I'm trying to locate an emergemcy source of power to operate my 2meter
base rig in the event of a power outage. My HTX-242 manual states the
current drain of the transmitter as 8A @ 45W and 4A @ 10W. Would a 17aH
jump start battery work? Or is there something better, yet not to costly?

On Sun, 28 Mar 2004 11:09:13 -0500, "KC8WVG , Bill"
wrote:

I'm trying to locate an emergemcy source of power to operate my 2meter
base rig in the event of a power outage. My HTX-242 manual states the
current drain of the transmitter as 8A @ 45W and 4A @ 10W. Would a 17aH
jump start battery work? Or is there something better, yet not to costly?

Yes it will. It is a nice package for the battery, and has many other
uses as well.

If you do the math, you will get close to two days operation on a
5/5/90 duty cycle.

However, you may wish to add something like an Anderson PowerPole
connector, as the ciggy lighter outlet and plug may not be happy with
the 10 Amp draw (rounding up a little for good luck).

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

KC8WVG , Bill wrote:


I'm trying to locate an emergemcy source of power to operate my 2meter
base rig in the event of a power outage. My HTX-242 manual states the
current drain of the transmitter as 8A @ 45W and 4A @ 10W. Would a 17aH
jump start battery work? Or is there something better, yet not to costly?

This transceiver is being used for voice, right?

Figure worst case you'll be transmitting 20 percent of the time at 45
Watts, receiving (with squelch open) 75 percent of the time, and in
standby (with squelch closed) 5 percent. Standby current is 0.5 A;
let's assume receive current as 1.2 A. At 45 Watts, your average
transmit current will be 0.2*8, or 1.6 A. Your average receive current
will be 1.2*.75, or 0.9 A. Your average standby current will be 0.5*0.05,
or 0.025 A. Add them all up, and you get 2.525 Amps as an average. This
is approximately 5.5 hours from your prototypical 17 AH "jump start battery",
based on the most common rate for calculation AH capacity being one that
discharges the battery over 20 hours and the fact that your average current
draw is a little more than three times that rate. The figure of 5.5 hours
does include a fudge factor as well.

Best case (you're not NCS, just calling in and responding when NCS calls
you), figure 10 percent transmit at 10 Watts, 10 percent receive, and 80
percent standby. Your average transmit current becomes 0.1*4, or 0.4.
Your average receive current becomes 0.1*1.2, or 0.12. Your average
standby current becomes 0.5*0.8, or 0.4. Average current is now 0.4 +
0.12 + 0.4, or 0.92 Amps. A straight-line approximation shows a
discharge time of 18.48 hours under this load. You could reasonably
expect 18 hours under this best-case scenario.

disclaimer
If this is a critical application you might want to consult with someone
who does these calculations for profit. I just do them for fun.
/disclaimer

Bottom line is if you expect power to be out more than 5.5 hours and to
impose heavy loads on your backup battery then you'll need either more
battery or a photovoltaic system to help keep it topped up under load,
while if you expect power to be out less than 18 hours and to impose
only light loads on your backup battery then your 17 AH jump start
battery should be adequate.

HTH
--
To design the perfect anti-Unix, write an operating system that thinks
it knows what you're doing better than you do. And then adds injury to
insult by getting it wrong.
- esr

KC8WVG , Bill wrote:
I'm trying to locate an emergemcy source of power to operate my 2meter
base rig in the event of a power outage. My HTX-242 manual states the
current drain of the transmitter as 8A @ 45W and 4A @ 10W. Would a 17aH
jump start battery work? Or is there something better, yet not to costly?


I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.
In winter, I'm most concerned about the gas heat not working and the
pipes freezing. Conversely, in summer, I worry about the freezer
thawing. Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority. A power outage is a great time for a
nap...maybe even with the old lady...

If you don't already have a rig in the car, it's not too hard to set up
so you can throw it in the car in such an emergency.

A handheld can also serve the emergency needs...and can serve to satisfy
your 2-meter Jones while walking or shopping or whatever else takes you
away from the rig.

The biggest problem with the portable battery station is that you don't
use it...it goes flat...sulphates...and can't hold a charge when you
need it. I charge mine on a regular schedule and it still goes flat...

mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

On Sun, 28 Mar 2004 12:11:22 -0800, mike wrote:

I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.

As a member of the county emergency services, the problem starts
when the power goes out.

Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority.

It is when the "same two guys" are the County Emergency
Manager and the County Communications Officer that such a
facility is necessary.

A power outage is a great time for a nap...maybe even with the old lady...

I don't need a power outage for that.... ggg

The biggest problem with the portable battery station is that you don't
use it...it goes flat...sulphates...and can't hold a charge when you
need it. I charge mine on a regular schedule and it still goes flat...

My station power supply is a Size 31 100 AH Marine Deep Cycle
Gel-Cell battery with continuous float charge (13.5 V) by dual AC
supplies and suitable diode isolation. All equipment runs on 12V,
and all wiring and distribution devices are UL and USCG marine
approved. Gel-cells don't go flat when float-charged and the usual
battery life is about 5 years.

Steady-state (receive-only) draw is 5A (then again I have 3
transceivers, 6 receivers, and 4 TNCs on-line 24/7.

Contrary to what an earlier poster said, such a setup will not
power the station for the number of hours determined by the AH
rating divided by the steady-state load (in my case 100/5 or 20
hours). After about 6 hours, the no-charge battery bus voltage
will drop to about 11.3 volts at which point several 12 V devices
fail to operate and go off-line. That's what standby generators
are for.

--
73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

On Sun, 28 Mar 2004 12:11:22 -0800, mike wrote:

I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.
In winter, I'm most concerned about the gas heat not working and the
pipes freezing. Conversely, in summer, I worry about the freezer
thawing. Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority. A power outage is a great time for a
nap...maybe even with the old lady...

The concern is not about talking with your buddies on 2M, but for
those who are involved in various emergency communications functions,
including their local Emergency Ops Center, their state's emergency
operations, ARES, MARS, SATERN, Red Cross, etc.

Many hams are involved with these efforts, and many times in natural
(hurricanes) or not so natural (WTC) disasters have been the only
reliable source of communications.

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

Gary S. wrote:
On Sun, 28 Mar 2004 12:11:22 -0800, mike wrote:


I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.
In winter, I'm most concerned about the gas heat not working and the
pipes freezing. Conversely, in summer, I worry about the freezer
thawing. Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority. A power outage is a great time for a
nap...maybe even with the old lady...


The concern is not about talking with your buddies on 2M, but for
those who are involved in various emergency communications functions,
including their local Emergency Ops Center, their state's emergency
operations, ARES, MARS, SATERN, Red Cross, etc.

Many hams are involved with these efforts, and many times in natural
(hurricanes) or not so natural (WTC) disasters have been the only
reliable source of communications.

OK, I can see the need for a handheld or mobile to go rescue someone.
Seems like there would be limited need for a fixed isolated station.
You can have only so many coordinators...and they usually end up in the
sheriff's office on a generator. And those people know about emergency
power.

I used to do communication for hurricaine shelters back in the '60s.
Was mostly a waste of time. I don't remember anyone ever NEEDING
communication to/from a fixed shelter.


Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom



--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

Gary S. wrote:
On Sun, 28 Mar 2004 12:11:22 -0800, mike wrote:


I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.
In winter, I'm most concerned about the gas heat not working and the
pipes freezing. Conversely, in summer, I worry about the freezer
thawing. Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority. A power outage is a great time for a
nap...maybe even with the old lady...


The concern is not about talking with your buddies on 2M, but for
those who are involved in various emergency communications functions,
including their local Emergency Ops Center, their state's emergency
operations, ARES, MARS, SATERN, Red Cross, etc.

Many hams are involved with these efforts, and many times in natural
(hurricanes) or not so natural (WTC) disasters have been the only
reliable source of communications.

OK, I can see the need for a handheld or mobile to go rescue someone.
Seems like there would be limited need for a fixed isolated station.
You can have only so many coordinators...and they usually end up in the
sheriff's office on a generator. And those people know about emergency
power.

I used to do communication for hurricaine shelters back in the '60s.
Was mostly a waste of time. I don't remember anyone ever NEEDING
communication to/from a fixed shelter.


Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom



--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

mike wrote in message ...
KC8WVG , Bill wrote:
I'm trying to locate an emergemcy source of power to operate my 2meter
base rig in the event of a power outage. My HTX-242 manual states the
current drain of the transmitter as 8A @ 45W and 4A @ 10W. Would a 17aH
jump start battery work? Or is there something better, yet not to costly?


I'd be interested to hear peoples' thoughts on what constitutes a
2-meter emergency during a power outage.
In winter, I'm most concerned about the gas heat not working and the
pipes freezing. Conversely, in summer, I worry about the freezer
thawing. Being able to talk to the same two guys I talk to every day
on 2-meters is NOT a priority. A power outage is a great time for a
nap...maybe even with the old lady...

Like when a hurricane breezes through town and takes all the light
poles with it. In many parts of town, the lights can be out for DAYS,
not hours. I done seen it firsthand in 1983 with Alicia. Luckily, it
wasn't ours though. :/ Ours stayed on. But the people across the
street were on a different circuit, and their's was off for a long
time. The guy I work with is two blocks away, and his lights were off
for a week or two.

If you don't already have a rig in the car, it's not too hard to set up
so you can throw it in the car in such an emergency.

I have that too. In Alicia, I actually rode out the hurricane sitting
in the car, not in the house. It was fun watching all the power lines
short together in the wind, and then in turn, blow up the transformers
that fed them. They would glow a weird greenish color. The whole sky
looked like that from them constantly blowing all over the area.

A handheld can also serve the emergency needs...and can serve to satisfy
your 2-meter Jones while walking or shopping or whatever else takes you
away from the rig.

I have that too. That way I'm covered when sitting on the pot...

The biggest problem with the portable battery station is that you don't
use it...it goes flat...sulphates...and can't hold a charge when you
need it. I charge mine on a regular schedule and it still goes flat...

I have battery power in the shack at all times. Have for nearly 15
years. I have a 706 that runs off battery power all the time. Except
I use big batteries. At least a full size car battery, and preferably
a deep cycle. 17 AH? That wouldn't last me doodley on the 20 amp max
706...I use 100 AH plus batteries. The charger is fully automatic, so
thats not a concern. One plus to my bigger batteries is I also have an
inverter. So I can run a light bulb, and a TV, whatever if I want to.
I've had to do this quite a few times when the lights have gone out.
Sometimes, it's taken a few hours to get them back on. If I eventually
had to recharge a battery during a lights out, I can either swap with
the car, or I can also just take it out and plug it into the car via
the radio power cable. I use anderson power connectors on everything
12v. Any connector will plug into any other.

It depends on the area, but having battery power is just plain good
sense in Houston Texas. You'll eventually use it. As far as
emergencies, I'm covered from just about every angle you can think
of...We are due another big storm. Houston is so built up, a hurricane
just rips it to shreds. If we ever get a storm that is 150 mph,
Houston will be totaled. I'm talking big time. Alica just about
ruinated it, and it was a wimpy 105 mph job...It did roll right down
main street though...Made a heapum big mess. I look at old pix of the
damage and it's amazing. Trees blown down right and left. Our whole
street was covered in blown down trees and tree branches. MK

It depends on the area, but having battery power is just plain good
sense in Houston Texas. You'll eventually use it. As far as
emergencies, I'm covered from just about every angle you can think
of...We are due another big storm. Houston is so built up, a hurricane
just rips it to shreds. If we ever get a storm that is 150 mph,
Houston will be totaled. I'm talking big time. Alica just about
ruinated it, and it was a wimpy 105 mph job...It did roll right down
main street though...Made a heapum big mess. I look at old pix of the
damage and it's amazing. Trees blown down right and left. Our whole
street was covered in blown down trees and tree branches. MK

What a bunch of wussies.
You ain't lived till you've been thru a hurricaine in Port Arthur.
Two blocks from the Gulf of Mexico and two feet below sea level.
That big battery had better be in the attic...and in a box to protect it
when the roof blows off.

And still, I don't think I ever handled any IMPORTANT traffic.
I'll waive
the public service banner if it helps keep the spectrum, but I don't
believe it.
I'll wager that 90% of the people with battery backup are of no value
in an emergency...not cause they're not motivated or stupid...it's that
there's nothing for them to do as long as they're fixed in one spot.
If you want to be helpful, put your rig in your vehicle...or your boat
if you live near the coast. Or put your repeater up high and put a
generator on it.
mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/