Archive for the 'DIY'
Changing the microphone ICOM HM36
Today I pulled out my closet the old mans hand mic HM36 that many home ICOM transceivers.
Appeno I was handed, I remembered that on the net there are illustrated several changes to improve the modulation of this microphone and having a half hour of free time I took advantage.
A quick search on the net and immediately checked the change I was looking for, nothing difficult, just unsolder two electrolytic capacitors, a resistor and solder in place dell'elettrolitico labeled C1 on the circuit, a 10,000-pF ceramic capacitor (tantalum or 0, 01 uF the polarity), actually easier to do than to say.
I enclose two photos of before and after modification are explanatory:
Base of the microphone with R1, C1 and C2 dissaldati
Base of the microphone with a ceramic capacitor C1 replaced by 10.000pF
ARDUINO + GPS + APRS Part 1
An Arduino
For some time I dusted off my Arduino and I decided to commit myself to a couple of projects.
First I want to assemble an APRS tracker mounted on a motorcycle to track my speed.
Will run in conjunction with a handheld 5 watt, specifically a Yaesu VX150, but it will also display the "judgments" NMEA to control both the operation and positioning of the other beacons around me.
Everything can be done very simply by a TinyTrak 3 of Byonics but want to put the fun to assemble and program everything with their hands?
So I started with a shopping list:
- A new Arduino Duemilanove oo rev. 3
- GPS
- TNC Modem
- LCD Screen
- Software
- Cables, wires and Cavini
- a Handheld Radio (my Yaesu VX150)
Radio Shield AX25
The Arduino I already had at home, at any rate, I ordered an Arduino UNO to be used in the final cut.
For the GPS I was looking at some sites that sell the GPS shield for Arduino when I remembered to have at home a Bluetooth GPS, namely a HOLUX M-1000, to the astonishment I found that this GPS has a serial interface RS485 (with levels TTL 3.3 V - 5V) disguised as a Mini USB B, therefore perfectly compatible with the serial that comes with Arduino.
For the modem, TNC I orientated towards a shield specially produced by Argentdata also equipped with the necessary library for implementation from the software side.
Even the LCD screen I have found it convenient to turn a shield preassembled so that brings on board an LCD model Nokia 6610 is already mounted on different phones.
Nokia 3310 Shield
The necessary software is all open source, in particular the two libraries needed GPS to find the site ARDUINIANA namely NewSoftSerial and TinyGPS.
For cables and cords Cavini there are problems the drawers are full and palmarino is already in the house.
Now the work begins, the next!
Dipole or Windom?
After about two years of honorable service of my Carolina Windom Radio Works, model 80 short, it went to hell (literally, given the closeness of my QTH with the Vatican).
The Front End of all radio, I had at the station, has begun to saturate the medium-wave broadcasts of RAI and I could not make a QSO with the QRM that exceeded the 9 +20 (if it was OK).
One morning, in desperation, I call my friend Charles IK0APA and, thanks to the promise of a breakfast bar, we went to the roof and hooked to my antenna switch of a small antenna for HF SSB portable, the MP1 of Superantennas, without even adjust it for a specific band.
Miracle, the reception was very silent, and after a quick adjustment I have completed two quick QSO on 80 meters, but then what happened?
It was evident that the Radio Works had something wrong!
For those unfamiliar with the Carolina say that it is made with two asymmetrical arms, by a balun, by a length of coaxial cable of about 3 meters and passes and by a choke, the vertical portion of the house is called "vertical radiator".
The hypothesis is the one that after two years of bad weather, something has penetrated inside the balun or choke (read water) or toroids have been a good cook 
.
At this point a solution that was urgent, though not definitive, I put in condition to do radio.
I remembered lying in a drawer of a 1:1 balun Diamond, so I somno used immediately to make a nice dipolino, about 10 meters. per arm and the balun at the center.
Particular dipole 80 meters
Two ceramic insulators on the ends and running quick on the radio to try.
I did not make specific calibration of the tuner, but I trusted the station (very badly and you say I agree) but it was late and I did not want to stay on the roof at sunset.
However, good agreement in 20 meters, in 18, 21, decent on 80 meters, about 24 and about 28 meters.
For the moment, the dipole has been mounted that way, but wait a moment for a finer adjustment.
Diary of a building SoftRock RX
This is a small article about a diary that I wrote in 2007 and published on another web site, bring him back because she can still be interesting for someone:
How to take 10 days to build a SDR receiver
Sunday, March 25, 2007,
I never kept a diary for the first time I did it during the construction of an SDR Receiver SoftRock.
Not just begun the construction of my SoftRock, I thought I'd keep a diary that would document the construction.
I did not want the usual manual with photographs and doodles of the components that make so much scopiazzatura of electronic journals.
I simply wanted a job description to guide step by step in the realization of a SoftRock, describing the equipment used and was full of photographs to illustrate visually the progress of work.
The work was completed in ten days, using the scraps of spare time and writing hand to hand on my PC, the work proceeds.
Currently, the SoftRock V6 has been replaced by SoftRock Lite, the printed circuit board smaller and square, but especially mono band.
Obviously the construction notes can be useful even to those who undertook the construction of the Lite.
For some time I was looking for a hardware based on a microprocessor that could easily programmable and reusable introduced me to programming with relative ease.
Currently the open source platform cheaper, but at the same time easily expandable, interfaced with extensive documentation readily available (and free .... which is good) is our national ARDUINO.
The current version (Arduino Duemilanove) is based on an ATMEL microprocessor and offers the following features:
- ATmega328 microprocessor
- Operating voltage 5V
- Input Voltage (recommended) 7-12V
- Input Voltage (limits) 6-20V
- Pin digital I / O 14 (of which 6 are used as PWM outs)
- 6 analog input pins
- DC current for the legs of the I / O 40 mA
- DC Current for 3.3V Pin 50 mA
- Flash Memory 16 KB (of which 2 KB used by bootloader)
- SRAM 1 KB
- 512 bytes EEPROM
- Clock speed of 16 MHz
The small Arduino
The hardware is really tiny, only 6.5 cm. x 5.5 cm., has a USB interface for connection to computer programming, can be powered from the same USB port, and hooking up a power source external to 9/12 Volt.
On board as well as ports in the highlighted features include three LEDs, two for the monitor program and a control output coupled n.13, pulsant a reset and ISP connector for programming.
The programming software, USB drivers, and anything else necessary for programming can be freely downloaded from the official website of ARDUINO .
Squidoo also a tool to assist in the development of projects based on the Arduino platform, which simplifies prototyping and not just the documentation, or FRITZING , to discover aanche to help us in our small DIY projects.
The best way to get started with Arduino and buy herself a (or autocostruirlo, on the arduino site found everything we needed, file for eagle pcb, circuit diagrams, in short, everything you need to DIY an Arduino serial), load the software and start Dagi many examples, both readily available on the official website is online (try to write Arduino inside Google).
Obviously there are support libraries for interfaccaire almost everything in the final photographs attached a little example of a classic interface 16X2 LCD.
The next step? Arduino adapt to amateur radio, I'm already planning on the basis of cwbeacon coupled to a small TX on 28,322 Mhz, then the next project will be a function of the repeater screen YAESU FT817.
Arduino and Breadboard
My Call
