First is first...
SOLD!
Primul meu ICOM IC-703+ este de vanzare!
Dupa un eveniment distructiv accidental (o supravoltare datorita functionarii defectuoase a unei surse de laborator), m-am incumetat inainte de Craciunul lui 2024 sa il repar.
Reparatia a durat cam o luna, primul pas fiind identificarea componentelor defecte si plasarea de componente echivalente pentru a testa functionarea.
Apoi, dupa identificarea acestora, au fost comandate piesele originale, unele dintre ele avandu-le deja "pe stoc", achizitionate preventiv in urma cu multi ani (celebrul uPC2709).
Dupa aducerea in stare de functionare, am instalat si un filtru Collins CW de 500 Hz, YCF-115C.
Pentru ca am doua, acesta este de vanzare.
Se da impreuna cu microfon HM-173.
Cablu de separatie, bonus!
Pret: (400 Eur) - 2000 Lei + transport prin curier.
Disponibila fisa de service in care sunt evidentiate toate reparatiile. Contact prin email, indicativul @ gmail
Somehow, you end up into an ICOM HF eco-system.
You have an IC-7300 or 7100 or 7000 or anything else; a radio that can do HF and you also have an IC-AH-4 the "wonder ATU" from ICOM.
You mod it to be more modular and portable as I did, ready for field use.
Maybe you want to use some other radios on the same antenna system or you want to go portable with a Xiegu G90 and you said to yourself: "I could put that AH-4 to good work but the ATU will not work with anything but ICOM radios".
Well, you may be wrong!
The AH-4 can and should be used with other radios because it is a small gem! But how?
A small independent control box can be used with other radios to tune various antennas, from wires to loop antennas and this is what I done recently.
It is in a crude form, maybe I will make it with the help of a microcontroller or maybe I will leave like it is now because, it is working well!
What do you need?
-ICOM AT connector;
-One Red and one Green LEDs
-Two PCF817 or similar optocouplers;
-Two 1N4148 or 1N4001 diodes (not mandatory);
-Three resistors between 1.2 KOhm and 2.2 KOhm (these values where tested);
-a temporary SPST push button;
-a small test PCB or any other solution to mechanically fix all together.
The schematic:
Power up the box. The Green LED will lit.
START and KEY have 5V (UP).
Set the radio to 5W in carrier mode (AM, FM, CW) and press PTT or CW Key.
Momentary press the button TUNE. The RED LED will lit.
The START line (from radio to ATU) will go down; the ATU will respond with KEY going down for the tuning cycle (request for carrier). Side note: if you didn't press the PTT or the CW Key before pressing TUNE, now it's the moment to do that!
During the tuning cycle, the AH-4 will request from the radio (which is not connected to the control lines) to transmitt a 5 W carrier.
Thus the IC-1 LED will lit and the corresponding transistor will keep START line down as long as the tuner need for the tuning cycle. Keep PTT or CW Key pressed on the transmitter.
When the RED LED is going off, the tuning solution is achieved.
Note: there are situations when the tuner will not find a solution for the antenna; the RED LED will go off and will lit again, the tuner will start a second sequence then will go in bypass mode.
I suggest using a small SWR meter between the radio and the ATU or watching the built in SWR meter to be sure a tuning solution was aquired.
This is my version:
Our EmComm group ( RVSU ) is using the IC-7100 from ICOM as primary HF Radio.
We therefore must be able to use it on the full range of frequency so we "mod" it.
Actually, we modified the configuration diode matrix so the radio will TX from
0.1 MHz - 199.999 MHz and
400 - 470 MHz.
It will still not transmitt AM on the VHF and UHF.
ATTENTION!
-The modification cand damage your radio!
-Do not transmitt out of the authorisation privileges!
-I have no responsibility for what are YOU doing with YOUR radio.
Pictures are said to worth thousand words, so I give you two thousand:
Before
The removed diodes are soldered on one side of the pads just to have them handy when the mod will be reversed (if needed).
The Spring is here full power so is the war just North of Romania so our Emergency Communication Team (RVSU) is preparing for... field day!
Our standard in HF EmComms are ICOM radios and ATU's; we are using IC-7100 as our main HF radio paired with T2FD antennas for NVIS and AH-4 with verticals and wires for various Long Range HF.
In this post I will briefly show one modification for the AH-4 Automatic Antenna Tuner (one of the best in my opinion, for 100W output power).
It consist in changing the way the Coaxial RF cable and the Control cable are connected.
Because our concept is based on modular kits, the AH-4 must be able to be installed quick, reliable and we must have provisions to modify the setup if the field conditions required so and this must be done by operators with minimal training.
The way those cable connect to the Tuner box is pretty against "field use" principles therefore, a solution must be found.
Another problem is the fixed lenght of the cables. Just 10m might not be enough in certain scenarios and while another coaxial can be added with the help of a female-female adapter, require intimate knowledge from the field operator and present some fatal risks for the integrity of the radio or the ATU if the wires are connected in the wrong way.
So, another solution must be found!
First, the RF connector must be moved from inside the ATU to the outer case.
The SO-239 (UHF-female connector) will be seated just where the cable clamp was.
The connector is a good quality one, from Amphenol.
Unfortunately, the plastic will not support the mechanichal stress of the connector so a small plate was cut from a piece of Aluminium.
Then, the ATU's case was prepared to accomodate the SO-239; the backplate was threaded for 3mm screws for better electrical contact.
This coaxial patch was made from some cable left from GSM sites and I know it can handle easy 100 W up to 100 MHz. So, I prepared it to be used here.
I removed the original piece of metal with the old SO239 and make some scratches on the Ground pad to install the coaxial patch.
A few words about choosing the right cable:
In the field you need various lenghts of cables. Often those cables are cut, lost, or even forgotten at the base.
The ATU is drawing less than 1 Amp, typical around 200 mA. The control signals are at TTL logical level (5V) and the "protocol" is nothing more than pulling to ground or to +5V so nothing special with this cable must be observed.
Can be a cheap cable and it is desirable to be found easy. Long story short: what if I could use a FTP cable? Well, on my balcony I have an AH-4 which is connected to the radio with this kind of cable and for 2 years performed extremely well.
The problem with my AH-4 is that i modified it very ugly; the female RJ-45 connector is placed on a cut into the case and, believe me, it looks bad!
In this case, I decided to use something that I already have in my junk box from a never-finished project. A RJ-45 female-male patch cable designed for panel mounting.
Checked and it was just the right lenght! So, I could start making the square hole from the round one!
And this how it is. I put some hot glue to seal the holes but I forgot to take pictures...
This is the electrical diagram for the RJ-45-MOLEX adapter:
Now we can use (almost) any lenght of network UTP cable and (almost) any lenght of coaxial changing them in the field. And, if there is need for the network cable to our applications and no need for HF, we can use the cable for that purpose.
I hope this is an usefull ideea and will inspire other "brave hams"...
Some notes:
73 de YO3HJV, Adrian.
I was reading a post in a FB group. Someone was asking for a CW IF filter for his ICOM IC-703 radio. Specifically for a F-52A, CW 500 Hz 455kHz filter.
As I already have a FL-52A into my IC703, this one stood a looooong time in the shelf.
While I took a picture of the FL53, I noticed there is a serial number on the filter. The serial number was 501 and i thought, "Damn, just five hundred of these untill i got mine"?
Then, I was courious and opened the other filter, the FL-52A. And, surprise, this one was "001"!
So, I got the first FL53A filter from ICOM!!! Dude, brand new, in the original box, mint condition!
Should I start a collection?
I wrote a request for informations to ICOM, I hope they will answer!
I had some projects to made and those involve external ATU connectors for ICOM radios; I think it's better to have some informations here for anyone looking for them.
Electrical connection for ICOM External ATU 4 pin MOLEX connector:
Thus I searched on various retailers for those connectors and I found them made by Molex.
The connector case manufacturer's code is 03-09-2041.
The crimp pins manufacturer's code is: 02-09-2103
You can buy them from MOUSER:
Connector-Mouser part: 538-03-09-2041 TARIC:8547200090 ECCN:EAR99 COO:US
Pins-Mouser part: 538-02-09-2103 TARIC:8536699099 ECCN:EAR99 COO:US
Icom to LDG antenna tuners electrical connection:
ICOM IC-703 ATU
ICOM IC-7100 ATU
ICOM IC-7000 ATU
ICOM IC-7300 ATU
ICOM IC-7600 ATU
ICOM IC-746 ATU
ICOM IC-718 ATU
| $FE | $FE | ra | $E0 | $17 | $xx | $FD |
$FE | $FE | ra | $E0 | $1C | $01 | $01 | $FD |
| $FE | $FE | to | fm | $05 | $21 | $00 | $08 | $13 | $01 |
| $FE | $FE | to | fm | $28 | $## | $FD |
| $FE | $FE | to | fm | $1A | $05 | $01 | $56 | $## | $FD |
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.
