Sega Master System II power supply

I was testing some Sega Master System 2 vintage game consoles with a friend and we couldn't get a signal out of them. I used a portable TV with analog tuning to look for the RF signal and nothing. So we tried a different antenna cable, checked the wallwart output, cross-checked with a C64.... Then we found the original Sega PSU and .... OPS! ... SMS2 uses the "Japanese" polarity with (+) on the outer ring and (-) on the tip.

A cold shiver hit us: had we fried all three consoles? Were they already cooked (probably)? Regardless we tried with the right PSU and the signal was there on UHF channel 36 (about 603 MHz)!!

The good news is that Sega used a polarity reversal trick of some kind, but they forgot to put a "power on" LED. The required voltage is 9V.

Happy retroconsoling!

HF portable June 2025

Last Tuesday I had the chance to spend a couple of hours outside in a location where I could do some portable QRP HF. The setup is my usual FT817, end-fed thrown over a tree branch, homemade tuner and CW paddle.

Many flies joined me on the table and many mosquitoes enjoyed my ankles. I had 3 QSOs on 20m, a local friend, a French station in CW and a Belgian in SSB.

I might want to change the capacitor in the EFHW tuner and use a more robust box since the antenna wire pulls quite hard. Weight is not an issue since this location is 50m from the parking lot.