Insane in the membrane!

OBDII in indian cars

I was interested in an OBDII sensor for our car here and wanted do buy a ScanGuageII for it. The compatibility information available at http://www.scangauge.com/ was inadequate as it mainly dealt with cars made in USA. While searching for compatible cars in India, I came across these posts at Team-BHP and there really are a few cars with OBDII interfaces. From what I read there, it seems none of the cars made by Maruti Autos work with standard controllers even though they claim to have it and even feature a port for the same. So, in a nutshell, if you have a car from maruti autos, don't even dream about a OBD2 controller as its gonna be a waste of money. There are claims that most of the cars by GM, Honda, Ford all work with OBD II. So, choose your next car wisely if you wanna sport one of these geeky gadgets ;)

Labels: computers, electronics, geek, hardware, obd2

Posted by Sarath at 3/19/2008 11:00:00 PM | 1 comments read on

Taste of failure

Today, I tried to build a PCB of a programmer for PIC micro controller 16F628. I wanted to use an easy prototyping method and I decided to go for the method specified here and here.

Soon, I went out hunting for Ink jet photo quality glossy paper in a few shops, and they all were out of stock. Then i remembered a friend who owns a Image / graphics studio and he gave me 2 A4 sheets and did not take money for it even though I insisted a lot. His site is here. Those sheets were high quality Epson ones. Next trip, to my friend who has a high quality Laserjet Printer. I installed the Cadsoft Eagle software in his system and took a couple of printouts.

Once I had the printed sheets, came back home, and did the standard procedures, like cleaning the PCB, cutting it to the required size, not a clean cut, but I had a crude cut using a BIG hacksaw. I didn't have acetone (Thinner) here, so i cleaned my PCB with some Zippo Lighter fluid. Got my Clothes Iron and started ironing it, and the problems started. one layer at the back of the paper started melting, so I kept a backing paper behind it and continued ironing. And soon the backing paper got stuck to the photo sheet. First reaction was, so what?

Made a trip to the kitchen, and started boiling water for cooking my PCBs till the paper came out, but unfortunately, even after 30 minutes of continuous boiling torture, the paper wouldn't move!, and I let it stay there for another 30 minutes, and i finally removed the paper and found, that the toner did not get transfered fully. I had some partial tracks here and there. Which was not useful for me. Repeated with the other circuits and all of them failed.

I am unsure what made the process fail, was it the paper? the Zippo fluid? or an over heated Iron? I have no idea, But I guess I will try it again tomorrow. Will update this post with further findings and failure stories (hope not!) and observations about this comparatively easy trick. Making me insane thinking about what went wrong anyways.. so, lets see how it goes tomorrow.

Good night!

Labels: DIY, electronics, Etching, how to, PCB

Posted by Sarath at 3/04/2008 09:33:00 PM | 2 comments read on

IrDA interface for your mainboard

Many modern main boards have an IrDA connector on board, but the required transceiver is often missing. if you can't find the exactly fitting module for your main board, you can probably use a module from another main board if you connect it in the right way. just see the main board documentations (or search the web) and compare the pinouts. irda modules normally need 4 signals: gnd, +5v, rxd and txd.

or you can build your own IrDA module! All you need is a IrDA transceiver and some resistors and capacitors.

The original article could be found here.

There is also a Silicon Chip Australia project on the same topic, using the same components. Their PCB layout surely looks better too.

Images below.

PCB Layout is here.

Have fun building it.

Labels: computers, DIY, electronics, guides, infrared

Posted by Sarath at 3/01/2008 04:22:00 AM | 0 comments read on

50MHz 500Watts Linear Amp Using IRF510

I came across this site with a super design that uses 16 cheap IRF510 power transistors to get 500 Watts of RF power. Now, this is an Ideal amp for hams in India as these transistors are available very cheap over here.

Here is the link to the site. You can find the entire PCB layout, Schematics etc there.

http://frenning.dk/OZ1PIF_HOMEPAGE/50MHz_IRF510.htm

I have put this in my to-do list and in the mean while, i hope you like building it.

Labels: amateur radio, electronics, ham radio, HF, power amplifier, radio, RF, RF amplifier

Posted by Sarath at 2/29/2008 05:43:00 PM | 0 comments read on

Bitx20 Version 3 from VU3SUA Construction Notes

I have been building this board from past few days and was searching for some help regarding the tuning parts of various sections. And I asked Sunil to help me with some images, notes and he updated his blogs with a couple of pictures. His blog is available here. When I looked closely, I found that those images and tutorial work was actually done by Leonard L Leeper (KC0WOX). His home page is here. The complete set of instructions he wrote is here. Great job Leonard!!.

Update on 05/03/2008

I couldn't access Leonard's site most of the times for checking up information, So I am just copy pasting the information i found in leonard's page along with the images so that the visitors can see them, basically a mirror.

Here goes,

Bitx20 Version 3

After building a Far Circuits Bitx20 and a Hendricks's QRP Kits bitx20a kit, I decided to build another bitx after seeing this posting:

A new batch of Bitx PCB, in glass epoxy ,masked, roller tinned and with
component place-ment is in ready stock for delivery world-wide.
Also available is the pcb for Avala 01 Sdr monoband tcvr.

I am giving a very special discount on the pbc's. To know further about
the discount, kindly send me a mail at suillakhani123@ gmail.com

I sent off my email and received this back:

Dear Leonard,
The Bitx Version 3 PCB is for $10 PCB +Coils+1 No 2570 transistor.
The Avala sdr pcb is for $5.Shipping is extra $ 10.

I looked at this web page to get an idea what the Avala sdr was and decided that I couldn't pass up a deal like this.

After a trip to paypal, the boards for the bitx and the avala were ordered. Soon I received a package in the mail. In it was 3 pcb's. This was the bitx board along with some of the specialized parts. The other boards were the PA board and the Avala board,

There was enclosed, a schematic, a component layout, and a few other pages of documentation.

After examining them, I decided to make an "exploded" layout drawing using a section-by-section approach to the assembly and testing. I will function test each section as it is assembled. This will almost insure that the board will function when everything is completed. I already had an head start on the project as this would be the 3rd Bitx I had built. I already knew what the signals should look like in each stage.

Bandpass filter section

RF Driver stage

VFO Section

Bandpass filter section

I decided to start with the antenna end and soon I had the following parts placement diagram for the bandpass filter section.

Next I assembled it and connected a sweep generator to the input and my oscilloscope to the output.

After a little tweaking, this was the final result. The scope is displaying from 10mhz to 20 mhz. Each division is equal to 1mhz.

Rf Driver Section

Following my plan to work from the antenna back, the next section was the RF driver stage. It was the next logical section of the board to populate also.

With the drawing done, the next step is assembly, then add a little power, no smoke, that's good, and a signal input.

Then on to test with the scope. 100mv 14.2mhz in, 1.5 volts out. That was open circuit and we probably won't get that when we hook to the PA, but for now, thats a gain of 15. On to the next stage!

VFO section

The VFO section stands on it's own and will be easy to test so I choose that as the next section. A transformer was furnished with the boards but it would have to be rewound as the VFO needed about 9uh's of inductance and the transformer maxed out around 5uh. Depending on the variable capacitor you tune with, the turns on the inductor may have to be adjusted but 50 should be plenty and then you can remove some to adjust the frequency up. My test capacitor tuned from 15-377pf and the VFO had almost a 500khz tuning range so setting the frequency shouldn't be really critical. I didn't tweak the range on mine as I will do that when I install it into a case.

Next I assembled it and connected my oscilloscope to the output. You can see the power connection for the test

I checked it out with the scope. A little over 3.5 volts. This will be less when the transformer is hooked up due to it's loading. There is some distortion of the sine wave so we know there is some harmonic content.

A quick look with the spectrum analyzer to see what the 2nd harmonic looks like.

1 Mhz/div horizontal. The left is 0hz and the right is 10mhz. Each vertical division is 10db. It looks like the 2nd harmonic is down about -25db.

Time to drink a cool one and then pick a new section to do next.

First Mixer section

This section is a little harder to understand. I've included a picture to help show the diodes placement. The colors below are the wire color connections if you use red, brown, and green wire. If you use different colors, substitute them for mine.

We need to wind the trifilar transformers. Use the small binocular cores and wind 13 turns of trifilar wire onto the cores. 1 turn is a trip through both holes ending up where you started. We need 2 transformers. I had red, green, and brown #28 wire. The cores aren't big enough to use larger wire. The original drawing called for #32 but the size doesn't make much difference as long as it will fit into the core. The different colors make keeping the windings straight easier. When pulling the wire through the holes in the cores, be careful not to scrape the insulation off. The binocular cores can have sharp edges. When you are done, it should look like this.

Now you can place them on the board as shown above. The final placement should look like this.

Notice the direction of the bands on the diodes. Make sure the leads don't short together.

2nd IF Section

Before we start installing components, now is a good time to install all of the wire jumpers on the top of the board. It will make testing easier as we will connect to the rx or tx line plus the 12 volt line to power the appropriate circuit during test.

This section is almost identical to the the RF Amplifier section so it shouldn't present any difficulties.

I found a board problem on mine. On the left picture, notice there is no right hand hole for the 100 ohm resistor in the lower left corner. It's easily fixed simply by soldering the right lead of the resistor to the wire adjacent to where the hole should go.

Your board should now look like this.

Lets test it!

Testing the receive side is a problem as there are many frequencies present after the mixer and when looking at them with a scope, it is confusing. Lets look at the receive side using a spectrum analyzer.

Here's some of the frequencies at the input to the crystal filter. It's a good thing that most of these will go away because they won't go through the filter. Part of the reason there are so many frequencies here is because we are overdriving the antenna input circuits with 10 millivolts input. Lets look at what happens when we reduce the input to the mixer. This is normally done by decreasing the RF gain, either with a manual control or agc on the rf amplifier.

This is a reduction of 10db of input signal. That made a big difference. The VFO harmonics are still there but a lot of the mixer products are drastically reduced. Remember, each vertical division is 10db and a reduction to 1/10th of the power. Lets reduce the input another 10db.

That almost eliminated all of the excess mixer products. This is a 20db reduction from the first picture. 20db is 1/100th of the original power or 1/10th of the original voltage so we now have 1mv input at the antenna connector. Under normal operation, that's still a big signal. Our receiver should see signals down to around .3 micro volts.

Linear Amplifier section

The version 3 linear amplifier board has 2 very nice additions. The first, the RF signal is switched between rx and tx by relays. This cures a problem I found with the Far Circuits board that I cured by adding relays. The other main addition is an AC power supply. It is setup to accept an AC input and has a rectifier and voltage regulator on board. This allows 13 volts to be fed to the bitx board for it's supply voltages and a higher voltage unregulated to be used on the IRF510. Above is the original board setup.

I made a few modifications to the board. The board looks like this. Power supply on the right and the IRF510 lower left on the big heat sink.

I wanted to use a 22 vac transformer that I had so I needed to use a 35 volt capacitor. I had a 6800 mfd at 35 volts in the junk box so I used it. I had to move the 2 - .1 ufd capacitors to get room for the big filter cap so I put them on the back of the board using some chip caps I had. The spacing worked out just right. Just to the right of them is the original pads for the 2 electrolytic caps.

I used 3 amp silicon diodes so I had to drill out the holes a little and then stand them up vertically. The 6800 ufd cap was hot melt glued to the board after soldering the wires for it into place.

After hooking up the power transformer,, I measured 30 vdc for the IRF510 and 13.6 volts for the bitx. The next step will be to test it after I complete the bitx. I'll be interested in the power out with the higher voltage.

Labels: amateur radio, DIY, electronics, ham radio, how to, radio

Posted by Sarath at 2/26/2008 01:54:00 AM | 0 comments read on

Bitx20 Kit from VU3SUA

Yay!!, I received my Bitx20 kit from Sunil Lakhani(VU3SUA) today. I was jumping with joy as i received it. The postage + the time in transit was very normal. And he had included Front end coils, Balun Cores, Dumbbell cores, and a transistor that is a little difficult to obtain in local shops. He also sent me a free Frequency Counter PCB!!! I love this guy!!.

The boards were of excellent quality, some spacings are some times a little large and some time a little short, but its okay since it is totally designed here. The PCBS were all plated and masked. Very well made I would say.

Here are the contents.
1. 1x Bitx20 Main Board,
2. 1x Power supply and Linear Amp PCB,
3. 4x Front end Transformers (Already wound),
4. 7X Balun Transformer Cores,
5. 2x Dumbbell transformer cores,
6. 1X 2SC2570 Transistor.

The packing was excellent, he had taken utmost care to pack them properly with a polythene cover, then a paper cover (had a contents listing), and a thermocol protection around this cover and then all these covered in the standard cloth based packing used for Speedpost. Yes, I did spend a lot of time unpacking it :).

I will post the photos of the PCB as well as the contents of the kit in this post as soon as I can arrange a digital camera.

So, I am back to building the kit now, have fun :), and hang in there for more.

Labels: amateur radio, electronics, ham radio, HF, power amplifier, Power supply, radio, RF, RF amplifier

Posted by Sarath at 2/22/2008 11:31:00 PM | 0 comments read on

Yaesu FT-101ZD cosmetic restorations

A good post about the restoration of Yaesu FT-101ZD. Nothing deep in there, just cosmetic details only. Here is a link.

http://www.electricsoftware.co.nz/Default.aspx?tabid=141&EntryID=25

Labels: amateur radio, electronics, radio, Yaesu

Posted by Sarath at 2/22/2008 05:19:00 AM | 0 comments read on

AVALA-01 SDR

AVALA-01 is an excellent monoband SDR (Software defined Radio, PC Controlled) design.
It was designed by Tasić Siniša (YU1LM), a Serbian Radio Amature.
His words. "New mono-band SDR transceiver AVALA-01 is ADTRX-2 transceiver with built in power amplifier and band oscillator all on one board. Transceiver is optimized for work with one sound card and Duncan M0KGK software. With unique PC control setup AVALA-01 is working in all other programs and with all types modulations SSB, CW, DIGITAL....also."

You can get the circuit details here.

You can get the printed circuit boards from Mr. Sunil Lakhani VU3SUA. His blog page with the details are here. Let him know that you have been to my site :).

Labels: amateur radio, electronics, ham radio, radio, RF, SDR

Posted by Sarath at 2/13/2008 05:55:00 AM | 0 comments read on

Bitx20 Transceiver

Here, I will explain briefly about this transceiver. This is a design done by Ashhar Farhan, an Indian Amateur Radio Operator and an electronics engineer. It is a bidirectional SSB transceiver. His original design can be found here. This is an excellent 20 meter radio which is quite cheap to build. You can build the entire thing within $15 or around Rs.650/- . You can also find another one of his designs here.

And once this design was released for the public, there were many enthusiasts who devoted their time and tweaked it to perfection. And they formed a Yahoo group called Bitx20. If you are interested in the project, I suggest that you sign up there. You will need a moderator to approve your subscription, but the wait time is negligible.

There are many kit manufacturers promoting this design and you can find some of them here.

QRPKits: A full kit for Bitx20. $90USD.
VU3SUA BITX: Pre wound front end coils and Balun cores, rest of the components has to be bought locally. $8USD or around Rs:300-350 including postage within India. Please contact Sunil Lakhani and he will send you the information required to purchase the board.

Here is a picture of his board.

Or, In case if you like to etch it yourself, the pcb layouts are available within the files section of the Bitx20 Yahoo! group.

So, thats it for today. Good luck on building your Bitx20. Have a good one.

Labels: amateur radio, electronics, ham radio, HF, radio, RF

Posted by Sarath at 2/13/2008 05:27:00 AM | 0 comments read on

USB-Serial

Here is something every ham shack should have. As you all know there are many rigs which needs a connection to the computer's serial port for software control. And these days the number of serial ports available on most of the main board is limited to just one. This is simply not enough for the needs of an amateur or any electronics enthusiast. Yes there are several el cheapo USB/RS232 adapters available. But I have always wanted an industrial quality serial port adapter to go with my shack. Here is something I came across recently and found it does the job very nicely in controlling my rigs / id-o-matic and a PIC burner. I don't have to fiddle around the cables anymore.

Check out their line of products.
http://www.usbgear.com/USB-Serial.html

Or, If you wanna do it like an average electronics - computers geek, here is what you need.

Four USB to serial Adapters, they cost you like $5 USD a piece.
One 4 port USB Hub - $3
Some high quality ribbon cables (Cables from your old IDE hard drive cables is great).
An enclosure where you can fix all these stuff. Make proper holes on the front panel for RS232 connectors and a single USB port connector on the back of the enclosure.

1. Remove the casing of these adapters and remove the USB connectors from each of those adapters, and wire a 4 wire ribbon cable to where the connectors of socket were.

2. Remove the female sockets from the hub after taking off its cover and solder the 4 wire cable to the socket connections directly. Make sure the connections are correctly done as we are dealing with built in power supply.

3. Do the above 2 steps for each of the other 3 USB serial adapters.

4. Now , connect all these adapters to the back of the front panel, and tighten the screws on the RS232 connector in the adapter so that they don't move.

5. Fix the USB hub board on the base of the enclosure using a couple of spacers.

Connect a USB cable to the hub and see if everything is working properly. In some hubs with LEDs on each of the USB connectors, you can extend them using a simple 2 wire cable to the front panel, or you can extend the LED on the adapter itself to the front panel.

6. You don't need to provide additional power source for these ports, USB cable supplies enough voltage to drive these 4 ports.

Pack everything and enjoy. Total cost of this project will be lesser than $25.

Cheers!!

Labels: cable, computers, electronics, hardware, RS232, serial, USB

Posted by Sarath at 2/12/2008 10:38:00 PM | 0 comments read on

Dealing with RF interference

Here is a guide that deals extensively into RF interference.

Here you go.

RADIO FREQUENCY INTERFERENCE (RFI) Notes
M.D.Lowell, N1LO October, 1998

Progress: Through July 1999 archive

Check http://www.qsl.net/n1lo.

Another very well documented guide here.

http://www.kyes.com/antenna/interference/tvibook.html

Make sure you make good use of these guides.

Labels: amateur radio, cable, computers, electronics, ham radio, hardware, HF, interference, radio, RF

Posted by Sarath at 2/12/2008 06:25:00 AM | 0 comments read on

Cheap ADSL Filter dissected.

There are many CHEAPASS ADSL filters available in most of the electronics shops in india. Costs around Rs. 40/- each. The function of this filter is, to make sure that the ADSL Signals don't interfere with the Voice signals and vice versa. Here is a circuit That shows a standard ADSL filter.

And the one Which I bought, Has just 2 inductor coils, value unknown, Wish i had an inductance meter.

Here is how it is wired internally.

Wall o--- IND COIL ---o Phone
Wall o--- IND COIL ---o Phone

There are no capacitors used in this circuit at all. And this method will not give an ideal low pass filter. L2 and L4 are needed since we're dealing with the 'Tip' and 'Ring' of a phone line. So, while it is cheap, be carefull when you buy these filters.

Will add actual photos here soon.

Labels: ADSL, electronics, internet, lowpass filter, telephone

Posted by Sarath at 2/07/2008 08:02:00 AM | 0 comments read on

Build your own Vacuum Tube?

This guy is crazy!!, He even makes his own vacuum tubes!!

http://paillard.claude.free.fr/

The page is in French, but use the Google translator link provided to read. Very interesting video there.

Labels: amateur radio, DIY, electronics, geek, generic, ham radio, hardware, HF, how to, radio, RF

Posted by Sarath at 2/06/2008 05:48:00 AM | 0 comments read on

Elektor 1987 20 meter SSB Receiver

Searching out this article took painstakingly long. This was featured under the retronics section in a recent Elektor magazine. Even though they said there is a free download of this article available in their site, there was nothing. It took long hours of search to pull it out from a cache. I am posting it here to save the trouble for any one interested.

Have fun with it people :)

87051u.pdf

Labels: amateur radio, electronics, ham radio, HF, how to, radio, RF

Posted by Sarath at 1/23/2008 07:34:00 AM | 0 comments read on

QEX Magazine

There is a good collection of QEX magazines I came across in rapidshare.

Have a look.

http://rapidshare.com/users/Q52ZAP

Labels: amateur radio, DIY, electronics, guides, ham radio, HF, radio

Posted by Sarath at 1/23/2008 05:54:00 AM | 0 comments read on

Hack your radio for Airband

Here is a simple hack you can do to your cheap AM/FM radio. With a few adjustments, you can receive AIRBAND (Flight to Tower Comms).

http://www.make-digital.com/make/vol09/?pg=29&u1=texterity&cookies=1

There are dedicated receivers for these and here is one from Elektor if you want to have a dedicated receiver.

http://www.elektor.com/magazines/2002/march/vhf-airband-receiver.55620.lynkx

Enjoy.

Labels: amateur radio, electronics, hack, ham radio, HF, radio, RF

Posted by Sarath at 1/16/2008 05:25:00 AM | 0 comments read on

Circuit Cellar Magazine

Labels: electronics, magazine, rapidshare

Posted by Sarath at 1/12/2008 08:56:00 PM | 0 comments read on

Nuts & Volts Magazine

Labels: electronics, magazine, rapidshare

Posted by Sarath at 1/12/2008 08:38:00 PM | 0 comments read on

Silicon Chip (Australia) Projects

A good list of projects came in Silicon Chip Magazine
Download location at the end of post.

6-Channel IR Remote Volume Control - Part 2
10-Channel IR Remote Control Receiver
12-channel Infrared Remote Control
12V Flourescent Lamp Inverter
45-Second Voice Recorder Module
A 2_4GHz High-Power Audio-Video Link
A Digital Thermometer-Thermostat
A Dirt-Cheap, High Current Power Supply
A Low-Cost 50MHz Frequency Meter
A Poor Man's Q Meter
A Programmable Continuity Tester
A Programmable PIC-Powered Timer
A 'Smart' Slave Flash Trigger
A 'Tiptronic-Style' Gear Indicator
A Windows Based EPROM Programmer
A Windows-Based EPROM Programmer - Part 2
Active 3-Way Crossover for Loud Speaker Systems
Adjustable DC-DC Converter For Car
Alternative Power Regulator
Antenna & RF preamp for weather satellites
Appliance Energy Meter, Pt_1
Appliance Energy Meter, Pt_2
Automatic Single-Channel Light Dimmer - Part 2
Automatic Single-Channel Light Dimmer
Balanced Microphone Preamp
Bidirectional Motor Speed Controller
Big-Digit 12-24 Hour Clock
Build A Professional Sports Scoreboard, Pt_ 2
Build A V8 Doorbell
Build A Water Level Indicator
Build An AVR ISP se-ri-@l Programmer
Build The Decision Maker
Bulid Your Seismograph
Car Battery Monitor
Carbon Monoxide Alarm
Charger For Deep-Cycle 12V Batteries, Pt 2
Circuit Notebook 3
Circuit Notebook 4
Circuit Notebook 5
Circuit Notebook 6
Circuit Notebook 7
Circuit Notebook -8
Circuit Notebook -9
Circuit Notebook -10
Circuit Notebook -12
Circuit Notebook
Circuit Notebook-
Circuit Notebook=
Compact 0-80A Automotive Ammeter
Component video to RGB converter
Controlled Automatic Table Lamp Dimmer
Courtesy Light Delay For Cars
Digital Instrument Display for Cars - Part 1
Digital Instrument Display for Cars - Part 2
Direct Conversion Receiver For Radio Amateurs - Part 1
Direct Conversion Receiver For Radio Amateurs - Part 2
D-I-Y remote control for a model train layout
Dr Video Mk_2 An Even Better Video Stabiliser
Driving Light and Accessory Protector for Cars
ESR Meter 1-Mk_2
ESR meter hints
ESR Meter Mk_2
Fridge-Door Open Alarm
Getting into WiFi, Pt_ 3
High-efficiency power supply For 1W Luxeon Star LEDs
Home-Brew Weatherproof 2_4GHz WiFi Antennas
Improved Speed Controller for Universal Motors
Inductance & Q-Factor Meter, Pt_1
Inductance & Q-Factor Meter, Pt_2
IR Remote Control Checker
keyb18xa_bas-
Lapel microphone adaptor for PA systems
Lead-Acid Battery Zapper
Level meter for home theatre systems
Linear Supply For Luxeon 1W Star LEDs
Long-Range 4-Channel UHF Remote Control
Long-range 16-channel Remote Control System
MIDI Theremin, Part 2
More Fun With The PICAXE - Part 3 Heartbeat Simulator
More Fun With The PICAXE - Part 4 Motor Controller
More Fun With The PICAXE - Part 5 A Chookhouse Door Controller
More Fun With the PICAXE A Shop Door Minder
MUDLARK A205 Valve Stereo Amplifier
Not Another CFL Inverter
OLED Displays Better Than Plasma Or LCD
One-chip Transceivers for easy UHF Data Communications
PIC Controlled 32-LED Knightrider
Picaxe-18X 4-channel datalogger
PICAXE Application Special PICAXE 08 Port Expansion
PICAXE Application Special PICAXE Telephone
PICAXE Infrared Remote Control
PICAXE- Part 9 Keyboards 101
PICAXE The New Millennium 555
PICAXE(s) -are these chips the New Millenium 555
Poor Man's Metal Locator
Portable PIC Programmer
PortaPAL Public Address System - Part 2
Printer Port Hardware Simulator
Programmable Flexitimer
Real Yagi Antenna For UHF CB
Receiver For Radio Amateurs - Part 2
Remote Volume Control For the Ultra-LD Amplifier
RFID Security Module
RFID Tags - How They Work
Rolling Code 4-Channel UHF Remote Control
RTTY Modulator
se-ri-@l Stepper Motor Controller
Shorted Turns Tester
Shut That Mutt
Silicon Chip 1
Silicon Chip 2
Silicon Chip 3
Silicon Chip 5
Silicon Chip 6
Silicon Chip 7
Silicon Chip 8
Silicon Chip Electronics 4
Silicon Chip Online - A Lap Counter For Swimming Pools
Silicon Chip Online - Low Cost 1HZ 10MHz Function Generator
Simon Says
Single-Channel Light Dimmer - Part 2-
Smart Card Reader and Programmer
SMS Controller, Part 2
Solar Powered Wireless Weather Station
Starpower - A Switching Supply For Luxeon Star LEDs
Sunset Switch
SuperCharger Addendum
SuperCharger For NiCd & NiMH Batteries - Part 2
SuperCharger For NiCd & NiMH Batteries
Telephone Dialler For Burglar Alarms
Telephone Headset Adaptor
Test Your Reaction Times With A Digital Reaction Timer
The Battery Guardian
The Coolmaster Fridge-Freezer Temperature Controller
The Mesmeriser
The Micromitter Stereo FM Transmitter
The PICAXE Part 6 - Data Communications
The PICAXE Part 8 - A Datalogger and Sending it to Sleep
Three Do-It-Yourself PIC Programmer Kits
time lapse camera
Updating the PIC Programmer and Checkerboard
USB Power Injector
USB-Controlled Power Switch
Versatile Micropower Battery Protector
Versatile Multi-Mode Timer
VHF Receiver For Weather Satellites
Video Enhancer & Y-C Separator
Video Formats Why Bother
Video-Audio Booster For Home Theatre Systems
Whistle & Point Cable Tracer
White LED Driver
WiFry Cooking up 2_4 GHz Antennas
1-A Programmable Continuity Tester
1-SMS Controller Pt_1
4 Digit Crystal-Controlled Timing Module
4-Minute Shower Timer

http://rapidshare.com/files/56390000...chip_part1.rar
http://rapidshare.com/files/56398409...chip_part2.rar
http://rapidshare.com/files/56405234...chip_part3.rar

PASS: dcapro

Labels: electronics, hardware, magazine, Project, rapidshare

Posted by Sarath at 1/12/2008 08:35:00 PM | 4 comments read on

Everyday Practical Electronics Magazine

Labels: electronics, magazine, rapidshare

Posted by Sarath at 1/12/2008 08:30:00 PM | 1 comments read on

Frequency Counter.

A nice freq counter.

While browsing the web, I came across a cool freq counter that you can add on to your home brewed radio. Here it is.

http://www.cumbriadesigns.co.uk/kits.htm

Enjoy!

Labels: amateur radio, DIY, electronics, ham radio, HF, radio, RF

Posted by Sarath at 1/09/2008 06:02:00 AM | 0 comments read on

Battery Charge Monitor

When I was checking up free circuits, I came across this project and when looked at this name I realised these were my college mates. I have no Idea where they are. I am posting their project here.

PS: Siddharth used to play Quake 3 with umpteen nude hunter bots (an addon skin for the hunter bot) and he used to watch them fight each other. hehe.

sept99_chargemonitor.pdf

Labels: DIY, electronics, Project

Posted by Sarath at 12/09/2007 10:45:00 AM | 0 comments read on

Hooked on to Amature Radio.

The radio bug bit me again....

I have been modding, tuning many radio circuits these days to (mis)use them for other purposes ;). So the thought flashed again, why not take up the Amature Radio Exam and get a call sign and home brew a transceiver. So I am on it from the past few months. The biggest issue, is learning Morse code. One of the main criteria here to pass the ASOC exam.

Here are the details of the stuff I am using to learn for the Exam.

ABCs of Amature Radio, EFY Publications Rs: 75/-
G4FON Koch Morse code Trainer. (Free)

I have setup a 40 meter band simple dipole antenna. I will post the image, and constructions details here later.

Labels: amateur radio, electronics, ham radio, HF, radio, RF

Posted by Sarath at 12/04/2007 05:32:00 AM | 0 comments read on

Interests and Projects

Community Wireless Network in my small town.
* Complete Wireless roaming within the town and optional long links..
* Centralised AAA facilities. Single Sign-on to use any service available within network.

Inventry So Far
* 3 Pringles Cans (Empty now :))
* Couple of N-Female Radiators
* Couple of Pig tailes
* 2 Old computers ready to run on CF cards and act as gateways!, Pretty Solid, eh?

Yet to receive
* Nokia GPS Module LD-3W (Bluetooth), Bought it for mapping + antennae alignments.

Yet to Purchase
* A foundry L3 24 port Switch (Available for around $100 in ebay!)
* Parabolic Grid Antennae (Got a good source who can give it real cheap, around $20 a piece)
* A couple of old DTH antennae (Got some nice offers, Money!!, Damned Money!!)
* 3 WRT54GSs, Lost them to an eBay sniper (One day i will have them and these guys will be loaded with Freifunk)
* Intersil PRISM based wireless NICs for the PC based nodes. (This one is getting rare)

Voice Over IP services
* Free In-Network Calling using VOIP (SER)
* Cheap Unlimited Calling to more than 20 countries (200 Rupees PM for Primary Country and 50 Rupees PM for every additional countries) Planning to use Broadvoice and fwdOUT ;)
* A couple of X100P clones are waiting for me to have some spare money..

Partner in Crime > Sajith @ http://www.sajith.org

I need support for this project, Any one who are ready to put in their efforts are welcome.
Please donate your Old computers, Wireless routers to the project and we can make good use of them!

Labels: computers, electronics, hardware, interference, Project, voip

Posted by Sarath at 8/17/2006 11:15:00 AM | 1 comments read on