VHF Transceiver
MilitaryRadio
Posts: 18
Hello Friends,
The Italian radioamateur website published my VHF Transceiver project based on the Propeller CPU. You can view the document at this url:
http://www.ariroma.it/docs/projects/prop-4m.pdf
I'm sorry, at the moment the document is only in Italian, soon I'll write an English version, anyway I think it is possible to understand everything looking at the pictures and schematics.
Bye
Paolo
The Italian radioamateur website published my VHF Transceiver project based on the Propeller CPU. You can view the document at this url:
http://www.ariroma.it/docs/projects/prop-4m.pdf
I'm sorry, at the moment the document is only in Italian, soon I'll write an English version, anyway I think it is possible to understand everything looking at the pictures and schematics.
Bye
Paolo
Comments
Great work
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DTQ
Now, I'm designing another transceiver on 2 meters (144 Mhz) that has the same controller card.
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DTQ
Well done!
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"Where am I? Where am I going? Why am I in a handbasket?"
I don't read Italian, but it's easy to tell from the photos and diagrams that this is an amazing piece of work. Congratulations!
-Phil
The radio needed a lot of work but it was a great satisfaction to get it working.
Bob : VE1RLL
Here's an example from your Italian Ver :
Introduction
When it was granted to amateur radio by the Ministry of Communications the opportunity to testing of transmission and reception on the 70 Mhz decided to make a transceiver on this band.Unfortunately, the construction of radio has taken at least two years of time and when it was completed on Ministry of Communications had revoked the license to use the 4 meters. If in the future will once granted, then this transceiver can be used in meantime can only be considered a laboratory experience.
The transceiver is a device that I realized synthesized FM, driven by microprocessor mounted not only discrete SMD. I prefer the traditional components SMD components it is certainly easier installation and when working on prototypes welding is easier and you can use the sockets for the IC.
This radio was designed by adopting a technique that computer scientists call "bottom up" by upwards. I started from individual components - the CPU card, card receiver, card transmitter - and I landed a full radio. Designing device at a Once you can focus your attention on the individual parts, putting them to work in point with the instrumentation and then assemble them together.
First I designed and built the controller board, initially working on cards millefori then land a real double-sided PCB. The controller card has designed with the aim of being reused in other projects. The controller presents these interfaces: keyboard, LCD display, data lines generic input / output. On board the card I also provided a clock to store the date and time and an analog / digital converter (ADC)for the conversion of tensions in binary values. For programming is an integrated MAX3232 which allows direct connection to the PC serial port. As processor
I decided to use instead of the excellent PIC microcontrollers typically used in this such projects, a micro controller is very innovative: the "Propeller" of Parallax. The propeller is a RISC microprocessor with 8-bit to 32 working in parallel for a computing power of 160 MIPS. http://www.parallax.com/dl/docs/article/Propeller_Firmware_magazine_ITA.pdf Some might object that this CPU is too powerful for a radio of this type, and
surely this is true but to test an electronic component or software is required prove it is not enough on paper to study its characteristics. This radio can be regarded as a "test bed" to test the use of the Propeller and its interaction with the external components.
Once the CPU has come the turn of the receiver. A site of components electronics (http://www.alltronics.com) I found a card that contained a surplus Tuner Mitsumi 407-A26. This tuner has a front-end Mosfet very sensitive, with a mixer output signal at 10.7 MHz and a VCO. The Tuner is able to tune into a range of frequencies from 60-150 MHz. The site also has the schematic and documentation. After
I have unsolder the Tuner connected to a Fujitsu PLL used in some kits New Electronics and a MC3361 that is a narrow band FM receiver. The transmitter is certainly the least complex of the radio. 'When viewed from an oscillator VCO based on a New Electronic LX.1235 / 3 and the same used in the PLL MB1502 receiver. On the base of the TX are also relays for switching supply.
Prop-4m rel. 2.0 September 2009
Post Edited (Bob Lawrence (VE1RLL)) : 9/15/2009 7:57:17 PM GMT
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Links to other interesting threads:
· Home of the MultiBladeProps: TriBlade,·RamBlade, RetroBlade,·TwinBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index) ZiCog (Z80) , MoCog (6809)
· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm
I have always been in awe of RF and have never really had much opportunity to play with it myself, so it's good to see such a design.
As a note of interest we are always looking for unlicensed low-power digital transceivers and there are many chips and solutions around but if someone of your experience and caliber were to contribute a project along these lines I'm sure we would all be interested.
I noticed from your schematic though that the digital control side can be improved and the component count could be reduced appreciable with just with a few simple changes. The 74C922 chip stood out as the first pin to bowl over
*Peter*
Thanks for your comments. You are right about the possibility of reducing some components in the digital card. This radio is just an homebrewed object build for personal use and not to be produced in large numbers. I consider this construction as a "Test bed" to discover Propeller functionalities. Now, on the experience of this radio I decided to design another transceiver (on 144 mhz) more affordable for cost and component availability.
bye
Paolo
not a big black box with a usb port and antenna jack!
I have it on my to-do list to make a 6-meter transceiver because I don't have that band
and nobody makes a radio I like with it. (except YAESU 857D or FT-450 maybe?)
Leon
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
Post Edited (Leon) : 9/16/2009 12:54:31 PM GMT
····http://forums.parallax.com/showthread.php?p=743002
in which a digitally-tuned receiver covering the AM broadcast band was demonstrated using only a Propeller. With a suitable RF frontend and broadband downconverter, I believe it's possible for the Propeller to take over duties as a tunable IF stage and audio processor. It remains to be seen, however, which modulation modes can be accommodated in this fashion.
-Phil
Lleon
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle