The SDR ... Its Alive !!

Hello!

After some QRL , I found some time to work on my SDR Receiver which i have mentioned about in my earlier posts. After adding a BC 547 RF Preamplifier, I connected it to my PC and fired up M0KGK's SDR decoder and voila .... I picked up this transmission from a "french" (Not sure) Station. It still needs tweaking and boxing up but alas, It fianally works.

The Preamp is powerful enough to bring in weak stations with just a 3 Mt wire thrown around the room!

A well deserved break , I should Say!!

73's

Ragav

Back after a long spell ....

Hello!!
Its been a long time since i updated this blog.

Almost a YEAR!!!!

College QRL had kept me from my shack and i decided to break the spell and attended a Software Defined Radio Workshop By VU3WJM, OM Rahul. Anna University, Chennai had done a great job of arranging a workshop to promote SDR's here.

Shyam, 3UBR and I got a kits of a simple SDRx for homebrewing. Since Shyam's Interest in the subject is simply too high, I took some tips from him which gave me a lot of things to think about before I could say "Yeah....I think I understand now..."

Once back in the shack after a brief dinner, I set my sights on the kit. I quickly put together the 5V regulator section and tested it. Next were the Jumpers on the board. After some struggling the jumpers were soldered on. Next were the Resistors, Followed by the non-electrolytics. Then came the IC sockets. The electrolytics and the Crystal were soldered only after the 2 transistors.

After a short break I returned to the shack with the pin layouts of the 3 IC's :

1. 74HC74
2. 74HC4053
3. NE5532

The Pin voltages were measured and were found to be well within the specs of the IC's. Next in line were the 2 transistors. No problems there. Frequency measured was at 28.325 Mhz.

Close enough!

Now to interface it with a good PC (My laptop lacks a Line IN).

I have M0KGK,Rocky and WinRad installed. Lets see :)

73's

Ragav

P.S.: I also got the New BITX v3 PCB from VU3SUA and WOW... look at it guys!! absolute fun to assemble! More on that later!!!

A Simple USB PIC Programmer !

Hello!

I was on the hunt for a USB PIC microcontroller programmer after losing interest in the GTP-USB-Lite.

After a night long search, I found the June Bug Programmer by Blueroom Electronics. The programmer Side is a PICKit 2 Version without the EEPROM's used for On the Go Programming.

The trick to getting this programmer to work is to use a 18F2550 programmed with a .Hex file provided by Microchip. Once this is done, you can calibarate and use the programmer. Oh yes! Once the Chip is programmed, you can update it's firmware by pressing a Push-button on-board.

This makes sure you can program the latest supported PIC micro controller.

This Is a Must Have for Any Hobbyist!!!

Since The PCB is not available on the internet, I decided to ask Theo, a Young Lad who seems to have the knack, even though he is not into RF Design and Construction (yet!).

Here is the PCB and the Component Layout in PDF format.

The Hardware is supported by MPLAB and the hex file can be found in the MPLAB installation directory.

More Updates soon!

73's
Ragav

Getting a VHF Rig!

Hey!



I am finally getting a VHF rig after much pushing around. The Rig ( A KYD TK-750A) is on its way from Bangalore! Here Is a Picture with all specs...covers the whole VHF spectrum!!!

Thanks to VU2POP (Prathap) ,VU3KCA (Keerthy) ,VU3TLR (Sujay) ,VU3UBR(Shyam), VU3HMU (Barath....Yes he is finally Licensed) !!!!

Drop a Call on 2 meters (Main repeater is on 145.175 600 Positive Shift)

73 !

Ragav

Broadcast SDR receiver !

Hello People!

I received these plans for a Broadcast Software Defined Radio Receiver from OM Sarma In Hyderabad. It Uses a LC tuned VFO to cover 3-16 Mhz. Although this can be used to tune to Amateur radio transmissions it will be difficult to fine tune into a signal....

Use One of the following sofwares to decode the signals:

• Rocky
• Win Rad
• M0KGK SDR
• SDRadio

Here are the files:

• Documentation
• Local Oscillator Schematics
• PCB Component Layout
• PCB design

Three Cheers for VU3WJM OM Rahul for the design!!!

Will be making this soon!

73's

Ragav

RX 20 and The Signal Gen Project

Hello!



Here are the schematics of the RF gen which is a PLL VCO . The original circuit was designed by KD1JV.

The RF gen proves to be a cheap source of signal for checking your homebrew Receiver.

Here is the documentation for the RX-20 circuit.

more up in next post!!!

73's

Ragav

Hamfest India - 2007

Hello!



I came home a couple of days back from Guntur after attending the much awaited HamFest India '07. I really appreciate VU3 RSB OM Sharath Babu for organizing this hamfest and for also personally seeing to it that all delegates were happy throughout the visit.

The photos can be seen over here

Had a Great Eyeball with VU2POP,VU3KCA,VU2RMU,VU3URJ,VU3HDK and a lot of other Hams....Best part is I got an eyeball with ex.VU2FAX OM Farhan!!

73

ragav