I was very proud of this, until I showed it to a colleague. What a load of crap, he said. I referred him to the diode. He remained unimpressed. What do you need that for, he asked? Indignantly, I demonstrated the diode. It was a very nice shade of red. Load of crap, he said again. After all, you can tell when it's on the station by listening to it, he said. Defeated, I and my diode retired hurt. The BBL stumps and bails are the same - a fetching light but ultimately useless.
Which is what a lot of people were saying about T20 recently. Twenty20 cricket was in trouble, they all said. Dying, maybe. That was until the T20 flagship, the Indian Premier League, completed the signing of a new sponsor (Pepsi) for a staggering $88 million over five years.
Before that, the drums had begun to thump ominously. The T20 phenomenon was stalling, they said, based on the fact that the previous IPL sponsor, an Indian realty group, had decided not to renew after spending $55m over the previous five years.
The Big Bash has started off more like the Train Smash, with TV ratings down 30 per cent and crowds down almost 40 per cent from the same stage last year (after nine rounds). Some commentators called it "second season syndrome", a concept which I previously thought only applied to rookie players who enjoyed a good debut season before discovering that defences had worked them out the following year.
Others say there are mitigating factors like an earlier start to the competition, several rain-affected games and some which were simply not competitive; they all played a part in the switch-off mentality.
The downward trend means the national average for TV watchers was roughly equal, according to one report, to a repeat of Swamp People, an American reality series about Louisiana natives who hunt alligators for a living.
Of course, it's all about money. A new broadcast deal is being negotiated with Cricket Australia believing it will more than recoup the A$10.5m loss on the BBL with TV rights forecast to bring in about A$20m a year. That'll keep the players happy - and Warnie'll be back next year with another new delivery, maybe a "money ball" or maybe, for the suggestible, a "gulli-ball".
In New Zealand, the HRV Cup does not seem to have set many alight - we mean this not in a self-immolation sort of way but more in a stumps-and-bails context - with its new Friday night games, though there were 5500 at Eden Park on Friday night, not too bad for a pre-Christmas match.
In Bangladesh, they are kicking off the second season of their T20 league, with England authorities warning players about appearing there though the major objection seems to be the difficulty the players had getting paid after the first effort and the threat of corruption.
It's all a bit wearying, isn't it? I attended the first international game of T20 in this country - New Zealand vs Australia at Eden Park, with the Black Caps decked out in the old Beige Brigade uniforms and the Marshall brothers wearing big-hair wigs. All good fun and laughs and the great Ricky Ponting won the match by playing proper cricket shots.
Since then, there has been so much T20 cricket that I can't watch it any more. T20 is the potato chip of cricket. There's plenty of them, mildly interesting if they are crisp and fresh but, ultimately, they don't satisfy real hunger and they are laden with fat. For the players, T20 is happily laden with fat bundles of cash and you are never ever going to hear a New Zealand IPL player, for example, moan about the IPL. There's too much money in it. They are not going to come out and say: "It's boring, it's just a few minutes of thrashing around to feed the ignorant masses and bring wealth to the players and the sport."
As one recent international player told me: "If you are preparing for a test and you feel a niggle in the hamstring and the IPL is coming up, what do you do? It's pretty clear. It's human nature, isn't it? When you are being paid $1m in the IPL and $350,000 for your New Zealand contract, what do you do? That's human nature too."
The T20 novelty hasn't just worn off, it's become fossilised. Many believe that the shots played in cricket's version of the smash and grab raid are ugly, misshapen things which instil bad habits in our batsmen. Like yesterday's woeful attempt by the Black Caps to be aggressive against South Africa. If that's Brendon McCullum's captaincy blueprint, bring back Ross Taylor.
Even in India, public opinion briefly turned against the IPL when England won the recent test series there.
Give me Ponting's proper cricket shots any day - artistry, not artifice. All the cross-bat slogs, the reverse sweeps and even McCullum's clever ramp shot can't compete with that.
And is there anything sadder, anything more pointless, than a one-sided T20 game? It's like going to see an F1 Grand Prix only to discover someone's taken all the wheels off the cars.
T20 is about as much fun as an irritable bowel. I know about the money. But you'd hope there is an alternative as, in spite of Pepsi's bubbles in India, the end may still be nigh. Things, to bastardise an old advertising slogan, might go better with croak.
