During the years of use of my Kenwood TH-D74 I noticed that the battery indicator is a little bit confusing.
I never knew precisely how much "juice" I had in the battery from what the radio show on the LCD indicator.
So, being a brave ham I decided to put some clips on the battery contacts and make some measurements and correlate them with that little icon on the upper right side of the screen.
Under 7.2V:
7.2V - 7.4V
7.4V - 8.0V
8.0 V - 8.4V
Between 7.2 and 7.3V, the battery indicator is changing the colour from red to green.
The observation was made with the voltage going from 8.4V to 5.5V - the lowest voltage for which the radio is still working.
Having the radio already connected to my smart power supply, I thought it is the right occasion to make some measurements for the current draw in various configurations.
Here they are...
-GPS OFF
-Battery Save OFF
-SQ ON
-TNC OFF
VFO A: 160 mA
VFO B: 168 mA
VFO A + VFO B: 205 mA
VFO A + VFO B, SQ ON, vol@1/2: 270 mA
FM Radio ON: 210 mA
SD Rec ON: +15 mA
GPS ON: +30 mA
TNC ON: +~ 2mA
What about when transmitting?
Well, here they are, also:
EL (Extra Low)
VHF: 465 mA
UHF: 401 mA
L (Low)
VHF: 775 mA
UHF: 708 mA
M (Medium)
VHF: 1060 mA
UHF: 990 mA
H (High)
VHF: 1868 mA
UHF: 1920 mA
I want to stress out that these values are determined against my radio and can vary on others.
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!
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.
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:
A few days ago, Tony, YO3FXF came to our laboratory with a very nice looking Kenwood R-5000 Communications Receiver.
He asked us to install the optional filters and gave us a YK-88SN and a YK-88C IF filters.
The first one is a SSB 1.8kHz SSB filter while the second one is a 500Hz CW filter. Both of them (like the other two already installed filters) are centered on 8,830.7 kHz and compatible with other Kenwood transceivers (TS-440, TS-430 etc.)
Another thing Tony asked us was to take some pictures while working in the radio. So we documented the operation.
First step was to take a look to the Kenwood R-5000 Service manual.
We learn that the filters are connected one after another, in cascade.
The wider filters are maintained into the circuit wjile selecting the narrower ones. This method is credited with mode efficiency in rejecting unwanted signals.
Preparing for opening the upper panel.
Inside view.
The IF and audio board with a lot of conectors and wires.
Old style power supply with a bulky transformer, rectifier filtering and stabiliser.
We put a label on each connector. On the PCB is a small number circled. That is the connector numer.
Some of the wired connectors are not connected, hence the "NC" on that!
All the wires removed from the PCB.
Some sort of Christmas tree appears!
The bare circuit board outside the case.
The filters are prepared to be installed.
We marked the screws with a black permanent ink to know from where was removed.
It looks that someone removed at one time some filters. Might be some flux marking from the factory.
We soldered the new filters on their places.
On the "M1" we put the YK-88SN and on the "N", the YK-88C. We also clean the solder with isop. alcohol.
A close inspection revealed that we did a good job.
By the way, the original soldering was made with no-ROHS alloy.
We could work at abt.370 Celsius degrees; less thermal stress on the board and filters.
Some pictures with the new filters installed.
We also put the jumpers in the "Filter YES" position.
A quick test with a small antenna result in a "All OK".
Yeap, I have a Kenwood HS-5 radio headphones. Nice, comfortable and impressive headphones.
But, there is a "but" here!
They are mono headphones.
One can ask "Why stereo headphones on ham radio"?
Well, most of modern transceiver has a secondary receiver.
You can use this for listening in split pileups to maximize the chance for a QSO or, in heavy noise you cand use the second receiver as a "Brain DSP" helper.
On two receivers, the noise is different but the signal is the same. The ear-brain DSP will surely take the signal out of noise better than any IF-DSP found in the most expensive rigs!
I can use a HI Stereo headphones but these are special designed for radio communications and does not reproduce the signals below 300 Hz and above 4000 Hz, which means that they will simply reject all the other signal than voice.
After a couple of years of just wondering how can I made them stereo, today I made it...
I take the time for photos, so, you can click on them to see it in full detail detail.
First thing is to carefully open the outer protection without ruin the plastic bezel. Use a screwdriver and gently remove the metal case. There a re two tab-locks that keep that metal case to the plastic bezel.
Lift one first and gently separate the metal case; identify the exact position.
The second one is at 180 degrees; use the screwdriver for that too!
These tabs are delicate so don't mess with to much muscle on it!
As a generaly reccomandation, in these days, too much force means you didn't choose the right way.
After removing the metal case, you see that the black wire is common for both headphones. We will left this one in place.
The red and the white ones are on our "radar".
You may sold them separately without no other concern, just be careful to put some isolation on the solders.
In my pictures you will see some resistors.
These are two 240 Ohm resistor in series with each transducer.
The reason is that I wanted to reduce the hiss on the headphones when I listen at low volume. Seems that all major radio manufacturers made the same mistake on the audio chain. They tend to put a lot of amplification on the Audio PA stage so, at low volume, there is a lot of noise.
And not the band noise, just the stage inherent noise.
A good way to reduce it without modification on the radio is to listen to high volume; in this case, you need to reduce the sound pressure on the ears.
One way to achieve this is to put some resistors in series with the headphones!
Carefully solder the resistors (may be just one for each side, but has to be the same value - test before for comfortable audition) and put some isolation on them.
After that, place the metal case on the headphones and this is it!
Of course, you have to put a stereo jack on the other side of the cable...
A did a quick test on FT-2000 and the result is amazing! Worth trying this 30 minutes mod!
