In the car in Warsaw, Poland just now I was surprised to hear @TheRadCaroline coming through loud and clear on 648kHz AM. After a few minutes the signal faded out, to be replaced by @MurskiVal all the way from Slovenia.

"Daddy, why has the battery gone all puffy?" This is the USB charger supplied with a toy drone. Just a 3.9 ohm resistor in series with the (lithium) battery. No wonder it overcharged. Charger, and battery, now retired.

Prove you're a robot

#OTD 27th Sept 1825, LOCOMOTION № 1 ran along the Stockton & Darlington Railway. Now, Britain’s rail & heritage sectors have united to get this incredible replica train to do the same. So, hop aboard at 10x speed for your own ride… back in time! (PS. thx @kylieminogue 🥰)

Enjoying doing analogue measurements to verify the results of digital calculations. Where's the fun in an FFT when you can twiddle knobs instead?

The most INSANE Bohemian Rhapsody flashmob you will ever see!! With 30 musicians and singers in the streets of Paris 😍 Lead singer: @mickeycallisto Lead guitar: Olly Pearson Pop choir: DDKN sisters, @sone_sings and @colinesicre Counter-tenor solo: @michaelkonesaki

This is a surprisingly accurate insight into Polish society...

I can remember when we'd take a bucket and spade or a ball on a trip to the park with the children. Now we have to take this.

I'm sure I've got plenty of low-pF capacitors somewhere but lying on the bench was a strip of 47pF ones. Try sticking one in series with one of the existing crystal load capacitors to reduce it a bit. It works! The radio can talk to the others now. Happy offspring. /end

The radio chip is a BK4819 and a data sheet is available. It says the master 26MHz crystal should be accurate to 2.5ppm, which is pretty ambitious for a toy. The example circuit diagram shows a trimmer on one leg of the crystal but that's not present in this radio. /4

A check with the spectrum analyzer confirms this. The faulty one is about 10kHz low on each channel compared with the others. Doesn't sound like much at 446MHz but it matters for narrowband FM. /3

Inside is this board. Neat, but there's not much to see and nothing to adjust. I had a feeling the radio was off frequency because it would sort of make contact when set to a different channel to the other set. /2

My children have these toy PMR446 walkie-talkies. We have three of them. Recently the blue and green one wouldn't communicate with the other two. Time for Dad to investigate. 🧵/1

Put it back together with nearly all the screws and it still works. Job done. /end

Add a bit of Kapton tape to try and prevent a recurrence of the fault. It's pretty certain to get dropped again! /7

Yay! It works. Son will be happy. /6

Add a bodge wire to the other wise of the via through the convenient hole in the board. /5

Looks like a bit of damage to this via connected to pin 6 (CLK) of the serial Flash chip which presumably holds the firmware. That's going to cause problems. /4

Looking at the construction closely, the pins of the printer motor come awfully close to the board just here (shown with the printer mechanism lifted a bit). /3

It comes apart nice and easily with a few screws, and is quite neatly made inside. There's a main PCB with the camera, printer and screen connected by FFC connectors. This one fell on to a hard floor and now does nothing except blink the display backlight briefly. /2