Homebrew 5 Watts 40m CW Transceiver Using TIA Amplifiers. Si5351 Based Superhetrodyne Receiver

All design ideas from the EMRFD book. Thanks to W7ZOI, KK7B, W7PUA. And i'm blessed to get this book in India at a second hand book seller. I told him to reserve any radio related books, one fine eve he called me about this book. I also bought ARRL 2011 book. If i'm not using the design concept from this book, then its a shame on having the book. So, here is my QRP Project..

1st design requirement is, front facing 4" speaker. No compromise.

I wanted this to be a self powered, no need to search for DC adapter. The transformer salvaged from old HI-FI cassette player. 15V 2A. I used 12V regulated power supply for TIA chain. Rest using unregulated 17V. 

Close up view

From right >> RX/TX antenna relay >> 40m BPf >> 1st TIA amp >> VFO diode ring mixer >>10MHz ladder filter >> 2nd TIA amp >> 10MHz BFO >> 2nd diode ring mixer >> 2N2222 preamp >> audio power amp >
ULN2003 for all relay switching

Transmitter stage. >> 2N2222 >> BD139 >> 2SC1971 >> 5th order LPF . 2SC1971 gives spurr free 5 watts clean output with 17V 2A. I connect SI5351 clock output directly to 2N2222. All are TV balun cores. Cause thats what i have.

Side tone oscillator , Power supply and audio amplifier close up view

This is my own SI5351 clock generator board using ATMega8. ( I Hate arduino. ). I'm using C language in this project, but assembly version is in progress. You can find details about this PCB on this blog, look for SI5351 DDS board..

The speaker is from old National Panasonic cassette player. Excellent audio quality.

 

Etched TIA Amp board, i made about ten PCBs for future uses. Around 1" x 1" approx

Initial layout. Modular PCB system makes very easy to assemble and troubleshoot.