[TenTec] Orion & Motorcyle battery

[Zivney, Terry L.]

W4ZV says:

	I've ordered an Orion and for the first time will be
using an outboard DC supply (a used Astron RS-35M
is on the way).  I often get short power glitches since I am
in a rural location and am concerned about getting resets
on Orion since I understand it takes awhile to reboot (how
long?)  I'm thinking of getting a small battery (motorcycle)
to place between the RS-35M and Orion.  This would stay
fully charged and might help prevent unwanted resets by
brief power glitches.

	Has anyone ever done anything like this?  Is it even
necessary or is there enough residual energy in the PS
filter caps that brief interruptions (typically <10 sec) are not
a problem?  I  don't really want to buy a UPS large enough
to power Orion but is there a simpler solution?


K6SE says:

Transmitter:

My Orion's transmitter puts out a bit more than 100 watts (as indicated
on my Drake W-4 wattmeter) into a 50-ohm dummy load on all 9 bands.  The
power output is easily adjustable in one-watt increments from 1 to 100
watts (as read on the LCD display).  While transmitting, the SWR is
displayed as "SWR 1.0:1" or whatever the value might be.  I used an
MFJ-4322 power supply which is rated at 13.8VDC and 22 amps intermittent
duty and 20 amps continuous duty.  The power supply didn't glitch when I
checked the output power into the dummy load.

On my antennas, the SWR can be much higher if I transmit far from the
antenna's resonant frequency.  I did this out of curiosity to see if the
Orion's power output would automatically be reduced like it is on most
other rigs.  Transmitting with an indicated SWR of 5:1 showed that there
was no cutback of the power output.  I ordered my Orion without the
optional built-in antenna tuner, so this was gratifying.

The PA transistors draw more current when transmitting into a high SWR
and my 22-amp power supply would trip at full power under these
circumstances.  I recommend using a 25-amp (or greater) power supply.


Note to both from N4TZ:

For many years, through many generations of TenTec gear, the SWR protection
has been very simple, yet elegant.  Design the PA so that it can put out
rated power into any SWR, then protect the PA against overheating by
limiting the current.  The current limiting is done OUTBOARD by the over
current protection built into the matching power supply.  As the total
current needs of the rigs have increased over the years, the matching
power supplies have increased the overcurrent cutout accordingly, from
18A to 20A to 21A to 22A, etc.  The Orion has a rating of 25A for the
cutout.  Your power supply, if not a TenTec, should have the overcurrent
protection set at 25A to safely power the Orion.  For a number of years,
TenTec sold external, very fast acting breakers of the appropriate current
rating for use in mobile operation.  There have been numerous threads
on the TenTec reflector on this topic over the years.  {Airpax and Tentec
are the search terms to use)  

Enjoy your new Orions.  I'll make do with my OMNI VI+s for another season....

Terry Zivney, N4TZ/9