QRP MINIMA DIGITAL BOARD

 

A complete logic to a all-band sw transceiver.

55 cm2   115 mA       Lo included  10 MHz - 260 MHz   around +16 dBm out.
I use a Spark-Fun Breakout board, i do not have RS232 on my computers.
I don't think the the pcb was aimed for adapt directly back of the lcd, but i find it possibility to do that, no wires just connectors.

I am really glad i came in to this project, Minima.
I used the test for LCD and I/O from AE5PH a few minutes after ended the soldering all is completed tested. I program in 10MHz, 3,75+20, 17.2 +20?   and 28.4+20 MHz for test.

I spend last weekend to measure the spurious, output level, and later phase noise.
I started this blog with the DDS-60 so i compared this to the Si570 unit.

Si 570 was around +16 dBm from 10MHz - 260 MHz. (10 dB atten to instrument)
DDS60 was 8.5 - 6 dBm out, 10 - 48.4 MHz

I use my home-breve spectrum analyzer.

And here is some phase nose measurements.

Si570  f = 10 MHz, Fnoise = 149dBc @ 10 kHz offset.

Si570  f = 23,75 MHz, Fnoise = 145dBc @ 10 kHz offset.

Si570  f = 37,2 MHz, Fnoise = 138dBc @ 10 kHz offset.

Si570  f = 48.4 MHz, Fnoise = 138dBc @ 10 kHz offset.

Si570  f = 144,3 MHz, Fnoise = 129dBc @ 10 kHz offset.

i think it is a relay good value.

DDS60 f = 23,75 MHz , Fnoise = 123 dBc @ 200-300kHz offset.

Here is the spurious list for Si570 @ 23.75 MHz

374665,-105.567

2.97076e+006,-105.015

3.30659e+006,-84.054

3.48848e+006,-105.268

4.47881e+006,-101.74

Nice values.

Here is the spurious list for DDS60 @ 23.75 MHz

432.174,-104.615

651.559,-105.865

866.931,-107.598

8217.29,-106.33

16483.7,-91.9783

19704.9,-94.6973

33065.9,-91.1369

38828.2,-93.0068

40964.1,-98.8106

48969.1,-78.3117

65155.9,-91.3816

83652.8,-84.6034

100000,-81.2614

115349,-84.2683

148096,-82.02

180225,-83.4377

197049,-79.2568

227295,-80.9892

248513,-71.561

297076,-77.092

342676,-72.7429

395275,-80.2696

424529,-80.6772

447881,-75.4794

545047,-80.7331

712382,-75.0742

738273,-74.7648

836528,-76.63

1.23886e+006,-75.5836

I also check the Output Z.

Si570 was 13 ohm  from 10MHz - 150MHz.

DDS60 was close to 50 ohm at 10 MHz and little higher @ 48.4 MHz.

I have never test so mutch on a LO signal, i enjoy to build and measure. 

No i lock forward to start with the main board next weekend.

This is the schematic for this PCB.

Thanks to Ashhar Farhan the designer.  

Thomas Sarlandie driver for Si570.

PP2KR Kleibe PCB-Maker, tanks a lot.