Lunar Amateur Radio Satellites DSLWP-A1/A2

Mingchuan Wei BG2BHC reports DSLWP is a lunar for­ma­tion fly­ing mis­sion for low fre­quen­cy radio astron­o­my, ama­teur radio and edu­ca­tion, con­sists of 2 microsatel­lites. Devel­oped by stu­dents at the Harbin Insti­tute of Tech­nol­o­gy the ama­teur radio pay­load onboard DSLWP-A1 will pro­vide telecom­mand uplink and teleme­try / dig­i­tal image down­link.


Every­body knows that the so called “BIG GUNS” will win the con­test, but you will have fun even if you come in the 9999th . When “Hams” (Ama­teur Radio Oper­a­tors) talk about the Big Guns, they are talk­ing about the radio sta­tion that anoth­er Ham is oper­at­ing. These sta­tions are built usu­al­ly just for con­test­ing. On the out­side is a few acres (could be stretch­ing it a bit) of anten­nas that are of spe­cial types (beams, dipoles, and ver­ti­cals) for dif­fer­ent fre­quen­cies at legal heights (up to 250 feet). These anten­nas are on tow­ers with guide wires to hold them straight in the wind, and the anten­nas are mount­ed on rotors so the oper­a­tor can turn them to the desired direc­tion.

The inside of the “SHACK” has at least two of every­thing. Am not going to get into all the equip­ment that is in here or the lines/coaxes that run to the anten­nas as that would take too long and not part of this arti­cle.  There of course is (HF, VHF, and UHF) radio(s) with anten­na tuners and the dif­fer­ent ampli­fiers (will put out up to 1500 volts on HF, less on high­er fre­quen­cies). These sta­tions are set up by indi­vid­u­als or clubs that are inter­est­ed in con­test­ing and cost thou­sands of dol­lars (since they are all over the world it could be rubles or the cur­ren­cy of that coun­try!). Of course then there are the “LITTLE LITTLE LITTLE GUYS” that don’t have mon­ey to put thou­sands into radio equip­ment, all they have is an anten­na and a radio to trans­mit on! As you can see, con­test­ing is made of Hams with dif­fer­ent amounts of equip­ment, and they all are in the same con­test and com­mu­ni­cate with each oth­er as the object of a con­test is to see how many con­tacts you can make!

In con­test­ing there are sev­er­al dif­fer­ent modes, and for a con­test that has dif­fer­ent modes involved, they are on sep­a­rate week-ends. Modes are a method of com­mu­ni­cat­ing, and it can be voice (AM or FM), set of fre­quen­cies (HF, VHF, UHF), or dig­i­tal (RTTY, CW, and oth­ers). The rea­son that I have said ‘and oth­ers’ for dig­i­tal is that there are always new modes that Hams are using for com­mu­ni­cat­ing. Some con­tests can run for sev­er­al week-ends and have var­i­ous types of com­mu­ni­ca­tion between the oper­a­tors, each week-end has a dif­fer­ent mode of oper­a­tion for the same con­test such as voice and morse code. Which ever mode of oper­a­tion, an oper­a­tor still trades the same infor­ma­tion with the oth­er oper­a­tor. That is loca­tion of sta­tion (i.e.: coun­try, state), call let­ters, RST (receiv­ing strength of sig­nal), and pow­er of trans­mit­ting sta­tion. The exchange can include more infor­ma­tion, but it depends on the con­test and the mode that is used for that con­test.

HF or High Fre­quen­cy is known for its bounce capa­bil­i­ties. It can/will bounce off of the earth or the atmos­phere, but some fre­quen­cies are affect­ed by the day­light (heat­ing) or night­time (cool­ing) time of day capa­bil­i­ties of this type of acro­bat­ics! These fre­quen­cies also will pen­e­trate to a cer­tain depth in most objects. When an oper­a­tor has day­light con­di­tions they will oper­ate on the upper part of the spec­trum, as night approach­es the oper­a­tors will migrate to the low­er part of the spec­trum. As can be expect­ed the mid­dle part of the spec­trum (around 20 meters) has both day­light and night­time abil­i­tie

VHF (Very High Fre­quen­cy) and UHF (Ultra High Fre­quen­cy) are main­ly line of sight fre­quen­cies with short dis­tance com­mu­ni­ca­tion. Occa­sion­al­ly under cer­tain weath­er con­di­tions a odd­i­ty called tun­nel duct­ing will trans­port a sig­nal back and forth for sev­er­al hun­dred miles from local­i­ty to local­i­ty, this is an excep­tion and not the rule! Sig­nals in this area are Microwave fre­quen­cies and the pow­er sent to the final for trans­mit­ting is reg­u­lat­ed by the FCC (Fed­er­al Com­mu­ni­ca­tion Com­mis­sion) and part of the test to achieve an Ama­teur License. Some radios in these fre­quen­cies are set to a sta­tion­ary fre­quen­cy are called repeaters, all repeaters are lim­it­ed by some con­tests as to the type of con­tacts they can make, straight con­tact with­out the use of a repeater is legal and not reg­u­lat­ed in con­tests. In con­tests for high­er fre­quen­cies the radios and anten­nas are either mount­ed on some­thing mobile or are very portable and can be set up and tak­en down very eas­i­ly.

The world is divid­ed up into grid squares each one mea­sur­ing approx­i­mate­ly 70 miles by 100 miles (more like a rec­tan­gle). These grid squares are then des­ig­nat­ed by two let­ters and two num­bers (LLNN), These grid squares are than bro­ken down into small­er squares (3 miles by 4 miles Rec­tan­gles again)) and is des­ig­nat­ed by two let­ters at the end of a larg­er grid square (LLNNLL) to give a bet­ter loca­tion. The ham operator(s) that is involved in this kind of con­test­ing will try and find the high­est point with-in that square for their con­tacts and move to anoth­er square! The same con­tact is legal as long as it is from or to anoth­er grid.

Con­test­ing on the Ham Radio can be fun no mat­ter what mode it is in! It is my belief that every Ham Oper­a­tor should be involved in at least one con­test no mat­ter which mode it is in! You do have to turn in the con­tact sheets with­in a cer­tain time frame for recog­ni­tion. There usu­al­ly is either a cer­tifi­cate or pin stat­ing which con­test they were in, as well as the year that it took place. Guess if you win, that would be anoth­er feath­er in your hat as I nev­er have, but I look at all the con­tacts that I have made and how far away they were and that is all the feath­er I need!

Source by Dave Glass



Ham radio oper­a­tors have so many dif­fer­ent oper­at­ing modes and tech­niques in their tool chest; it is often hard to decide where to focus your atten­tion. This will pro­vide the read­er with a short primer on oper­at­ing char­ac­ter­is­tics in the VHF and UHF ama­teur radio bands. Ama­teurs who oper­ate in the VHF and UHF region of the spec­trum are often referred to as weak sig­nal oper­a­tors.

Most pop­u­lar is the 2 meter band. This is because they are often push­ing the enve­lope of capa­bil­i­ties in this region of the fre­quen­cy spec­trum and as such often are work­ing with very weak sig­nal strengths from oth­er ham radio oper­a­tors. To oper­ate suc­cess­ful­ly in this envi­ron­ment hams nor­mal­ly turn to high­er pow­er sta­tions, very sen­si­tive receivers and much larg­er and high­er anten­nas. In the VHF and UHF bands, the height of the anten­na is crit­i­cal as well as the gain of the anten­na. Anten­nas in the VHF and UHF range used for weak sig­nal com­mu­ni­ca­tions are almost always YAGI anten­nas with many ele­ments. These anten­nas can reach and often exceed 25 feet in length. They also are very direc­tive in terms of sig­nal strength, which means you need to be point­ing the anten­na in the geo­graph­i­cal area in which you want to com­mu­ni­cate. Point­ing of the anten­na is done many ways, some use what is called the “Arm-strong” method where you turn the anten­na by hand, this is imprac­ti­cal in most cas­es how­ev­er. Hams rely on rota­tors to both turn the anten­na and know in what direc­tion it is point­ing.

For weak sig­nal work most ama­teurs rely on either Sin­gle Side Band (SSB) or Con­tin­u­ous Wave (CW) modes. How­ev­er, now with com­put­ers and spe­cial­ized soft­ware avail­able, hams are able to uti­lize what are known as dig­i­tal modes to com­mu­ni­cate using very weak sig­nals. Using dig­i­tal sig­nal pro­cess­ing soft­ware, known as DSP, hams can com­mu­ni­cate in instances where the human ear could not hear the sig­nal, but the com­put­er and soft­ware makes it pos­si­ble to pull the sig­nal right out of the noise!!!

So far we have dis­cussed “ter­res­tri­al” com­mu­ni­ca­tions on the VHF and UHF bands, mean­ing the sig­nal was point to point between two ground sta­tions. There are oth­er modes used in the VHF/UHF region that go beyond just ter­res­tri­al com­mu­ni­ca­tions. They are Earth-Moon-Earth or EME and Mete­or scat­ter modes of oper­a­tion. EME involves bounc­ing a sig­nal off the Moon, and mete­or scat­ter is reflect­ing the radio sig­nals off the ion­ized trail from mete­ors enter­ing the earth­’s atmos­phere! There are even hams radio satel­lites in orbit around the earth which hams use to com­mu­ni­cate over long dis­tances in the VHF/UHF bands. The satel­lite basi­cal­ly oper­ates as a “repeater” in space, where the sig­nal goes up to the satel­lite and is retrans­mit­ted to anoth­er ham well beyond nor­mal line of sight for the VHF/UHF bands.

Amaz­ing stuff is going on all time in the world of ama­teur radio, get involved today! Between choice of oper­at­ing bands, week­ly con­tests and work­ing very dis­tant exot­ic sta­tions on the oth­er side of the world, ama­teur radio remains an excit­ing hob­by today.

Source by Joseph E John­son



As a trained severe storm spot­ter (not chas­er) I need to make accu­rate posi­tion reports when I make severe storm reports des­tined for the Nation­al Weath­er Ser­vice and the coun­ty Emer­gency Man­ag­er (usu­al­ly at the 9−1−1 call cen­ter). By train­ing we report the dis­tance and direc­tion from the near­est major inter­sec­tion. This is where prob­lems can enter the equa­tion.

These reports are via a ham radio net­work. The assump­tion is that we clear­ly pro­nounce the names of the roads we are near for exam­ple. And that we know the dif­fer­ence between being on a street, road, avenue, etc.. That, of course, is as long as we can see the road signs in the pour­ing rain, dark­ness and winds that we dri­ve through. Next con­sid­er­a­tion is the guess at the dis­tance and direc­tion from the near­est inter­sec­tion. How accu­rate is that in a rain storm? Then comes the issue of map loca­tion. Does the map that the per­son you are report­ing your loca­tion to have the lev­el of map detailed need­ed to locate the roads you are report­ing? More impor­tant­ly, does every­one in the com­mu­ni­ca­tions net­work have the same lev­el of map details?

Intro­duc­ing a nice solu­tion — APRS (Auto­mat­ic Pack­et Report­ing Sys­tem) Con­nect­ed to a GPS sen­sor on one side and a ham radio on the oth­er side a TNC (ter­mi­nal node con­troller) trans­mits any ham radio oper­a­tor’s EXACT coor­di­nates (with­in about 50 feet) to (effec­tive­ly) a Google map on the inter­net. Any­one any­where that has an inter­net con­nec­tion (and many with just a ham radio sta­tion with­out an inter­net con­nec­tion) can dis­play the exact loca­tion, alti­tude and direc­tion of trav­el (at least) almost instant­ly. Since Google maps are zoomable to var­i­ous lev­els the desired lev­el of detail is but a click or two away.

Trav­el path is also be auto­mat­i­cal­ly plot­ted. A nice bright blue line con­nects the red dots that rep­re­sent the points of trans­mis­sion of the APRS device. A quite nice fea­ture of an APRS Google map (see an exam­ple at http://APRS.FI) hap­pens when your mouse point­er hov­ers over one of the red trans­mis­sion points. A sep­a­rate red line pops up that indi­cates what ham radio sta­tion heard the trans­mis­sion. With that infor­ma­tion you can trace the route of the data from the GPS device into the inter­net.

Anoth­er nice fea­ture of report­ing data via dig­i­tal data trans­mis­sions to the Nation­al Weath­er Ser­vice is that many peo­ple that have access to the inter­net Google map can view the infor­ma­tion at one time.

As a side note, Face­book — the social net­work — now has an APRS appli­ca­tion that makes these APRS maps of all of your friends avail­able at the click of one but­ton from your Face­book page! One pos­si­ble appli­ca­tion is to have the Nation­al Weath­er Ser­vice become friends for all severe storm spot­ters. Then they would have this data avail­able at the click of one but­ton!

Source by Jon Kres­ki

Category: Digital, Misc, Software


Hel­lo!” Was the very first word every broad­cast over the radio. Few folks that are not entrenched in Ham Oper­a­tion know the his­to­ry of the radio.

Who Is Regi­nald Fes­senden?

Regi­nald Fes­senden invent­ed the radio! Cana­di­an Regi­nald Fes­senden adopt­ed his love of trans­mis­sion when he was a mere lad. After Alexan­der Gra­ham Bell invent­ed the tele­phone young Regi­nald has been quot­ed as say­ing to a fam­i­ly mem­ber “Why do they have to have wires?” This was the first step in a life long jour­ney to answer that very ques­tion.

Like all great inven­tions, the ear­li­est attempts were mis­er­able failed attempts. His the­o­ries earned him a gov­ern­ment con­tract, Fes­senden, and his assis­tant Thiessen, worked dili­gent­ly to meet the chal­lenge until they were able to meet with suc­cess.

Fes­senden found­ed the Nation­al Elec­tric Sig­nal­ing Com­pa­ny (NESCO) with mon­ey invest­ed by two wealthy fruit com­pa­ny own­ers once he had ful­filled his con­trac­tu­al oblig­a­tions to the gov­ern­ment, because of his failed attempts the gov­ern­ment opt­ed not to renew fund­ing. As part of the Unit­ed Fruit Com­pa­ny he worked to fig­ure out a way for their ships at sea could com­mu­ni­cate with the folks back in Pitts­burgh.

The mon­ey that his back­ers invest­ed bought high pow­ered trans­mit­ters and anten­na sys­tems. In June of 1906 the first ever voice trans­mis­sion was sent and received suc­cess­ful­ly a total of 12 miles away. Fes­senden con­tin­ued to plug away at improve­ments until he reached the point where he knew his inven­tion was a suc­cess.

Six months after the first ever voice trans­mis­sion over the air waves a sur­prise trans­mis­sion to ships on the day before Christ­mas in nine­teen six.

As his wife and employ­ees as co-con­spir­a­tor’s he pre­pared a spe­cial Christ­mas pro­gram On ship oper­a­tors were told to tune in to receive a spe­cial Christ­mas mes­sage on Decem­ber 24th at 9:00 pm. Radio oper­a­tors sat stunned when 9:00 pm rolled around and a voice came over the air call­ing out “CQ, CQ”.

This was the first “radio” pro­gram. Ships across the North Atlantic were treat­ed to Han­del’s “Largo” played on a Vic­tro­la and “O, Holy Night” played for “the audi­ence” by Fes­senden on his vio­lin.

The Rest Is His­to­ry

This new tech­nol­o­gy called Radio set the world on fire. Hob­by­ist and ear­ly day techies could not get enough of this device and loved the idea of talk­ing to peo­ple may miles away with­out being tied to a cord. They were, and are still, called “ama­teur” radio oper­a­tors. Long before com­mer­cial broad­cast­ing was on the radar “ama­teur” radio oper­a­tors filled the air­waves.  Offi­cial laws were first insti­tut­ed in 1912 by con­gress. A new­ly formed agency was put in place by the fed­er­al gov­ern­ment in nine­teen twen­ty sev­en that was respon­si­ble for reg­u­lat­ing radio usage includ­ing ham radio oper­a­tions.  Ama­teur radio oper­a­tors have been on the cut­ting edge of com­mu­ni­ca­tion since the incep­tion of the radio. They were the first to use cell phones and the first to use FM broad­cast.  The inven­tor did not know the impact he would have on the world.


Source by Stan­ley Braver­man

Category: General News

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