When I wanted to calculate something in the radio shack, I used to google for the formula and then execute it on a scientific calculator. Just now I wanted to know "5dbm as peak to peak voltage across 50 ohms" so I asked ChatGPT which responded very helpfully:
This is really useful. I look forward to having it built in to my phone.
I generally use superglued on MePads from QRPme but burn through them at a great rate. Recently I had a go at cutting insulating tracks on PCB with a Dremel cutter wheel.
I purchased a set of diamond (really?) tipped hole saw bits intending to use them to cut my own pads but this didn't really work as the thickness of the cut is so wide you make a big hole and get a very small pad.
By using the hole saw to just cut the copper layer I get a nice insulated pad and it's not hard to add extra pads to a circuit under construction. Here's a diode ring modulator currently on the bench:
https://www.abc.net.au/listen/programs/nightlife/nightlife-technology-peter-marks/104564546
Recently I've been working on an AM transmitter for 40m. It occurred to me that FM should be much simpler to produce. I had ordered some varactor diodes recently and first tried to FM a crystal or ceramic resonator. I can't get much deviation and the audio did not sound good.
Then I remembered a post on Soldersmoke about a largely unknown but surprisingly stable oscillator called a Franklin oscillator. It has two transistors and has a very light load on the tuned circuit.
Rather than the variable supply transistor I fitted a 5V three terminal regulator. Coupled to the tuned circuit is a varactor diode with an electrolytic capacitor through which line audio is inserted. There's a trim pot to set the DC to the diode.
Initial results are quite promising.
The brilliant Charlie Morris, ZL2CTM, has an excellent video on the Franklin oscillator.
Thanks Stephen, VK2BLQ, for the tip.
