Ive made several regenerative receivers over the years. Practical wireless april 20 regenerative receiver the. The circuit is designed with high input impedance fet transistors, the use of this type transistors provides in first two stages very simple schematic. For a regenerative receiver to work properly we need to carefully control the feedback to just. This is exactly what we do in a regenerative receiver. I will post pictures and a better description when i have done so.
The circuit diagram of the regenerative receiver mfj8100 is shown in figure 1. The wbr regenerative receiver for 40meter band youtube. These guys were building from just a schematic and a description of the coil winding, not a manual. If youre not familiar with the wbr circuit, aa1tj writes more about it here. A high performance regenerative radio circuit salad. It is a pdf file and i could not post a link to it, also you need to be a arrl member to open it. It seems a poor tradeoff to lose sensitivity to just stop some oscillation leaking out of the receiver, when you can put a simple active buffer between the detector and the antenna to do the same without loss.
This gives it very high frequencyspecific gain and a measure of selectivity. Ken wa4mnts pdf tutorial is here, and chuck k7qos is here. Mar 30, 2018 the wbr regenerative receiver for 40meter band. Back in 2003, an experimental colpittstype shortwave regenerative receiver was made public on the web by this servant. A simple but very sensitive regen receiver for 40 meters by rick andersen, 2004 revised and expanded 11506 i have revised this article as of january 15th, 2006, showing an alternative to the toroidcore inductors of the original design. The um58 receiver is an extended 2valve version of that design. Jul 06, 2014 this is a tune through of 6900 to 7500 khz with my newlybuilt wbr receiver based on the modified schematics from aa7ee. Using the schematic of the short wave regenerative detector receiver and parts list as a guide, install and solder all the components into the pc board. The full design notes are available in two pdf files, the notes below are an extract for this web page. C1 is adjusted to set the radio into the 40m band and c2 then acts as a fine.
A threetransistor receiver the fet as a regenerative detector by walter f. Variation on junk box bipolar regenerative receiver. This receiver uses a 2n4416 jfet orj31, which provides a more sensitive detector than an mpf102. This is a homebrew regenerative receiver, mostly based on several designs by charles kitchin n1tev. The completed wbr receiver darn those frontpanel fingerprints.
It was reported to tune from the 22meter band up to the 11meter band with a single set of coils. Superregenerative receiver srr for short range hf band. Fist of all, use capacitor as throttle regen control, this is the key factor for smooth regen control. Building aa1tjs crosscoupled wbr regenerative receiver post by qrpgaijin sun sep 14, 2014 2. A regenerative receiver with agc for 80 meters or 310 mhz shortwave. One example is the schmitt trigger which is also known as a regenerative comparator, but the most common use of the term is in rf. There is a better way, though, to get high gain from the 386 without the particularly high hiss that comes from using that 10uf cap between pins 1 and 8.
Both chuck and jay reported that they were spending way too much time playing with the regen. A regenerative receiver with agc for 80 meters or 310 mhz. Variation on junk box bipolar regenerative receiver january 22, 2015 july 1, 2015 raycharlesring rf this version removes the direct coupling of q2 in the previous version and increases the emitter resistor as well, finally the regeneration control is moved to the emitter circuit. The receiver tunes the entire 30m band 1010010150 and performs quite well. Building a wbr regen receiver for the 31m broadcast band or. To get the most out of a regenerative receiver you have to know a few tricks, often use two or three. Some of the output of the amplifying device is applied back to its input so as to add to the input signal, increasing the amplification. It was an intriguing design for me, as it employed a wheatstone bridge arrangement to minimize oscillator radiation into the antenna without the use of an rf amplifier stage.
I will post pictures and a better description when i. Would someone like to post a schematic of this receiver here. Building aa1tjs crosscoupled wbr regenerative receiver post by qrpgaijin. Wbr2 will try to correct some of these deficiencies, but for now, wbr1 represents success. The wbr a simple high performance regen receiver for 40m. Here is a link about wbr receiver for more details. A regenerative receiver or autodyne was invented in 1914 by edwin armstrong. This 2valve regenerative receiver is a folly, actually. Building aa1tjs crosscoupled wbr regenerative receiver. Rockey, is directly mapping from value tube version. N1tev published article on arrl said the regen receiver can compete most of heterodyne receiver actually. Some of the parts i used were rare and unobtainable as new parts. I decided to build it after i found back a few parts of a 1valve regenerative receiver i constructed when i was 12 years old.
Building aa1tjs crosscoupled wbr regenerative receiver the. Wbr receiver implementation notes 3 march 2012 final page 5 indicator and a means to determine the frequency that is being listened to. Overview invented by armstrong in 1922 and widely used in vacuum tube circuits until the 1950s it was replaced by the superheterodyne receiver due to its poor selectivity and sensitivity pros. Secondary winding 12 and capaci tors c3 and c4 select the received sig nal while tickler winding 1. Wbr 2 will try to correct some of these deficiencies, but for now, wbr 1 represents success. I through is a simple receiver that should be easy for most anyone to build, regardless of his experience. Jun 24, 2014 it has been almost 3 years since i first built n1byts wbr a regenerative receiver for the 40m amateur band. For example four capacitors in the component list have locations on the circuit board but do not appear in the circuit schematic. Hello, and welcome to big nicks alfred morgan 1tube regenerative receiver page. Jul 26, 2015 a regenerative receiver is just an amplifier that is almost but not quite at the point of oscillation. See this regenerative receiver design for an example of. After digging through various tv tubes and pulling up datasheets, i found a 33gy7 that contains a diode and pentode, which could be used as the rectifier and audio output respectively and the 12at7 for the regen and preamplifier. Operation was found to be satisfactory with the prototype built on a protoboard and a ground plane fixed underneath. Building a wbr regen receiver for the 31m broadcast band.
Variation on junk box bipolar regenerative receiver circuit. It consists of an amplifying vacuum tube with its output connected back to its input through a positive feedback loop thereby amplifying the incoming radio signal by a large factor. A regenerative radio receiver is unsurpassed in comparable simplicity, weak signal reception, inherent noiselimiting and agc action and, freedom from overloading and spurious responses. The regenerative receiver, regen radio was a popular form of radio receiver in the 1920s and 1930s. An fet version of the 1v1 regenerative receiver, designed and built by c. A modern, transistor version of armstrongs circuit, patented in 19, is shown in fig. There is also an explanation of how the radio works, what the vacuum tube does, and how to operate the radio.
A regenerative receiver is just an amplifier that is almost but not quite at the point of oscillation. Where a triode is used for the detector, the plate supply can be varied, or in the case of a pentode, the screen g2 voltage. The aa8v twinplex regenerative receiver how to use and get. As an added plus, the design virtually eliminates the negative aspects of regenerative receivers such as antenna radiation, frequency pulling, microphonics and hand capacitance effects. Drm i do like that the schematic you posted includes a stage of audio preamplification before the lm386. Regenerative shortwave receiver pf c8 d1 d2 r4 20120 pf 1 06 pf sw3 0. The schematic shows the coupling cap and audio output jack tapping off of q3. That receiver never worked properly and i tore it apart. This is a new regenerative receiver for the short wave bands. So many of these simple designs dont do that, with the result being af output that is marginal for driving a speaker. Superregenerative receiver for short range hf band applications 3 1. In my circuit i omitted the input bandpass filter and connected the antenna. Vacuum tube receivers and transmitters the transmitter described in this chapter uses the most ancient vacuum tube technology i could, while still sounding pretty good on the air.
The regen radio was one of the many inventions in radio technology that was made by edwin armstrong. Rf amplifier, the regenerative detector and the audio amplifier. But they are experienced builders and it was a snap to build. This is a tune through of 6900 to 7500 khz with my newlybuilt wbr receiver based on the modified schematics from aa7ee. The basic paradigm of this design is to break up the traditional oscillating detector into a separated regenerative amplifier and detector circuit. I was determined to replace the diode with a hollowstate equivalent to make a true alltube regenerative receiver. The aa8v twinplex regenerative receiver how to use and. Ive had a lot of fun with the modified wbr wheatstone bridge regenerative receiver which i built. A regenerative receiver can be constructed using a single transistor. Borden radio armstrong one tube regenerative receiver. This project was my first regenerative radio receiver and one of my favorites as well.
I am not interested in the whole article due to issues, but i am only interested in a schematic of this receiver. I have not yet built this receiver, but intend to do so asap. The space left at the top righthand side of the front panel was in case i found a way to hook up a frequency counter to the regenerative detector while in oscillation in order to provide a frequency readout. The schematic is available many places this is one of the first receivers i built, using the version from the radio handbook 1936 regenerative. The big advantages of the regenerative receiver, its simplicity and cost, are also its downfall. See more ideas about ham radio, short waves and radio design. The circuit is the same as that of an oscillator with the addition of some form of control on the feedback. A printed circuit board is available to speed construction of this project. In this pamphlet, along with the instructions to assemble the kit, are a brief history of the vacuum tube, early radio development and notes on edwin armstrong and his invention of the regenerative radio receiver. Jun 30, 2011 or you can run a wire from the regen antenna connection into or near another receiver and tune around until you pick up the howl from the regen oscillator. As shown in the updated schematic of the audio section, i added a passive audio filter to kill some more of the high frequencies whistling heterodynes, etc.
The extra transistors and ics allow for speaker operation and for other improvements in performance. The detector is a plate detector, where rf is fed back to the amplifier via a partially rf decoupled source normally bypassed all the way for rf when used as a detector. It uses readily available parts and covers 3mhz to around 12mhz. The regen receiver is an amazing piece of electronics. How to build a crystal or regenerative radio radio boat. The input is an antenna buffer that presents a high impedance to the antenna and results in a short wire acting like an active antenna. The antenna and earphone jacks have been permanently. Jun 19, 2009 here is a sensitive regenerative receiver has been published in practical wireless april 20. It has been almost 3 years since i first built n1byts wbr a regenerative receiver for the 40m amateur band.
I wont be publishing the schematic for the wbr receiver here, as its not mine. I wont forget how exciting it was for me to build such a humble radio that so greatly outperformed the crystal receivers that i had been building up to that point. As a result this form of radio deserves its place in this summary of the different types of radio available. Lange, wiyds vex in this age of crowded hands and sophis ticated communications systems, there is room for the lowly regenerative receiver. The regenerative radio receiver or, even superregenerative radio receiver or, regen if you prefer, are basically oscillating detector receivers. A regenerative circuit is an amplifier circuit that employs positive feedback also known as regeneration or reaction. The wbr a simple high performance regen receiver for 40m by. But have you ever considered whipping up a regen receiver.
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