Tag Archives: Regenerative Receivers

Email prompts Bill to pull his regenerative receiver off the shelf!

Many thanks to SWLing Post contributor, Bill Meara who shares the following article from the excellent SolderSmoke Podcast blog:


2014 “Off the Shelf” Regen Comes Off the Shelf (Two Videos)

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:

https://soldersmoke.blogspot.com/2014/09/schematic-for-off-shelf-regen.html

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.

Read this post and more on the SolderSmoke Daily News!

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Ron reminds us that MFJ still offers a shortwave radio kit

Following up on our recent MFJ post, SWLing Post contributor, Ron, writes:

Another thing about MFJ is they still offer the MFJ-8100 as a kit or built. This is the only regenerative receiver available as far as I know.

Mr. Jue and his guys did a couple of tweaks like limiting band coverage to insure stability, using 1/8 inch 3.5mm stereo phone jacks and use an LM386 audio IC to drive headphones or speaker.

The whole thing is in a metal enclosure to minimize hand capacitance found in most regens.

The QRP crowd likes to use the 8100 with flea power CW rigs, it’s that good.

And it’s been in production far longer than the Heathkit GR-81 or any of the Knight Kit regens, too.

Thank you for sharing that, Ron! I had completely forgotten about this little kit when someone recently asked about the availability of Ten-Tec regen receiver kits (that are, sadly, no longer on the market to my knowledge)! I might have to grab one of these kits–looks like a fun one to build.

Click here to check out the MFJ-8100K.

By the way, I also believe the NM0S Ozark Patrol regen kit is still available from the Four State QRP Group. Click here to check out the product page. It doesn’t have a metal enclosure like the MFJ, but it’s also a fun kit to build.

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Bruce’s passion for SWLing and single transistor regenerative receivers

Many thanks to SWLing Post contributor, Bruce (VE3EAR), who shares the following:

I live in the village of Saltford, ON, Canada, near the eastern shore of Lake Huron. It’s a quiet location signal wise, and I’m lucky that I have enough property to erect some big antennas. My two favourites are a 1200 foot long terminated Beverage, aimed at 50 degrees true, which targets Europe and the UK. The other is a 333 foot perimeter delta-loop, apex up and oriented north-south. Both antennas are fed with RG-6 coaxial cables and impedence-matching transformers.

I use the loop with a recently acquired Airspy HF+ Discovery SDR and the Gqrx SDR software, in my iMac. I like to listen to amateur activity on 160, 80, and 40 metres, along with the few shortwave broadcast station that are still on the air. I also like to listen to the trans-Atlantic air traffic control stations in Shannon, Ireland and Gander, Canada.

I once heard a U2 spy plane returning from a mission over Russia!

My other hobby is designing and building simple, one transistor regen receivers, most of which tune the AM broadcast band, although I have built a couple covering the lower portion of the HF broadcast bands as well, just for a challenge. All my receivers are built breadboard style.

My favourite of them is one based upon the Vackar oscillator, with the addition of a diode detector and “Benny”, as is used in crystal radios.

Here is the schematic of the Vackar circuit:

The diode and “Benny” connect to the collector of the transistor, then to a pair of home made headphones using two telephone earpiece elements installed in a pair of hearing protectors. The receiver is both very selective and very sensitive. Here is a pic:

Most of the electronics are on a proto-board, which allowed easy component substitutions during the build. When I had it optimized, I decided to leave it that way! The controls, left to right, are on-off switch, regen, fine tuning, main tuning, and range selector switch, hidden behind the reduction drive. Audio is taken from the DET OUT jack, to either the headphones described above, or to an audio amplifier for listening with a speaker.

Bruce, it sounds like you certainly have an excellent spot and excellent antennas for DXing! I love regen receivers as well and radio design can hardly be more simple.

Thank you for sharing!

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Video: EB3DYW’s Homebrewed regenerative receiver

While browsing a videos on YouTube, I stumbled across this demonstration of a brilliant little homebrewed regen receiver by Javier Guillaumet (EB3DYW):

Click here to view on YouTube.

What a beautiful little receiver!

Though I’ve build a number of receiver kits, I’ve never built one from scratch. Someday, I will muster up the courage and do so, though!

If you like home-grow regen receivers, you must check out Dave Richards’s Sproutie II regen receiver as well. A true work of art!

Post readers: Do you have any homebrew projects to share? Please comment!

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The KRC-2 shortwave regenerative receiver kit

KRC-2 shortwave regenerative receiver kit1

Tony Westbrook recently contacted me about a regenerative receiver kit he has designed and produced in the UK.  It’s called the KRC-2.  Here’s the product description:

1 – 30 MHz with band spread tuning.

Regeneration with a difference. The regeneration setting on the KRC-2 is unaffected by the receiver tuning or the antenna coupling. How do we achieve this? The regenerative stage is fixed at 10.7MHz and used as an IF amplifier. The main receiver board is extremely simple to construct using only one FET and an audio IC. Like all the KRC kits it comes with a comprehensive construction manual which brings this project well within the grasp of the keen constructor. It was referred to as “a very sensitive little receiver” by Rob Mannion of Practical Wireless. Its unconventional design and simplicity should amaze even the experienced constructor. Case size 7 x 4 x 3 inches. 6 x AA batteries supplied.

According to Tony, the kit comes with everything; UK orders are even supplied with batteries. Tony stated, “the only thing the customer needs is a soldering iron, solder cutters, etc.”

By request, Tony sent a few construction photos and three videos of the radio in operation:

Photos

KRC-2 shortwave regenerative receiver kit4KRC-2 shortwave regenerative receiver kit11 KRC-2 shortwave regenerative receiver kit10 KRC-2 shortwave regenerative receiver kit8 KRC-2 shortwave regenerative receiver kit7 KRC-2 shortwave regenerative receiver kit3 KRC-2 shortwave regenerative receiver kit2 KRC-2 shortwave regenerative receiver kit9 KRC-2 shortwave regenerative receiver kit6 KRC-2 shortwave regenerative receiver kit5

Videos

Video 1

Video 2

Video 3

Click here to view the KRC-2 and Tony’s other kits. 

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Dave unveils the Sproutie MK II regenerative receiver

SproutieMKII

My talented pal, Dave Richards, has built yet another home-brew regenerative receiver––which he dubs the Sproutie MK II––and wow, it’s a thing of beauty.

Dave tells me has been working on this receiver for many months, and upon viewing the following photos of it, it’s clear to see why he took his sweet time. As in his original Sproutie, a vintage HRO dial has taken pride of place as the centerpiece of his rig; it looks stunning.

But the Sproutie MK II is not only painstakingly-crafted on the outside; like Shaker furnishings, wrought for the eyes of God both outwardly and within, the interior of Dave’s receiver is equally well-crafted.

Okay, maybe that’s a little over the top…but if you doubt me, just join me in admiration of this board:

SproutieMKII-board

As for performance?  Of course, with such a clean interior, the Sproutie II performs like a champ.  Dave posted a few videos showing how his new receiver commands the airwaves and aptly handles AM, SSB, and CW.

That’s an amazing piece of kit you’ve created there, Dave!  Hats off to your incredible craftsmanship.

Check out Sproutie II on Dave’s blog, where you can read a full account of how he designed and built this gorgeous regen receiver.

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Video: Dave’s “Sproutie” home-brew regenerative receiver in action!

IMG_7321

My good buddy, Dave Richards (AA7EE), has just posted videos of his home-brew regenerative receiver–nicknamed “The Sproutie.” [You may recall an earlier post about this very receiver.]

Below, you’ll find a video where Dave tunes in broadcasters with The Sproutie–she certainly has ears!

Dave, that’s a simple, beautiful little radio you’ve built there.  I love the HRO knob–form and function at its best.

Readers: be sure to check out Dave’s full post about the Sproutie along with another video. If you haven’t yet, bookmark Dave’s blog–it’s a good one!

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