Last updated: 2021, October 22 11:46:01
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  • Yet another ferrite toroid calculator – but is it any good? – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – signal / noise degradation (SND) – more detail – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – signal / noise degradation (SND) – owenduffy.net
  • Signal to noise degradation (SND) concept – owenduffy.net
  • Gamma matches get blamed for a lot of stuff – owenduffy.net
  • Estimating characteristics of a sample of coax from dimensions and properties – owenduffy.net
  • On testing two wire line loss with an analyser / VNA – part 3 – owenduffy.net
  • On testing two wire line loss with an analyser / VNA – part 2 – owenduffy.net
  • On testing two wire line loss with an analyser / VNA – part 1 – owenduffy.net
  • The mower appears affected by Ethanol – owenduffy.net
  • The mulcher appears affected by Ethanol – owenduffy.net
  • Do I ‘need’ a masthead preamp to work satellites on 2m? – G/T vs G/Ta – owenduffy.net
  • QEX on SWR dependence on output impedance #2 – owenduffy.net
  • Chinese chainsaw review – SX25 #1 – owenduffy.net
  • QEX on SWR dependence on output impedance – owenduffy.net
  • Measurement of one of those ham lore components – figure 8 twinline – owenduffy.net
  • Do I ‘need’ a masthead preamp to work satellites on 2m? – terrestrial noise scenario – owenduffy.net
  • Honda GX390 6kVA genset maintenance – owenduffy.net
  • Do I ‘need’ a masthead preamp to work satellites on 2m? – space noise scenario – owenduffy.net
  • MFJ-261 – review of review – owenduffy.net
  • On testing coax cable loss with an analyser / VNA – part 4 – owenduffy.net
  • On testing coax cable loss with an analyser / VNA – part 3 – owenduffy.net
  • On testing coax cable loss with an analyser / VNA – part 2 – owenduffy.net
  • On testing coax cable loss with an analyser / VNA – part 1 – owenduffy.net
  • Review of inexpensive Chinese thermostat – DST1020 – owenduffy.net
  • Small 2-stroke engines and popoff pressure – owenduffy.net
  • Small engines and green fraud – owenduffy.net
  • JDY-31 Bluetooth SPP module – owenduffy.net
  • IoT water tank telemetry project – 4-20mA / 1MPa pressure transducer trial – owenduffy.net
  • Measuring a 1/4 wave balanced line – nanoVNA – owenduffy.net
  • Measure transmission line Zo – nanoVNA – PVC speaker twin – loss models comparison #3 – owenduffy.net
  • IoT water tank telemetry project – HC-SR04 – third trial – owenduffy.net
  • Measure transmission line Zo – nanoVNA – PVC speaker twin – loss model derivation – owenduffy.net
  • CirroMazzoni Baby small transmitting loop – a desk study – owenduffy.net
  • A template for an air filter foam element – owenduffy.net
  • IoT water tank telemetry project – HC-SR04 – second trial – owenduffy.net
  • Pitfalls of series stub matching with coax – owenduffy.net
  • IoT water tank telemetry project – JSN-SR04T-3.0 – first trial – owenduffy.net
  • BME280 vs BMP280 – owenduffy.net
  • IoT water tank telemetry project – ultrasonic sensor – owenduffy.net
  • IoT water tank telemetry project – GY-US42v2 – first trial – owenduffy.net
  • Coil former made of cast acrylic sheet – owenduffy.net
  • IoT water tank telemetry project – HC-SR04 – first trial – owenduffy.net
  • An interesting study in the effect of fixture on impedance measurement – owenduffy.net
  • A common scheme for narrow band match of an end fed high Z antenna – surely it is a 1:9 transformer? – owenduffy.net
  • A common scheme for narrow band match of an end fed high Z antenna – owenduffy.net
  • Replacing the crystal in a Seiko V158-0AD0 watch – owenduffy.net
  • IoT water tank telemetry project – ultrasonic sensor – HC-SR04 – owenduffy.net
  • Stacking two ferrite cores of different permeability for an RF inductor – owenduffy.net
  • Differences in two similar simple untuned small loop configurations – owenduffy.net
  • IoT – owenduffy.net
  • You are being redirected...
  • The fine print – owenduffy.net
  • nanovna – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – owenduffy.net
  • owenduffy.net – Page 2 – Mostly electronics…
  • owenduffy.net – Page 146 – Mostly electronics…
  • October 2021 – owenduffy.net
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  • December 2018 – owenduffy.net
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  • December 2017 – owenduffy.net
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  • December 2016 – owenduffy.net
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  • December 2015 – owenduffy.net
  • November 2015 – owenduffy.net
  • October 2015 – owenduffy.net
  • September 2015 – owenduffy.net
  • August 2015 – owenduffy.net
  • July 2015 – owenduffy.net
  • ESP8266 IoT BME280 temperature, humidity and pressure – 06/2021 update – owenduffy.net
  • IoT water tank telemetry project – part 4 – owenduffy.net
  • Reassembling a certain common chainsaw clutch – owenduffy.net
  • Another small efficient matching transformer for an EFHW – 2643251002 – owenduffy.net
  • Shorting winding sections of a ferrite cored EFHW transformer – owenduffy.net
  • RF Power Meter 2 (RFPM2) – display update – owenduffy.net
  • Small efficient matching transformer for an EFHW – a Simsmith model – owenduffy.net
  • A simple generic Simsmith model of a linear push-pull Class B broadband HF power amplifier – owenduffy.net
  • Ferrite cored inductors at HF – flux, loss and saturation – owenduffy.net
  • SNTP synchronised clock v1 – boxing it up – owenduffy.net
  • owenduffy.net – Page 145 – Mostly electronics…
  • EB104 alternative output circuit – owenduffy.net
  • A desk review of the MiniPa100 kit – #2: transformer T2 turns ratio – owenduffy.net
  • Desk study of M0DGQ’s 150W HF PA – owenduffy.net
  • A desk review of the MiniPa100 kit – #1: characterise the output transformer – owenduffy.net
  • SNTP synchronised clock v1 – display options – owenduffy.net
  • SNTP synchronised clock v1 – a preview – owenduffy.net
  • Fix for a certain TM1637 LED display – owenduffy.net
  • Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ #2 – owenduffy.net
  • ESP8266, ESP32 reset – the (ugly) detail – owenduffy.net
  • owenduffy.net – Page 144 – Mostly electronics…
  • (How) does this balun work? A variation on the theme … – owenduffy.net
  • Logging temperature meter (ltm) v1 – DS1820B support – owenduffy.net
  • Some pretty woolly thinking on measuring Thevenin equivalent source impedance of a ham transmitter – owenduffy.net
  • Measure transmission line Zo – nanoVNA – PVC speaker twin – owenduffy.net
  • Logging temperature meter (ltm) v1 – reducing ADC noise – owenduffy.net
  • Collins 30-L1 on FT-8 – owenduffy.net
  • A 1:1 RF transformer for measurements – based on noelec 1:9 balun assembly – owenduffy.net
  • Logging temperature meter (ltm) v1 – prototype trial run measuring ECT – owenduffy.net
  • RF Power Meter 2 (RFPM2) – update 04/21 – owenduffy.net
  • Logging temperature meter (ltm) v1 – prototype VY NTC calibration – owenduffy.net
  • N6THN’s novel balun – flux leakage – owenduffy.net
  • A handy 230VAC 15A inline power meter based on an inexpensive module from eBay – owenduffy.net
  • owenduffy.net – Page 143 – Mostly electronics…
  • N6THN’s novel balun – an explanation – owenduffy.net
  • N6THN’s novel balun – owenduffy.net
  • Logging temperature meter (ltm) v1 – prototype Vin calibration – owenduffy.net
  • Logging temperature meter (ltm) v1 – a preview – owenduffy.net
  • Engine coolant temperature sensors – a closer look – owenduffy.net
  • Phase nonsense – owenduffy.net
  • RK2672AM – calibration – owenduffy.net
  • Diagnosis of engine coolant temperature gauge issue with a certain vehicle – owenduffy.net
  • A handy 230VAC 10A inline power meter based on an inexpensive module from eBay – owenduffy.net
  • Baofeng UV-5R battery and charging experience – owenduffy.net
  • Comment on KN5L on balun CMRR – series through impedance fixture – owenduffy.net
  • owenduffy.net – Page 142 – Mostly electronics…
  • Comment on KN5L on balun CMRR – two wire line example – owenduffy.net
  • Comment on KN5L on balun CMRR – coax example – owenduffy.net
  • ESP8266 IoT BME280 temperature, humidity and pressure – owenduffy.net
  • ESP8266 IoT DHT22 temperature and humidity – evolution 3 – owenduffy.net
  • Baofeng BF-T1 (BF-9100) – initial impressions – owenduffy.net
  • Comparing sensitivity figures of an AM receiver and SSB receiver – owenduffy.net
  • Low power Guanella 1:1 balun with low Insertion VSWR using a Fair-rite 2×2631540002 – measurement of Zcm – owenduffy.net
  • Low power Guanella 1:1 balun with low Insertion VSWR using a Fair-rite 2843009902 binocular – measurement of Zcm – owenduffy.net
  • RF Power Meter 2 (RFPM2) – owenduffy.net
  • Baofeng BF-F8HP battery and charging experience – owenduffy.net
  • Baofeng GT-5TP battery and charging experience – owenduffy.net
  • Small efficient matching transformer for an EFHW – owenduffy.net
  • Low power Guanella 1:1 balun with low Insertion VSWR using a Fair-rite 2843009902 binocular – design workup – owenduffy.net
  • Review of MXITA SMA-8 #2 – owenduffy.net
  • owenduffy.net – Page 141 – Mostly electronics…
  • Return Loss Bridge – some woolly thinking – a Simsmith model of a reflection bridge – owenduffy.net
  • Return Loss Bridge – some woolly thinking – owenduffy.net
  • Low power Guanella 1:1 balun with low Insertion VSWR using a pair of Fair-rite 2631540002 suppression sleeves – design workup – owenduffy.net
  • Transmission line filter for a field day station – implementation – owenduffy.net
  • On Insertion Loss – owenduffy.net
  • Transmission line filter for a field day station – designs – owenduffy.net
  • owenduffy.net – Page 140 – Mostly electronics…
  • Measuring OC and SC transmission line sections – owenduffy.net
  • (How) does this balun work? – owenduffy.net
  • Estimating transmission line Zo – λ/8 method – nanoVNA – success – owenduffy.net
  • A magnetics review of the VK3AMP Sontheimer directional coupler – owenduffy.net
  • Basic measurements of the VK3AMP Sontheimer directional coupler for a N2PK wattmeter – owenduffy.net
  • Failure estimating transmission line Zo – λ/8 method – nanoVNA – Smith chart perspective – owenduffy.net
  • Failure estimating transmission line Zo – λ/8 method – nanoVNA – owenduffy.net
  • Select a ferrite core material and sufficient primary turns for a low InsertionVSWR 50Ω broadband RF transformer – comparison of measured and predicted – owenduffy.net
  • Fair-rite’s ‘new’ #43 permeability data (2020) – owenduffy.net
  • A Smith chart should go round in circles – owenduffy.net
  • Surely there cannot be more forward power than the transmitter makes? – owenduffy.net
  • owenduffy.net – Page 139 – Mostly electronics…
  • Select a ferrite core material and sufficient primary turns for a low InsertionVSWR 50Ω broadband RF transformer – nanoVNA – loss components graph – owenduffy.net
  • A DIY thermostat based on the MS1230A controller – owenduffy.net
  • Select a ferrite core material and sufficient primary turns for a low InsertionVSWR 50Ω broadband RF transformer – nanoVNA – owenduffy.net
  • Phase of s11 and Z – owenduffy.net
  • The quarter sized G5RV with hybrid feed – owenduffy.net
  • A thermostatically controlled pot for waxing leg hold traps – owenduffy.net
  • The devil is in the detail… – owenduffy.net
  • Optimal common mode impedance of a common mode choke – owenduffy.net
  • Fox flasher MkII update 2/2021 – owenduffy.net
  • Improving ‘s21 shunt-through’ measurement of low impedances – more detail – owenduffy.net
  • Improving ‘s21 shunt-through’ measurement of low impedances – owenduffy.net
  • owenduffy.net – Page 138 – Mostly electronics…
  • Antenna system resonance and the nanoVNA – owenduffy.net
  • Improving ‘s21 series-through’ measurement of high impedances – more detail – owenduffy.net
  • Improving ‘s21 series-through’ measurement of high impedances – owenduffy.net
  • Nichols: The Two Bird Experiment – a Simsmith model – owenduffy.net
  • Calculate Loss from s11 and s21 – convenient online calculator – owenduffy.net
  • Measure transmission line Zo – nanoVNA – CCS RG6 – owenduffy.net
  • Nichols: The Two Bird Experiment – owenduffy.net
  • Conductors for a Guanella 1:1 balun – discussion – owenduffy.net
  • The requisite knowledge does not come in the box – owenduffy.net
  • nanoVNA – touch screen problems – owenduffy.net
  • nanoVNA – measure Transmission Loss – example 5 – owenduffy.net
  • Low power Guanella 1:1 balun with low Insertion VSWR using a pair of Jaycar LF1260 suppression sleeves – owenduffy.net
  • owenduffy.net – Page 137 – Mostly electronics…
  • High voltage test of a couple of PTFE insulated silver plated copper wires – owenduffy.net
  • An example and explanation of unexpected common mode choke flashover – owenduffy.net
  • Mornhinweg ferrite core measurements – #61 – owenduffy.net
  • Using complex permeability to design with Fair-rite suppression products – owenduffy.net
  • Black body emissivity of ferrite core material – owenduffy.net
  • Calculate ferrite cored inductor – rectangular cross section – enhancement – chamfered corners – owenduffy.net
  • MH1210A, MH1230A operating instructions – owenduffy.net
  • Jaycar LO1238 ferrite core – owenduffy.net
  • Mornhinweg ferrite core measurements – #31 – owenduffy.net
  • Gauss based ferrite core loss – owenduffy.net
  • Disturbing the thing being measured – coax line – owenduffy.net
  • Amidon’s method of rating ferrite inductors and transformers – owenduffy.net
  • owenduffy.net – Page 136 – Mostly electronics…
  • Quantifying performance of a simple broadcast receive system on MF – owenduffy.net
  • nanoVNA – measure Transmission Loss – example 4 – owenduffy.net
  • KL7AJ on the Conjugate Match Theorem – analytical solution – Simsmith – owenduffy.net
  • nanoVNA – measure Transmission Loss – example 3 – owenduffy.net
  • nanoVNA – measure Transmission Loss – example 2 – owenduffy.net
  • owenduffy.net – Page 135 – Mostly electronics…
  • nanoVNA – measure Transmission Loss – example 1 – owenduffy.net
  • Magnitude and phase of V2/V1 for a 180° transmission line section – owenduffy.net
  • Antennas – Page 2 – owenduffy.net
  • Magnitude and phase of I2/V1 for a 90° transmission line section – owenduffy.net
  • Magnitude and phase of V2/V1 for a transmission line section – owenduffy.net
  • ?feed=rss2&cat=22
  • Tuning electrical line length using phase of measured s21 – nanoVNA – owenduffy.net
  • PERL vs Python pre / post processing NEC – owenduffy.net
  • The j value – owenduffy.net
  • Applying the RG6/U to a 40m Inverted V Dipole antenna – owenduffy.net
  • On measuring antennas through integral halfwaves of transmission line – owenduffy.net
  • On the measured phase of s11 in a matched system – owenduffy.net
  • Applying the RG11A/U to a 40m Inverted V Dipole antenna – owenduffy.net
  • 144MHz beacon observation from Wellington NSW – 3 aircraft reflections – owenduffy.net
  • Checkout of a roll of Commscope 4510404 CCS RG11A/U – Zoc, Zsc based MLL calculation – nanoVNA – owenduffy.net
  • Steel as an antenna radiator – owenduffy.net
  • Fox flasher MkII – owenduffy.net
  • owenduffy.net – Page 134 – Mostly electronics…
  • Checkout of a roll of Commscope 4510404 CCS RG11A/U – Zoc, Zsc based MLL calculation – owenduffy.net
  • Checkout of a roll of Commscope 4510404 CCS RG11A/U – owenduffy.net
  • A walkthrough of using a Rigexpert AA-600 to make a quick measurement of loss of a new roll of CCS RG11 – owenduffy.net
  • A model of current distribution in copper clad steel conductors at RF – comparison with Severns 2000 – owenduffy.net
  • High and low Z responses of a resonant / antiresonant shorted / open transmission line section – owenduffy.net
  • KB1CKT measurement of a roll of RG6/U – owenduffy.net
  • Loss of ladder line: copper vs CCS (Seminole 1320 vs 1321) – KN5L’s measurements – owenduffy.net
  • Loss of ladder line: copper vs CCS (DXE-LL300-1C) – KN5L’s measurement 11/2020 – owenduffy.net
  • A low cost two wire transmission line using high strength aluminium MIG wire and agricultural trellis clips – owenduffy.net
  • owenduffy.net – Page 133 – Mostly electronics…
  • RG6/U with CCS centre conductor – shielded twin study – why is it so lossy? – owenduffy.net
  • nanoVNA – evaluation of a voltage balun – RAK BL-50A – owenduffy.net
  • Loss of ladder line: copper vs CCS (DXE-LL300-1C) – revised for 25/07/2018 datasheet – owenduffy.net
  • nanoVNA – evaluation of a voltage balun – W2AU 1:1 – owenduffy.net
  • what-exactly-happens-to-the-signals-hitting-a-common-mode-choke? – owenduffy.net
  • Some pretty woolly thinking about the operation of common mode chokes in antenna systems – owenduffy.net
  • Active monopole + RTL SDR + RPi Spyserver experiment – owenduffy.net
  • The devil is in the detail – real world transmission lines and loss under standing waves – owenduffy.net
  • The devil is in the detail – real world transmission lines and ReturnLoss – owenduffy.net
  • 4:1 current balun – review and fix – owenduffy.net
  • owenduffy.net – Page 132 – Mostly electronics…
  • Measurement of recent ‘FT240-43’ core parameters – owenduffy.net
  • nanoVNA – RG6/U with CCS centre conductor MLL measurement – owenduffy.net
  • RG6/U with CCS centre conductor – shielded twin study – owenduffy.net
  • nanoVNA – measuring cable velocity factor – demonstration – open wire line – owenduffy.net
  • ESP32 WROOM32 – A possible fix for failure of auto-program facility – owenduffy.net
  • Battery contact corrosion on digital calipers – owenduffy.net
  • Working a common mode scenario – VK2OMD – voltage balun solution – owenduffy.net
  • Working a common mode scenario – G3TXQ Radcom May 2015 – voltage balun solution – owenduffy.net
  • Working a common mode scenario – G3TXQ Radcom May 2015 – owenduffy.net
  • Photo Voltaic Array – unbelievable efficiency from Chinese sellers – owenduffy.net
  • owenduffy.net – Page 131 – Mostly electronics…
  • A dipole centre insulator from HDPE cutting board – owenduffy.net
  • Windows 10 – sound device Signal Enhancements – owenduffy.net
  • nanoVNA – experts on improvised fixtures – owenduffy.net
  • Sydney harbour is a beautiful place – owenduffy.net
  • Leaflet / OpenStreetMap map rendering on devices with tiny pixels – owenduffy.net
  • Simsmith bimetal line type – revision #1 – owenduffy.net
  • A model of current distribution in copper clad steel conductors at RF – capturing conductor curvature – owenduffy.net
  • Distance to fault in submarine telegraph cables ca 1871 – the leap expanded – owenduffy.net
  • owenduffy.net – Page 130 – Mostly electronics…
  • Review of MXITA SMA-8 – owenduffy.net
  • The ZS6BKW five band antenna – discussion of an NEC model – owenduffy.net
  • Distance to fault in submarine telegraph cables ca 1871 – owenduffy.net
  • An experimental propagation beacon on 144MHz – owenduffy.net
  • nanoVNA – tuning stubs using TDR mode – owenduffy.net
  • NEC sez… – owenduffy.net
  • SDR# (v1.0.0.1732) – channel filter exploration – owenduffy.net
  • A Smith chart view of EFHW transformer compensation – owenduffy.net
  • A model of current distribution in copper clad steel conductors at RF – owenduffy.net
  • Stacking of Yagis and antenna effective aperture – owenduffy.net
  • Desk review of the AAA-1C as an active dipole antenna – owenduffy.net
  • Small untuned loop for receiving – a design walk through #4 – owenduffy.net
  • owenduffy.net – Page 129 – Mostly electronics…
  • Noise figure of active loop amplifiers – the Ikin dynamic impedance method – owenduffy.net
  • Noise figure of active loop amplifiers – some thoughts – owenduffy.net
  • Small untuned loop for receiving – a design walk through #3 – owenduffy.net
  • RG6/U with CCS centre conductor at HF – owenduffy.net
  • Small untuned loop for receiving – a design walk through #2 – owenduffy.net
  • Small untuned loop for receiving – a design walk through #1 – owenduffy.net
  • Review of iFIX RT300M v2 LED tester – owenduffy.net
  • Finding the electrical length of the branches of an N type T – #4 – owenduffy.net
  • Loss of ladder line: copper vs CCS (DXE-LL300-1C) – owenduffy.net
  • Finding the electrical length of the branches of an N type T – #3 – owenduffy.net
  • Finding the electrical length of the branches of an N type T – #2 – owenduffy.net
  • Finding the electrical length of the branches of an N type T – #1 – owenduffy.net
  • Performance of a small transmitting loop with varying height – NEC-5.0 – owenduffy.net
  • owenduffy.net – Page 128 – Mostly electronics…
  • Adjustable plank refurbishment – owenduffy.net
  • Calculation of impedance of a ferrite toroidal inductor – from first principles – owenduffy.net
  • nanoVNA – measuring cable velocity factor – demonstration – coax – owenduffy.net
  • nanoVNA – measuring cable velocity factor – owenduffy.net
  • PllLdr application – ATTiny44 & AD9833 in Codan 6801 – owenduffy.net
  • Arduino Nano – FT232RL test pin floats – owenduffy.net
  • Small untuned loop for receiving – it’s not rocket science – owenduffy.net
  • nanoVNA-H – Deepelec test jig – owenduffy.net
  • YouLoop-2T and the self resonance bogey at MF/lowHF – owenduffy.net
  • Oyster conversion – #2 – 24W – owenduffy.net
  • Equivalent circuit of an antenna system – owenduffy.net
  • owenduffy.net – Page 127 – Mostly electronics…
  • LED plate analysis – 24W round plate with driver – owenduffy.net
  • (How) does this balun work? (Tonna / F9FT balun for Yagis) – owenduffy.net
  • Chinese R7s LED replacement – review – owenduffy.net
  • AD9833 / PllLdr checkout – owenduffy.net
  • STC-1000 firmware change – STC-1000B – owenduffy.net
  • Antenna analyser – what if the device under test does not have a coax plug on it? – owenduffy.net
  • 144MHz propagation experiment – antenna – owenduffy.net
  • Simsmith bimetal line type – owenduffy.net
  • LED Driver measurement – #2 – owenduffy.net
  • LED plate analysis – D44-22P-01 – owenduffy.net
  • owenduffy.net – Page 126 – Mostly electronics…
  • Rigexpert Antscope2 – v1.1.1 – owenduffy.net
  • Rigexpert AA-600 N connector dimensions – owenduffy.net
  • AIM4170 – de-embedding the feed line in remote measurement – a simple match – owenduffy.net
  • AIM4170 – de-embedding the feed line in remote measurement – owenduffy.net
  • LED lamp failure analysis – GU10 230VAC 7W – owenduffy.net
  • nanoVNA-H – measure ferrite transformer – Noelec balun – owenduffy.net
  • Chinese LED ratings – LED plate drivers – owenduffy.net
  • Chinese T8 LED 4′ tube teardown – owenduffy.net
  • VSWR ripple – owenduffy.net
  • Transformer loss from half return loss – owenduffy.net
  • owenduffy.net – Page 125 – Mostly electronics…
  • nanoVNA-H – another hardware fail – battery socket – owenduffy.net
  • TKDMR TD2B LED tester review – owenduffy.net
  • SND implications of variations on the untuned small loop at MF/lowHF – owenduffy.net
  • U-BLOX LEA-6T GPS module – for experiments – owenduffy.net
  • APRS duplicate removal – owenduffy.net
  • Osram Substitube tear down – owenduffy.net
  • Towards understanding the YouLoop-2T at MF/lowHF – owenduffy.net
  • A transmission line 1:4 impedance transformer – owenduffy.net
  • Small untuned loop for receiving – simple model with transformer – owenduffy.net
  • nanoVNA-H – Port 1 attenuator for improved what??? – owenduffy.net
  • Return Loss Bridge – some important details – owenduffy.net
  • owenduffy.net – Page 124 – Mostly electronics…
  • nanoVNA – promotion by cheats – owenduffy.net
  • nanoVNA-H – woolly thinking on MLL measurement – owenduffy.net
  • RG6 cladding thickness report – owenduffy.net
  • nanoVNA-H – thinking laterally – owenduffy.net
  • Chinese CH2 terminal block (CH1 CH3) – owenduffy.net
  • Conversion of oyster luminaire to LED – owenduffy.net
  • MFJ ATU hand effects on capacitor knobs – owenduffy.net
  • nanoVNA-H – de-embedding the feed line in remote measurement – owenduffy.net
  • WIA 4:1 current balun – further measurements – owenduffy.net
  • 4:1 current balun – identifying bad ones – owenduffy.net
  • owenduffy.net – Page 123 – Mostly electronics…
  • nanoVNA-H – Port 2 attenuator for improved Return Loss – owenduffy.net
  • A common mode choke for a VDSL pair – LF1260 core – owenduffy.net
  • nanoVNA-H – measuring an inductor – is it a no-brainer? – owenduffy.net
  • Trial of prototype stand alone GPS logger – owenduffy.net
  • ATUs and periodic maintenance – owenduffy.net
  • Measuring balun common mode impedance – #3 – owenduffy.net
  • Small common mode choke for analyser antenna measurements using 2843000202 (BN43-202) – owenduffy.net
  • nanoVNA-H – continuing USB-C repair – owenduffy.net
  • NEC – vertical monopole ground wave study – owenduffy.net
  • NEC – vertical monopole radiation resistance study – owenduffy.net
  • Milton Moore’s power supply test – owenduffy.net
  • STC-1000 firmware change – owenduffy.net
  • Current regulation dynamics of Atten APS3005S – owenduffy.net
  • Power meter + dimmer – owenduffy.net
  • owenduffy.net – Page 122 – Mostly electronics…
  • An Arduino utility for the RW1990 rewriteable serial number touch memory – owenduffy.net
  • 4NEC2 – summary statistics discussion – owenduffy.net
  • Programming a certain type of Chinese 315/433MHz EV1527 compatible remote relay – owenduffy.net
  • FT240-43 matching transformer for an EFHW – NEC model at 3.6MHz – owenduffy.net
  • Small efficient matching transformer for an EFHW – NEC model at 3.6MHz – owenduffy.net
  • Exploration of feasibility of ground wave comms on 80m VK2OMD-VK1EA – owenduffy.net
  • LDF4-50A shield prep with simple hand tools – owenduffy.net
  • nanoVNA-H – continuing USB-C woes #2 – owenduffy.net
  • RF transmission lines – quite old art – owenduffy.net
  • nanoVNA – VSWR in terms of 400Ω – owenduffy.net
  • nanoVNA-H – measure ferrite transformer – owenduffy.net
  • Annual inspection of antenna reveals balun box issue – owenduffy.net
  • Review of W8TEE, AC8GY STL (Radcom Feb 2020) – owenduffy.net
  • owenduffy.net – Page 121 – Mostly electronics…
  • Reinforcement of nanoVNA-H connectors – performance discussion – owenduffy.net
  • Windowed ladder line – single core CCS 21% IACS – owenduffy.net
  • Radcom Feb 2019 “cable balun” – comment on Radcom “The last word” letter – owenduffy.net
  • W551 CCS windowed ladder line – a guide to low end loss – owenduffy.net
  • nanoVNA-H – continuing USB-C woes – owenduffy.net
  • Simsmith bimetal line type – a comparison around the first MLL minimum – owenduffy.net
  • Measuring coaxial cable loss by reflection with a directional wattmeter – owenduffy.net
  • Measuring coaxial cable loss by reflection with a VNA – owenduffy.net
  • Measuring coaxial cable loss by transmission measurement with a directional wattmeter – owenduffy.net
  • owenduffy.net – Page 120 – Mostly electronics…
  • Measuring coaxial cable loss with a voltmeter – owenduffy.net
  • Chinese wattmeter / power analyser fix – owenduffy.net
  • Stub matching loss can bite you – owenduffy.net
  • A thinking exercise on Jacobi Maximum Power Transfer #4 – owenduffy.net
  • The transmitter matching problem – owenduffy.net
  • owenduffy.net – Page 119 – Mostly electronics…
  • Strength of reinforcement of nanoVNA-H connectors – owenduffy.net
  • nanoVNA-H – recovery – owenduffy.net
  • A thinking exercise on Jacobi Maximum Power Transfer #3 – owenduffy.net
  • A thinking exercise on Jacobi Maximum Power Transfer #2 – owenduffy.net
  • nanoVNA-H – rework of v3.3 PCB to v3.4? – owenduffy.net
  • A thinking exercise on Jacobi Maximum Power Transfer – owenduffy.net
  • nanoVNA-H – measure 40m low pass filter for WSPRlite flex – owenduffy.net
  • RFPM2 – current probe – #3 – owenduffy.net
  • nanoVNA-H – v3.3 USB problems – owenduffy.net
  • A mount for the coax relay driver development prototype – owenduffy.net
  • nanoVNA – measurement of two 920MHz LoRa antennas – owenduffy.net
  • nanoVNA – that demo board and its U.FL connectors – owenduffy.net
  • owenduffy.net – Page 118 – Mostly electronics…
  • Coaxial Collinear – dielectric loading the outer conductor – owenduffy.net
  • HanRongDa HRD-831 FM transmitter – configuration and review – owenduffy.net
  • nanoVNA user post provides an interesting example for study #1 – owenduffy.net
  • Normalised RMS voltage of a full wave phase controlled power waveform – owenduffy.net
  • nanoVNA-H – measure 144MHz Yagi gain – planning / feasibility – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines #6 – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines #5 – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines #4 – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines #3 – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines #2 – owenduffy.net
  • Antennas – disturbing the thing being measured – open wire lines – owenduffy.net
  • Soldering iron – temperature control failure – owenduffy.net
  • Implementation of G5RV inverted V using high strength aluminium MIG wire – impedance measurements – owenduffy.net
  • owenduffy.net – Page 117 – Mostly electronics…
  • RFPM2 – current probe – #2 – owenduffy.net
  • nanoVNA – a surfit of choices – owenduffy.net
  • MFJ-1786 loop antenna – a study of the matching scheme – owenduffy.net
  • MFJ-1786 loop antenna – measurements and NEC-4.2 model at 10.1MHz – analysis tools – owenduffy.net
  • MFJ-1786 loop antenna – other models at 10.1MHz – owenduffy.net
  • Radcom Feb 2019 “cable balun” – owenduffy.net
  • Radcom Feb 2019 “cable balun” – a deeper look – owenduffy.net
  • MFJ-1786 loop antenna – measurements and NEC-4.2 model at 10.1MHz – owenduffy.net
  • nanoVNA-H – coax connectors – owenduffy.net
  • nanoVNA-H – supplied cables – owenduffy.net
  • owenduffy.net – Page 116 – Mostly electronics…
  • NEC model of figure 8 transmitting loop – owenduffy.net
  • nanoVNA-H – a summary of the experience so far – owenduffy.net
  • Acrylic plinth for small card modules – CNC router make – owenduffy.net
  • On the concept of that P=Pfwd-Prev – owenduffy.net
  • The system wide conjugate match stuff crashes out again – owenduffy.net
  • AD8310 module for HF current probe – owenduffy.net
  • nanoVNA-H – sweep of a coax line section with OC termination – owenduffy.net
  • nanoVNA-H – T-Check test – owenduffy.net
  • CNC6040 router project – cut of enclosure for grbl_ESP32 – owenduffy.net
  • nanoVNA-H – measure ferrite core permeability – owenduffy.net
  • owenduffy.net – Page 115 – Mostly electronics…
  • nanoVNA-H – measure equivalent core loss resistance – owenduffy.net
  • nanoVNA-H – a ferrite cored test inductor impedance measurement – s21 series vs s11 reflection – owenduffy.net
  • nanoVNA-H – Chinese junk? – owenduffy.net
  • nanoVNA-H – a ferrite cored test inductor – drilling down on a glitch – the fix – owenduffy.net
  • DfuSe – dependency on Visual C++ 2013 runtime – owenduffy.net
  • RFPM2 – current probe – owenduffy.net
  • nanoVNA-H – a ferrite cored test inductor – drilling down on a glitch – owenduffy.net
  • nanoVNA-H – standalone VHF antenna VSWR sweep – owenduffy.net
  • nanoVNA-H – mobile UHF antenna VSWR sweep – owenduffy.net
  • nanoVNA-H – a ferrite cored test inductor – owenduffy.net
  • nanoVNA-H – first experience – owenduffy.net
  • nanoVNA-H – occasional glitches in measured data – owenduffy.net
  • Series match for a half wave dipole – owenduffy.net
  • Rigexpert AA-600 reference plane – owenduffy.net
  • IoT – exploration of LoRa – part 3 – owenduffy.net
  • owenduffy.net – Page 114 – Mostly electronics…
  • nanoVNA MOD v3 – a first look – owenduffy.net
  • nanoVNA – a first plunge – owenduffy.net
  • SimSmith – looking both ways – an LNA design task – owenduffy.net
  • Transmitter / antenna systems and the maximum power transfer theorem – owenduffy.net
  • CNC6040 router project – test cut of a Jiffy box – owenduffy.net
  • owenduffy.net – Page 113 – Mostly electronics…
  • Walter Maxwell’s teachings on system wide conjugate matching – a SimSmith example – owenduffy.net
  • Cooking the books on VSWR – Bird43 indication – owenduffy.net
  • Cooking the books on VSWR – owenduffy.net
  • CNC6040 router project – spindle speed linearisation – using new grbl_ESP32 feature – owenduffy.net
  • CNC6040 router project – spindle speed linearisation – owenduffy.net
  • Noise Figure Y factor method calculator updated – owenduffy.net
  • Noise Figure – Equivalent Noise Bandwidth – owenduffy.net
  • nanovna-saver – a first look – owenduffy.net
  • Is it 290K or 293K? – owenduffy.net
  • Update for NFM software (v1.19.0) – owenduffy.net
  • Maximum acceptable receiver noise figure – derived from ITU-R P.372-13 guidance – owenduffy.net
  • Noise Figure measurement of a converter / transverter – owenduffy.net
  • owenduffy.net – Page 112 – Mostly electronics…
  • Optimum receive system noise figure for given ambient noise – Flex 6700 – owenduffy.net
  • Optimum receive system noise figure for given ambient noise – Flex 6600 – owenduffy.net
  • Minimum ambient noise level – ITU-R P.372-13 guidance – owenduffy.net
  • Franklin antenna – how does it work? – owenduffy.net
  • End Fed Half Wave matching transformer – 80-20m – LO1238 variant – owenduffy.net
  • S/N degradation is related to external noise level and receive system internal noise – owenduffy.net
  • owenduffy.net – Page 111 – Mostly electronics…
  • End Fed Half Wave matching transformer – 80-20m – 2xFT240-43 variant – owenduffy.net
  • Post post implementation review R134a replaced with HyChill Minus 30 – owenduffy.net
  • Online calculator of ferrite material permeability interpolations – more detail – owenduffy.net
  • Holux web site missing / offline, Holux ezTour crippled – owenduffy.net
  • OpenLog for TinyTrak – inline DE9 adapter – owenduffy.net
  • Diagnosing a possible antenna problem by comparison with a baseline – owenduffy.net
  • Refurbishing the push button in action cam cases – owenduffy.net
  • Matching a 5/8λ ground plane – a single stub tuner example – owenduffy.net
  • Trapped dipole – owenduffy.net
  • owenduffy.net – Page 110 – Mostly electronics…
  • Designing with binocular ferrite cores – published Al values – owenduffy.net
  • Designing with binocular ferrite cores – Σ(A/l) – owenduffy.net
  • Do Distortionless Lines exist? – owenduffy.net
  • Comparison of BN43-202 / 5t with BN73-202 / 2t for rx only on low HF – small broadband RF transformer – 50:200Ω – owenduffy.net
  • Transmission lines: departure from ideal Zo – owenduffy.net
  • Basic programming jig for STC15F104E and STC15F204E chips #3 – owenduffy.net
  • XH plug savers on the STC U8W & U8 programmer – owenduffy.net
  • Garden hose couplers – there has to be a better way – owenduffy.net
  • RF transformer design with ferrite cores – saturation calcs – owenduffy.net
  • RF transformer design with ferrite cores – initial steps – owenduffy.net
  • An online expert on the unsuitability of #43 for HF UNUNs – owenduffy.net
  • Speaker tick generator #2 (for polarity testing) – owenduffy.net
  • Fox flasher MkII update 7/2019 – owenduffy.net
  • owenduffy.net – Page 109 – Mostly electronics…
  • Basic programming jig for STC15F104E and STC15F204E chips – owenduffy.net
  • From lossless transmission line to practical – Zo and γ – owenduffy.net
  • SimSmith example of VSWR assessment – owenduffy.net
  • ESP01S IoT – Thingspeak GET submission – owenduffy.net
  • On working with complex Zo – owenduffy.net
  • ESP01S first experience – owenduffy.net
  • On negative VSWR – Return Loss implications – owenduffy.net
  • On negative VSWR – a worked example – owenduffy.net
  • owenduffy.net – Page 108 – Mostly electronics…
  • On negative VSWR – owenduffy.net
  • Trying to make sense of the STC U8W chip programmer – owenduffy.net
  • Fox flasher MkII – update 07/2019 – owenduffy.net
  • The private and public scope of coaxial cable – owenduffy.net
  • Average power of SSB telephony – experimental verification – owenduffy.net
  • Power rating of a ferrite cored transformer or balun – owenduffy.net
  • Average power of SSB telephony – owenduffy.net
  • Fox flasher MkII – high power 2 LED solar powered beacon – update 6/2019 – owenduffy.net
  • owenduffy.net – Page 107 – Mostly electronics…
  • Fox flasher MkII – high power 2 LED solar powered beacon – update 6/2018 – owenduffy.net
  • High end VSWR compensation in a ferrite cored RF transformer – owenduffy.net
  • Estimating the Insertion VSWR in a ferrite cored RF transformer – owenduffy.net
  • Estimating the magnetising or core loss in a ferrite cored RF transformer – owenduffy.net
  • Derating rectifier diode current – owenduffy.net
  • Using SPICE on antenna baluns – owenduffy.net
  • Guanella’s 1:1 balun and his explanation – Zcm – owenduffy.net
  • Hitachi DB3DL2 UC3SFL repair – owenduffy.net
  • Guanella’s 1:1 balun and his explanation – owenduffy.net
  • Exploiting your antenna analyser #30 – owenduffy.net
  • EFHW exploration – Part 2: practical examples of EFHW – owenduffy.net
  • owenduffy.net – Page 106 – Mostly electronics…
  • EFHW exploration – Part 1: basic EFHW – owenduffy.net
  • Pawsey Balun – what is it good for? – owenduffy.net
  • Pawsey Balun on an asymmetric load – bench load simulation – owenduffy.net
  • Pawsey Balun on an asymmetric load – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – small broadband RF transformer using medium µ ferrite core for receiving use – 50:200Ω – owenduffy.net
  • Nagoya NA-771 2m/70cm antenna – owenduffy.net
  • Capacity test of aftermarket NB-6L batteries #2 – owenduffy.net
  • A balun puzzle – discussion – owenduffy.net
  • A balun puzzle – owenduffy.net
  • Capacity test of aftermarket NB-6L batteries – owenduffy.net
  • owenduffy.net – Page 105 – Mostly electronics…
  • Equivalent noise bandwidth – IC-7300 CW Rx Filter2 – (500Hz sharp) – owenduffy.net
  • Equivalent noise bandwidth – IC-7300 SSB Rx Filter2 – (2400Hz sharp) – owenduffy.net
  • DSZH WK-6889 – temperature sensor – owenduffy.net
  • Post implementation review R134a replaced with HyChill Minus 30 – owenduffy.net
  • Geometry factors for some common Fair-rite binocular ferrite cores – owenduffy.net
  • A symmetric compensation stub using coax – owenduffy.net
  • Measuring trap resonant frequency with an antenna analyser – measurement of a real trap – owenduffy.net
  • Measuring trap resonant frequency with an antenna analyser – owenduffy.net
  • owenduffy.net – Page 104 – Mostly electronics…
  • Comparison of R134a and HyChill Minus 30 – owenduffy.net
  • Exploring HyChill Minus 30 – owenduffy.net
  • Inherently balanced ATUs – part 4 – owenduffy.net
  • Broadband providers are not equal – owenduffy.net
  • Inherently balanced ATUs – part 3 – owenduffy.net
  • Inherently balanced ATUs – part 2 – owenduffy.net
  • Inherently balanced ATUs – owenduffy.net
  • Voltage symmetry of practical Ruthroff 4:1 baluns – finding TLT Vout/Vin – owenduffy.net
  • A low Insertion VSWR high Zcm Guanella 1:1 balun for HF – more detail #3 – owenduffy.net
  • A low Insertion VSWR high Zcm Guanella 1:1 balun for HF – more detail #2 – owenduffy.net
  • De-embedding transmission line to allow remote measurement – owenduffy.net
  • Another measurement of a balun’s Insertion VSWR – owenduffy.net
  • An interesting case study of measurement of a balun’s Insertion VSWR – owenduffy.net
  • owenduffy.net – Page 103 – Mostly electronics…
  • Review – Chinese heating / cooling controller ITC-308 – owenduffy.net
  • Choosing a toroidal magnetic core – ID and OD – owenduffy.net
  • W0SJ matching transformer for an EFLW (Laird 28B1540-000) – owenduffy.net
  • Sumo broadband Internet access – owenduffy.net
  • Exetel broadband Internet access – owenduffy.net
  • Online expert on coax loss – owenduffy.net
  • Voltage symmetry of practical Ruthroff 1:1 baluns – owenduffy.net
  • Voltage symmetry of practical Ruthroff 4:1 baluns – owenduffy.net
  • owenduffy.net – Page 102 – Mostly electronics…
  • AIM 916 produces internally inconsistent results – owenduffy.net
  • VU3SQM directional wattmeter build – #4 – owenduffy.net
  • W5KV’s transmitting loop measurements – DELUXE HG-1 PreciseLOOP 7MHz – owenduffy.net
  • Measuring common mode current with a scope – owenduffy.net
  • Australian amateur population trends 1998 – 2018 – owenduffy.net
  • VU3SQM directional wattmeter build – #3 – owenduffy.net
  • owenduffy.net – Page 101 – Mostly electronics…
  • Designing a Gamma Match – confirmation of as-built antennas – owenduffy.net
  • Measuring balun common mode impedance – #1 – owenduffy.net
  • VU3SQM directional wattmeter build – #2 – owenduffy.net
  • KA0KA’s Youtube test of ATU balance – owenduffy.net
  • VU3SQM directional wattmeter build – #1 – owenduffy.net
  • Elecraft CP-1 directional coupler – magnetics review – owenduffy.net
  • The first 21 days of Exetel broadband Internet access – owenduffy.net
  • On Thevenin’s theorem – #2 – owenduffy.net
  • On Thevenin’s theorem – owenduffy.net
  • owenduffy.net – Page 100 – Mostly electronics…
  • Counterfeit FTDI – another form – owenduffy.net
  • The first seven days of Exetel broadband Internet access – owenduffy.net
  • ISP adapter for Arduino Pro Mini / Pro Micro – owenduffy.net
  • Yet another change of Internet broadband access – owenduffy.net
  • IoT – exploration of LoRa – part 2 – owenduffy.net
  • A low Insertion VSWR high Zcm Guanella 1:1 balun for HF – owenduffy.net
  • IoT – exploration of LoRa – part 1 – owenduffy.net
  • RFPM2 – calibration files – owenduffy.net
  • RFPM2 – calibration – owenduffy.net
  • owenduffy.net – Page 99 – Mostly electronics…
  • Arduino SAMD21 bootloader protection II – owenduffy.net
  • Motorola TAD1000B Folded Coaxial Antenna – discussion – owenduffy.net
  • An explanation of W5DXP’s ‘line extender device’ – owenduffy.net
  • Rigexpert’s Antscope takes a bigger step backwards – owenduffy.net
  • owenduffy.net – Page 98 – Mostly electronics…
  • AIM 915a produces internally inconsistent results – owenduffy.net
  • Dragino LG02 review – owenduffy.net
  • IoT – exploration of LoRaWAN – part 1 – owenduffy.net
  • AIM 915 produces internally inconsistent results – owenduffy.net
  • When simple explanations target a simple audience – owenduffy.net
  • Hams helping hams – owenduffy.net
  • Australian amateur radio licensing reform (2018) – owenduffy.net
  • Measuring ambient noise level using a spectrum analyser #2 – owenduffy.net
  • owenduffy.net – Page 97 – Mostly electronics…
  • Online calculator of ferrite material permeability interpolations – additional materials – owenduffy.net
  • Balancing a ceiling fan – owenduffy.net
  • Amateur Radio – Page 68 – owenduffy.net
  • Antenna Tuners (ATU) – Page 5 – owenduffy.net
  • Radio-Kits SWR meter – build and review – owenduffy.net
  • Antennas – Page 40 – owenduffy.net
  • Backtracking in APRS – owenduffy.net
  • Mapping trips from APRS archives – owenduffy.net
  • Zig zags in APRS tracks – owenduffy.net
  • APRS – Page 2 – owenduffy.net
  • APRS – Page 8 – owenduffy.net
  • ?feed=rss2&cat=6
  • Inside the YHDC SCT013 current transformer – owenduffy.net
  • SCT-010-000 current transformer protection – owenduffy.net
  • EmonTx3 v3.4 ‘wired’ implementation – owenduffy.net
  • Arduino 1.6.12 – adding Optiboard boards.txt – owenduffy.net
  • Arduino 1.6.12 & 1.6.13 AVRDUDE issues – owenduffy.net
  • ADS1115 ADC checkout – #1 – owenduffy.net
  • Fan controlled by humidity sensor – pre implementation data gathering – owenduffy.net
  • Fan controlled by humidity sensor – owenduffy.net
  • Time to get some experience with 32bit microcontrollers – some progress – owenduffy.net
  • Time to get some experience with 32bit microcontrollers – owenduffy.net
  • Arduino thermistor thermometer – a tutorial – owenduffy.net
  • Fan controlled by humidity sensor – design technique – owenduffy.net
  • Arduino app to set DS1307 Real Time Clocks – owenduffy.net
  • Arduino – Page 2 – owenduffy.net
  • Arduino – Page 3 – owenduffy.net
  • ?feed=rss2&cat=15
  • Review of the Amidon AB_200_10 balun – owenduffy.net
  • A low Insertion VSWR high Zcm Guanella 1:1 balun for HF – more detail – owenduffy.net
  • Baluns – Page 2 – owenduffy.net
  • Baluns – Page 7 – owenduffy.net
  • ?feed=rss2&cat=24
  • NodeMCU devkit V1 deep sleep – owenduffy.net
  • ESP8266 remote power display for energy monitor – EV3 – 5V display – owenduffy.net
  • ESP8266 remote power display for energy monitor – EV3 – owenduffy.net
  • ESP8266 remote power display for energy monitor – owenduffy.net
  • ESP8266 remote power display for energy monitor – EV2 – owenduffy.net
  • ESP8266 IoT DHT22 temperature and humidity – evolution 2 – owenduffy.net
  • Computing – Page 2 – owenduffy.net
  • Computing – Page 6 – owenduffy.net
  • ?feed=rss2&cat=26
  • Apples have just come off the trees – owenduffy.net
  • ?feed=rss2&cat=23
  • WBT-4000W 230V AC dimmer / motor speed controller – owenduffy.net
  • A flexible test panel for microcontroller based power control projects – #2 – owenduffy.net
  • A flexible test panel for microcontroller based power control projects – owenduffy.net
  • Electrical – Page 2 – owenduffy.net
  • Electrical – Page 4 – owenduffy.net
  • ?feed=rss2&cat=10
  • Electronics – Page 2 – owenduffy.net
  • Electronics – Page 21 – owenduffy.net
  • ?feed=rss2&cat=7
  • Maker – Page 2 – owenduffy.net
  • Maker – Page 13 – owenduffy.net
  • ?feed=rss2&cat=34
  • Measurement – Page 2 – owenduffy.net
  • Measurement – Page 6 – owenduffy.net
  • ?feed=rss2&cat=28
  • Cheap Chinese wristwatch #2 – owenduffy.net
  • Cheap Chinese wristwatch #1 – owenduffy.net
  • Mandarin & Lime Marmalade – owenduffy.net
  • Australian Lime & Lemon Marmalade – owenduffy.net
  • Tahitian Lime Marmalade – owenduffy.net
  • Australian Lime Marmalade – owenduffy.net
  • The old wheelbarrow will not die – owenduffy.net
  • Leafeater retro fit – owenduffy.net
  • ?feed=rss2&cat=5
  • A little programming adapter for 4 x 2mm pitch pads – owenduffy.net
  • Inductance of sensorless brushless DC motors – owenduffy.net
  • A Demagnetisation Risk Index for a sensorless brushless DC drive – owenduffy.net
  • Standardised processing of instrument screen captures – owenduffy.net
  • Demagnetisation in a sensorless brushless DC drive – owenduffy.net
  • Hobbyking Multistar 4220-650Kv – owenduffy.net
  • Regenerative braking and electronic power supplies – owenduffy.net
  • RCTimer 4215-530Kv BLDC motor checkout – owenduffy.net
  • CC3D F4 fraud – owenduffy.net
  • RC models – Page 2 – owenduffy.net
  • RC models – Page 7 – owenduffy.net
  • ?feed=rss2&cat=12
  • Anytone AT-D868UV: initial impressions – owenduffy.net
  • Calibrating the Elecraft N-GEN – owenduffy.net
  • Calculation of received noise power given ENB and ENR – owenduffy.net
  • Equivalent noise bandwidth – IC-7300 SSB Rx Filter2 (2400Hz soft) – owenduffy.net
  • IC-7300 S-meter calibration accuracy – owenduffy.net
  • Receivers – Page 2 – owenduffy.net
  • Receivers – Page 5 – owenduffy.net
  • ?feed=rss2&cat=30
  • A cheap and cheerful data logger – owenduffy.net
  • Raspberry Pi 2 initial impressions – owenduffy.net
  • On-air testing of APRS digipeater with a crafted suite of test records – owenduffy.net
  • RPi headless aprx server using soundmodem – owenduffy.net
  • Cron configuration improvements for Raspberry Pi – owenduffy.net
  • Real time clock for Raspberry Pi – owenduffy.net
  • Notes on my fork of aprx – owenduffy.net
  • Headless aprx APRS server – RPi packages – owenduffy.net
  • Headless aprx server trial – owenduffy.net
  • Headless aprx server – trial wrapup – owenduffy.net
  • Towards a reliable APRS iGate – #2 – owenduffy.net
  • Towards a reliable APRS iGate – owenduffy.net
  • RPi – Page 2 – owenduffy.net
  • ?feed=rss2&cat=29
  • Slot.it orange CA20Z build – owenduffy.net
  • Slot.it CS23B build – owenduffy.net
  • Slot.it CA20Z build – owenduffy.net
  • Slot.it CA20A rework – owenduffy.net
  • ?feed=rss2&cat=31
  • AE7PD’s transmitting loop measurements – owenduffy.net
  • Findling & Siwiak 2012 measurements of an Alexloop – discussion – owenduffy.net
  • Findling & Siwiak 2012 measurements of an Alexloop – owenduffy.net
  • G3CWI 2018 measurements of an Alexloop Walkham – owenduffy.net
  • Single turn coaxial loop resonator analysis – owenduffy.net
  • G3CWI’s ground wave tests Jul 2017 using WSPRlite – owenduffy.net
  • STL propaganda indeed: QW vertical – dipole – STL model pattern comparison – owenduffy.net
  • STL propaganda indeed: dipole – STL pattern comparison – owenduffy.net
  • STL propaganda indeed – owenduffy.net
  • Small Transmitting Loops – Page 2 – owenduffy.net
  • Small Transmitting Loops – Page 9 – owenduffy.net
  • ?feed=rss2&cat=4
  • First full month of Amaysim broadband broadband Internet access – owenduffy.net
  • First full week of Amaysim broadband Internet access – owenduffy.net
  • Review of 10 months of iiNet broadband Internet access – owenduffy.net
  • iiNet broadband Internet access – speed observations – owenduffy.net
  • Review of 5 months of iiNet broadband Internet access – owenduffy.net
  • First month of iiNet FTTN broadband Internet access – owenduffy.net
  • Queueing in data networks – owenduffy.net
  • Telecommunications – Page 2 – owenduffy.net
  • ?feed=rss2&cat=2
  • WW1WW’s matching transformer for an EFHW – owenduffy.net
  • PD7MAA’s BN43-202 matching transformer for an EFHW – owenduffy.net
  • AIM 914 produces internally inconsistent results – owenduffy.net
  • Test equipment – Page 2 – owenduffy.net
  • Test equipment – Page 17 – owenduffy.net
  • ?feed=rss2&cat=11
  • Transmission lines – Page 2 – owenduffy.net
  • Transmission lines – Page 26 – owenduffy.net
  • ?feed=rss2&cat=13
  • VSWR meter trap for the unwary – owenduffy.net
  • 40m filter for WSPRlite flex – owenduffy.net
  • Another RFI mod of a speaker mic for DMR use – owenduffy.net
  • Transmitters – Page 2 – owenduffy.net
  • Transmitters – Page 16 – owenduffy.net
  • ?feed=rss2&cat=1
  • RBN for antenna comparisons – Radcom 2018 – owenduffy.net
  • A tutorial on estimating the impedance of a toroidal ferrite cored inductor for radio frequencies – owenduffy.net
  • W3LPL’s paired WSPRlite test – test 2 – owenduffy.net
  • Signed application programs – owenduffy.net
  • AIM 865A Refer to Antenna facility – owenduffy.net
  • Measuring balun common mode impedance – #2 – owenduffy.net
  • AIM 865A produces inconsistent / incorrect results – owenduffy.net
  • AIM 882 produces internally inconsistent results – owenduffy.net
  • Uncategorized – Page 2 – owenduffy.net
  • ic9350 updated to support 3040 – owenduffy.net
  • Roger Beep fitted to MFJ-1263 microphone / rig switch – owenduffy.net
  • Tunemate update – owenduffy.net
  • VK1OD Roger Beep project documentation – owenduffy.net
  • ?feed=rss2&tag=aim-use-issues
  • Accuracy of AIMuhf system – AIM910B vs several recent versions on a ferrite cored inductor – owenduffy.net
  • Accuracy of AIMuhf system – AIM910A vs several recent versions on a ferrite cored inductor – owenduffy.net
  • Characterising an unknown ferrite toroid – owenduffy.net
  • 2.4:1 balun design failure – owenduffy.net
  • A walk through of a practical application of AIMuhf/AIM900A #2 – owenduffy.net
  • A walk through of a practical application of AIMuhf/AIM900 – owenduffy.net
  • AIM use & issues – Page 2 – owenduffy.net
  • AIM use & issues – Page 3 – owenduffy.net
  • ?feed=rss2&tag=designing-high-performance-vhfuhf-receive-systems
  • Designing high performance VHF/UHF receive systems – Part 7 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 6 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 5 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 4 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 3 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 2 – owenduffy.net
  • Designing high performance VHF/UHF receive systems – Part 1 – owenduffy.net
  • ?feed=rss2&tag=exploiting-your-antenna-analyser
  • Exploiting your antenna analyser #29 – owenduffy.net
  • Exploiting your antenna analyser #28 – owenduffy.net
  • Exploiting your antenna analyser #27 – owenduffy.net
  • Exploiting your antenna analyser #26 – owenduffy.net
  • Exploiting your antenna analyser – contents – owenduffy.net
  • Exploiting your antenna analyser #25 – owenduffy.net
  • Exploiting your antenna analyser #24 – owenduffy.net
  • Exploiting your antenna analyser #23 – owenduffy.net
  • Exploiting your antenna analyser #22 – owenduffy.net
  • Exploiting your antenna analyser #21 – owenduffy.net
  • Exploiting your antenna analyser – Page 2 – owenduffy.net
  • Exploiting your antenna analyser – Page 3 – owenduffy.net
  • ?feed=rss2&tag=ic-7410-tests
  • IC-7410 tests – 03 – Noise Figure – owenduffy.net
  • IC-7410 tests – 02 – digital audio output – owenduffy.net
  • IC-7410 tests – 01 – linearity – owenduffy.net
  • ?feed=rss2&tag=noise-figure-meter
  • Using an attenuator for NoiseLo/NoiseHi in NFM – owenduffy.net
  • VK2OMD ambient noise measurement 144MHz – 20140217 – owenduffy.net
  • ?feed=rss2&tag=rfpm1
  • Return Loss sweep using IC7410, RL bridge, and RFPM1 – owenduffy.net
  • A prototype data logger for RFPM1 – owenduffy.net
  • Transmit performance of 2m hand held transceivers – absolute gain estimates – owenduffy.net
  • Transmit performance of 2m hand held transceivers – owenduffy.net
  • Near-field field strength measurements using the RFPM1 – owenduffy.net
  • Review of Boswell et al paper “Performance of a small loop antenna in the 3-10 MHz band” – owenduffy.net
  • VK3AQZ RF power meter (RFPM1) – adjust Tx power example – owenduffy.net
  • VK3AQZ RF power meter (RFPM1) – filter response example – owenduffy.net
  • dB, dBi, and dBd – owenduffy.net
  • On Witt’s calculation of Matched Line Loss from Return Loss – owenduffy.net
  • Review of inexpensive Chinese thermostat – 8010F #2 – owenduffy.net
  • Programming jig for STC15Fx DIP-8, DIP-28 chips – owenduffy.net
  • Flashing LED driver using an ESC – owenduffy.net
  • Review of inexpensive Chinese thermostat – MH-1210 #2 – owenduffy.net
  • Using the AIM to measure matched line loss – owenduffy.net
  • Thermistor for CBAIV – owenduffy.net
  • Baofeng GT-3TP MkIII review – owenduffy.net
  • Antenna span tensioner using a counterweighted halyard – owenduffy.net
  • Antenna span spring tensioner – owenduffy.net
  • June 2015 – Page 2 – owenduffy.net
  • June 2015 – Page 3 – owenduffy.net
  • Dodgy Chinese thermocouple thermometer – owenduffy.net
  • A test run of the generic heating / cooling controller with 10k NTC thermistor sensor – owenduffy.net
  • Thermal observations on Neosid 28-053-31 ferrite toroid – owenduffy.net
  • Interpreting temperature rise in ferrite cored RF transformers and inductors – owenduffy.net
  • owenduffy.net – Page 3 – Mostly electronics…
  • December 2018 – Page 2 – owenduffy.net
  • November 2018 – Page 2 – owenduffy.net
  • Matched Line Loss of generic RG6/U Quad Shield CCS – owenduffy.net
  • KN5L measurement of JSC 1318 windowed ladder line – MLL @ 4.2MHz – owenduffy.net
  • Transmission line measurements – learning from failure – owenduffy.net
  • Inferring Matched Line Loss from Half Return Loss measurements – Zo error – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – small broadband RF transformer – discussion of ferrite material choice – owenduffy.net
  • Feasibility study – loop in ground for rx only on low HF – SDR for measurement? – owenduffy.net
  • August 2018 – Page 2 – owenduffy.net
  • Implementation of G5RV inverted V using high strength aluminium MIG wire – 12 month review – owenduffy.net
  • Pulsar V233-0060 stripped down – owenduffy.net
  • WSPR for A/B tests – a discussion – part 4 – owenduffy.net
  • WSPR for A/B tests – a discussion – part 3 – owenduffy.net
  • Initial review of Owon virtual (USB) oscilloscopes – owenduffy.net
  • WSPR for A/B tests – a discussion – part 2 – owenduffy.net
  • Adjusting modulation level on FM mobiles etc. – owenduffy.net
  • Agat Russian mechanical stopwatch fix – owenduffy.net
  • WSPR for A/B tests – a discussion – part 1 – owenduffy.net
  • March 2018 – Page 2 – owenduffy.net
  • January 2018 – Page 2 – owenduffy.net
  • Chinese no-name 1-500MHz Return Loss Bridge – owenduffy.net
  • Comparing toroidal inductors of different core dimensions – owenduffy.net
  • Molasses derusting of steel – owenduffy.net
  • Review of inexpensive Chinese thermostat – MH1230A – owenduffy.net
  • On winding configuration of EFHW matching transformers – owenduffy.net
  • The sign of reactance – challenge reality check – owenduffy.net
  • The sign of reactance – a challenge – owenduffy.net
  • The sign of reactance – challenge solution – owenduffy.net
  • The sign of reactance – challenge discussion – owenduffy.net
  • Ellington 3 x FT240-52 matching transformer for an EFHW – owenduffy.net
  • Tuned Plate Tuned Grid oscillator – a simple, but complete explanation – owenduffy.net
  • What is a Ground Plane Antenna? – owenduffy.net
  • G3LNP balun with symmetric ‘matched’ load – owenduffy.net
  • G3LNP balun – owenduffy.net
  • Fixes #1: magnetic stirrer with heating plate and digital display XB 85-2 – owenduffy.net
  • Review: magnetic stirrer with heating plate and digital display XB 85-2 – owenduffy.net
  • October 2017 – Page 2 – owenduffy.net
  • A low cost 50Ω termination for measurement purposes – owenduffy.net
  • DL4YHF 50MHz counter on a Chinese TB-244746 PCB – owenduffy.net
  • “No short antenna is more efficient than a resonant-length antenna” – owenduffy.net
  • Small untuned loop with MMIC LNA on 80m – owenduffy.net
  • Failure to treat impedance as a complex quantity leads to… – owenduffy.net
  • Demonstration of the GR1606B for antenna Z measurement and calcs – owenduffy.net
  • 4-20mA Pt100 input for the generic heating / cooling controller – owenduffy.net
  • September 2017 – Page 2 – owenduffy.net
  • GPS antenna plot – owenduffy.net
  • August 2017 – Page 2 – owenduffy.net
  • Chinese batteries – 5 x 2/3A 1.6Ah NiMH cells – owenduffy.net
  • Chinese BN-V11U NiMH replacement battery – owenduffy.net
  • Review of Hantek DSO8102E hand held oscilloscope – owenduffy.net
  • July 2017 – Page 2 – owenduffy.net
  • Extrapolating VSWR of a simple series resonant antenna – owenduffy.net
  • Typical zinc thickness on zinc coated products used for antennas – owenduffy.net
  • 80m half wave dipole made from galvanised fence wire – owenduffy.net
  • Finding the inductance of the outside of LDF4-50A – owenduffy.net
  • Loss components in an NEC model of a Small Transmitting Loop – owenduffy.net
  • Measuring SSB telephony Peak Envelope Power – owenduffy.net
  • Exploiting waveguide mode of the loop conductor in a small transmitting loop – owenduffy.net
  • June 2017 – Page 2 – owenduffy.net
  • A search for some mid power white wide angle LEDs – owenduffy.net
  • Shunt matching a loaded HF whip – discussion – owenduffy.net
  • Shunt matching a loaded HF whip with just a VSWR meter – owenduffy.net
  • Power in a mismatched transmission line – owenduffy.net
  • G4JNT’s observation of bandwidth effects on WSPR SNR – owenduffy.net
  • Small untuned loop for receiving – NEC model – owenduffy.net
  • W3LPL’s paired WSPRlite test – test 1 – owenduffy.net
  • May 2017 – Page 2 – owenduffy.net
  • The Mobius strip loop – ham benefits – owenduffy.net
  • The fraud of energy efficient lighting – LED lighting – owenduffy.net
  • Quiet HF antennas and E and H fields in the near field zone – owenduffy.net
  • LNR Precision small transmitting loop – owenduffy.net
  • Current and voltage implications of a small transmitting loop power ratings – owenduffy.net
  • CHA P-Loop 2.0 small transmitting loop – owenduffy.net
  • April 2017 – Page 2 – owenduffy.net
  • Review of Dodd’s WSPR based antenna comparison – owenduffy.net
  • Loss in open wire + coax hybrid feed arrangements – owenduffy.net
  • Loss of windowed ladder line at MF/HF/VHF – owenduffy.net
  • March 2017 – Page 2 – owenduffy.net
  • Modifications for Jasic 200A TIG welder and pedal – owenduffy.net
  • NH7RO 7-foot diameter QRO STL for 40M – owenduffy.net
  • Check / calibrate frequency accuracy of IC-7300 – owenduffy.net
  • Does common mode current flow inside coax? – owenduffy.net
  • PD7MAA’s BN43-202 matching transformer for an EFHW – full measurement set – owenduffy.net
  • Thoughts on binocular ferrite core inductors at radio frequencies – owenduffy.net
  • Common failings of EFHW matching transformers – owenduffy.net
  • PD7MAA’s BN43-202 matching transformer for an EFHW – measurement of a prototype – owenduffy.net
  • Earth electrodes in parallel – owenduffy.net
  • January 2017 – Page 2 – owenduffy.net
  • Tytera MD-390 DMR portable evaluation – owenduffy.net
  • Improving quadcopter stability at very low throttle using Complementary PWM – owenduffy.net
  • Max thrust: Hobbywing XRotor 40A (MkII) vs BLHeli Hobbywing XRotor 40A (MkII) vs SimonK Hobbyking 9261000003 40A – owenduffy.net
  • AU ordinary power plug, plug packs and extension cord sockets – owenduffy.net
  • BLHeli Hobbywing XRotor 40A (MkII) vs SimonK Hobbyking 9261000003 40A – owenduffy.net
  • BLHeli 14.8 damped light and active freewheeling – owenduffy.net
  • Hobbywing XRotor 40A (MkII) – owenduffy.net
  • December 2016 – Page 2 – owenduffy.net
  • Grebenkember’s original Tandem match – owenduffy.net
  • KitsAndParts.com QRP SWR bridge – owenduffy.net
  • DMR distance limit – owenduffy.net
  • TV upgrade – MER optimisation – owenduffy.net
  • TV upgrade – owenduffy.net
  • Coil32 inductance calculator – owenduffy.net
  • Some thinking on ground wave as we enter another solar minimum – owenduffy.net
  • Polarisation of man made noise – an 80m case – owenduffy.net
  • Polarisation of man made noise – owenduffy.net
  • Backup for NBN VDSL access – owenduffy.net