Walter KA4KXX spotted an error in the schematic of my 2014 "Off the Shelf" regen receiver: The source resistor on the MPF-102 should be 2200 ohms, not 2.7 ohms. See:
Walter's e-mail caused me to take this old receiver off the shelf. In this video you can listen to it in action on the shortwave broadcast bands. In a second video I put it on the 40 meter ham band and listen to some SSB.
Geoff N6GWB and his eldest have produced a really wonderful receiver, and have joined the elite ranks of those who have built their own receivers. Congratulations to both! ( Be sure to watch the video below.)
Geoff writes:
Though I built it, my eldest has retained naming rights. Behold the Rad Radio Receiver, an Soldersmoke inspired build. It’s a 40m DC reciever. I had planned on making this a truly 50-50 N6QW N2CQR build, but I needed to get it done for a show and tell this Wednesday. I have N6QW dual JFET RF amp and mixer modules. I have the N2CQR ceramic ocillator circuit from the 2017 DC receiver project. I had planned on including the all analog audio amp from the more recent N2CQR DC project, but alas, time got the best of me. I was hoping to make the whole thing all-analog. (I thought the all analog would get me more “hard work” kudos at the show and tell.) I ended up including a LM386 audio amp making this a bit of a cyborg.
I have included pictures of the receiver open and closed. The closed pic includes bespoke decals. I have also include a brief movie demonstrating the audio.
Many, many thanks for the inspiration and knowledge!
I picked this transceiver up at Winterfest for one dollar. 40 meters. Superhet receiver with 455 kc ceramic filter and 2 NE602s. Crystal controlled one watt transmitter on 7039.5 kc. I emailed Jeff KA2BKG and asked him to slide up a bit to my freq. I am glad he did. Thanks Jeff.
FB Justin! I really like the board that you are using as a base for the project. And you have some great mentors in Nick and Loren.
It is wonderful that you have that receiver working. But I would tweak and peak quite a bit before taking on the transmitter. Get a decent outside antenna -- even a dipole or a 1/4 wave with counterpoise would be a big improvment. Like this one:
And try to square away the grounding on the board (maybe some copper tape from Amazon) and the power supply you are using (I hope it is not one of those noisy wall warts). When you are experimenting, it can be useful to power varous stages with 9V batteries -- this is a good way to find out where noise is coming from. If your AF amp is squealing at 12 volts, you need to break the feedback loop that is leading to oscillation. Often the feedback is through the power supply. Finally, try to get that homewbrew crystal filter working -- if the bandpass is uneven, you just need some impedance matching at the input and output.
Great work Justin! Keep at it. 73 Bill
Bill,
I am sending video and pictures of my 40m superhet that I built. I have it on the floor in an extra room in the house. The antenna is a stock vhf dipole that came with my rtl sdr which I use as a spectrum analyzer. In one of the clips I am receiving RW7K. I have been working on the station for the past year with help from Loren Moline, WA7SKT through texts when I have a problem. The LO / VFO is from Nick Woods Videos.
Next, I will build an outdoor antenna and the transmitter section. I first started homebrewing at the beginning of the pandemic, but this is by far my largest accomplishment. I would like to thank you and Pete for the soldersmoke videos which have been a great inspiration.
I will send more updates when the transmitter section is finish along with a much longer description of the projects
Thank you
Justin Elliott AC8LZ
Bill, Pete, and Dean
Thank you for the compliment. Pete, I want you to know, I’m a huge fan and I enjoy the one-liner jokes. I enjoy your contributions to the videos when you’re on Dean.
Here are pics / videos of my superhet.
The bandpass filter is a homebrew version of qrp labs design for 40m, I had to add an extra capacitor to get the bandpass where I wanted it. It is 6.9mhz to 7.32mhz.
Mixer / demods are ade-ask.
The rf amps are kits i bought online, assembled, then used the schematics to replicate. They are the W7OI created and which have been mentioned on the channel
The LO/VFO are arduino driven from Nick Woods (M0NTV) YouTube channel. I believe episode 26
The crystal filter was built for 9MHz, but when I swept it I found the bandpass was saw toothed, so I used a commercial filter that Loren Moline WA7SKT sent.
The audio amplifiers are a Common Emitter Amp I found on YouTube, I can’t recall the channel and a commercial amplifier, which I can now reproduce as I have the schematics.
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