Minima QRP Transceiver Setup

I won’t to describe a little off the process to get this Minima up and running. Early in the spring I set up this pc board to put main board and digital board connected, and to check tx and rx.

BFO.

First problem I could not hear any station clear SSB, I figured out that the bfo. was on the wrong side,  lo is over  f0, see BFO wrong. This is now changed so it is working.

Filter.

Next problem was filter 15-30 MHz didn’t switch in when move to 18MHz. I think it was hw problem check agene now fault. Time to lock at sw. and there it was, I added this line,

pinMode(BAND_HI, OUTPUT); ?

and now it works , original from Radiono - The Minima's Main Arduino Sketch.

Modulation.

The rx. woks fine listening on 80m. But tricky to get power out. I try to put out mic signal and ston, to modulate. The level at modulator is low. I have build Bitex or more exactly MKARS80 and it works grate from beginning, the difference is a emitter-follower. I build this on my board, it dossent effect rx level much.

Now I can have a grate signal on modulator.

Next the ston. is a bit low for monitoring, change R41 10 ohm to 22 ohm value sounds ok. But for modulation docent work. Try signal from T13 collector its much higher, but impedance in mic stage is to low so one possibility is to connect at mic input, I will fine tune later. I also change emitter resistor 220 ohm to a trim pot, 500 ohm, to adjust mic level

Button.

The SW. WA0UWH has made locks grate so I decided to install 7 buttons for the final setup.

I am now working hard to get the LP-Filter after the PA to work,

Theoretical loss and loss in practical. Stay tuned I will be back.