"The Talking Doll"A 40m Regenerodyne Receiver by AA1TJ
An interesting circuit appeared in the April 1961 edition of CQ Magazine; "The RXT-2," by W6MMC. This was a 40m regenerodyne receiver using three Philco transistors and one Raytheon CK-768.
http://web.archive.org/web/20101124023555/http://aa1tj.com/thetalkingdoll.html

"The Virgin" A DC 40M Receiver by KK9JEF
My first HF receiver project is complete.
It’s not fancy. It’s rock-bound with no ability to QSY. It only has a single RF gain control up front. It’s direct conversion, so it hears all signals on both sides of its frequency.
https://kk9jef.wordpress.com/2016/02/29/the-virgin-a-dc-40m-receiver/

12BH7 single Direct conversion receiver by JF1OZL
I picked up many valves on the broken TV-sets on the street about 30 years ago. I got many 12BH7A on them. In these days (in the end of 1990's) I made a radio to receive 7MHz SSB and CW signal with these valves stocked.
https://www.qrp-ja.net/jf1ozl/12bh7single.html

12BH7A two vacuum tube direct conversion radio by JF1OZL
Sometimes I introduced on the Japanese CQ magazine that some vacuum tube can be used by 12VDC on its plate voltage. That of December 1992 I introduced pair of 6BM8; 7MHz super radio.
https://www.qrp-ja.net/jf1ozl/12bh7.html

2 types of 2 transistor 7MHz radio by JF1OZL
I will show you two types of 7MHz radio. Both types are single conversion super heterodyne.
https://www.qrp-ja.net/jf1ozl/2trrx.html

40 Meter Belles Receiver by WA6OTP
This is the new 40 meter Receiver building project for the Western Belles, a YL group here in Southern Oregon.
http://www.wa6otp.com/40bells.htm

40 meter CW/SSB Receiver by K9GDT
The K9GDT 40m receiver is a solid state receiver that offers a very high level of performance for the 40m Amateur Radio Band. It has excellent sensitivity, selectivity, and dynamic range.
https://www.qsl.net/k9gdt/radio/40mrx/40mrx.htm

40m Band Direct Conversion Receiver by DL2YEO
Building a practical and usable direct conversion receiver for the 40 m CW band is not as simple as it might appear. Broadcast station signals from the adjacent 41 m band, will easily overload most direct conversion mixer designs ..
http://www.qrp4u.de/docs/en/40m_rx/index.htm

40m Band Receiver without ICs by DL2YEO
Today it is very difficult or quite impossible to purchse components that are best suited for QRP circuits. Mixer ICs like the NE602/612, ceramic filters SFE7.02, RF power transistors up to 5W belong to this group.
http://www.qrp4u.de/docs/en/40m_discrete_Rx/index.htm

40m Band Superhet Receiver by DL2YEO
By the addition of one integrated circuit and some passive components, I was able to convert my earlier developed 40-meter direct conversion receiver design into a superhet model.
http://www.qrp4u.de/docs/en/40m_superhet/index.htm

40m DC receiver (1) by PA3COR
The design for this receiver is based on an earlier design by Steve KD1JV. it is build around two analog switches TS5A3157. These switches have on resistance of ca. 5.5 Ohm 10 times smaller as the often used 74HCT4053 switches.
https://www.pa3cor.nl/electronics/40m-dc-receiver-1/

40m DC receiver (2) by PA3COR
After my previous attempt at building a 40m DC receiver failed (I received nothing but noise while at my Kenwood HF receiver, plenty of signals were heard), I made some changes to improve the sensitivity and to add some features that were desperately needed..
https://www.pa3cor.nl/electronics/40m-dc-receiver-2/

40m or 80m Regen RX by G3XBM
The regen receiver is an amazing piece of electronics.
With the circuit shown the receiver can pull in SSB/CW stations well from all over Europe on 40m (or 80m) with ease.
https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-or-40m-regen-rx

40m Regenerative Receiver by DU1VVS
The first regenerative receiver was invented by Edwin Armstrong in 1914 and was been a standard receiver both for commercial and in amateur use long before the spread of super regenerative receiver.
http://hevirred.blogspot.com/2012/08/40m-regenerative-receiver.html

40m WBR receiver by PH2LB
Inspired by some fine projects in the SpratMagazine (the journal of the GQRP Club), just for fun, I build a WBR 40m regen receiver as described in the QST from August 2001.
https://www.ph2lb.nl/blog/index.php?page=40m-wbr-receiver

5 stage super heterodyne receiver made by only 2 transistor by JF1OZL
Reflex is defined as a construction of a receiver ,using one stage of wide band amplifier as a RF amplifier and an audio amplifier by setting a proper band pass filter input and out put of an amplifier.
https://www.qrp-ja.net/jf1ozl/2trr.html

7MHz band monitor scope by JF1OZL
I made a 7MHz band monitor scope. It exchanges all existing signals of that timing of 7MHz-band to viewer image like a hill on the oscilloscope.
https://www.qrp-ja.net/jf1ozl/bms.html

7MHz receiver by JF1OZL
One day on the second hand shop on my town, I found the FM tuner sold only with 10 dollars. That tuner was old type. The frequency display of it was not digital but made by a needle and a thread. I bout it and made SSB rcvr.
https://www.qrp-ja.net/jf1ozl/7mhzradio.html

7MHz Receiver by G3PTO
I decided to build this receiver, having become totally disatisfied with the TS120 receivers performance on 7Mhz.
http://www.qsl.net/g3pto/forty.html

7MHz SSB to MW-AM convertor by JF1OZL
These days, they have hybrid-radio's named Mini-compo in every home. With this machine, you can hear 7MHz SSB signal by the MW-radio of mini-compo. Because MW-radio has no BFO, it cannot demodulate the ssb signal.
https://www.qrp-ja.net/jf1ozl/7MMW.html

A regenerative receiver for the 40 m band by LA3ZA
I've had a lot of fun with the modified WBR (Wheatstone Bridge Regenerative) receiver which I built Manhattan-style some years ago. The design builds on the receiver described by Daniel Wissell, N1BYT in QST August 2001. Although it doesn't match a good superheterodyne, you get more performance per component than in any other receiver!
http://la3za.blogspot.com/2011/06/regenerative-receiver-for-40-m-band.html

Austin's Regenerative Receiver by AA5TB
Back in 2002 my then 7 year old son Austin wanted me to help him build a radio. At that time I helped him build a cigar box crystal radio set. He enjoyed that radio but since then he has taken a liking to CW ...
http://www.aa5tb.com/aus_reg.html

Bartling RX 40 durch DF4ZS
Der Empfänger ist trotz seiner gewollt spartanischen Ausführung signalfest und trennscharf. Der VFO ist abgesetzt, langzeitstabil und driftet bei sorgfältigem Aufbau ca. 100 Hz/h.
http://www.qsl.net/dl5dbm/Projekte/Klipper/bartling%20RX%2040.htm

Binaural Receiver for 40 Meters by WB8ICN
Actually it started out wanting to play with a ceramic resonator oscillator and this receiver had one. So I built the oscillator first…it worked first time and I am quite happy with the results thus far.
https://wb8icn.wordpress.com/2014/05/05/binaural-receiver-for-40-meters/

Binaural Receiver Update by WB8ICN
Swapped out the experimental variable cap I was using for tuning and installed a salvaged 27 to 267pf variable cap. Also made some voltage measurements for my data book.
https://wb8icn.wordpress.com/2014/05/07/binaural-receiver-update/

CORUJINHA - 40m SWL RX by PY2OHH
Um RX fora do comum ... com um rabicho de fio como antena... funciona melhor que muito radio comercial...
https://www.qsl.net/py2ohh/trx/corujinha/corujinha.htm

CW Receiver for 80 and 40 Meters by KC6WDK
This amazingly sensitive and dependable "Simplest Ham Receiver" is capable of receiving CW (Morse Code) signals. It is crystal controlled and thus very stable and immune to drift and hand-capacitance detuning.
https://www.qsl.net/kc6wdk/QRP/receiver.htm

CW Receiver for 80 and 40 Meters with I.C. Audio Stage by KC6WDK
The easy 80 and 40 meter Simplest Ham Receiver described on this site has proven to be versatile, stable, durable and effective. However, interest and curiosity has been expressed for a version with an audio amp section using integrated circuits instead of transistors.
https://www.qsl.net/kc6wdk/QRP/icreceiver.htm

DC-40 - A Simple Receiver for 7 Mhz by VU3VWR
I came across this very interesting design on the internet and decided to get on with the construction. The design is by VU2FAX OM Ashhar Farhan (Of the BITX fame :) ).
http://vu3vwr.blogspot.com/2007/08/dc-40-simple-receiver-for-7-mhz.html

Digital radio for SWL and BCL by JF1OZL
About 20 years ago, 7400 series IC's began to used. Then I made small game with 2 switches and several LED's with 7400 series. In these days, 4000 series IC's is popular. Many of them are the copy of 7400 series.
https://www.qrp-ja.net/jf1ozl/digir.html

Direct conversion 40m receiver by PY2OHH
After building several types of receivers and study filters and impedance adaptors, we decided to publish the results. It is a direct conversion receiver, very simple, easy to mount, it does not need an etched pcb, it is not necessary to wind coils, the parts are available in our commerce or some of them can be obtained from scrounge and it has low cost.
https://www.qsl.net/py2ohh/trx/rcvr40direct/rcvr40direct.htm

Eenvoudige ontvanger voor 40 en 20 m met ongewoon afstemmechanisme door PA2OHH
Geert Paulides PA7ZEE had weer eens iets leuk bedacht, een zelfbouwwedstrijd van een kortegolfontvanger!!!
Het leek me een leuke gelegenheid om eens te experimenteren met een directe conversie ontvanger met de vrij onbekende RA3AAE mixer.
http://www.qsl.net/pa2ohh/07swrx1nl.htm

EMRFD Direct conversion 40m receiver in a tea caddy by LBØMG
I woke up one day eager to build something simple (at least I thought is was simple) and opened up the first chapter in EMRFD and decided to build the 40m direct conversion receiver.
http://diycrap.blogspot.com/2016/05/emrfd-direct-conversion-40m-receiver-in.html

JABUCA a 40m CW receiver by PY2OHH
As here in Brazil the QRP transmitter construction was very extended, there was a hole for receivers. Our idea is the JABUCA can be used making line with other tramsmitter like the Alf, the Alfinete, the Carrapato, etc.
https://www.qsl.net/py2ohh/trx/jabuca/JABUCA2.htm

Japanese Neofight Receiver by JF1OZL
In old days there are many "Japanese someting" in Japan. They are American culture translated to Japan. For example the singer who sings the song of Space battle ship Yamato was called as the Japanese Prethry.
https://www.qrp-ja.net/jf1ozl/neof.html

LED MOSFET Receiver by WN5Y
The LED MOSFET Receiver is considered a 'buildable' version of the "DX Receiver", which is another all MOSFET design, using a single balanced RF amplifier, a single balanced mixer, and a MOSFET 455kHz IF strip.
http://www.pan-tex.net/usr/r/receivers/ra02000.htm

Lidia 40 project Direct conversion receiver CW/SSB for 40m band by SP5DDJ
When Lidia 80 was completed and fully tested I decided like during previous projects Aquarius, Taurus and Libra try to run on other bands. My choice was 7MHz because this band is wider than before and full of stations to listen to.
https://www.qsl.net/sp5ddj/Lidia%2040%20DC%20Receiver/Lidia%2040%20-%20DC%20Receiver.htm

NE602 40m DC Receiver by PA3COR
My google search came up with an image of a 20m PSK31 receiver designed by DG2XK hosted by VA3IUL.
Could I redesign this receiver based on the circuit diagram alone and could I change it to my favorite band 40m?
https://www.pa3cor.nl/electronics/ne602-dc-receiver/

One-Cubic-Inch Direct-Conversion Receiver by N5ESE
When my wife Carolyn showed up, sporting an Altoids "Tiny Box" (of mints), she was surprised at how I carried on about it. Upon seeing the 2-1/4 x 1-3/8 x 1/2" box, I immediately began considering what I might build inside it.
http://www.n5ese.com/dcrx.html

Poundshop FM Radio Conversion to 40m amateur use by GØUPL
PETE MORRIS G1INF started all this! First, read his notes on the 40m conversion.
SVERRE HOLM LA3ZA found a way to get more AF output.
http://www.hanssummers.com/poundshop.html

QRSS DC Tube RX 40m by OK2BX
Some time ago came my son Tomas ok4bx with idea monitoring QRSS signals. I liked that idea and I decided made in my free time, I am in pension, that I will build something related with QRSS.
http://web.bxhome.org/blog/ok2bx/2013/02/qrss-dc-tube-rx-40m

Regenerative Receiver by DK3BI
It uses two 12AH7 double triode tubes. They just happened to be available in my junk box. The first two triodes work in a cascode circuit, where the very first one is connected in a Hartley configuration.
https://www.dk3bi.de/my-regenerative-receiver/

Simple direct conversion receivers for 40m by PY2OHH
We were studying some simple receivers for the 40m band, as a fact these receivers cover all the HF bands even to 30MHz only changing the local oscillator - VFO / VXO. We built some types, all of them worked, some of them with better results.
https://www.qsl.net/py2ohh/trx/rxsimpleshf/rxsimpleshf.htm

Simple receiver with the 74HC4066 IC by PY2OHH
Base board with the modules built and soldered getting a mechanic fixation and a common and efficient ground too.
In the VXO above the 10µH blue Sontag inductor it is the 7.15MHz ceramic resonator.
https://www.qsl.net/py2ohh/trx/4066rx1/4066rx1.htm

Simple receiver with the 74HC4066 IC (2) by PY2OHH
Following the pace of our friend and namesake Onno, PA2OHH, we built a simple receiver (already published here) for the 40 meter band, using the 74HC4066 as mixer and buffer. As there were two surplus gates yet we decided to use one as the VXO with ceramic resonator.
https://www.qsl.net/py2ohh/trx/4066vxo/4066vxo.htm

The MRX-40 Mini Receiver by K8IDN
After exploring very low power (QRPp) communication by bulding a 40 meter Micronaut CW transmitter, I took on the challenge of constructing a tiny 40 meter companion receiver.
http://www.arrl.org/files/file/Technology/tis/info/pdf/99759.pdf

The Wheatstone Bridge Regenerative Receiver by AA3SJ
I have not had much experience with regenerative receivers, but the WBR is far superior to the others I have built. I was surprised at the WBR's ease of use and the clarity of it's signals.
http://www.qsl.net/aa3sj/Pages/WBR.html