Hello again Victor,
With regards to battery replacement, if you are anything like me and are drowning in ocean of AA NiMH batteries, you can buy very cheap adapters to C and D size. The Ds can hold 3 AAs, so are usefully more powerful than the expensive and relatively gutless NiCad C and D size available these days. The 510/5550 holds 8 D type btw
You have motivated me to have another look at my TC 510-2. Would you believe the original NiCad battery pack accepted a charge?! I now see that my functional issues are probably self inflicted. Before I got the NiCad pack, I just used a 12v D.C. power source using the connector. I assumed (!!) centre pin hot, but no, it appears the sleeve is positive when I measure with battery pack installed. Hopefully I've just burnt a resistor. So, bear that in mind when yours arrives!
Regards,
Phil
