Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
http://soldersmoke.com
I'm guessing that most of you have never listened to a regen receiver that uses only one transistor. So in these videos I've tried to capture the experience. The audio that you hear from the receiver is from a small I-phone microphone taped to the one of the headphones on my DLR WWII headphones. So you are hearing it just as I hear it -- with no additional amplification. Here is N0WVA's schematic. When I tune the "regeneration" control I am turning the knob on the variometer. The broad or "bandset" tuning control is essentially N0WVA's 25 pf cap. My fine tuning control (the one that I use the most in the video) is the equivalent of the smaller cap in parallel with the larger tuning cap.
I had trouble shooting the video for this post -- taping the mic to the headphone turned out to be a bit difficult. So I ended up with a few extra (and imperfect) videos. I include them here for anyone who might want to listen some more to a single transistor regen. (I have a few more -- let me know if you'd like to see them!)
In the next one, at the end I throw the switch to transmit allowing you to hear what "sidetone" sounds like on the ET-2
Thanks for posting the demo, I'm impressed! Good to hear after listening about it in the podcast. 73 de Walter, AC4IM... still in Italy at the San Vito solar observatory.
I was wondering what you were using for the sidetone. I see it is the "receiver blocking" method. :)
Spotting your transmit signal is probably the largest hurdle to overcome with a regen. It may be possible with total shielding and clean antenna switching, but that takes away from the nostalgia of an open air station. Could you imagine doing this without crystal control? Imagine basically four free running oscillators all trying to stay close to each others frequency as the table vibrated and power supply voltage ramped up and down. Dont breath on the tank circuit!
Re Anon, there are techniques that don't require you to spot your tx signal on a regen. For example you could have a second tx crystal with its frequency shifted 800 Hz (eg VXO) from the crystal in the tx. That second tx crystal could be in an oscillator running all the time to provide a BFO for the regen rx. The regen rx would be brought to the point of oscillation but not oscillating. There's some 1930s(?) QST articles about the merits of a separate BFO for regens.
Alternative you could configure your tx so the local osc is running all the time and have that as your BFO for the rx. But you will need to shift it 800 Hz to get an offset. That could even be done manually eg with a variable capacitor in series (and an inductor if you want more VXO range).
Another thing that could be useful is putting a tx crystal in the antenna lead of the regen - that will act as a crude xtal filter. You might hear an interesting change in noise as you adjust the rx to near that frequency.
Instrument storage boxes updated
-
While getting some equipment off a shelf I knocked some thing down and they
landed on a nanoVNA, cracking the screen.
I think it is time to make some ...
2021 - The Year of Nostalgia. A 60 Year Trip
-
A 60 Year Time Trip!
Starting with Today (2/22) -- The N6QW Conversion of the Dentron Scout HF
SSB.
2/26/2021 --- More Update Info.
Just ran across anot...
Hunting For NDBs In CLE265
-
*WC - 332 White Rock, BC*
It's almost* CLE* time once again! '*CLE*'s are '*C*o-ordinated *L*istening
*E*vents, and NDB DXers around the world focus...
A Personal Milestone: Published on Paper
-
As far back as I can remember, I have had a fondness for words and
language. Even in the second grade, learning the roots of words, their
suffixes and pr...
Mt Feathertop (VK3/VE-002) 11th Jan 2021
-
Mt Feathertop (1,922 meters) is the second highest mountain in south
eastern Australia (Victoria), and according to many commentators, the most
picturesque...
Yet more new AVRs
-
In a previous blog I mentioned the new atmega4809 and AVR128DA parts. Well,
it seems I missed two other new families, the AVR128DB and AVR128DD series.
I’v...
Re-engineering my 1st “Shirt-pocket” transceiver
-
When the project of building a very small transceiver was accomplished 4
years ago, I still lacked lots of skills in setting up electronic circuits
using S...
The Complete DXer
-
Odds are that, if you're reading this, you're probably familiar with two
other jewels from the ARRL bookstore: *Solid State Design For The Radio
Amateur...
-
A Simple Speech Processor
(For QRP/SSB Homebrew Transceivers )
Over the last few weeks I had been thinking to build a small AF speech
processor to add to...
Modifications to the Dayton/FDIM-2019 Antuino
-
The Dayton Antuino has sub-optimal performance. This is a short note on
improving it to an 80 db range of measurements. The trouble with Antuino
2.0 (the o...
A New Look for your uBitx!
-
Adding a "Cool Blue" Display to your uBitx!
The standard "green background" with black lettering frequently reminds me
that I suffer from Chronic seasicknes...
Thanks for posting the demo, I'm impressed! Good to hear after listening about it in the podcast. 73 de Walter, AC4IM... still in Italy at the San Vito solar observatory.
ReplyDeleteI was wondering what you were using for the sidetone. I see it is the "receiver blocking" method. :)
ReplyDeleteSpotting your transmit signal is probably the largest hurdle to overcome with a regen. It may be possible with total shielding and clean antenna switching, but that takes away from the nostalgia of an open air station. Could you imagine doing this without crystal control? Imagine basically four free running oscillators all trying to stay close to each others frequency as the table vibrated and power supply voltage ramped up and down. Dont breath on the tank circuit!
Doug N0WVA
I Love your minimalist leanings, and CW. FB! Keep soldering! Ed KC8SBV
ReplyDeleteRe Anon, there are techniques that don't require you to spot your tx signal on a regen. For example you could have a second tx crystal with its frequency shifted 800 Hz (eg VXO) from the crystal in the tx. That second tx crystal could be in an oscillator running all the time to provide a BFO for the regen rx. The regen rx would be brought to the point of oscillation but not oscillating. There's some 1930s(?) QST articles about the merits of a separate BFO for regens.
ReplyDeleteAlternative you could configure your tx so the local osc is running all the time and have that as your BFO for the rx. But you will need to shift it 800 Hz to get an offset. That could even be done manually eg with a variable capacitor in series (and an inductor if you want more VXO range).
Another thing that could be useful is putting a tx crystal in the antenna lead of the regen - that will act as a crude xtal filter. You might hear an interesting change in noise as you adjust the rx to near that frequency.
ReplyDeleteThis comment has been removed by a blog administrator.
ReplyDelete