Another mode that can be worked using the same hardware interface as was used in the previous digital mode work is Amateur SSTV.
The abbreviation ďSSTVĒ is meant to mean Slow Scan Television, but for Amateur HF use ďSSTVĒ means the ability to send still pictures on the HF phone bands.† It would be impossible to send television signals that are the same as are used commercially on HF ham bands.† A compatible analog TV signal requires a bandwidth of 6 MHz and obviously it would take up more bandwidth than an entire ham band in order to transmit one such TV signal.†
SSTV, as HF hams use it, has evolved from earlier days where only black and white signals of much poorer resolution could be transmitted. †Amateur SSTV has been around since 1958.† It started long before there were home PCs.† The most popular SSTV program can now utilize the full colors of modern PC displays that are now available to computer users.† Because of its limited bandwidth, and thus speed, ham SSTV can not transmit streaming video in the way that JAVA and other computer formats can.†† Before PCs were available, sending still pictures via ham radio was a big development and it required some expensive equipment to do so.† Today it is possible to post pictures on web sites, which can be visited by all of our friends and relatives and thus the romance of HF picture communication may have lost its original impact.† It takes ham spirit to go on expeditions to the South Pole, and it takes some of the same ham spirit to transmit DX pictures where QSB and QRM might blank out parts of them and they may appear snowy, even when they donít come from a polar expedition. The way SSTV is now used involves first making SSB phone contact on a phone band frequency and then telling the ham that you are QSOing with to get set to receive a picture.† Then you send the picture.† The picture may take a few seconds to a few minutes to be completely scanned.††
You can send any picture file that your PC can store. This includes scanned pictures from you scanner, pictures from your digital camera, and pictures that you have received and saved from the Internet or from other Ham SSTV QSOs.
All you need to do this is the freeware available at:-
There you will get a link to download the latest version of Mokoto Moroís, JE3HHTís, software which is called MMSSTV.†† Even if you donít intend to transmit pictures yourself it might be a good idea to be set up to receive them if you are an HF phone operator.† SSTV is specifically expected to be used at specific phone frequencies.† Donít look for 2 way QSOs on those frequencies unless you are equipped for SSTV.†
The frequencies that are earmarked for SSTV are 3845, 7171, 14230, 14233, 21340 and 28680 MHz.† That gives one frequency for each on 75 meters, 40 meters, 15 meters and 10 meters. On 2 meters 145.5 MHz is used for ham SSTV on space missions. †The most activity is on 20 meters, where 2 frequencies have been allocated.† Although some operators donít like it, it is possible to use other HF phone frequencies for SSTV if the designated frequencies arenít available but most hams wait to use the listed frequencies.
Early users of SSTV had to use surplus CRTs that were taken from radically scanning radar systems.† These CRTs had a type P7 phosphor which could glow long enough to display an entire SSTV picture.† Green P1 phosphor CRTs used for oscilloscopes, and P4 phosphor TV picture tubes fade too fast because of there low persistence to be used for SSTV.† This is not a problem now that PCs are used because the pictures are stored in RAM and can be held as long as needed to scan any picture.†† The full color capabilities of the computer can also be used.†
Slow scan TV techniques were used in sending TV pictures to Earth from the first lunar landing.† At that time the slow frame rate of the SSTV was converted to a normal TV frame rate by using a scan converter on Earth, which would increase the frame rate by sending each SSTV picture as many times as needed to have the same frame rate as conventional TV.† When this was done the lunar landing videos could be broadcast for all TV viewers to view.† Although the moving pictures produced did not flicker when this method was used, the action appeared jerky because of the initially slow frame rate.
Hams can also transmit conventional TV signals, which are called Amateur TV (ATV).† They must be on UHF or microwave ham bands.† Since many people now own camcorders and DVD players setting up an ATV station is not as expensive as it once was.††† Cable TV converters and cable ready TV sets are able to tune to some ham channels.†† When they are fed by an antenna instead of the cable they can receive the Ham TV signals.†† Modulating a UHF ham transmitter is not expensive because the modulator can utilize the same hardware that is used to convert audio/video from a VCR or DVD player to produce TV at a TV set antenna input.†† ATV has had many enthusiasts and has had publications devoted to it.†† If interested, you can find out more by doing a web search.
†††† †Last weekend we had some nice weather, and I did some
hiking with XYL Jody (N2OEB) in
Last month I took my Tesla
Coil to the LI Wireless meeting, and did the demo there. It went real well, and
I got a few verbal invitations to do it at some other clubs and societies on
With the warm weather here, I put my tractor/plow back into the shed, and stowed the snow shovels and salt bags. Sure enough, mid-week, the temperature dropped into the low 40s and we had snow for about 30 minutes. But, this time of year, it never lasts long. No shovels needed.
We are also only 2 months
away from our Field Day exercise. Hopefully, weíll have some volunteers to help
this year. Donít forget, that I intend to sell my house next Spring† (early 2007) and move to
Other than that, thereís not
much new here at the Company. Iím in IT and there are some tight budgets for
some reason. Some early retirements have happened, and people are leaving.
Thatís could affect my job situation when I go to
As Bob mentions a few times
in this newsletter, our April meeting will not be at UL, weíll be at a site in
IMPORTANT:† NOTICE OF CHANGE OF APRIL GARC MEETING LOCATION.
the UL will not be available for the GARC meeting on April 19th,
Jack Cottrell has arranged for the meeting to be held at
Sunrise Highway (Rt. 27) turn south on
Also see GARC website for any possible change.† The location for the May meeting has not yet been determined.† Watch for news in the May newsletter or on the GARC website.
INTERNATIONAL MARCONI DAY
Radio Central Amateur Radio Club (RCARC) will again be sponsoring Marconi Day,
Here is another cryptogram:
L†† XF†† MSG†† CGHN†† FAVGZ ††AW†† X†† FAVGHO†† FXQAH-UGOGHXZ,
LíCG†† LOWAHFXMLAO†† CGUGMXJZG†† XOLFXZ†† XOV†† FLOGHXZ,
L†† TOAY†† MSG†† TLOUI†† AW†† GOUZXOV,†† XOV††† L†† PDAMG†† MSGLH†† WLUSMI†† SLIMAHLEXZ,
WHAF†† FXHXMSAO†† MA†† YXMGHZAA,†† LO†† AHVGH†† EXMGUAHLEXZ.
†† -- Y.† †I.†† ULZJGHM--††
Solution to Marchís Cryptogram:
A POET CAN SURVIVE EVERYTHING BUT A MISPRINT.†† ĖOSCAR WILDEó
[This was a difficult one.† It applies to careless cryptogram makers as well as poets.]
†† ††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††Page 4 †
CQ DE WA2LQO APRIL 2005
GRUMMAN AMATEUR RADIO CLUB
MINUTES OF GENERAL MEETING -3/15/2006
The meeting was called to order at by Pat.
TREASURERS REPORT Ė Ed, WB2EAV††† ††††††REPEATERS Ė Gordon, KB2UB
Finances continue to be in good shape.†††††††††† ††††††††††Nothing new to report.†
VE REPORT Ė Bob, W2ILP†††† †††††††††††††††††††††††††††††NET REPORT- Zack, WB2PUE
Two applicants failed Technician exams.†††††††††††††††† 146.745 net not very active.
One applicant upgraded to General.†††††††††† †††††††††††††††145.330 repebandplansater is good.
VEs present were AB2NT, KB2QFT,††††††† †††††††††††††††Sunday morning 40-Meter net was poor.
KC2HNN, W2ILP and W2QUV.† †††††††††††††††††††††††††††††††††††††††††
†† †††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††† ††††††††††††††††††††††††
The UL will not be available for the next two meetings.† Please read the web site or contact other club members to stay informed about meeting location.
NN2C, brought a tape of the Braveheart DX Expedition to
The meeting was adjoined at .
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 Thursdays.
†††††††††††††††††††††††††††††††††††††††††† 145.330 MHz (- .600) at Thursdays.
[Tone for both repeaters is 136.5 Hz]†††††††† (ARES/RACES) Mondays
General Meetings of the GARC
are held on the third Wednesday of each month, starting at .††
The meetings are usually held at the Underwriters Lab,
††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††† ††††††††††††††††††††††††††††††††††††††††††††† ††††††††††††††††††††††††††††††††††††††††††††††
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. ††††††††††††††††††††††††††††††††††††††††††††††††††††††
††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††† †††††††††††††††††††††††Page 5
INTERNET LINK OF THE MONTH FOR INTERNERDS
The internet link for this month is:- http://www.bandplans.com/index
This is a very useful web site which gives frequency information for most of the modes now being used by radio amateurs.† If you didnít find the frequencies for the digital modes I have discussed here in the newsletter, you can probably find them by using this site.† There is also information about various net frequencies, which could be of interest to many of us.† For example there is a new Flying Hams Club net from a newly formed club, which consists mainly of pilots and hams who are interested in aviation or avionics.† I had joined their reflector which is on Yahoo, after reading about them in QRZ.†† This is not the old Flying Hams Club, which was founded by K6BX (sk). ††Most of these guys are young small aircraft owners.
It is important to check with the suggested frequency limits if you operate digital modes.† You can start a ruckus if you donít stay within in the right frequency ranges.† Even W1AW has recently been strongly criticized for broadcasting on what some hams believe is a reserved frequency for a differing mode.
ED HARE SPEAKS ABOUT BPL ON
Ed Hare, ARRL Lab Manager, lectured at a meeting of the EMC Society of the IEEE at BAE Systems in Greenlawn on April 4th.† The meeting was well attended by engineers and hams, as well as hams who are also engineers.†† The subject was the potential of interference by Broad Band over power lines.† The subject was well illustrated by power point projections that Ed had prepared which were based on FCC and vendor measurements, as well as his own spectrum analysis. There was an actual video/audio program of Edís mobile HF radio while he drove through BPL areas.†† BPL has been tested in several areas with mixed results.† There is always some interference to nearby HF receivers but the range of harmful interference does seem to differ for different systems.† A ďplug ĖinĒ system intended for BPL within a single building is quite different than a BPL system coupled to long overhead power lines.† BPL on power main lines is the greatest source of interference over large areas. Notch filters can be used to reduce some of the worst interference at specific frequencies.† Notch filters are not really component type filters, although effectively they act as lumped constant filters.† They are simply the elimination of specific carrier frequencies.† They cost nothing, but may reduce the broad band system capabilities somewhat. †There were no engineers present to represent either BPL vendors or power companies.† Thus there was no heated debate.† The Part 15 FCC regulations that apply to BPL specify recommended limits, however if the limits are exceeded there may be no FCC action taken unless the interference proves to be harmful.† As we had seen when RF field strength measurements had to be taken to apply radiation hazard limits it is very difficult to accurately measure electric and magnetic fields at HF frequencies because of antenna near field radiating characteristics and ground reflections.† Many vendor measurements were taken only one meter above the ground.† Hams who operate from a fixed location may file complaints against BPL, but mobile ham operators may simply be asked not to operate in areas where interference is excessive.†† In other words, if no harm can be proved no action may be taken.† The meeting was enjoyable as was the pizza and soda that was served.† There is a great deal of recognition between well known engineers and well known hams on Long Island and the informal chatter after the meeting was enjoyed by all, just as much as the expert technical questions posed to Ed Hare, who responded with a good sense of humor. †Although many hams have sent e-mails about BPL interference probabilities to the head of LIPA, it is believed that BPL testing will begin in Hauppauge in the near future.
†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††††
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
†This being April, I had considered making this newsletter an April Foolís edition.† I decided not to do so.† I have to stick to real facts here.† Any fooling around here has to be done on a non-intentional basisÖ.purely accidental. ††Anyway one manís foolishness might be another mans hobby, and vice versa.
†As you can see in the box to the right of
here, the GARC VE sessions will now be given in room:
The GARC has had a long tradition of holding VE exams on the second Tuesday of each month and club meetings on the third Wednesday of each month.† We must thank Jack WA2PYK† and Pat KE2LJ for their efforts in finding a meeting place for this month. It wasnít easy.† Our speaker at the April meeting will be Frank Fallon, N2FF, ARRL Hudson Division Director.
W2ILP (Intentionally Limiting Philosophies)
CQ de WA2LQO
†VOL.† 79,† NO.† 4
Bob Wexelbaum† W2ILP
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
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:
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 driverís license or other picture ID.
Until further notice, VE exams will be
All applicants should contact W2ILP to preregister if possible so as to conferm location, but walk-ins may still be accepted.
For any information e-mail: -
email@example.com or phone: -
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.
Early hams built only CW transmitters but when radiotelephony was being developed hams began to build Amplitude Modulated (AM) transmitters. Phone operation required getting a Class A License, which later became the Advanced Class.† The basic CW ham license then became a Class B license, and later a General Class license.
The most common way to produce AM was to plate modulate the transmitterís final RF power amplifier.† This required an audio voltage amplifier to increase the output of a microphone and drive a power modulator.†† The modulator was thus a high powered audio amplifier.† If the DC plate input of the final was a kilowatt, then to get 100% modulation the modulator would have to produce about 500 watts of audio output.† Care would have to be taken so as not to overdrive because if the modulation exceeded 100% this would lead to both audio distortion and spurious RF output.† The modulator usually was a push-pull circuit using two power amplifier tubes.† These tubes operated in Class B, which means that each tube amplified half of the audio wave form.† The final RF amplifier could operate in Class C, which means it only needed to amplify half of the RF wave.† The RF tank circuit would act as a sort of a flywheel, causing the wave to become nearly sinusoidal.† This method of AM plate modulation is known as high level modulation.† Later methods permitted modulating the RF section of transmitters at an early stage and thus not requiring as much audio power as final plate modulation.†† Hams experimented with other modulation methods which were sometimes advantageous.† If the RF final amplifier was a pentode or tetrode tube, l screen modulation could be used.