--- In "oryoki2000" <> wrote:
> A less expensive solution could be fabricated from a plastic battery hold=
er and four "D" size NiMH rechargable cells. Rob Danielson has provided in=
structions to create a 10 cell battery here.
>
> http://www.uwm.edu/~type/audio-reports/BatteryPack_NiMH_722/Battery10KaHr=
_722_744.htm
>
> You could build your own 4 cell version by modifying these instructions.
>
> --oryoki
Hi All
I did this just yesterday.
I already had the necessary bits and pieces -
a/ 8 4500 mAhr D cells
b/ suitable plastic box with terminals (remains of a previous amateur radio=
bit of kit ; now defunct).
Went out to Maplins and bought a suitable power plug to match socket on 661=
and a lead to go from terminals to power plug. Also a 4 D cell battery ho=
lder. Total cost of these was =A33-97p inc 15% tax. I see I can buy 8 700=
0 mAHr D NiMH D cells for =A331. allowing for one change of batteries I co=
uld have a field pack of 14000 mAHr for =A335 - can't be bad! As it stands=
I have a 9000 mAHr field pack for just =A34. The D cells are charged by a=
n external, separate multi cell charger.
The four NiMH batteries supply 5.2V fully charged with the 661 recording, 4=
8V phantom to 3032s. This will probably drop to 5.0V after some use. They=
should continue to supply 4.8V until exhausted.
The supplied Marantz wall wart gives a constant, no load, 5.25V.
When the battery pack is connected the 661 display shows the external power=
symbol. Not sure yet how the 661 will deal with the situation when the ex=
ternal batteries are exhausted. I assume it will do a smooth changeover to=
the internal batteries. Certainly pulling out the external power plug eff=
ects an instantaneous, smooth change over to internal batteries. It theref=
ore seems that, without a change of external batteries, the external batte=
ry pack plus internal batteries will give 7000 mAHr. This is probably long=
enough for my recording needs.
The following photos show my set up
Pack (with top removed) ready for transport to field with 8 batteries
m("N08/3390988494/","//www.flickr.com/photos/16206551");">http:
Pack contents ready to power the 661. Only 4 cell holder in view
m("N08/3390988240/","//www.flickr.com/photos/16206551");">http:
Cheers
TomR
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