSORS, it will transmit voice messages, telemetry and an SSTV image on a nine minute cycle as it orbits Earth.

 

The batteries powering the satellite are expected to last for about a week after deployment, and SuitSat’s free-floating, decaying orbit should cause it to re-enter Earth’s atmosphere after six weeks in space.  The SuitSat signal should be strong enough to be heard using a VHF transceiver or scanner and a simple antenna; thus making it an ideal project for students to monitor and track.

 

SuitSat’s payload also includes a CD containing hundreds of school pictures, artwork, poems and student signatures. For more information, see article “This is SuitSat-1 RSORS” by Frank Baur, KA3HDO, on the AMSAT Web site:-

http://www.amsat.org/amsat-new/articles/BaurSuitSat/index.php

Editor’s Note:

Knowing that my 2-Meter antenna was limited, I kept looking at my E-mail.  I am in a chat reflector with Hams who belong to Mensa.  Some of them have experience tracking SATS. I monitored 145.990 on February 3rd.  I can not report hearing SuitSat.  By midnight local time I received a report from Bill, K1ATVof Mesa Arizona that SuitSat, affectionately known as Ivan Ivanovitch, (the Russians called it Mr. Smith) was dead.  It was alleged to have died after two orbits, probably because the batteries froze or electronic components failed. Shortly after that KU4OS of Florida reported hearing a weak carrier that was probably from SuitSat.  He believed that “Ivan” might still be alive, but now very weak. Reports can from DN2VA and DL0WH that they had heard it at 0917 UTC, but they was the last creditable reports that I could find reported on the Internet.

 

                                                      “SuitSat” (continued)

Amateur Radio satellite tracking and communication is an interesting part of our hobby.  Although I was a member of AMSAT when it originally started, I am no longer a member.  Those who want to get information about satellites, both the ones carrying Amateur Radio equipment and others may find it via the AMSAT web site, along with tracking information.  Therefore this month I am generally calling attention to the AMSAT web site:-

http://www.amsat.org/    

Ham related satellite news can always be found via http://www.arrl.org

 

Satellites are either geo-stationary or orbiting types.  All use different RF frequencies for up-link and down link.  Anyone who is serious about tracking them or communicating with those that have Ham repeaters on them should stay in contact with ARRL and AMSAT for relevant information.   Satellites have been used to increase favorable public opinion about ham radio.   Hams have volunteered to set up equipment at schools in the U.S. and other nations so that school children and teachers may talk to astronauts.  Almost all astronauts hold ham licenses, at least as Technician Class operators.  This includes Russian astronauts and others who have ham licenses and call letters issued to them by their own nations.   Many, but not all, of the school demonstrations have been successful.   They have lent purpose to our hobby and helped it to be considered an educational hobby, as it should be. 

IEEE CHARPERSON IS A HAM

 

In the February 1, 2006 issue if the local IEEE newsletter, “The PULSE of Long Island”, Chairperson, David Wolff called CQ.  He is WB2IHS.  Dave wrote about his first DX QSO in 1974.  He said that the IEEE is supporting LIM-SAT, the Long Island Museum of Science and Technology (www.limsat.org) and the Executive Committee should also support Amateur Radio in pre-college engineering programs.  I had attempted to make connections for Ham Radio with the IEEE in the past.  I had not had any success.  I contacted Dave, WB2IHS, recently and told him about the GARC’s VE program.   I am a Life Member of IEEE and offered to follow up on any program that can bring new hams into our hobby.      ---w2ilp--

 

 

PUZZLE

Here is another cryptogram:-

 

AKS  PKXVQ  AU  HVS  JMUPEMBJDBXF  QMVC  BFPVMTFEU  IMXN  EXNJTFBUP  QMVC 

 

WBNBD  DKU  HMTFQP  XI  QMVCP  AU  ETF  CUD?  AU  QXF’D  HVS  TVDX  BFPVMTFEU  DKTD

 

 WBNBDP   DKU   HMTFQP   XI   ETMP   DKTD   NBCKD   KBD    VP.     –HXH   AUG---

 

Solution to January’s cryptogram:

ALL GOOD BOOKS ARE ALIKE IN THAT THEY ARE TRUER THAN IF THEY HAD REALLY HAPPENED AND AFTER YOU ARE FINISHED READING ONE YOU HAPPENED TO YOU.

 --ERNEST HEMMINGWAY--

 

                                                                                                                                                 Page 6

 


GARC VE SESSIONS

 

We are continuing to proctor exams for all classes of ham licenses on the second Tuesday of each month starting at 5:00 PM.

 

The present exams are:

Element 1: 5 WPM CW,

Element 2: Technician

Element 3: General   

Element 4: Amateur Extra Class.

 

The fee for 2006 is $14 for all exams taken at one sitting. 

 

Applicants for upgrades should bring a photocopy of their license and their FRN number.

 

New, first time applicants should be aware that their Social Security number will be required on their application form.  All applicants should bring driver’s license or other picture ID.

 

At the time of this writing it is known that the February 14th VE session can not be held at UL.  The February session will probably be held at Briarcliffe College, in Bethpage, in a building that was formerly a part of Grumman.  Applicants and VEs should standby for updated detailed location information, which I will e-mail to all concerned.  It will also be posted on the GARC web site, as soon as it is firmed up.

 

For any information e-mail: -

w2ilp@optonline.net or phone: -

(631) 499-2214

 

Study material information is available at the http://www.arrl.org or the http://www.w5yi.org web site.

All VECs use the same Q & A pools.

Since the beginning of the VE program the GARC has provided opportunities to take ham exams monthly, during all twelve months of every year.

 

Bob Wexelbaum, W2ILP

and the Grumman VE team.

                                   

 

CQ de WA2LQO

February 2006

 VOL.  79,  NO.  2

 

EDITOR

Bob Wexelbaum  W2ILP

(631) 499-2214

w2ilp@optonline.net

 

CONTRIBUTING WRITERS

PAT MASTERSON, KE2LJ

And all the members of GARC (we hope!)

 

CQ de WA2LQO is published monthly by the Grumman Amateur Radio Club for its members and friends. Send articles and amateur equipment advertisements to:

KE2LJ or W2ILP

 

ELECTRONIC SUBMISSIONS

If you want to submit articles or amateur equipment ads via e-mail do the following:

1. For submission direct to editor call him at above number to set up a transfer.

2. For e-mail transfer:

Internet Address

bat@grumman.com

 

 
EDITORIAL

 

 I have now edited this newsletter for one year.   I hope that everyone enjoys reading it. I have tried to take notice of the desires of the membership.  As I have said before:- Ham Radio means different things to different people, and although I am trying, I know that there may be some who do not care to read everything that is in the newsletter.

I have been conducting VE sessions, as coordinator for the GARC for 15 years now and have seen many changes in the FCC regulations and the testing of applicants.  The most recent information is that there will be a complete overhaul of the written exams for all classes that is now scheduled to take place on a different time table than originally expected.  The Q & A material changes will be announced here when they are firmed up. It is expected that the new Technician exam will be made easier for new applicants and the new Extra Class exam will be made more difficult for new technologies.  It is also anticipated that the remaining 5 wpm CW exam may be eliminated as it has been in other countries..  Also the location where we give our VE sessions will probably change. [See VE Sessions Box].

 

VY 73,

 

W2ILP (I License People)…with the help of the VE team, a VEC and the FCC.

 

GRUMMAN AMATEUR RADIO CLUB OFFICERS FOR 2005

 

President                Pat Masterson              KE2LJ            V01-01    516-346-7125

Vice President       Gordon Sammis            KB2UB          Retiree     631-666-7463

Secretary               Karen Cefalo                KC2OPX                        
Treasurer               Ed Gellender                  WB2EAV        X02-14   516-575-0013

1Yr Board Member    Zack Zilavy            WB2PUE        Retiree     631-667-4628
1YrBoard Member     Dave Ledo              AB2EF

1Yr Board Member    Bob Christen          W2FPF           

2Yr Board Member    Bob Wexelbaum     W2ILP         Retiree     631-499-2214

2Yr Board Member    Jack Cotterell         WA2PYK       Retiree     516-249-0979

Trustee WA2LQO        Ray Schubnel        W2DKM      Retiree

 

STANDING COMMITTEE CHAIRMEN

 

Meeting Programs       Contact a Board Member

FCC Exam Coord.      Bob Wexelbaum     W2ILP                          631-499-2214

 

 

GRUMMAN AMATEUR RADIO CLUB OFFICERS FOR 1997

 

President                        Pat Masterson          KE2LJ           B38-111        346-6316

Vice President               Gordon Sammis       KB2UB         C63-005        575-1846

Secretary                       Peter Rapelje            N2PYV          Retiree           676-0694

Treasurer                       Phil  Simonetti          N2ZED          K10-14          346-8124 

2Yr Board Member     Paul Chalson            WA2FOF       A16-043        224-8153

2Yr Board Member     Howard Liebman    W2QUV         Retiree           433-7487

2Yr Board Member     Martin Miller            NN2C             Retiree           423-8153

1Yr Board Member     Zak Zilavy                WB2PUE       Retiree           667-4628

1Yr Board Member     Hank Niemczyk      W2ZZE          Retiree           796-3212

Trustee WA2LQO        Ray Schubnel           W2DKM       C31-005        575-5036

 

STANDING COMMITTEE CHAIRMEN

 

Meeting Programs       Contact a Board Member

FCC Exam Coord.      Bob Wexelbaum     W2ILP                                   499-2214

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 


GRUMMAN AMATEUR RADIO CLUB

Sixty Years 1944 -2004

P.O. Box 0644

Bethpage, NY 11714-0644

 

 

 

                                                                                                        FIRST CLASS

                                                                           DO  NOT DELAY

                          TECHNICAL BITS                

 

If you own any old communications receiver, that was designed for Hams or Short Wave Listeners, before Single Sideband (SSB) Phone became popular; you might see how it provided only for CW or Amplitude Modulated (AM) modes.  As mentioned previously, the Dynamic Range of the receiver was usually increased by an AGC system, when the receiver was switched to the AM mode.  A negative voltage from the AGC usually drove the S-Meter. When the receiver was switched to the CW mode, the AGC was either completely eliminated or it operation modified. In the CW mode the operator was expected to manually control the receiver’s amplification by use of an RF gain control.  Then the S-Meter might go ballistic, and not be very useful on most receivers. During CW operation a Beat Frequency Oscillator (BFO) would be energized.  It was turned off in the AM mode.  The frequency of the BFO differed from the center frequency of the receiver’s last I.F. amplifier.  The difference of the two frequencies produced a beat, which was an audible tone.   This tone could be manually adjusted by a control knob.  While a 1 kHz tone was popular for most CW operators, the tone could be adjusted to suit the user and the exact audio frequency of the tone was not critical.

CW signals consist of only a keyed RF carrier with no audio modulation.  This is why a BFO is needed to give the signals an audible tone.  Next month we will discuss SSB and its requirements, and see how they differ from the needs of the old boat anchors.  In all of the better receivers the local oscillator(s) and BFO needed to be stable and provisions were made for voltage regulation to increase their stability which required use of neon or argon VR tubes.