PA and Driver for next QRP Transciver

I has built a driver for the PA. I started to lock at “Building a Transceiver” by EI9GQ and G4LFM. Side 118 it has a promising setup of RD06HHF1. The test showed god result. Next step was to put it together with the PA. I has little more to do with the optimize power transfer from driver to PA, but it will work just to optimize performance. In The plot from VNA it was 30dB atten from the output to VNA, its means gain in driver is close to 20dB.

PA For next QRP station

I by this PCB from K5BCQ a long time ago. Now I hade time to build and test the performance and it locks weary promising.  I measured max 42.7 dBm out.  But I think 42dBm 16W is more ok to not stretch the PA to much. The flatness is better then -0.7 dB from 1.8 – 52 MHz. It means that the work with the output transformers is grate.

I waiting for driver transistor to put in front of this module. I will put info here as son I has test the driver.

Link PA description K5BCQ

A BP filter for my next QRP Transceiver

I came across this YU1LM interesting side a time ago. Really interesting result. I build tree of this filter to check the performance, and get very close to the description but I don’t use so accurate values, that’s way I think it is worse loss in the passband. But I will go for this type.

 I has also tested pin diodes and other diode to use as switch, BAT18, BAP70-3, BAP51-02, BA592, BAP50-04 and 1N4148, I chose BAP70-03. I have read that some has problem with IM product when using diodes my test don’t show up worse with diode compared to without.

 I use 2 generators and a hybrid combiner a generator G1 in passband -12 dBm and G2 to different frequencies to test for IM -70 - +17dBm. If there is IM product it is worse without filter, so I can’t blame the diodes for that.

dokument http://yu1lm.qrpradio.com/INPUT%20HF-6m%20BP-LP%20FILTERS%20FOR%20SDR%20TRANSCEIVERS%20-%20YU1LM.pdf

The Measurment.

Stay tuned I working on PA for QRP. 

de SM4HNG

Si5351

Small wonderful VFO and BFO

I get this PCB from SM5CJW nearly a year ago. 5 Component, 2 resistor I2C pullup  1 decoupling 100nF, the Si chip and Xtal 25 MHz. Work grate directly.

Earlier i use Adafruit  module, and NT7S sw for Arduino.

Stay tuned I working on a QRP Transceiver.

My DS15001

I order this before the summer. Last weekend it was time to solder the kit. After turning on the Oscilloscope I see the test signal a short time then the screen was dark. The adj is connected to encoder did not work in both direction. After google about this, I was shore the small pcb. was mounted upside down with the encoder. The behaviour was different but don’t work. After checking the schematics and measuring around the encoder it was shore the PCB was broken in one track to the encoder. After a strap all run nicely. I fixed a 9V NiCad Battery and a box for that.

Here is the troubleshooting Trouble

A video about the Osciloscope Video

Electronic

Electronic Compass

In the winter i spent time to test a sensor BNO055. This was a success it works from start, has built in tilt compensating and calibration. Only a few rows of code. It has two register  to read the current calibration state for system all sensors and magnetic sensors all values  > 0, gives correct directions.

Above photo, first digit is magnetic sensor status second is system status 0 – 3. My next try vas to integrated with Fox receiver and it also works., no effect of metal box.

I also try a sensor LMS303, but this this I can’t get to work.  I has cod to make tilt compensation and calibration. It doesn’t  give me 180 deg. Difference from N to S direction and also W – E so I lev it for now.

The BNO055 has been on two competitions, and the first direction after start was tree spot on and the other 2 just a few degrees off, it was a 80m fox-run.

See adafruit BNO055

POWER METER

This power meter is now finished. A port is LTC5532 and port B and C is classic AD8307. I make my own PCB for this, today you can by AD8307 from Ebay sold for a few dollar.

I connected a LCD display and Encoder. Draw 5V from Arduino Uno to all tree PM boards. Output from A to A0, B to A1 and C to A2.

Then little sw doing the work.

LTC5532 can’t find a formula so I use my generator for input and read levels by ADC and put a table on my serial port than past in to the code, like this.

if(u0>3.4604)

  P1 = 8.0;

else if(u0>3.3822)

  P1 = 7.8;

else if(u0>3.3040)

  P1 = 7.6;

…………..

else

  P1= -21.2;

Then port A is working.

Port B and C. use my generator put in 0dBm and -40dBm read the level in V0 – V40/40 = x V/dB around 23 – 37 mV/db, put it in the code.

if(port==1)   //Cal Port B

{

   for(int i=0; i<10; i++)

     a1 = a1 + analogRead(A1);

   u1= a1/10;

   u1 = 5.0 * u1 /1023;

   pmSet.cal1 = u1;

}

 

To get stabile values I average 10 times.

P2 = (u1 - pmSet.cal1)/0.0242  + pmSet.atten[1] + freqComp[1][pmSet.freq[1]];

pmSet.cal1 = u1 att 0dBm input, calibrated in menu.

pmSet.atten = attenuation infront off power meter 0 – many dB integer values, set in menu.

freqComp[1][pmSet.freq[1]] = freq compensation set in code, measurd by generator @ 0dBm on varying frequencys (16 pcs.).

double freqComp[3][16] = {{0,0,0,0.3,0,-0.2,-0.1,-0.4,0.1,2.9,1.4,4.0,3.8,6.7,12.5,10.4},…….

Unit can be set dBm or W, in menu. Convert to W

if(pmSet.unit == 1) //Unit W

{

  P2 = pow(10,(P2-30)/10); 

}

Jumping over to new project, magnetic compass and PA 1296 MHz, stay tuned.