Noi "jucatori" pe piata DMR

Anul 2014 vine cu noutati pe piata DMR, crescand competitia in acest segment.
Devine din ce in ce mai evident ca echipamentele DMR incep sa intre pe piata aducand competitorii fata in fata cu un rezultat previzibil: scaderea preturilor.
Nu poate decat sa ne bucure ca radioamatori, reteaua MARC-DMR avand o rata de crestere impresionanta, ce depaseste cu mult IRLP, ECHOLINK si sufland rece in coasta D-Star.
Avantajul standardului "deschis" devine un avantaj direct pentru radioamatorul care doreste sa utilizeze o statie compacta cu care, totusi, sa poata lua legatura si cu alti radioamatori din lume sau care calatoreste prin Europa (si nu numai) si vrea sa mai auda o voce de acasa.
Daca pana de curand aveam la dispozitie doar echipamente Motorla/Vertex si Hytera, iata ca in anul 2014 vom putea deja vorbi despre o piata in care exista oferte pe toate buzunarele.
Nu pot decat sa ma bucur ca "pariul" meu pe DMR acum vreo doi ani se confirma!
 

KENWOOD 

In sfarsit, Kenwood anunta intrarea pe piata DMR, deocamdata cu doua
modele de statii portabile si, in curand, cu un repetor.
Modelele TK-D200 si TK-D300 sunt disponibile atat in banda VHF cat si in UHF.
Sunt disponibile versiuni cu afisaj si fara, cu tastatura completa sau restransa.
Modelele TK-DxxxG au si GPS incorporat iar durata de exploatare a bateriei este anuntata ca fiind de 18 ore! Ramane de vazut in ce conditii sunt aceste ore...
Kenwood a fost satirizat de lansarea in DMR dar compania a sustinut ca nu fac decat sa concureze pe piata restransa din Europa in timp ce NEXEDGE ramane principalul produs digital pentru restul globului.

  
CONNECT SYSTEMS

O mica firma americana care insa produce in China a anuntat recent intrarea in comunicatiile DMR cu o statie portabila destul de modesta dar care se anunta a fi o adevarata "lovitura" pe piata radioamatorilor intrucat, noua, costa pana in 200 USD (pret in USA)!
CS7000 se gaseste in versiune VHF si UHF si, din cate se spune, este perfect compatibila atat cu Motorola cat si cu Hytera, fiind rezolvate unele probleme la firmware in ultima actualizare.
Statia este "Basic", fara ecrane color si cu un acumulator de capacitate destul de mica (1700 mAh) dar la pretul asta nu cred sa fie prea multi carcotasi si este de asteptat ca piata chineza sa furnizeze rapido niste accesorii mai cu "muschi".
Soft-ul de programare este gratuit (uraaaa) si de abia astept un sample sa ma joc nitel cu ea!

Desi pe ici pe colo se zvoneste ca permite doar mod digital, din specificatii aflam ca sunt doua versiuni, una cu 32 de canale alta cu 1000 si ca ambele functioneaza DMR/FM. Simplu si farabriz-briz-uri, cred ca va fi in curand subiect de vorba si prin YO!

TAIT

Fara pret, destinat evident institutiilor care platesc "fara numar", TAIT este si el un jucator pe piata DMR care vine cu solutii complexe de tip repetor sau trunk.
Il trec aici doar ca sa nu il uit, nu pentru ca o sa vedem prea curand portabilele TP9300 pe meleagurile mioritice...

Nu sunt deloc urate chiar daca afisajul este monocrom...


VERTEX

Vertex se pare ca se desparte de Motorola in ceea ce priveste echipamentele DMR si alege calea "ieftina" furnizand o gama noua, eVerge (???) de statii la un pret de aproximativ 400 USD.
De ce "ieftina"? Simplu! Se vand si pe Amazon, chestie ce mi se pare penibila pentru un producator de talia Yaesu! Probabil insa ca tinta este atat de jos ori disperarea atat de mare incat nu se mai uita pe unde isi intind taraba (sau cearsaful)!

Chiar sunt ieftine insa nu stiu cat de bune. Unele review-uri denota multumire; pretul este bun.


Reteaua MARC-DMR a radioamatorilor evolueaza frumos; acum un an erau putin peste 200 de repetoare, in prezent s-a depasit cifra de 500!

Pentru cei care doresc sa genereze un codeplug cu lista de contacte, CLICK aici.

LCD to a LPT port on my Thinkpad

I did had some spare time and I was looking around for a quick project.
I am using a Thinkpad X61 with a docking station on which I have native COM and LPT ports. Both are nice to connect something.
In my junk box i do have some toys that was never used.
One of them is a a Vacuum Fluorescent Display (or VFD) from a POS. It's a 2x20 dot matrix display used for showing the merchandise price to the customer.
I want to use it (sometime, in the near future) as a big display for my ICOM IC-7000...
The first step was to check if the display is OK.
According to the self-test mode, it's a CD7220-I display, for 24V DC, with a 5x7 matrix 9,2 x 6 mm character and, best of all, its RS232 compatible!
Works nice and is expecting a small PIC to work with!

After that, my bench was somehow in need for another "action" so I was looking in the junk box and found a  nice 4x20 LCD!
This was best for connecting to my laptop to show some summaries...
So, I connected to the LPT port...

Drop a line for more informations...
73 de Adrian, YO3HJV

KENWOD TM-D710G

Kenwood announced the latest VHF/UHF mobile radio with APRS and Echolink functionality.
Well, it's a little embarrassing because the Echolink is not the latest trick in connecting remote repeaters or radios (altough the simp[liest one) and a GPS inside the front panel is not a very complicated matter.
As a fact, I done my own RC-D710G (bragging!) a few years ago and it works nice!
Maybe I lost a patent, who knows?

ICOM IC-7000 and CODAN 9350 auto-tune antenna

After a looooong search, I bought a CODAN 9350 radio with 9360 antenna. After playing a lot with the radio I concluded that is not the best option for a mobile HF setup so I put a ICOM IC-7000 with a LDG Z100 Plus ATU onto my car.
Maybe the ICOM is not better than CODAN in term of reliability or sound but in a Ham's world, the VFO is essential stuff.
So, I was wondering if i can put the CODAN 9350 to work with the ICOM after I read a lot of positive stuff about the Codan antenna.
As you maybe know, the antenna has a control socket with a dedicated connector (military grade) on the antenna side. The original cable that came tih the Codan setup has had a DB15 male connector to the radio side.
ICOM has a dedicated connector for a external ATU - ICOM AH4; on the same connector we have the power supply from the radio and command signals.
A little research on the internet gave me VK1OD's website where he shows a dedicated Protocol converter. As the 9360 has a very nice feature of a RF Preamplifier, very useful for scanning, it's higly recommended but the know how is a little costly and I am not sure that I really need that preamplifier.
To keep it short, I found that a direct connection between the ICOM and CODAN 9360 it is possible!

For the cable I used the LDG "Y" accessory cable which have a nice ICOM connector. Of course, I cut it to connect the wires to a DB 15 female.

The AMPHENOL connector on the CODAN Radio side:

Here is the cable diagram:

ICOM CONNECTOR        DB15              AMPHENOL

           KEY                         11                              D
           START                      4                               C
           + 13,8 V              12 AND 13                    A
           GND                   14 AND 15                     B

After testing, looked to me that the setup is OK and working. Unfortunately, I do not have (yet) the adequate bullbar for that antenna.

yo3hjv 

 

PS

Some other interesting resource:

https://github.com/darksidelemm/IC-9350/tree/master/Icom9350

https://github.com/TheSkorm/IC-9350

 

 

ARHAB Special design antenna

A couple of years ago I was asked by Florin Mingireanu and Catalin Beledea to assemble a team for Stratospherium I experiment.
The goal was to have the balloon tracked via APRS both on air and ground after landing.
We had to use a Byonics tracker, the 10W version but we was limited somehow by the battery due to the limit in weight for the payload.
Instead of maximizing the transmitted power and using the maximum power, I was thinking to use less power but with a better antenna. After all, this is how we are doing on QSO's, no?

Ground Plane antenna diagram

Using a ground plane antenna which have the main lobes above the ground plate or counterpoises was out of question. Other disadvantage was the big null below the radiator. If the antenna was put downside, the second null (the one continuing the radiator) was to be exactly where the tracking team was, so it was the time to design something new.
I approach the new design having in mind that the receiver has to be below the payload so, the diagram has to be relevant in this.

I used MMANA-GAL for simulations and, after various (crazy) designs, the turnstile antenna capture my attention.

Classic Turnstile antenna

But the "classic" turnstile was, somehow, too heavy for our balloon so it has to be simplified.
Well, with not too much expectations, I put into MMANA a simple 2 x 2 dipole to see if my intuition will show something interesting. The ideea was to put two dipoles in paralell to lower the impedance close to 50 Ohm.

The simulation result was encouraging so I trimmed further more the design and made a few PCB to verify the theory. Of course, there was a lot of coat hangers but, fortunately, my wife is very understanding!
I measured the SWR with a Anritsu Sitemaster 331 and the results was well under 1:1.2!
The final result is below; the drawings are hand made but I hope that are clear to everyone who want to made this antenna.
In "real life", the antenna performed very well, radiating a lot below the balloon and very little at low negative angles. Therefore, distant reception was not so good but under the "belly" it was plenty of RF. We used only 3W from the tracker and all was OK.
The same antenna (not only the same design but the same PCB and wires) was used in Stratospherium II and Eclipser I in Australia in 2012.
We observed two more "features": the antena performed well when the payload was on the ground (we received the signals from the payload at about 4 km) and the antenna helped the payload to remain stable, countering the drag force from the wind on the parachute after landing.
As for the name of this antenna, I don't know! Leave a short comment if you have some ideeas. Or questions.
73 de YO3HJV, Adrian

The wires

The PCB

Assembly

MMANA-GAL simulation

SWR results with ANRITSU SITEMASTER 331

Before launching Stratospherium I

Before launching Stratospherium II