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This is likely about as good as it gets: ??

A few minor changes:

? The two diodes D15 D16 are now a single BAT54S, so the balancing pot at R105 is not not needed or stuffed.

? ?No C103, no L4, all BC849's are actually MMBT3904's.

That should be pretty close. ?Are you seeing anything else?

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Thank you for the PNG files of the schematics.?? Do you have the mechanical layout of those two boards dimensions and hole sizes and hole mounting positions (x,y in milimeters)?? I am creating a http://LibreCAD.org drawing for a Metal Box Enclosure and want to create a drill holes for mounting the boards to the metal enclosure.? I do not have a Bitx40 Kit, to just directly measure the board and create the CAD Layout directly.?? Thank you for your help with outer dimension of the board, and the hole sizes and the hole pattern layout in a x,y format in milimeters (or inches).? Sarma vu3zmv

Board dimensions:? It’s a bit larger than some of my existing 40m homebrew transceivers at 128 x 114 mm for the main board.? Is this correct measurement?

See files here:

/g/BITX20/files/Enclosures_Metal_or_Plastic/Metal_Box_files/Metal%20Box%20Files

/g/BITX20/files/Enclosures_Metal_or_Plastic/Metal_Box_files/vu2xes_Aluminum_Case

Photos of Hand Made Aluminum Case:

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected] group.

File: lcd_Metalbox_bottom.dxf

Uploaded By: Fred Finster

Description:
LCD Metal Box Bottom Half Aluminum Box for Bitx40 case. Kiran VU2XES http://bitxhacks.blogspot.com/2017/02/vu2xes-cad-files-for-bitx-box.html Holds the LCD in the front with holes for microphone, headset audio, Encoder Knob, Volume Knob

You can access this file at the URL:
/g/BITX20/files/Enclosures_Metal_or_Plastic/Metal_Box_files/vu3psz_Aluminum_Case/lcd_Metalbox_bottom.dxf

Cheers,
The Groups.io Team

Gentlemen,

I have looked at a number of schematics but do not seem to find the one matching the current Bitx40 R3 transciever being sent from India.

Could someone please point me in the right direction or send a link to the correct file(s)

Tnx,

PJH, N7PXY

No Raduino here, but do have a Nano to play with. ?Here's a code scrap to replace that final clause in doTuning() to give the tuning pot a bit of hysterisis. ?Perhaps somebody could try it out.

  // the tuning knob is at neither extremities, tune the signals as usual
  else if (knob != old_knob){
    static char dir_knob;
    if ( (knob>old_knob) && ((dir_knob==1) || ((knob-old_knob) >5)) ||
         (knob<old_knob) && ((dir_knob==0) || ((old_knob-knob) >5)) )   {
       if (knob>old_knob) {
            dir_knob=1;
            frequency = baseTune + (50l * (knob-5));
       } else {
            dir_knob=0;
            frequency = baseTune + (50l * knob);
       }
       old_knob = knob;
       setFrequency(frequency);
       updateDisplay();
    }
o
   tone(CW_TONE, sideTone);
   tone(6, 1000);

Also, if you want a 1000hz square wave on pin 6 as a test signal, just execute this line somewhere:

? ? tone(6,1000);

That sets up a counter-timer to continuously generate the square wave while the Nano goes off and does other things.

Shut it down with

? ? noTone();

Jerry, KE7ER

Thanks very much for this, John.

For the record and/or posterity, I was unable to get a full 1A from HF Sigs' board #869.

I turned both R136 and RV1 fully clockwise, then opened RV1 until the Fluke 87 showed 100mA. ?(Amp input; meter on the A/mA setting)

R136 had to rotate almost fully CCW to get a solid 7W output power on the WM-2 Wattmeter. ?The PA was only drawing about 740mA at that point.

The IRF510's heatsink was warm to the touch, and the resting current draw was up to about 150mA. ?I turned RV1 a bit CW so the 'warm' current was 100 mA. ?Current with a strong 'ahhh' and a solid 7W out still shows about 740mA draw by the PA.

I'll have a CARE package from Mouser tomorrow - I'll get the signal on the o-scope on the dummy load and check the output signal then. ?In the mean time, I have a solid, intelligible signal on the SDR receiver now - thanks for that!

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Has anyone succeeded with adding CW properly? I have seen several possibilities on here, but no working examples. If yes, how did you do it? Or is it just impractical, like making milk from chalk and water? I was planning to at least inject a tone from a simple circuit for antenna tuning. But I took down my friends G5RV jr. in favor of a better 40 meter only dipole. No tuner needed for either end of the band. A 20 watt BITX CW signal could be a lot more successful than my MFJ-9240 CW transceiver which is about 6-7 watts, and works great for QRP. ??

I am sure a narrow audio filter switched in, would be helpful for focusing on a signal. But how do you put a signal smack on the tuned frequency without rebuilding the whole thing?

On a side note, I used my tablet to generate a 1khz tone, and held the mic to the tablet speaker to check the SWR while adjusting the antenna tuner. Worked great when I had that other antenna up.