One problem with rectifiers is that they ground and unground the
RF path 120 times a second (60 Hz) and unless bypassed will add a hum
to a received station that has nothing to do with ripple. Many supplies
have this fault.
The effect is that the antenna system is changed 120 times a second.
I say go with batteries.
Having purchased NiMH cells and a charger, they're also useful for
other devices. Get 8 AA cells to start, 4 in the radio and 4 charging.
Don't let them run completely down. The clock in the 7600 will
run them to zero, and unfortunately the weakest cell gets
reverse-charged by the others if that happens, which is not good
for that cell.
--
Ron Hardin
On the internet, nobody knows you're a jerk.