Google Bard on two wire line Zo

What’s that… the centre to centre distance is less than the round wire diameter… a physical impossibility… never mind, Google Bard can solve it!

Not only solve it, but warm you with a bit of humanistic chat to lend credibility to its answer.

This is worse than your average online expert on social media! A high tech automaton that is not fit for this purpose?

PS: I hope my doctor does not use Google Bard to recommend my treatments!

Screen capture of the nanovna etc using a Python script

I find it convenient to capture the screen from my tiny devices directly to a computer over the USB connection.

I use a script derived from Ho-Ro’s nanovna-tools.

The script emits a png of the screen, and a png of the screen with the colours inverted (for presentation and printing).

Above is a screen shot from a tinysaultra.

The script is published on github: .

RFPM2 – current probe – #4 – TinySA Ultra

I have been asked about compatibility of the RFPM2 current probe with the TinySA and variants.

The current probe was intended for use with a broadband 50Ω RF power meter, but could also be used with a Spectrum Analyser with 50Ω input or an oscilloscope with 50Ω input.

RFPM2 – current probe described a current probe for use with a power meter calibrated in dBm (eg RFPM1 and RFPM2). RFPM2 – current probe – #2 exposed some of the build details. RFPM2 – current probe – #3 showed the implementation.

Above the current probe with RFPM2. Whilst this is not of a clamp-on design, the aperture in the core is sufficient to pass a DIN 7/16 connector through. Continue reading RFPM2 – current probe – #4 – TinySA Ultra

Unjamming your Irwin folding utility knife

I purchased two of these Irwin folding utility knives, they seemed like a clever design that addressed the failures of every other folding ‘Stanley blade’ knife I have owned.

Above is the Irwin knife, the blade is secured by a dog on the button shown at top, and the button is blocked from being depressed except when the knife is folded at 45° as shown. Continue reading Unjamming your Irwin folding utility knife

Initial review of ECO-LFP210 LiFePo4 (LiFe) battery

A ECO-LFP210 10Ah 4S LiFePo4 battery was purchased on eBay for a solar powered project, cost about $65 delivered.

Above, the battery (the Anderson Power Pole connector is an addition). The battery incorporates a battery management system (BMS), so protected against over voltage, undervoltage, over current, and cell balance is preserved. Continue reading Initial review of ECO-LFP210 LiFePo4 (LiFe) battery

RPi Raspbian – are they serious?

I have used RPi over a number of years, always with the ‘official’ Raspbian distribution.

I have a single RPi 3B+ and several 2B models, I stopped buying RPi due to the RPi3B+ voltage issue. Yes, I purchased the official power supply (at uncompetitive price), and it failed in less than a year.

Came time to upgrade the 3B+ software, as much for security assurance as anything, and a quick desk study turned up this advice on , the Raspberry Pi Foundation website. Continue reading RPi Raspbian – are they serious?

Quick pressure test of SX25 chainsaw intake

I have had three of these SX25 chainsaws over the years. These appear to be clones of the Chinese Zenoah G2500, a single hand aborist’s saw of 25cc.

Air leaks into either fuel induction, whether in the liquid fuel lines, carburettor gaskets, intake manifold or crankcase spells early death for two stroke engines. It quickly results in lean mixture, lack of lubrication, overheating and seizure. Continue reading Quick pressure test of SX25 chainsaw intake

Holzforma / Farmertec G395XP chainsaw – initial evaluation

I purchased a Holzforma G395 chainsaw for $410 delivered but without bar and chain. It is a Chinese clone of the now discontinued Husqvarna 395XP It is a relatively old technology carburetted engine, prior to the strato technology (stratified scavenging) of the X-TORQ etc.

The Holzforma G395 has slightly lower published power rating than Husqvarna 395XP.

Previous experience documented at Holzforma / Farmertec G372XT chainsaw – initial evaluation shaped the approach with this one. Continue reading Holzforma / Farmertec G395XP chainsaw – initial evaluation

Rigol DM3058 firmware upgrade – post mortem

This item documents a failed attempt to perform a firmware upgrade on a Rigol DM3058.

By the book

The process attempted to upgrade the firmware from v2.02 to v2.03 using the method described by Rigol and upgrade file from their official website.

There were not power interruptions during the upgrade which hung and was shut down after an hour. I might add that I had just upgraded two other DM3058s using the same method, same USB stick.

Email was sent to Rigol Support for help, none came. No surprises there, Rigol are a Chinese company.

I have later found comments that the upgrade may fail if Rigol UltraSensor has been used on the instrument. Others comment on difficulties working with some USB sticks.

The firware is loaded into a flash (external) memory chip attached to a ADSP-BF531 processor chip.

Above, the 4MB flash memory chip branded Spansion, later to become Cypress, then Infineon. Continue reading Rigol DM3058 firmware upgrade – post mortem