Rustyaxe’s code, including #ham #radio #communications software
on 02026-09-22#video #toread on #survivalists using #JS8call for #QRP #radio on HF bands. Mentions that NVIS is difficult to direction-find. Demonstrates his in-attic dipole antenna for the 40-meter band to avoid the specter of the HOA. A lot of talking-head filler but I think under 50%. Later on he has a screencast of using the JS8Call software on 7.078MHz.
on 02026-08-10#video #toread about how magnetrons work. The dude has also made videos about Esaki and Gunn diodes. #electronics #hardware #radio
on 02026-08-07Hey, there’s a 3-month #ham #radio course starting at LU5CBA, Achaval 951, Parque Chacabuco, Capital Federal, on Monday. You have to go there every Tuesday or Saturday, or both if you like. Monday and Wednesday at 20:00 are the online classes. <mailto:secretaria@lu5cba.org.ar>.
on 02026-08-07Log de Argentina logged the 76th anniversary of Radio Club Morón (LU1DBQ), and has other #ham #radio events.
on 02026-08-07Radio Club Morón (LU1DBQ), founded in 01950, celebrated its 76th anniversary on April 16th, and is on Castelli street. On the photo it looks like Castelli 1580, and there’s a Hotmail address I can’t make out. #ham #radio
on 02026-08-07another review of the #JS8Call #radio #communications #protocols.
on 02026-07-28#PDF of the #FCC’s antepenultimate NOUO from March 25. This one is quite a bit spicier than the Jack Gerritsen and Conifer Communications ones: “The Federal Communications Commission (FCC or Commission) received a complaint from Allegheny County Pennsylvania Emergency Services (Allegheny County) concerning interference to its 911 emergency communications channel operating on 470.4375 MHz in Pittsburgh, Pennsylvania. On July 30, 2025, Agents from the Columbia Office of the FCC’s Enforcement Bureau (Agents) conducted an investigation and determined, using direction finding techniques, that the source of the interference to the Allegheny County system was a signal emanating from the residence of David O. Knudtson (Knudtson), licensee of amateur radio station KD3ASC. After the Agents notified Knudtson of the interference issue, he produced a handheld radio (identified as a BTech UV-Pro). An examination of the radio determined that it had been modified to monitor the Allegheny County channel, and its “Audio Relay” feature had been activated. This feature turned Knudtson’s radio into a simplex repeater that was retransmitting the Allegheny County channel. Knudtson surrendered the radio to the Agents. Subsequently, the Agents verified that the interference to the Allegheny County system had ceased.” #communications #RF #radio #law
on 02026-06-02#PDF of the #FCC’s penultimate NOUO (“notice of unlicensed operation”), from April 1, to Conifer Communications: “The San Francisco Office of the Federal Communications Commission’s (Commission’s) Enforcement Bureau has received a complaint of an unlicensed radio station operating on frequency 10.915 GHz located in Moccasin Peak, California. On September 24, 2025, Agents from San Francisco Office confirmed during an on-scene investigation that Conifer Communications was transmitting on 10.915 GHz from Moccasin Peak, California, with a license that had expired on February 12, 2024, and was not renewed.” #communications #RF #radio #law
on 02026-06-02#PDF of one of the three “notices of illegal pirate radio broadcasting” (NIPRBs) the #FCC issued in April. #communications #RF #law #radio
on 02026-06-02Blog of #FCC enforcement actions, including the Jack Gerritsen Notice of Unlicensed Operation, which seems to be the only NOUO they’ve issued since April 1, when they issued another one. Also they issued three NIPRBs in April (“pirate radio” notices, similar to NOUOs), but two of them seem to have been about two #radio stations in Jamaica, New York, on 90.1MHz and 91.9MHz. #communications #RF #law
on 02026-06-02#PDF #FCC “Notice of Unlicensed Operation” on a #ham #radio band, addressed to a Jack Gerritsen, responding to “multiple complaints from licensees in the amateur radio service concerning an unlicensed radio station operating on 146.415 MHz in Los Angeles, #California and causing harmful interference to licensed operators in the amateur radio bands.” I’m curious whether there’s a public list of all of these? #communications #RF
on 02026-06-02IP65-rated card-sized (85 × 65 × 6.5mm, 32g) #Meshtastic #LoRa node #hardware for #RFID tracking with #GPS over kilometers, “SenseCAP Card Tracker T1000-E”. #Pricing of US$39.90. Rechargeable 700mAh battery. Uses “global ISM bands in the 863-928 MHz range”. #electronics #radio #communications
on 02026-04-1601970s frequency shift pager standard for #radio data communication
on 02026-03-15“Reticulum is the cryptography-based networking stack for building local and wide-area networks with readily available hardware. Reticulum can continue to operate even in adverse conditions with very high latency and extremely low bandwidth.” #radio #decentralization
on 02026-01-06Discussion of #radio #decentralization including #Meshtastic and things called #Reticulum and #Meshcore.
on 02026-01-06waveguide cables made by startups #Point2 and #AttoTude may provide higher-speed data communication within #data-centers than copper wires using submillimeter RF. #radio
on 02026-01-06public-domain #video from 01964 (looks more like 01944, saying “United States of America War Office”, so maybe they got the date wrong) explaining FM #radio #toread
on 02025-12-12#video #toread by Tim Hunkin on the Secret Life of the #Radio. #electronics #communications
on 02025-12-12public-domain #video from 01944 explaining FM #radio with a simple tank-circuit transmitter (Hartley oscillator?) with a capacitive microphone in parallel with the tuning cap. His example is 40MHz with a ±40kHz max deviation (80kHz swing), which he says is the Army’s maximum deviation, plus a 10kHz guard band on each size. But in reality they used “reactance tubes” and phase modulation rather than capacitive mics for their transmitters. He says the key difference for an FM receiver is amplitude limiting (a “limiter”), plus of course FM demodulation itself, with a “discriminator”. The limiter is a vacuum-tube device that might have a transistor analogue. The discriminator is a tank, a diode, and a (bypassed) load resistor, tuned so that the “rest frequency” is at the steepest part of the tank’s Gaussian response, so basically you’re just turning FM back into AM and demodulating the AM. #electronics #history #radio #RF #communications
on 02025-12-12public-domain #video from 01944 explaining FM #radio with a simple tank-circuit transmitter (Hartley oscillator?) with a capacitive microphone in parallel with the tuning cap. His example is 40MHz with a ±40kHz max deviation (80kHz swing), which he says is the Army’s maximum deviation, plus a 10kHz guard band on each size. But in reality they used “reactance tubes” and phase modulation rather than capacitive mics for their transmitters. He says the key difference for an FM receiver is amplitude limiting (a “limiter”), plus of course FM demodulation itself, with a “discriminator”. The limiter is a vacuum-tube device that might have a transistor analogue. The discriminator is a tank, a diode, and a (bypassed) load resistor, tuned so that the “rest frequency” is at the steepest part of the tank’s Gaussian response, so basically you’re just turning FM back into AM and demodulating the AM. #electronics #history #radio #RF #communications
on 02025-12-12“The Russian Meteor-M orbiting satellites (there are two of them) have fair resolution and broadcast at 137.9 MHz with a signal strong enough to capture with a simple QFH antenna (fixed, omnidirectional) that you can easily build yourself. Their camera scans like a raster and transmits real time images as it passes overhead. The free SatDump software works fine for decoding.” #space #radio #communications
on 02025-08-27electrically long and short #antennas and loading coils and whatnot. #electronics #communications #radio
on 02025-08-24#Bluetooth #BLE can reach over a kilometer with “coded PHY” at 125kbps! #toread #radio #communication
on 02025-07-20#JS8 is a digital #radio #communications mode derived from #FT8; "JS8call" is GPLv3 software for it derived from WSJT-X. “Jordan Sherer designed 8-FSK modulation”. For #QRP. Super low bandwidth.
on 02025-06-12#USA regulator FCC permitting ultra-low power (whatever that is) on a 1GHz wide band in #6GHz #radio #communications
on 02024-12-13discussion of #USA regulator FCC permitting ultra-low power (whatever that is) on a 1GHz wide band in #6GHz #radio #communications
on 02024-12-13#Meshtastic #decentralized #radio #firmware is #GPL 3
on 02024-09-20#video #toread about #Meshtastic #decentralized #radio
on 02024-09-05#video #toread about broadcasting #LoRa without a #radio
on 02024-07-24#video #toread on running a pirate #radio station and getting busted by the FCC
on 02024-06-05#video on targeted offgrid comms with "T-Rex Labs" #paranoia. KT7RUN and KK4FMV are trying to communicate over a few thousand km using a 20-watt Xiegu G90 HF backpack ham #radio transceiver (20 and 17 meters). He mounts a mast on the trailer hitch of his jeep out in the middle of the Arizona desert and ran an inverted-V (dipole?) antenna from it, suffering a cactus injury. They’re going to try using the #JS8 digital mode with KN4CRD’s #JS8Call software on a Panasonic Toughpad running Ubuntu. Oh and maybe it’s actually 100 watts. He does succeed in talking to somebody in Tennessee with voice, and somebody in New York over JS8, and finally his intended contact. Finally he used a tiny pocket Garmin InReach MINI 2 satellite radio to communicate successfully.
on 02024-06-05#video of a detailed anatomy of an AM #radio transmitter doghouse and tower. #electronics
on 02024-06-04#video of demodulating AM #radio with a hot dog, or rather plasma to the antenna tower from a grounded hot dog
on 02024-05-09#video on telephone #decentralization with apparently some newly available mesh networking firmware, "Meshtastic" #radio running on #ESP32 hardware: encrypted text-based walkie-talkies using #LoRa on the Heltec WiFi_LoRa_32_V3 board, which has an ESP32-S3FN8 on board. Not low-power, though; half a watt idle! And the firmware is built on PlatformIO. You can flash it via #WebUSB on flasher.meshtastic.org. But it depends on a custom app on your cellphone for its UI, to which it communicates over Bluetooth (or USB serial or Wi-Fi), because the actual board only has two buttons, though it does have a respectable OLED screen which displays incoming text messages. It also needs the cellphone if you’re going to give it GPS. You can also use a browser app which uses your Wi-Fi or Bluetooth to talk to your local devices. The YouTuber reports he got messages through (spottily) at 5km from his 32nd-floor highrise balcony, using the 90-bits-per-second data rate, but at ground level at the beach, only about 150 meters of range, which he blames on the antenna. It can share private keys over QR codes to set up an encrypted channel, but by default doesn’t.
#latency on #STM32 #radio #hardware
on 02024-02-10#Radio frequency allocations chart in the #USA
on 02024-01-23Small magnetic loop (magloop, loopstick) #antenna design equations for #radio #hardware.
on 02024-01-23#SDR with the Microchip #AT86RF215 transceiver, which surprisingly can provide 13-bit LVDS #radio I/Q samples from its digital frontend. The transmitter is direct-upconversion with up to 1 MHz bandwidth and the receiver is 32Msps downsampled to 4Msps. #hardware
on 02023-07-15#radio #ham club #LU4DQ in Quilmes has started a magazine, maybe six issues a year
on 02022-10-12an article from 01953 on building a #radio around a point-contact germanium transistor, by George M. Rose, K2AH, who built the first radio transmitter using one. “the tiny devices that may revolutionize the electronic art” #hardware
on 02022-09-16Ossmann, the HackRF guy, gave a Defcon22 talk on retroreflection #radio #communication bug #hardware
on 02021-11-03retroreflection bug #radio #communication #hardware
on 02021-11-03retroreflection bug #radio #communication #hardware
on 02021-11-03#27MHz #hardware vendor explains super cheap #radio #communication
on 02021-09-06#27MHz #radio #communication range at 100mW (Czech legal maximum) might reach 10 km at a 1kbps data rate?
on 02021-09-06discussion of #radio #communication #hardware for cheap #27MHz radio-controlled cars
on 02021-09-06#Android supports #BLE (“Bluetooth Low Energy”) pulse #radio devices since Android 4.3; here are the APIs.
on 02017-04-151989 memoir of using cell phones and “trunk #radio systems” in #aviation, by George Goble
on 02017-04-15#radio #hardware using an #AVR to generate a square wave and carrier wave and a 2N7000 MOSFET to amplify the carrier wave and modulate it with the square wave.
on 02017-03-31on-off keying #radio #hardware: CW 433 MHz transmission easily controlled from an Arduino for US$1
on 02017-03-30new long-range #radio #hardware "LPWAN" technologies (“Sigfox”, “#LoRa”, “Ingenu”) transmit at kilobits per second over unlicensed spectrum to (in the case of Beep Networks’s LoRa test) a kilometer or two, or 16 km in rural areas with towers.
on 02016-09-24Lukas “laobeylu”’s page showing his FreeSRP software-defined #radio #hardware
on 02016-08-01comment thread on building the FreeSRP software-defined #radio #hardware from scratch, with the 18-year-old hacker Lukas “laobeylu” participating. They cost US$400.
on 02016-08-01The nRF24L01+ US$1.50 #hardware #radio can broadcast #Bluetooth Low Energy data with up to 16 bytes per packet.
on 02016-07-11