[Motorola] NTN1171A Rapid Charger for HT1000 Radios

[eric lemmon]

I have several NTN1171A Rapid Chargers for HT1000 portable radios.  I
noticed that some of them have four spring contacts while others have only
three.  I opened one of each to see what was different.  The three-contact
PCB has a part number of 8480648C01-P6, while the four-contact board has
part number 766V-A.  There are significant differences between them in
component count and layout.

I know that the NTN1171A charger is to be used only with NiCd batteries, and
was replaced by the RPX4747A charger, which can charge both NiCd and NiMH
batteries.  The RPX4747A is now NLA, so I can't examine its PCB to see if it
might resemble the 766V-A PCB.  Neither my HT1000 nor my Visar manuals
include any information about the NTN1171A or the RPX4747A chargers.

I am well aware that a NiMH battery can be toasted if placed in a NiCd-only
charger, and I don't want to risk damaging a new NiMH aftermarket battery.
I wonder: Is it possible that the four-spring version of the NTN1171A is
actually an early embodiment of the RPX4747A?  Moreover, is it safe to use
the four-spring NTN1171A to charge NiMH batteries?

73, Eric Lemmon WB6FLY