SDR (Software Defined Radio) HF Receivers and Transmitters SSB/ CW/ AM/ FM .... based on 74HC4066 IC from 30 kHz to 70 MHz

    SDR is future of radio, maximum flexibility a lot of possibility from the same hardware, what was very hard to achieve with hardware realization now is very easy by software  This is series of three parts, three articles are:

Parts 1 contain very simple receiver DR1 without image rejection receiver very simple but good start with the SDR receiving. This receiver was discovery for me and I spent a lot of time in testing and listening with it in different circumstances. It can be realized for the very short time for the one afternoon and it is very cheep. Present of image are not a big disadvantage like in DC direct conversion receivers but something about that later. This receiver can be used as a second or first IF in receivers after crystal filters which very easy reject unwanted image also. As demodulator it is far superior to the all other types common used demodulators in practice. I never didn’t measure S/N ratio in HF CW receiver 80 dB before it.  DR2 is also very simple and very good I/Q HF receiver frequency are limited to the 30 - 35 MHz with built in components.

HF SDR RECEIVER CW-SSB-DRM YU1LM.pdf

Part 3 SDR HF receivers DR1A (Advanced) similar to the DR1 but with improved specifications the same situation is with DR2A and improved DR2 and transmitter DT2A. Practical experience and answers on questions.

FINAL HF SDR RECEIVERS, TRANSMITTER YU1LM.pdf

 

 

  

SDR HF receiver DR2A first version built by Batko YU1OL  

SDR receiver DR2A built by Rahul VU3WJM

    

SDR receiver DR2A built on proto-board by Tuji JH3JMT    

 

SDR projects built by author Tasa YU1LM/QRP    

SDR HF I/Q S/H (Sample and Hold) Receiver - DR3X from 30 kHz-35 MHz  for 3 bands harmonically related with 1(one)  XTAL 

    I made local presentation of mine SDR projects  Audience was very surprised with very good received /demodulated  signal  quality, crisp and clear sound like HI-FI (high fidelity) not common for the most commercial RIGs. They were surprised with design simplicity also. SDR possibilities such as adjustable selectivity, noise reduction, NB noise blanker; waterfall, wide and narrow monitoring at the same time  … were discovery for most of them. Local HAMs first excitements with new SDR techniques ware replaced with some kind of  disappointment because most  HAMs like to tune LO (local oscillator) all over the working band .They aren't satisfied with +/- 20 KHz with fixed LO. I proceeded with mine SDR experiments and here is my solution to improve possibility of simple HF SDR receivers. DR3X receiver is  design now with 74HC4053 IC It enable  3 band receiving harmonically related with single oscillator. Of course all 3 bands  receiving is  without any input filter and realization is with an classic through hole size components.

DR3X HF SDR RECEIVER-YU1LM.pdf

SDR HF I/Q S/H (Sample and Hold)  Receiver - DR2B  from 30 kHz- 35 MHz with external LO (local oscillator)

    DR2B receiver PCB is product from DR3X receiver. Here  is one of 3 possible connection for DR3X . It is connection for external local oscillator with new PCB, it is very small compared to the original DR3X PCB. This receiver is similar very much to the previously published DR2  but even simpler.

DR2B HF SDR RECEIVER-YU1LM.pdf

DR2B SDR receiver built by Ramaz 4L7AR

DR2B HF SDR receiver built into SDR transceiver built by Jarka SP4XYD www.sp4xyd.republika.pl

SDR HF I/Q S/H (Sample and Hold) Monoband Receiver - DR2C from 30 kHz- 50 MHz with LO at working frequency

     After I made DR3X I decided to  try and enable mono-band  SDR receiving from 30 kHz to 50 MHz with LO working at receiving frequency. Here is my SDR  RX design realized with 74HC4053 IC also. This design is  good challenge to be build inside existing RIGs as parallel IF and demodulator. This solution is giving  advantage of use SDR signal processing through SB (sound blaster) card in PC . Better SB card give better possibility and better audio quality.

Monoband SDR HF receiver DR2C-YU1LM.pdf

First version of DR2C built by Miki YU1KM

DR2C SDR receiver with new PCB( combination SMT and classic size componnents) built in ICOM IC910 transceiver by Eduard UA4NX http://ua4nx.qrz.ru/SDR_910H.htm

   

HF SDR receivers DR1A and DR2 built by Miki YU1KM

  

SDR receiver DR2 built by Volker SM5ZBS

DR2 SDR Receiver soldered by my sons Stefan, Andrej and Bojan

DR2 SDR receiver built by Denis UN7DAQ 

DR2 SDR receiver built by Jean F1BEM

DR2 SDR receiver built by Danil UR3VCD

 WINRAD screen shot from YU1LM/QRP DR2A receiver on 7 MHz in RDA contest 2006

PowerSDR screen shot from YU1LM/QRP DR2A receiver on 7 MHz in WW CW contest 2006

SDR HF I/Q S/H (Sample and Hold) receiver- DR2D from 30 kHz- 50 MHz

    The DR2D is DR2B and DR3X modification . The DR2D is I/Q HF SDR receiver with possibility to work with 2 times higher LO frequency. This design is my attempt to help to all SDR fans who are using AD9850 DDS LO. With 60 MHz output LO frequency it is easy now to receive 30 MHz at RX input. This design is making small phase error which we can compensate in software or by hardware adjustment. Optimum design is possible for input frequencies lower than 15 MHz where RX dynamic is much important performance.

DR2D HF SDR Receiver YU1LM.pdf

SDR HF I/Q S/H (Sample and Hold) receiver - DR2-2 from 30 kHz- 35 MHz

      DR2-2 is DR2 modification .The DR2D is HF SDR receiver without any RF parts no coils only R,C and  cheap ICs but with outstanding performances. This design is my a small attempt to enable everyone to build very good HF receiver without any knowledge, measuring instruments except DMM (digital multi meter) only with small skill for soldering. New design is also design simplification compared to the original one.

DR2-2 HF SDR Receiver YU1LM.pdf

SDR HF I/Q S/H (Sample and Hold) receiver - DR2E from 30 kHz- 35 MHz

     DR2E is DR2 modification. DR2E is my attempt to improve previously published and realized DR2 design and overall specifications. DR2E has a new post detector amplifier realized as instrumental OP AMP.

DR2E HF SDR Receiver YU1LM.pdf

DR2E SDR receiver built on proto-board by Loic ex F6DEB

Additional measurements  on HF SDR S/H receiver DR2A with & Norbert DG1KPN

   I made a lot measurements on my  SDR and other designs and they consume  a lot of mine free time specially in attempt to improve some performances. Of course it is possible always to do some new  measurements. OM Norbert DG1KPN made some new one and we exchange few E-mails to improve DR2A receiver performances if it is possible .SDR S/H receiver DR2A has the best specifications from all my SDR S/H receivers.

DR2A additional measurements YU1LM&DG1KPN.pdf

DR2A SDR receiver built by Norbert DK1KPN 

DR2A SDR receiver built by Sergej RA3AJK

DR2A SDR receiver built by Philippe F1JRV

Correction for YU1LM previously published SDR designs

    I made a lot of designs and I am  trying  to do best from my side always. I made some mistakes because PCB and schematics are not done one from other. I made this two activity separately because PCB design in CAD not satisfying me with results which it made automatically. This is reason why I hadn't always good correspondence between each other. Also sometimes I made some correction on my realized PCBs before publishing and I accidentally  made some errors trying to do design better. I have ask all readers and homebrew apologize for  inconveniences  and ask all to help me and other homebrew fans to find them. I made check few times but mistakes obey Murphy low and it is hard to prevent them.

YU1LM SDR designs correction- November 2006.pdf

SDR HF I/Q S/H (Sample and Hold) receivers - DR2A+ and DR2A++- from 30 kHz- 35(52)MHz

    The DR2A SDR RX is my receiver with best overall specification. I tried to make good design even better. The achieved results with new DR2+ and DR2A++ are very good or better excellent. DR2A++ SDR receiver has now DR (dynamic range) IMD3 free close to the 100dB with SMD substitute Philips IC 74LVC 4066. DR2A+ is SDR receiver with single voltage supply and DR2A++ with dual power supply to obtain max specification.

SDR RXs DR2A+ and DR2A++-YU1LM.pdf

SDR HF I/Q S/H (Sample and Hold) receiver - DR2G from 30 kHz- 70(100) MHz

     The DR2G is my first completely SMD SDR receiver based on use SMD 74HC4066 or new better 74LVC4066 from Philips. I made very simple construction but with very good specification. The double side PCB was designed at that way that  it can be realized at home without metallization via-s. With all new 74LVC... components it can work even at 100 MHz!!!

SMT SDR RX DR2G-YU1LM.pdf