Monthly Archives: April 2014

Bandscan demo of my 40m direct conversion receiver

Here it is, folks, my latest accomplishment —  the refurbishment of my 40m direct conversion receiver, the “Mrad-40”.  See a YouTube of it (and me): Mrad-40 A few notes on it: I’m getting BAD shortwave broadcast breakthrough.  I’d put a … Continue reading

Posted in direct conversion, EMRFD, Mrad-40 | Leave a comment

Manhattanizing the Mrad-40

I’m almost done with my little Mrad-40 rig.  I didn’t get to work on soldering it into the box as much as I wanted to this weekend but tonight I almost finished it.  The troubles I’m having now are mostly … Continue reading

Posted in manhattan style, Mrad-40, QRPMe, TAPR VNA, transformers, VNA | Leave a comment

Test drive; pi network sim + measurement

What a fun night! I decided to hook up the existing NE602/LM386 circuitry as a “test drive” of my VFO (the circuitry that was in the old version of the MRad-40, on 2 pieces of perfboard).  It worked!  Although with … Continue reading

Posted in Mrad-40, pi network, Puff, TAPR VNA | Leave a comment

Oscillator honesty from ARRL; buffer and amp – dead JFETs

Let’s make the embarrassing confession right here at the beginning: Very few oscillators you see in published circuits or commercial equipment were designed by the equipment’s designer.  Almost all have been “Borrowed,” “Re-used” or just plain stolen.  While recycling in … Continue reading

Posted in amplifier, ARRL Handbook, buffer, Hartley, Mrad-40, oscillator | Leave a comment

Final VFO design for the MRad-40

First, if you haven’t already, please check yesterday’s posting about your favorite QRP/homebrew radio resources and leave a comment!  I got great comments already from Steve VE7SL but I KNOW many more people have read the blog since then!  Please … Continue reading

Posted in direct conversion, Hartley, Mrad-40, VFO stability | Leave a comment

What are your favorite homebrew radio groups and lists? Publications?

I know I get a few views on my blog each day, according to the blog stats.  So, I thought I’d pose you all a question.  Where do you go for the latest in QRP/homebrew radio news, Q&A, etc? About … Continue reading

Posted in Hackaday, Make magazine, QEX, QRP-L, SPRAT | 3 Comments

Is 1 Hz/hour good stability? :)

I’ve recorded and plotted data on thermal stability for versions 3 and 4 of my Hartley oscillator.  Below is what I got: V3.0 was the well known basic JFET Hartley circuit from EMRFD (as mentioned before) using a 50-6 toroid … Continue reading

Posted in EMRFD, Hartley, oscillator, VFO stability | Leave a comment