Measurements of TM electrical loads

Heh, for better or worse the newer ones are definitely more hi-tech. With more things to go wrong ...

[TexasCamper]

Dave,
quick question.....
you measured 0.2 amps on the "antenna preamp".
I assume this is for the TV antenna? If so, is this a phantom load that runs all the time or does something switch it on? (we've never brought TV or used the antenna).

The reason I'm asking is because I'm calculating my new amp-hrs using my new LED lights. And if this antenna preamp is always running, well let's just say I don't want it too!

-John

P.S. Thanks for the great data in this thread!

[ShrimpBurrito]

Originally Posted by TexasCamper

you measured 0.2 amps on the "antenna preamp".
I assume this is for the TV antenna?

Yes.

Incidentally, TV antennas by themselves don't consume any power, so if this device is a preamp (and I don't know what else it could be), then it's supposed to overcome signal loss incurred by transmitting the signal through a long cable. But the cable in the TM is not long enough to incur major signal loss, so I can't see how it can be very effective vs. not using one at all.

Originally Posted by TexasCamper

If so, is this a phantom load that runs all the time or does something switch it on? (we've never brought TV or used the antenna).

It only consumes power when the little black push-button switch on the coaxial connector faceplate is on. I think mine has an LED light to indicate power status.

Dave

Originally Posted by flakeyone

For those that have to use one, a CPAP machine for sleep apnea pulls 3.0 amps

I think the draw is determined by the setting level of your cpap

[scrubjaysnest]

If I can get my 10A full scale meter working again, I'll be checking our DC loads since I now have the solar panels operational.

[scrubjaysnest]

Originally Posted by Willyb

I think the draw is determined by the setting level of your cpap

Found this link about cpap loads, I don't know how valid it is as the battery voltages assumed are at zero effective battery SOC.

http://www.newtechpub.com/sleep/maga...s/power03.html

Also found this link:

http://www.cpaptalk.com/viewtopic.php?t=4590

Both of these tend to indicate no need to run a generator all night beyond piece of mind.

[scrubjaysnest]

Here is what I have measured for device currents:
single LED,36 leds, expensive brand 0.14 amps
single LED, 38 leds, cheap brand 0.41 amps
1 1146 bulb, in the hallway, 1.41 amps; less than expected
florescent fixture, 1.34 amps higher than expected
The famous toilet 4.58 amps
furnace pre-ignition 3.03 amps
running 3.44 amps
cool down 2.85 amps
convertor fan 0.23 amps

all readings include 0.01 amp for the solar controller
The water pump wasn't tested
radio and antenna are disconnected.

[Brittany Dogs]

Originally Posted by ShrimpBurrito

Yes.

Incidentally, TV antennas by themselves don't consume any power, so if this device is a preamp (and I don't know what else it could be), then it's supposed to overcome signal loss incurred by transmitting the signal through a long cable. But the cable in the TM is not long enough to incur major signal loss, so I can't see how it can be very effective vs. not using one at all.



It only consumes power when the little black push-button switch on the coaxial connector faceplate is on. I think mine has an LED light to indicate power status.

Dave

The amplifier found in the antenna is usually a signal booster and not just an amplifier to overcome the insertion or signal loss of the cable length. The amp is used to help pull in distant stations which is usually the case when camping. TV stations are usually a distance away and unlike homes in the area which use large roof antennas with high gain, most campers need to use fairly small antennas. Sadly, the amplifier also boosts the noise too. The amplifiers are especially helpful for UHF stations and lucky for us, many digital stations use the UHF spectrum.

Now .2 amps is 200 milliamps and that seems a bit high to me but I don't have a lot of testing done to dispute that either. Yes, the little black button on the antenna faceplate will turn this amplifier off.

[Joesjunk]

I found that in my 3124SL, the factory installed radio/cd/dvd/tv unit was drawing over 1/4 amp when powered off. I installed a switch to completely remove power from the unit. Now I have only small fractional current draw when I store the TM.

The LED lights do make a big difference.

Has anyone tried the floresent tube like LED to replace the lights in the TM?

[ShrimpBurrito]

Originally Posted by Brittany Dogs

The amplifier found in the antenna is usually a signal booster and not just an amplifier to overcome the insertion or signal loss of the cable length. The amp is used to help pull in distant stations which is usually the case when camping. TV stations are usually a distance away and unlike homes in the area which use large roof antennas with high gain, most campers need to use fairly small antennas. Sadly, the amplifier also boosts the noise too. The amplifiers are especially helpful for UHF stations and lucky for us, many digital stations use the UHF spectrum.

I'm no expert, but I do have a fair amount of experience in this area through my own tinkering. I'm not familiar with any such device that can "pull in" signals above what is received by the antenna. How is that even possible? You can't make a signal out of nothing. To my knowledge, the only way you can "pull in" distant stations downstream of the receiver is through antenna design (or as some may call it, "magic"), i.e. increase antenna gain (but still maintain the signal/noise ratio), make the antenna more directional, etc. Aside from increasing elevation and removing obstructions, that often simply means a larger antenna. To my knowledge, a pre-amp hooked to a set of rabbit ears set atop the TV adds no value. On the other hand, if your antenna is atop a 50-foot pole 50 feet from your house, and your TV is another 30 feet in the house, you're going to see a significant increase in signal strength from using low-loss cable and a mast-mounted pre-amp.

But I digress......

Dave