http://ka7oei.blogspot.com/2020/12/intruder-at-top-of-20-meter-amateur-band.html KA7OEI's blog Random musings - usually on a technical (nerdy) subject - perhaps related to amateur radio and things found at ka7oei.com and modulatedlight.org Tuesday, December 15, 2020 Intruder at the top of the 20 meter amateur band? It wasn't my intent to have this next post be about locating a source of a transmitter - but the temptation proved irresistible. Over the past several days I'd been working on an addition to the Northern Utah WebSDR: A temperature-based frequency control of the local oscillators on some of the receive chains. The receivers in question are based on the Si570 synthesizer and are prone to temperature-based frequency drift, and since they have internal reference oscillators, there is no way to externally lock them. For this temperature-based stabilization to work, I have correlated the room temperature with the actual frequency, so I have been frequenting the bands/receivers with the aforementioned issues and making measurements - but I digress: It was during this activity that I noticed this massive signal at the top of the 20 meter band, occasionally firing up and clobbering ongoing conversations by U.S. amateurs. [wide_signal_20m_2a] Figure 1: Waterfall display of the signal around 14.350 MHz. Invisible are ongoing QSOs underneath this strong signal. Click on the image for a larger version. What is it? Upon seeing this, I had my suspicions - but I fired up the TDOA (Time Direction of Arrival) system on the KiwiSDR network, using five receivers within the zone of reception scattered across the continental U.S. Multiple sessions of direction-finding over several days yielded similar results to this map: [wide_signal_20m_3a] Figure 2: TDOA results of the above transmission. Note that long-distance HF direction finding has significant uncertainties, so the above location is likely accurate to only a few 10s of km at best. Click on the image for a larger version. This clinched it - it was likely shortwave-based high-frequency trading. Who are they? As you may (or may not) know, the so-called "High-Frequency" trading utilizes the very small differences in the prices of trading instruments (stocks, etc.) that occur over time. The idea has nothing to do with "HF" like shortwave radio, but rather it is the notion that if one can buy or sell a tiny fraction of a second before someone else, differences in prices may be exploited. One of the aspects of this type of trading is that conventional means of data transport (e.g. fiber optics) is too "slow": Light travels at about 1/3 the speed as in open air through a glass fiber and this means that compared to a radio wave on a "direct" path, data transmitted via fiber will arrive later - and this does not include delays due to the equipment in that data network. What this means is that some entities are experimenting with the use of the HF bands for the most direct, point-to-point means of conveying this information possible - and it seems that some of this information is being transmitted on amateur bands, as the above indicates. Not surprisingly, these entities are very secretive - but others have done a bit of digging in public, FCC databases. Here are a few links: * ARRL News article about "High Frequency Trading". * QRZ thread about "High Frequency" trading. * "Sniper in Mahwah and Friends" article about High Frequency Trading. As noted in the QRZ thread, the Part 5 experimental license frequency includes the entirety of the 20 meter band, with no requirement for identification. While many amateurs seem to be surprised about this, I was not: There are several instances where Part 5 licenses have been issued (I can provide an example via email) - the applicant providing frequency ranges in their application that encroach on any number of other services - and been issued permission to operate there - but there's typically a caveat: They are not to interfere with existing, licensed services. It's this last point that's a bit tricky. Anyone that has operated on HF knows that this is a dicey proposition as it's entirely possible that other users of a particular frequency may not be able to hear - or be heard by - the "offending" station. As an example, if station "A" and "B" are in QSO - but the offending station can only hear - or be heard by - station "A", it cannot "know" to avoid transmitting while station "B" is transmitting. It would seem that those who make the rules have overlooked this particular of aspect of HF propagation when it comes to utilizing HF "whitespaces" (e.g. seemingly-unused frequencies.) "I've been getting QRM'ed - what can I do?" The complete list frequencies on which these operations are currently unknown - and the fact that they are not assigned specific channels may make such information impossible to know other than by direct observation. So far, the two frequencies of which I'm aware is that depicted above (around 14.350 MHz) and another around 4.4 MHz - but I have little doubt that there are others: If you spot similar signals on other frequencies, please comment. If you note similar interference issues, please contact your amateur radio representative. In the U.S., you may contact the Volunteer Monitor program at the ARRL (see information here.) Unfortunately, a quick search did not reveal any specific contact information regarding this program: If you have such information, please let me know via a comment. * * * Update: "Luke" noticed this post and tweeted it, emailing me a few links: Here's a bit of information others have dug up: * Delmarva Broadband is authorized 14.35-14.99 MHz at 186 kW. Contact is a law office in DC. See https://apps.fcc.gov/els/ GetAtt.htm * ... and M-Wave is authorized the 14-14.99 MHz at 16 kW. See https:/ /apps.fcc.gov/els/GetAtt.htm This page stolen from ka7oei.blogspot.com. [End] Posted by KA7OEI at 9:10 AM # Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest Labels: 20 meters, ARRL, HFT, High Frequency Trading, official observer, qrm, volunteer monitor No comments: Post a Comment PLEASE NOTE: While I DO appreciate comments, those comments that are just vehicles to other web sites without substantial content in their own right WILL NOT be posted! If you include a link in your comment that simply points to advertisements or a commercial web page, it WILL be rejected as SPAM! Newer Post Older Post Home Subscribe to: Post Comments (Atom) Blog Archive * V 2020 (15) + V December (2) o Locking the Icom IC-910H to an external 10 MHz (GP... o Intruder at the top of the 20 meter amateur band? + > November (2) + > October (1) + > September (2) + > July (2) + > June (1) + > May (2) + > April (1) + > March (1) + > January (1) * > 2019 (15) + > December (2) + > November (2) + > October (1) + > September (1) + > August (1) + > June (1) + > May (1) + > April (1) + > March (1) + > February (2) + > January (2) * > 2018 (13) + > November (1) + > October (2) + > September (1) + > August (1) + > June (1) + > May (1) + > April (1) + > February (3) + > January (2) * > 2017 (24) + > December (3) + > November (3) + > October (2) + > September (2) + > August (2) + > July (1) + > June (2) + > May (1) + > April (2) + > March (2) + > February (2) + > January (2) * > 2016 (16) + > December (3) + > November (2) + > October (1) + > September (1) + > August (2) + > July (1) + > June (1) + > May (1) + > April (1) + > March (1) + > February (1) + > January (1) * > 2015 (17) + > December (2) + > November (3) + > October (1) + > September (2) + > August (1) + > July (1) + > May (1) + > April (1) + > March (2) + > February (1) + > January (2) * > 2014 (17) + > December (1) + > November (1) + > October (2) + > September (1) + > August (2) + > July (1) + > June (1) + > May (1) + > April (1) + > March (1) + > February (3) + > January (2) * > 2013 (26) + > December (1) + > November (2) + > October (3) + > September (2) + > August (2) + > July (1) + > June (2) + > May (3) + > April (1) + > March (3) + > February (1) + > January (5) * > 2012 (26) + > December (1) + > November (1) + > October (2) + > September (3) + > August (3) + > July (3) + > June (4) + > May (9) # Subscribe To [arrow_drop] [icon_feed1] Posts [subscribe-] [subscribe-] [icon_feed1] Atom [arrow_drop] [icon_feed1] Posts [arrow_drop] [icon_feed1] Comments [subscribe-] [subscribe-] [icon_feed1] Atom [arrow_drop] [icon_feed1] Comments # Translate # Labels * "Faraday Flashlight" * "Faraday Torch" * 1:1 balun * 1:4 balun * 10 GHz * 10 meter dsb qrp transmitter * 10 MHz * 100 watt * 1171t * 12 volt * 15 kHz low pass filter * 160 * 1J18B * 1J37B * 1L6 * 1L6 substitute * 1LA6 * 1R5 * 1Zh18B * 1Zh37b * 1Zh18B * 1Zh37B * 2 meters * 20 meter * 20 meter filter * 20 meters * 2200 * 2200 meter band * 2200 meters * 222 MHz * 23cm * 24 GHz * 24 volt * 28 pin AVR * 3-500Z * 30.2 MHz * 4 wheeler * 40 meter * 4000 meter band * 4000 meters * 41 meter * 4315b * 50 ohm * 6 meter beacon * 6 meters * 60 kHz * 630 * 630 meter band * 630 meter lowpass * 630 meters * 70cm * 75 ohm * 75 ohm splitters in 50 ohm systems * 8 bit A/D converter * 8 pin AVR * 86730 * 87315 * A Battery * A/D converter * AB Battery * AC * AC filtering * AC powerwall * accuracy * active antenna * active filter * active whip * AGC * alignment * AM * AM beacon * AM broadcast * am lowpass * Amateur Radio * amplifier * amplitude modulator * annular eclipse * Antenna * antenna gain * antenna pattern analysis * antenna support * antenna switching for interference reduction * APD * APT * Arches National Park * arcs * ardf * Arduino * ARGO * ARRL * ARRL Field Day * atan * atan2 * Atmel * atomic clock * ATS-3A * attention-getting * attenuation * audio filter * audio hum filter * audio low pass filter * audio transformer * auto tuner * automatic volume tracker * autotransformer * Avalanche Photodiode * AVR * B Battery * BA5SBA * BA5SBA converter * BA5SBA SDR dongle * Baader * back-up * backpacking * balanced line * balanced modulator * ballast interference * balun * balun designs * band reject filter * band-pass * band-reject * bandpass filter * bass response * batter equalization * battery * battery charging * battery cut out * battery disconnect * battery isolator * battery pack * battery tester * BBAI * BBG * bcb lowpass * beacon * Beaglebone * bfo * bifilar * bill of materials * blank display * blink * blink brake * BN43-202 * bobbin * BOM * bp/br * brake light modulator * breaker * brick * broadcast band * BS170 * BSH12-N406L * BT-168D * cable * calibration * capacitor arcing * capacitor dropper * capacitor flashlight * capacitor melting * capacitor plate * capacitor plate damage * capacitor power supply * capacitor repair * catv * cavity * cell memory * cells * ceramic filter * charge * charge controller * charge equalization * charge equalizer * charge maintenance * charging * chinese battery tester * Chionaspis pinifoia * choke * circuit * circular polarization * circularly polarized * Class-E * clipper * clock not setting * coax * coax balun * coaxial balun * coherent * coherer * Colorado River * comb filter * combiner * common point ground * compressor * configuration * constant voltage * construction * Courthouse Wash * crossover * crystal heater * crystal oven * ct * CTCSS * Cuba * current monitor * current transducer * Cushman CE-50A * Cushman Communications Monitor * Cushman service monitor * CW * Cybernator * cycloid * cycloid dipole * daylight optical communications * daylight-tolerant optical receiver * daylight-tolerant receiver * dbm * DC * DC filtering * DC powerwall * DCF77 * DDS * DDS FM * DDS FM Modulator * de-emphasis * decoder * decoding * dendrite * deviation meter problem * DG8SAQ * diagram * diplexer * direct digital synthesis * direction finding * directional coupler * display * Display at sign * distortion analyzer * distortion meter * dongle * doubly-balanced mixer * Drake * Drake AC-3 * Drake AC-4 * Drake TR-3 * Driver Interference * DS7102 * dsb * DSP * DSP FM modulator * dual band * duplexer * dynamic range * E-field * E-field whip * E150 * Ebay RTL upconverter * Eclipse * Edcor * EEPROM * efhw * electrical panel * electronic ballast * Electronic Goldmine * ELT * EMC * EMI * end-fed half-wave * Enphase * Enphase M190 * EOS * EPIRB * equalization * equalization circuit * ESP8266 * external lock * external reference * eye protection * F connector * failure * fake glasses * fake viewing glasses * feeding balance line with a tuner * ferrite * FET * field day * field strength meter * Fifi SDR * filament regulator * filament transformer * fill factor * filter * filter for FM modulator * filtering * final * final transistor * FIR Filter * fixing bricked RTL-SDR dongle * flasher * float charger * floaty-thingie * fluorescent interference * fluorescent QRM * flyback * flyback transformer * FM * FM transmit * format change * fox hunting * fractional * fractional phase adjustment * free space * free space optical communications * free-space optical communication * frequency re-use * frequency response * frequency stability * frequency synthesis * Friendship Cruise * Fronius * FSO * FSO communications * fst4 * fst4w * FT-530 * FT-757GXII * ft-817 * FT50-75 * Fun Cube * G20787 * GaAsFET preamp * gain * gate current * gate current amplifier * generator * GFCI * Glencom * Goertzel * goofy light * gps * GPS antenna * GPS Frequency reference * GPS receiver * GPSDO * Green River * grid-tie * ground fault circuit interruptor * grow light RFI * H-500 * H-500 alignment * half-wave matching * Ham Radio * Handie-talkie * Harbor Freight 68691 * harmonics * Heathkit HL-2200 * Heathkit SB-220 * HELAPS * helium neon * HeNe Laser * HEX * hexode * HF * HF helical resonator * HF noise * HF RFI * HF transceiver * HFT * high current * High Frequency Trading * high pass * high voltage * High Voltage Supply * high-Q * Hiking * Hilbert transform * Hilbert transformer * HL-2200 * home power monitor * homebrew * homebrew shield * homebrew transformer * homemade shield * horizontal loop * HT * hum filter * humidity * IC-910H * ICSP * IF * if filter * IFR 1200 * IFR CPU * IFR FM/AM-1200S * IFR-1000S * IFR-1000S service monitor * IFR-1200S * IIR filter * improve sound * improving longevity * inaccuracy * inaccurate * inductor * insects * insertion loss * installation * Integrated DC amplifier * interference * interference from switching supply * interference to 2 meters * intermod * intermodulation * internal resistance * inverter * inverter noise * isolation * isolator * Isotemp * Isotemp 134-10 * jamming * jbl * JBL 2213H * jbl 4312 * jbl speaker * JBL speaker rebuild * jfet * jfet gate current * JJY * Joule Thief * jt9 * KA-801 * KA-8011 * Kenwood * kill-a-watt * kill-a-watt repair * Kiwi SDR * kiwirecorder * KiwiSDR * kiwiwspr * KT-7900D * KVA * l-400b * L-Band * l/c filter * laser * laser communications * laser communicator * Laser Modulator * laser pointer * laser pwm modulator * laser voice communicator * lazy loop * lcd shield * lead acid * Lead-Acid * LED * led communications * LED communicator * LED Driver * LED filtering * LED Interference * LED modulator * left-right * legal * lens error * lens problem * lens stuck * lens won't extend * lens won't work * lf * LF Engineering * LF-400B * LHCP * LiFePO4 * LiFePO4 batteries * LiFePO4 battery * LiFePO4 equalization * lifetime * light bulb * light bulb protectors * lightbeam communications * lightning damage * LiIon * line voltage * lithium * Lithium battery pack upgrade * lithium iron phosphate * LO * loading coils * local oscillator * locking DDS to 10 MHz * longevity * longwave * longwave receiver * low pass * low voltage cut-out * low voltage disconnected * low-dropout * LowFER * lowpass * lowpass filter * M-6 * M0NKA * M190 * M215 * M250 * magnet wire * mains hum filter * Marantz 2110 scope * Marantz 2110 transformer * master reset * matching * matching network * Maxewell Boostcap * Maxwell capacitor * mcHF * mcHF SDR transceiver * McKenzie * mechanical * Mechanically powered flashlight * MedFER * MedFER beacon * Mediumwave * memory * memory clear * meters * MF * microcontroller * microinverter * mini circuits * Mini-Circuits * mismatch * Moab * mobile transceiver * modulated light * modulatedlight * modulating laser pointer * modulation * modulator * monitor * more power * morse * motorcycle brake light * mppt * myantennas * narrowband filter for HF * neon * neon supply * NiCd * Nikon * Nikon S8100 * NiMH * nixie * nixie supply * Noise * noise detector * noise figure * noisy fan * noncoherent * notch depth * notch filter * Nyquist * NZ-1 * OCXO * official observer * omnidirectional * omnidirectional circularly polarized * open source * optical communications * optical detector * optical receiver * Optimizers * oscilloscope * oven * overdrive * overheated resistor * overload * overload prevention * Owon * P300 * P400 * paint can filter * pbox * PD85004 * pentagrid converter * perturb and observe * phase adjustment * photodetector * photodiode * photodiode receiver * photovoltaic * PIC * PIC DSP * PIC programmer * PIC PWM * PIC16F1847 * PIC16F88 * PICkit 3 * Picstart * Picstart Plus * PID * PID loop * PIN Photodiode * pine needle scale * pine needle spots * pine tree * pinhole photograph * pinhole photography * PL * PL decoder * PL tone * Plate Supply * plate transformer * PLL * POES * Polaris * power choke * power conditioner * power factor * power supply * power supply interference * power switch * power transformer * Power Wall * powering hf rig from D cells * PowerWall * preamp * processor reset * programmer * programming * programming board * programming socket * ProgRock * Project Red Line * protection circuit * PSK31 * push-pull tube amplifier * PV * PWM * Q-bit * QB-300 * qrm * QRM from USB power adapters * qrm prevention * QRP * QRP Labs * QRP-labs * QRSS * QRSS3 * quad band * quarter-wave matching * QYT * radio communications * radio frequency interference * Radio Habana Cuba * Radio Shack 22-510 * Radio Shack switching supply * Raspberry Pi * RaspberrySDR * reactance * receiver * reconekits.com * regulator * relay * remote antenna * remote squelch control * remove cover on DS7102 * remove cover on Owon oscilloscope * repair * repeater * repeater antenna pattern * repeater coverage * repeater frequency control * resistance * resistor lead weakening * reversal * RF * RF enclosure * rf processor * RF susceptibility * RFI * RFI filtering * RFI prevention * rfi reduction * RFI suppression * RHCP * ring and stub * rod tube * RTL SDR HF converter * RTL SDR upconverter * rtl_eeprom * RTL-SDR * RTL-SDR dongle * RTL-SDR eeprom * RTL.SDR * RTL2832 * Rubidium * russian rod tube * RV battery * RV generator start battery * S1800 * S8100 lens error fix * SA-2060 tuner * Samlex 1223 * Samlex switching supply * SARSAT * satellite * satellite speaker * SB-220 * schematic * scintillation * scots pine * sdr * SDR receiver * SDR Sharp * SDR transceiver * SDR upconverter * SDR# * SDRPlay * selective signal meter * Sense * Sense home energy monitor * sensitivity * separate hf receive antenna * separate receive antenna * series string * series-string * service monitor * shading * shake light * shake light power * shake light transmitter * shake powered transmitter * shield * shielding * shortwave spurious signal * shunt regulator * Si5351a * signal * signal booster * signal level measurement * signal meter * signal strength * sine * sine generator * sine wave * sine wave UPS * single sideband * Skyscan * Skyscan 86715 * skyscan atomic clock * skyscan bug * Skyscan clock * Skyscan clock not setting * sm3 * smd * smoke * SocoTran * Software Defined Radio * Software Defined Transceiver * solar * Solar charge controller * solar charger * solar eclipse * Solar Film * Solar Filter * solar panel * solar power * SolarEdge * Solargraph * sound card * source code * SP-75 * spark gap * spark gap transmitter * speaker * speaker limiter * speaker protection * speaker protector * speaker rebuild * spectran * spectrum lab * spectrum scope * Speech Processor * speedo * speedo repair * speedometer * speedometer repair * split transmit receive antennas * splitter * Sportsman * Sportsman 500 * spurious signal * spurious signals * spurs * squealing * squealing motor * squelch * squelch noise * ssb * ssb filter * ST-7900D * stand-alone transceiver * standalone SDR transceiver * stereo modulator * strong signals * subaudible * subaudible tone * subaudible tone decoder * subaudible tone encoder * subwoofer * Sun * Sunnyboy * supply * surface mount * susceptibility * swbc * switch * switch repair * switcher * switcher noise * switching power supplies * Switching power supply * switching supply * switching supply interference * synchronous repeater * synthesis * synthesized * synthesizer * t/r antenna switching * T8 ballast * T8 interference * T8 tube * tantalum capacitor * tantalum capacitor exploding * tap * TCXO * TDOA * telemetry * temperature * temperature control * Tesla * thermal coefficient * thermistor * through the air * TIA * TL431 * tone decoder * tone encoder. PL tone * too much bass * TR-7 * transceiver * transfer * transfer relay * transfer switch * transformer * transformer bobbin * transformer replacement * transformer winding * transimpedance amplifier * transmit converter * transmitter * Transoceanic * transverter * tripping on RF * TS-450 * TS-450 tuner motor lubrication * tube radio * TUNE capacitor * tuner * tuner efficiency * tuner potentiometer adjustment * turns ratio * turnstile antenna * TV * UARC * UHF * Ultimate 3S * ultracapacitor * Upconverter * upgrade * upgrade nicd to lithium * upgrade nimh to lithium * UPS * UPS interference * USB * USB charger * USB power adapter interference * using power transformers for audio * Utah * Utah Amateur Radio Club * variable capacitor * variometer * VC510 * VCO * VCXO * Venus Sun transit * Venus Transit * VHF * VHF RFI * viewing glasses * vlf * VNA * voice coil * volt-amps * voltage converter * voltage monitor * volume tracking * volunteer monitor * voter * voting controller * voting receiver * voting receivers * voting repeater * W6POP * W6QYY * WA7ARK * WA7X beacon * waterfall * waterfall display * weak signal * Weather Satellite * WebSDR * Wednesday Night Hike * whip antenna * WiFi * winding * winding machine * wire size * woofer rebuild * wsjt-x * WSPR * WSPR beacon * wsprd * wsprdaemon * WVNA * WWVB * WWVB clock * WWVB format * WWVB simulator * Yaesu * Yaesu FT-530 * Z3801 * Zenith * Zenith TransOceanic * zero dropout regulator * ZFDC-20-3 * ZFSC-2-1 * ZFSC-4-1 * ZFSC-4-3 * ZIF socket # (c) 2012 by Clint, KA7OEI and other parties as noted. Simple theme. Theme images by merrymoonmary. Powered by Blogger. #