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On this page you will find some homebrewing projects proposals.
I hope it will be possible to add other projects, mostly relying on the co-operation of all the interested people.
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          A little device which joins in a single microprocessor a digital programmable frequency meter and a control logic capable to lock a manually tuned VFO to its actual frequency. 
The locking function is software inhibited when a manual tuning is detected, so as to provide a completely automatic working

FLL VFO (PDF file - 130 Kbytes) 

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A "palm size" 1,5 W QRP rig operating on the HF in DSB and CW.
A lot of fun with this ultra-simple project wich employs a few components and is very easy to build and to align.
You may build it in the crystal or VFO (varicap) controlled version. The receiver is a direct conversion design.

DSB_RIG (PDF file - 100 Kbytes) 

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cwdec2_qst.jpg (269280 byte) Although designed primarily for learning CW, new and experienced CW ops are sure to like this simple and inexpensive CW decoder.
The decoder uses a  PIC16F84 microprocessor and a NE567 PLL as analog interface. The software automatically adapts to incoming CW at speeds between 5 and 30 WPM.
The circuit has been published in QST and appeared on the cover as reproduced here.


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A PIC16F84 based programmable micro-counter, the ideal complement for your next QRP transceiver. The counter will read frequencies over 40 MHz and needs only 15 mA of current. It is also possible to connect a prescaler with several prescale ratios, in a word.... it should be a pity not to build it 

PIC_FREQ (PDF FILE - 60 Kbytes)        

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qrp1_40.jpg (33655 byte) A simple CW QRP Transceiver for 40 meters band. The TX and RX sections are independent modules and may be built separately. Among the main features are :
5 W output power, Full break-in,  superhetherodyne receiver, four crystal ladder filter, full coverage of the band with a varicap controlled VFO and SSB reception capability.

QRP 40 m (PDF FILE - 100 Kbytes)

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qrp20_1.jpg (37232 byte) A 20 meters CW QRP Transceiver.
Only a little more complex RIG, but  you'll find  again RX and TX independent modules.
Main features :  5 W output power, Full break-in, superhetherodyne receiver with MOSFET RF and mixer stages, four crystal ladder filter, AGC and CW band coverage with   a conversion varicap controlled VFO.

QRP 20 m (PDF FILE - 100 Kbytes)

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dds.jpg (212136 byte) A 'next generation' VFO wich makes use of the DDS technology. It is equipped with an AD7008 DDS from Analog Device and an  ST62 microprocessor from Thomson, the frequency and the tuning step are shown on an LCD display. An ideal addition to your next professional transceiver.

VFO DDS (PDF FILE - 300 Kbytes)

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A "partial synthesis" VFO using the PLL technique, if you want to abandon the classic "free" VFO, but without excessive trouble, this project is for you.

PLL VFO (PDF FILE - 100 Kbytes)

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A simple frequency reader you may employ with a classic conversion VFO or to replace the mechanical tuning in some older RIG

CMOS Reader (PDF FILE - 120 Kbytes)

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designed by Francesco Morgantini IK3OIL