Hi Alan,
You probably do not want to use a "standard" battery charger. Many
battery chargers do not have much (or even any) filtering. They may put
out a half wave rectified ( lots of 60 Hz ripple ) or a full wave
rectified (lots of 120 Hz ripple) DC. This ripple will modulate your
signal. You do not necessarily need a highly regulated DC supply,
although that is probably desirable. You really do need a filtered
supply. If you use a regulated supply, you want to be sure that RF does
not get into the regulation circuitry.
I have a Ten-Tec 9420 to power my Hercules II. It is essentially four 20
amp (or so) regulated 12 VDC power supplies. And it is interesting to
note that the outputs of the four supplies run separately all the way to
the four power amplifier modules in the Hercules II. They are not
paralleled at either the power supply end or the load (Hercules II
amplifer) end. I don't know whether you need to do it this way. You
might consider running separate wires all the way from the amplifier
connector, and paralleling them only at the battery/power supply end.
I also have a SGC SG-500 amplifier, which needs a similar amount of
current at 12 VDC as the Hercules needs. I have never had a power supply
big enough to run it. I have in the past used various combinations of
regulated power supplies paralleled through diodes, charging a battery,
to power the SG-500. I have never had a problem with RF messing up the
regulation, however if my memory serves me well, I believe the manual
for that amplifier says you should not use a regulated supply for that
reason.
The most recent version of my power supply for the SG-500 has been a
single Astron PS-70 charging a pair of 6 V golf cart (deep cycle)
batteries in series. This has worked nicely. This particular Astron
supply is regulated but not adjustable from the front panel. It is
important to get the voltage adjusted properly to maintain the battery
charge, without overcharging them. The Astron PS-70 (and I presume many
others) do have a voltage adjust trim pot inside.
In general it is best to use either one battery of sufficient capacity,
or identical smaller voltage batteries in series, rather than full
voltage lower amperage capacity batteries in parallel. You definitely do
not want to parallel an old or small capacity battery with a new or
larger capacity battery. If you parallel batteries to get the current
capacity you need, use identical brand new batteries.
I think the ones I am using are T316 Trojans. They are 6 V batteries
about the size of car starting batteries back in the 50s and 60s, before
they started shrinking. L16s would be even better as they are about
three times the size. You could probably transmit at 500 watts output
during a short power outage using them.
DE N6KB
ARDUJENSKI@aol.com wrote:
I have spend about a week milling thru the Ten Tec Archives reading the
posts regarding running the Hercules II on battery power. I have read the wide
range of suggestions from a couple of 6v golf cart batteries in series to using
100 Ah deep cycle battery with recommendations for leaving charger attached
or turning it off during operation. One large battery or two smaller capacity
batteries in parallel?
WHAT I WOULD LIKE TO KNOW is what is the preferred best method (good
engineering) for using battery power providing make and model of battery and
charger. Is something like the A&A Smart Charger a good choice for this setup? Or a
standard RV charger?
_http://www.a-aengineering.com/home.htm_
(http://www.a-aengineering.com/home.htm)
My Hercules is a few weeks off before delivery so I am not privy to any
information that may be in the manual but I am sure it would not be specific
other than the battery rating.
I would appreciate your feedback and any sketches for your system if
necessary. I do know about the use of an acid proof battery case and it will be in a
well ventilated location
Thank you
Alan KB7MBI
Woodinville, WA
FISTS 5702 CC: 1885
SKCC 1988 NAQCC 058
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