CW QRP TRANSCEIVER UNDER $40

AN OLD PICTURE. NOW A SMALL SPEAKER IS IN TRX CASE:

VIDEO OF READY PROTOTYPE:

 

WCA ACTIVITY - LZ CASTLE ACRA - 2016

BACK OF TRX:
BNC antenna in/out, gain control pot, power cord, and arduino cable in/out for further extension if need, audio output after LM386, cw key input.

TRANSMITTER - half part from Chinese Forty9-er, with mods by Dr. Jack Purdum, W8TEE; Farrukh Zia, K2ZIA; Dennis Kidder, W6DQ, and LZ1DPN

1-st 49-er mod:

2-nd 49er mod:

DDS - > ARDUINO + LCD + AD9851
designed from AD7C and VK8BN :

DDS RF buffer + Power Supply 12V/5V :

RECEIVER
Direct conversion receiver designed from SM0XGY :

TX/RX RELAY CONTROL

AUDIO
Audio amplifier with LM386 (from somewhere in internet):

I'm use a Chinese Forty9-er from eBay , and receiver developed by SM0XGY, in his web site

http://www.waveguide.se/?article=ne612-receiver-experiment

Please, read the entire document: Purdum0316-QST-in-Depth-AssemblyManual.pdf

All changes are based on it. And I'm make few modifications in schematics from this pdf.  This PDF I've use only to assembly "Chinese" Forty9-er, because I'm build other DDS oscillator (not this from original pdf). Respectively,  My arduino code is modded on the basis from AD7C and VK8BN sketch.

In Chinese Forty9-er scheme, I finally change the count of LPF winding to run from 0 to 30 MHz  Remove several winding from L4 coil,  and replace 2 capacitors C17, C18  to 100 pF  (I don't remember now exactly, but I made LPF from 0 to 30 MHz, with an online calculator).

I also remove the consistent LC group (scheme LxCx - 1st mod in top pictures),  which replaces quartz and put a wire to bridge, to eliminate interruptions in his place.  And also remove the capacitor before quartz, to stop any frequency filtering.

After many tests I'm replace the both end transistors (in driver and PA) in transmitter stage: for Q6 - 8050, I put 2n3904, and instead of Q5 - D882, I am use BD139 with heat sink (not provided in the kit). I'm burn many BD139 and now use in ColectorEmmiter end 43V Zener Diode to protect end transistor.

ALL DATA FILES, PICTURES, LIBRARIES AND SOURCES YOU CAN DOWNLOAD HERE:

https://github.com/LZ1DPN/CWTRX0to50MHz-v1/

73 ES MNI DX'es!LZ7DP

RFT SEG-100 TRANSCEIVER ARDUINO RIG CONTROL VIA USB/SERIAL PORTS

Main arduino code (sketch) of this project is developed by Richard Visokey AD7C - www.ad7c.com.  Second revision is developed by VK8BN , to adding AD9851 support.

My revisions are:

Revision 3.0 - April, 2016 - AD9851 + ARDUINO PRO NANO + integrate cw decoder (uncontinued version).
Revision 4.0 - May 31, 2016  - deintegrate cw decoder and adding button for band change.
Revision 5.0 - July 20, 2016  - change LCD with OLED display and adding IF frequency support - now ready to control transceiver RFT SEG-100
Revision 6.0 - August 16, 2016  - software terminal support to control rig from computer with USB/serial interface. (Control buttons: 1 - up freq, 2 - down freq, 3 - step increment change, 4 - print state,  also add no_display support in DDS generator, for any computer terminal software.)

The scheme realized with OLED display and needs source code from file: ad9851oled.ino program sketch.
  
SOFTWARE REQUIREMENTS:

You need to install next libraries:

AdafruitGFXLibrary
AdafruitSSD1306
Rotary


HARDWARE REQUIREMENTS:

You should also to use a program to find the hardware address (hardware break) of the display. Usually it is on 0x3C and the program was written for this address, but they are will be other if You have/use other devices with arduino board. If the display don't show anything - this will be one reason. In zip file are special software - i2c_scanner.ino, who can detects the hardware addresses of I2C devices - use it.

 With OLED Display support: 

4 pins are used:

+5V - directly from Arduino 
GND - again from Arduino
A4 - Analog I/O from Arduino to SDA pin on oled display
A5 - Analog I/O from Arduino to SCL pin on oled display.

IF frequency is experimental measured from LSB signal of transceiver on 7 MHz. In  CW working actual frequency is shifted by about 1 kHz.(On CW, what's on the screen is less 1KHts with the actual frequency - if You are in 7005 on the screen, You are actually on 7006 kHz). In this version IF is set hardly, but can be done to change according to the type and scope of work (least according to the scope LSB / USB), which to me now not need. In above of 12 MHz My RFT trx is not tunning, whether for, or because from hardware limitations in LPF or BPF - it's not clear merged, but I'm not think/time to brighten now.

TRANSCEIVER SIDE:

You need to open RFT SEG-100 and unscrewed the top cover is evidence SMC connector (the pictures shown where) and fed directly the signal from DDS to the cable connector.

ARDUINO + AD9851 + DISPLAY 

This schema (with LCD) is developed by AD7C and VK8BN:

CONNECTION OF DDS WITH TRANSCEIVER:

Output from DDS to input of transceiver is realized with this schema:

 

ALL DATA FILES, PICTURES, LIBRARIES AND SOURCES YOU CAN DOWNLOAD HERE:

https://github.com/LZ1DPN/DDS-RFT-0-30MHz-v1/


ALL PARTS YOU CAN BUY HERE FOR ONLY ~ $21 TO ~$30 

http://www.ebay.com/itm/401090347198?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.com/itm/AD9851-DDS-Signal-Generator-Module-0-70MHz-2-Sine-Wave-and-2-Square-Wave-/311589687675?hash=item488c31517b:g:SGQAAOSwJQdXDIgs
http://www.ebay.com/itm/222113825031?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

73 ES MNI DX'es!LZ7DP