It was a tweet from an online friend in the world of amateur radio, featuring a transmitter design published in Sprat, the journal of the G-QRP club for British enthusiasts of low-power radio. The transmitter was very simple, but seriously flawed: keying the power supply line would cause it to exhibit key clicks and frequency instability. It would probably have been far better leaving the oscillator connected full-time and keying the supply to the amplifier, with of course a suitable key click filter.
We’ve all probably made projects that get the job done at the expense of a bit of performance and economy, and from one angle this circuit is a fantastic example of that art. But it’s not the shortcomings of direct PSU keying a small transmitter that has brought it here, but observation instead of what it represents. Perhaps my social group of radio amateurs differs from the masses, but among them the universal lament is that there is nothing new in a simple transistor transmitter that could just as well have been published in 1977 as 2017.