Software Defined Radio :)

I had tried to post messages before on the blog but strangely my browser just did not allow me to upload my posts and would keep showing errors and now that I have upgraded to Firefox I can go ahead and Blog without any other problems.

I recently saw a couple of Software Defined Radio Rx which are quite simple to construct on YU1LM 's Homebrewing Site. I was quite Impressed with what can be done with very little components.

The circuit of Interest to me is the DR2C . I am planning to homebrew this Nifty Little receiver to 14 Mhz (20 meters).

Rest later :)

73's

Microcontrollers and PIC Progamming

I was introduced to PIC Microcontrollers a few months back and got hooked on to it pretty soon.

Image Courtesy: KE4NYV

PIC Microcontrollers simply life a lot ..The .. especially for the QRP homebrewer ...

If you are new to microcontrollers check out mikroeleltronika's PIC tutorial.

If you are in need of a PIC programmer I reccomend FENG3's RCD PROGRAMMER.

More Soon :)

73's

DC-40 - A Simple Receiver for 7 Mhz

I came across this very interesting design on the internet and decided to get on with the construction. The design is by VU2FAX OM Ashhar Farhan (Of the BITX fame :) ).

The Receiver is a simple Direct Conversion design for 7 Mhz (40 meters) .

The Frontend coil is wound on a 1/2.in Tap washer (US: Faucet) with 32 Gauge Magnet wire.
The frontend is followed by a Double balanced diode mixer. The mixer trifilar is wound on TV balun cores (bought them at 5 bucks per core) . The VFO is 7 Mhz LC tuned.The VFO is followed by a buffer amplifier (The Buffer amplifier also reduces the noise).
The Mixer passes on the weak AF signal to a Preamp. The  volume is further amplified by a 386 Amplifier.

I got all the Parts yesterday and finished the Preamp section today. Since I had a 386 amp which I had constructed earlier {I make 2-3 modules when I get time so that I can use them later}

The Only Problem Faced during construction of the Preamp is that I had mixed up the wiring first as all the transistors looked the same and wiring it up on a prototyping board was tiring.

I also got time to wire up a Passive AF filter with the parts I had in my Junk Box. The filter has a bandwidth of 3 Khz and is enough for SSB reception. A switch in parallel to the filter serves as the filter bypass (For CW reception) ........

This Filter was designed by VE7BPO

The whole cost of the receiver comes to around Rs.100 ( around 6$).

I plan to construct the receiver as a weekend project(spending just sunday evenings) and should finish this off within the end of this month.

Source of the article can be found here. 

I have compiled the document and converted it to PDF for
 printable format (8 pages) and readable format (11 pages)  

Home Brewing in VU land

Hello !!!!!!!


Welcome to my Blog. I decided to start of witha blog so that I could share some info with hams who share the same interest : HOME BREWING

I started out with homebrewing even before I got my ticket .....
I got involved with electronics when i was in 9th Grade.(Now I am a sophomore in college). My mentor in electronics is Mr. Ramesh(Ex- VU2VTZ) . He always used to talk about how radio electronics was challenging and rewarding.
That started me off and my first RF Homebrew was a small room Bug which would
transmit in the BCB FM range.....It gave me many hours of fun and entertainment as I used to bug my own room and go to the terrace and would listen to my mom complaining about my Room and my Bed HI...HI.....

After a year I decided to write my ASOC (Amateur Station Operator Certificate)  and cleared it After that my wait begun  ....  I got my ticket 3 years later( in Jan '07 to be exact )

I am Currently working on 2 rigs for my shack :

1. The RM-96 SSB Transceiver capable of putting out 25 watts on 7Mhz
(Design by VU2 RM)
2. The BITX-20 SSB Transceiver with an output of 6 watts on 14 Mhz
(Design by VU2 FAX)

These are yet to be finished. FOr those who are interested do check out:
1. http://www.hamradioindia.org/downloads.php?d_op=getit&lid=41 (the RM-96 Design)
2.http://phonestack.com/farhan/bitx.html (The Bitx design)

Besides these I have these test instruments in my shack:

1. Frequency Counter
2. Test Oscillator
3. FCL-X meter(for mesauring frequency,capacitance and inductance)---still under progress
4. RF Probe

Homebrewing in VU land is a challenge as the Indian market does not offer Highend components and due to the heavy duty and customs it is nearly impossible
to buy components from DX.
We often end up using parts from either salvaged sets or active devices intended to work on AF ...