Honorable Mention: Steve AA7U's Dead-Bug Direct Conversion Receiver

 

That receiver is a thing of beauty.  Steve AA7U is 78 years old and retired from the electronics industry.  Now he does this just for fun.  

Look closely at Steve's board.  No pads!  That, my friends, is the dead-bug technique.  It is closely related to Manhattan style, but many builders prefer it.  You see it in a lot of builds by Wes Hayward W7ZOI.  I have some stuff built by Farhan using this technique. 

You will also notice the absence of the PTO screw/coil.  Steve made his receiver fixed frequency.  But a member of the group has sent him one, so Steve may soon be tuining around the 40 meter band.  FB. 

But all four stages are there.  And Steve did for us a lot of useful analysis: 

Steve writes:  

Hi Bill,

Attached is a picture of my DCR build. I used a fixed VFO since I don't
have a 3D printer (but just learned two folks are offering the printed
coil and have just ordered one). Mine is set for about 7130 kHz. I'm
using the cheap eBay Chinese audio transformer 1300 ohms. I've done
bench sig gen checks for weakest CW signal I can hear with headphones, 
swapping out different DBM diodes. 1N5819 -130 dBm; MCL ADE-1 mixer -129
dBm; 1N5711 HCD diodes -127 dBm; 1N4148 -130 dBm. My LO output was about
+6 dBm. Note the proper way to check LO output is to disconnect from the
DBM and terminate the LO with 51 ohms and measure the RF AC voltage
across the proper nominal 50 ohm load, then convert to Vrms and use an
online volts to dBm converter to get the LO power. Looking at the LO
voltage connected to the DBM does not give a correct LO power reading
(SSD and EMRFD also mention this). I see Dean's latest BPF comments
(where I learned of the audio amp R14 100 ohms vs. 10 ohms typo)
mentions the bypass cap on the LO jfet to increase LO output. I tried
that  yesterday and my LO output across 51 ohm load is now about +10.5
dBm (from the original approx +6 dBm) . The actual 8.2V zener diode
voltage directly affects LO output too, I tested 10 diodes, the lowest
was 8.05V, highest was 8.35V--higher voltage of course gives higher LO
output.

Here's one eBay seller of the inexpensive audio transformers I used  
https://www.ebay.com/itm/356127836595

(I'm 78 and retired from electronics, now do it for fun and hobby; I
have a modest bench of test gear--various Siglent stuff including
spectrum analyzer, etc.   I've been homebrewing stuff for many years.)

73,

Steve AA7U

Thanks Steve and ongratulations!