Yes, I pointed out that this model can't use a PP9 adaptor. They cost more than 2 x 3R12 packs anyway.
1) go flat on their own
2) lower voltage
3) Have to be taken out to charge
4) Fire risk to wiring if a short develops
5) Need the AA to 3R12 adaptor
6) Actually lower running time than Alkaline AA and 1/3 run time of 3LR12 in a Radio.
Why would you not use real 3R12 packs (keep it original), or get /make two of the AA adaptors pictured? 2x Alkaline 3LR12 or 6 x Alkaline AA in holders will last up to 10 years with intermittent use. Only leak of radio left on.AA adaptor Available on eBay.de
The 3R12 and 3LR12 are on eBay too. More common on eBay.de as people still bying the 3R12 in local shops for cycle, hand torch and Radio. When I was in Luzen in Oct 2013, the Lady of the house popped round to local shop for 2 x 3R12 (or maybe 3LR12) for a "music box". Quite cheap.
"LR" in a model means Alkaline version.
NiMH are best in power tools, high power lamps, two way radio, cameras, DAB radio and other high consumption devices. They are annoying and shorter run time in a Transistor radio