Today’s success: one direction of a Hayward/Kopski bi-directional termination insensitive amplifier. I used KSP10 VHF transistors and it’s delivering more gain than expected (30dB!) rather than 20dB from 2n3904. Careful construction, so no oscillation. I’ll just put it into a pad rather than re-biasing. But it worked first try, again. Lucky weekend ☘️ I’m calling this mixed Manhattan/Ugly style “ugly man” haha
I soldered up the BFO from the BITX20 that I modified down to 9MHz and to use parts I have on hand. One of those rare moments when you draw it up, solder it together, turn it on… and it just works! 🎉
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Mastodon.Radio is a Mastodon server for radio enthusiasts including the Amateur (Ham) Radio community, anyone interested in Shortwave Listening (SWL), etc. Come join us and talk radio, technology, and more!
You can find out more at https://mastodon.radio/about or contact the admin account @M0YNG
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Horusdemodlib v0.6.0 has been released. This is the official release of Horus Binary V3 which introduced ASN.1 UPER encoding, allowing for operators to utilise the high performing modem we've all loved while now have the ability to produce highly customisable telemetry in sizes from 32 bytes to 128 bytes!
I cannot express how amazing this is, how well it works, and how much work from multiple people went into making this happen.
Happy ballooning.
https://github.com/projecthorus/horusdemodlib/releases/tag/v0.6.0
Mastodon.Radio is a Mastodon server for radio enthusiasts including the Amateur (Ham) Radio community, anyone interested in Shortwave Listening (SWL), etc. Come join us and talk radio, technology, and more!
You can find out more at https://mastodon.radio/about or contact the admin account @M0YNG
#FeaturedServer #AmateurRadio #HamRadio #Radio #SWL #Shortwave #ShortwaveRadio #Mastodon #Fediverse #FreeFediverse
I cobbled together a 20m direction conversion receiver from the parts I had on my bench. All of these components are my own design except the mixer (ADE-1) and diplexer (W7EL) board. The audio amp is the one I designed and that @synx508 did the awesome testing work on, the VFO is the one I published yesterday, and the band pass is a 3 pole filter that I built as a starting point for a transceiver project. It sounds pretty good! Here's some video
I designed and built an analog varactor-based Colpitts VFO for the 20m ham radio band. It’s built around two BB910 diodes, a 10-turn pot, and two J310 JFETs. Has some warm up drift but is very stable after a few minutes. It was designed to use caps I already had. Very happy with this!
I used c0g caps and elevated the toroid and trimmer to keep heat away from them. Advice is to use air core here but the toroid takes less space. Note I removed the unnecessary heat sink.
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I just finished a 3 pole 20m band pass filter. Looks good on the NanoVNA. I used an odd mix of surface mount capacitors, hand wound Amidon toroids, and 1970s Soviet surplus trimmers. Very happy with the result though! #HamRadio #AmateurRadio
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Shipping notices from Mouser are always a little joy in the Inbox. 😊 #HamRadio #AmateurRadio
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#Radio accounts posting videos:
➡️ @pg4i - Amateur radio operator, especially Morse code
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#Radio accounts posting videos:
➡️ @pg4i - Amateur radio operator, especially Morse code
➡️ @n3vem - Amateur radio, amateur rocketry, radio rockets
➡️ @kd8bxp - Amateur radio, robotics, retro computing
➡️ @raek - Electronics & radio, building radio equipment
➡️ @flo - Retro tech incl radio transmitters & receivers
➡️ @vwestlife_makertube - All about classic technology including radios
➡️ @jmh59 - Railways, model trains, amateur radio
I got 90 of these quite good looking 6W-capable UHF MOSFETs for really really cheap and am looking forward to learning to build something with them. They are EOL, but with that many of them I should be able to do all the projects I'll want to do for quite some time.
https://www.renesas.com/en/document/dst/2sk3390-datasheet
They are being held for me in the US and so I need to arrange to get them sent over here. I have plenty of work to do first, though.
Here’s my BFR193 based discrete component audio amplifier. It does about 85dB of gain from two BFR193 transistors and one 2n3904. It’s pretty quiet for delivering all that gain. It’s derived from the Soldersmoke direct conversion receiver amplifier but with a lot of improvements, feedback, and different transistors and bias scheme. It will go into my next radio. I built it partly surface mount and partly with through hole in Manhattan style. Very happy with this! #HamRadio #AmateurRadio
Using BFR193 RF transistors in an audio amp introduces some interesting behavior! They will happily pick up stray high frequency (they are good to 2GHz) RF from even very short wires and amplify it quite a lot. I am running the first stage at nearly 35dB of gain at audio frequencies. When this UHF RF is damped, however, they are very quiet and sound very good. Quite a lot quieter than the general purpose transistors I previously used! #HamRadio #AmateurRadio
I'm designing a discrete component audio amplifier to stand in for the one from the Soldersmoke DCR for my next radio build. The original is intentionally simple, to make understanding it easy. That makes sense.
Mine is less simple but still only 3 transistors. I'm using two BFR193s and a 2n3904. It is derived from the Soldersmoke design, so it's still single-ended, with an audio transformer. It does 85-90dB of gain (much more!) with flatter audio frequency response. #HamRadio #AmateurRadio