Well, I have a Kenwood Automatic antenna tuner AT-300 and some ICOM Radios (IC-7300 and IC-703+) and I want to use them.
I tried to find on internet something already made but no chance. Looks like the Kenwood AT-300 is very rare or the fellow hams are using it as is intended, with a Kenwood radio.
It's not my case so, after a couple of years of thinking, I put myself together and I start to explore the possible solutions to connect the ATU to my IC-7300 radio.
First, the radio has a START and a KEY line and the "0" logic is +5V and the '1" logic is 0V. Same as the AT-300 which is good. The Kenwood AT-300 has the same voltage logic but the signals are TS and TT.
Basically, the Kenwood tuning procedure is:
-The TUNE on the radio is pressed
-The radio pulls down the TS line AND start transmitting around 10W CW.
-The AT-300 respond by pulling the TT down after about 100 msec. ONLY IF RF IS PRESENT.
-If a tuning solution is found, the tuning stops and the TS line is pulled up to 5V.
-After 15 seconds, the radio stops the RF and pulls up the TS.
-If the TT is still up, the radio return TUNING ERROR. If the TT pulls up BEFORE the TS, the radio show TUNED.
For bypass, the TS is pulled down for 500 msec. WITHOUT RF. To put the tuner in circuit, repeat this sequence.
The ICOM radios, have a slighty different "tuning protocol":
-The radio pulls down the START line.
-The tuner pulls down the KEY, causing the radio to transmit 10 W CW
-If the tuner found a tuning solution, the KEY is pulled up. From what I found using the Codan 9350 antenna, there is no time limit for keying the radio!
-If there is no tuning solution, the KEY is pulled up, then down for 70 msec. and then up again (and rest up).
The solution seems that is to "alter" the KEY and TS sequence with a microcontroller (Arduino).
Something like this:
-Press TUNE on the radio
-The radio pull down START
-The uC detect the START and pull down TS
-uC pull down KEY to transmit 10W CW
-uC monitors TT and pull up the KEY if the TT goes UP.
-If TT is still down after 15 seconds, the uC execute "TUNE FAIL" sequence as expected by ICOM radios.
Already made the test board. initially i thought to put some optocouplers for TS/TT and START KEY but after monitoring the voltages I saw no problem to connect them directly to the Arduino digital ports (max 5V). Of course, the signal lines are connected through some 470 nH inductors and the uC pins have 10 nF capacitors to the ground.
I believe this interface will be good to use it also on IC-7000 (have one and i will test it) and IC-7100.
Stay "tuned" for the next step!
73 de Adrian YO3HJV
LATER EDIT
Here is the first version of the code. Simple tuning, start and stops at the TUNE command from the Radio front panel command.
About the hardware:
The lines are directly connected to the Arduino board and the lines from the ICOM radios are tied up to +5V with 4k7 resistors in order for the radio to "see" the external ATU! Be aware that, if the output power is not set to be between 5-15W, the radio will turne to the INTERNAL ATU instead of the external, even with the lines pulled UP!
I was curious about the rubber sheet on the FPGA chipset. Some people say that is good for thermal dissipation. Therefore, I put an infrared thermal camera at work and took some pictures of that chipset (Altera Cyclone IV FPGA with 55k logic units) . When powered, the flexible rubber sheet shows that the temperature is almost at the room temperature.
Here is the board explained in the user manual of the radio.
You can see on the right side of the FPGA a small Al radiator. That is the ADC circuit, 14bit Linear Technology LTC2208-14, sampling at ~124 Msps. This chip is one of the the hottest chipset on the board at around 50 Celsius. The hottest is the 3V regulator, by the way! A big surprise came when I ripped the rubber sheet and I found the FPGA at around 50 Celsius also! I also measured the resistance of that rubber sheet to see if there is some electrical properties but found that the Ohm-meter showed hundred of kOhms. A quick conclusion: I am not sure about the purpose of that rubber adhesive sheet! Looks more like a thermal insulator than a radiator so I put it back!
Well, a long time ago, a bad guy stole my Kenwood TM V71 Front panel from my car. So I had a main unit without a front panel so I bought a second Kenwood, a TM-D710.
I used the RC-D710 from one radio to another but was too big to put it in my new car. Today, my TM-V71 have again a front panel (thanks for Difona and Kenwood Europe)!
Something still missing. Yes, the cable between the radio and the Panel!
I do have an extension kit DFK-3D so I took the diagram from the existing cable.
The original Kenwood part name I believe is 881H07-4370-02.
Yes, it has bugs! Ugly, big bugs crawling allover the screen!
I do have some memory positions occupied by some frequencies. Around 100...
I cannot use several software to connect to the TNC. Looks like some initialising problems.
I was trying to access the TNC via USB commands and nada!
I also observed that very often I got the red "STA" message, which means that the TNC Buffer memory is full. The stacked frame is transmitted when I manually press PTT.
When I reset the radio, erasing all the memories, the "STA" problem is gone! Still cannot run the TNC from RMS Express and have trouble to use APRSIS32.
Another bug is related to the battery: After some charges the Batt. Indicator shows only two bars but the voltage is 8.32-8.36 which means a full LiIon battery. If the battery is removed and reinserted, the indicator shows full.
Deja comunitatea radioamatorilor vorbeste despre noua portabila Kenwood ca despre o mica revolutie in zona statiilor portabile.
Desi era greu sa mai vii cu ceva nou in ecosistemul Digital Voice, Kenwood a indraznit. Ne propune o portabila care combina FM, D-Star si APRS adaugand facilitati intalnite in zona echipamentelor profesionale.
Experienta Kenwood in domeniul audio isi facesimtita prezenta iar eticheta "Kenwood-JVC" cere, parca, un soi de rigoare si excelenta, pe care noua portabila pare sa le confirme.
PACHETUL Contine statia, un alimentator in comutatie SMP de 13.8VDC/0.65 A (suficient pentru incarcare dar nu si pentru operare cu putere maxima), antena (aceeasi ca la TH-D72), un clips de centura de tip "clestisor", discret dar care lasa o impresie solida, statia propriu-zisa si un acumulator de 7.2V/1800mAh.
Avem un manual (pe care nu l-am deschis, spre rusinea mea), certificatul de garantie, toate impachetate in tiple.
PRIMA IMPRESIE
Statia este mai mica si mai compacta decat ma asteptam dupa ce am vazut-o in fotografiile de promovare.
Tastele au un feedback tactil destul de discret si, extrem de atractiv, au toate functiile retroluminate, spre deosebire de alte modele de statii portabile care au doar functiile principale.
Tastele sunt solide, nu din paterial plastic iar tastatura numerica are si o usoara inclinare despre care nu stiu daca vine din ratiuni estetice sau ergonomice.
AFISAJUL
Mic insa cu vizibilitate foarte buna. Fiind un TFT Transflective, are o buna vizibilitate pe timpul zilei iar pe timpul noptii se poate activa retroiluminarea.
MENIUL
Meniul se acceseaza cu tasta dedicata iar navigarea are loc cu tastele de directie. Structura imi aminteste de telefoanele mobile precursoare generatiei smart-phone, folosindu-se iconite pentru identificarea grupelor de sub-meniuri.
Kenwood a facut treaba buna structurand meniurile pe grupe logice, astfel ca setarile se pot face rapid si fara prea mare bataie de cap cu manualul de utilizare.
SUNT SUBIECTIV ACUM
Spuneam la inceput ca D-Star este sistemul ales de Kenwood pentru intrarea pe piata portabilelor DV. Mi se pare un pariu bun, standardul fiind bine pus la punct, Kenwood avand experienta din zona profesionala cu standardul CDMA spre deosebire de Yaesu care a improvizat C4FM dupa o aventura in zona profesionala DMR.
Combinatia D-Star+ APRS se pare ca era asteptata de multa vreme, portabilele ICOM avand standardul propriu de locatie cu ajutorul GPS (dPRS), incompatibil cu reteaua analogica.
Pe langa acest pariu DV, Kenwood a combinat in aceasta portabila si un receptor bunicel pentru SW si unul chiar bun pentru FM, amintindu-mi de motivul pentru care ma atasasem de TH-F7, receptia AM si SSB.
Primele incercari de a conecta BT la sistemul masinii au esuat. Mai am cateva trucuri de incercat inainte sa abandonez. Ar fi un mare plus daca as putea sa o folosesc in masina fara sa imi ocup mainile!
Meniul de ajustare a parametrilor audio ma face sa cred ca in interior are un "suflet" SDR, ceea ce ar fi si cazul la experenta si vointa inginereasca a Kenwood-JVC.
Pur si simplu, pentru ce este, statia suna extrem de bine!!!
Ca sensibilitate, in testele facuta in afara Bucurestiului s-a comportat mai bine decat portabila pe care o folosesc in mod curent si care este oarecum etalon: Icom IC E92.
In Bucuresti, in poluarea radio m-a surprins foarte placut! Suficient de sensibila (parca ceva mai bine decat TH-D72) si extrem de putin expusa la IMD! Aveam de gand sa utilizez atenuatorul in caz de IMD insa pana acum nu a fost necesar!
Pe ici pe colo lumea se plange de autonomia mica a acumulatorului. Putini tin cont de faptul ca acumulatorii compacti, moderni, de tip LiIon sau LiPol incep sa prezinte capacitatea maxima dupa un numar de cicluri de incarcare... Cu GPS-ul oprit, Battery Saver la 0.1s, retroiluminarea pe Auto 5 sec si la intensitate medie, acumulatorul la prima incarcare m-a tinut doua zile in ascultare de radio BC FM pe un VFO si monitorizarea unei frecvente de UHF in al doilea VFO. Evident, nu doua zile continuu dar niste ore bune in prima zi si ceva mai putin a doua zi. Apoi, in a doua seara am pus statia la incarcat.
Volumul de auditie este ridicat desi difuzorul este pe jumatate obturat de tastatura alfanumerica; in spatele sau montajul interior este astfel proiectat incat sa asigure o cutie de rezonanta.
Sensibilitatea microfonului este excelenta, modulatia fiind corecta si indestulatoare. Imi este clar ca exista o procesare discreta a vocii in cutiuta!
Spre deosebire de TH-D72, pe laterala gasim doar interfata USB nu si RS232 asa ca, "Adio AVMAP"!
Din fericire, pe acest port USB putem interactiona extrem de larg cu statia. Avem de ales intre placa audio USB sau iesire FI, putem folosi software-ul pentru programarea memoriilor care functioneaza in timp real, adica imediat ce modificam sau adaugam in tabelul de memorii, regasim modificarea in statie (ca la ICOM).
Intrucat am "intrat" in statie, pot sa va spun ca este solid construita si cu atentie pentru rezistenta la apa. Din nefericire, tastatura si difuzorul sunt parte din panoul frontal astfel ca o eventuala inlocuire a acestuia va scutura serios buzunarul. Ceea ce ne duce cu gandul la a gasi cat mai repede niste huse de protectie! Eventual si un incarcator tip Slide in.
MICI BAZACONII MAI MULT SAU MAI PUTIN UTILE
Balans intre VFO A si VFO B.
Inregistrare audio pe SD card. Din pacate, doar de pe un VFO, la alegere.
Doua taste cu functii alocabile de utilizator. Totusi, plaja functiilor este relativ limitata, asa mi s-a parut dar pana la urma am descoperit de ce nu se poate alege functia de SCAN pe aceste taste; SCAN se face apasand lung pe tasta de VFO sau de MR (memory), dupa caz... Mea culpa!
Statia poate fi utilizata ca tracker APRS dar si ca GPS LOGGER, traseul fiind salvat pe SD card.
Ah, de efect mi se pare posibilitatea de a modifica imaginea ecranului de start!
Ca si alte statii DStar, si la TH-D74 gasim o lista pre-memorata de repetoare DStar, care pot fi accesate corelat cu informatia GPS.
A'propos de GPS, acesta este unul dintre cele mai rapide pe care le-am vazut!
A mai ramas ceva? Nu stiu, daca mai gasesc, revin!
Filmulet de la aplicarea modificarii pentru extinderea de emisie:
Already made the test board. initially i thought to put some optocouplers for TS/TT and START KEY but after monitoring the voltages I saw no problem to connect them directly to the Arduino digital ports (max 5V). Of course, the signal lines are connected through some 470 nH inductors and the uC pins have 10 nF capacitors to the ground.
