After having our radios narrow-banded we observe a greatly increased power consumption by our radios. Batteries that lasted almost two days in the past are now dead in 4-5 hours. We purchased a new battery because we thought the old one was dying, but have the same short life with the new one. Our dealer says "Oh yeah, that's the way it is now - narrow-banded radios use far more power. Everyone has this problem."
I discussed this with a friend who is a commercial radio broadcast engineer. He told me that narrow-banded radios should not consume more power. If anything, they should consume a bit less.
Anyone else having a power issue or understand what is going on?
No, it has to be the radios. We have 10 crews running the narrow band radios. They now have to carry 2 optimum blue top batteries in each truck. Of course they also work 12-16 hours per day.
Are These Wide Band Radios Converted To Narrow ?
Or new narrow band units?
I would expect a new unit to use less power. The older wide band may be wasting a lot of power in a band choke device.
Conversions seldom work as good as a clean new design.
Paul in PA
Are These Wide Band Radios Converted To Narrow ?
No the new type units. I have also heard the same from Trimble and Leica dealers.
Buying New Narrow Band Radio Does Not Mean It Is New Inside
It could still be a conversion, new outside but still a conversion inside.
What they could do is like this:
Wide band radio, they do not cut the band in half down the middle.
They take the top 1/4 of your band and give it to a new band above you as the bottom 1/2 of it's new band. Likewise they take the bottom 1/4 of your band and give it to a new band below above you as the top 1/2 of it's new band. You keep the middle of a frequency. Suppose you have the technology for certain frequencies, you keep that technology and just choke off the top and bottom and onl=y transmit the middle. OK so far, but the receiver needs to get so much power. To equal that required power you need to double your existing output before you filter the top and bottom 1/4s out. Taking twice the power out of a battery for a constant time reduces the battery output time to 40-45% at the required voltage, fast drain.
If you are new to the market that new narrow band can only be accomplished by using some new technolgy. Designing from new for a narrower frequency can give you some power savings in the new technology and no need to waste 1/2 of the old output.
Paul in PA
mmmmhhh. Interesting discussion, thanks for bringing it up. Along with power-consumption issues associated with new or converted narrow-band radios, has anyone noticed any data through-put problems, perhaps associated with time of transmission of licensed call signs?
Another question, I wonder how many licensed users are actually xmitting their call sign on the mandated 15-minute interval? BTW, That's a rhetorical question. If you is or if you ain't, don't say it here. Just wondering if anybody has noticed throughput or RTK data latency problems with new narrowband radios.
Comments on the Narrow-Banding Data outputs, when using external 35-watt Base radio,
like the newer PacCrest ADL, when programming the radio for 12.5 kHz mode, selecting GMSK modulation, the over the Air Baud rate is locked down at 4800, the user cannot change the Baud rate to any other rate, (???). When setting up any RTK Base equipment, output GPS/Glonass data using RTK Message type RTCMv3, the 4800 Link Rate packets are pretty full, may not be enough room for all SV corrections, the Glonass SV's corrections may get dropped.
I have heard this feedback from some RTK users.
Switch to 4FSK modulation, or select CMRx, this problem goes away, but wait, gotta have a Tremble box to decode CMRx, hmmm...
Posted about this a little while back in this thread [msg]188045[/msg].
We are getting a 7 hour constant run time out of a 32 amp/hr battery with the listed settings. we have pushed the last couple of days and had to hook the truck battery up to it with jumper cables to finish the job. We are running at only 16 watts and still getting the range I have been needing. Bumping up to 25w when we are pushing range.
Yesterday I stop off and pickup a 54 amp/hr battery to try for a long day coming up on Tuesday. we will be 10 to 12 hrs of run time. Will let you know how it plays out.
Buying New Narrow Band Radio Does Not Mean It Is New Inside
Paul:
Our broadcast engineer says this is not the case...
Buying New Narrow Band Radio Does Not Mean It Is New Inside
I've never worked with data radios for surveying, but I've worked with voice FM radios. The simplest way to narrow the bandwidth from an FM transmitter is to reduce the strength of the signal that makes it from the microphone to the modulator. Then put a narrower filter in to make sure no stray bandwidth makes it out the antenna.
On the receiver, you could just leave the receiver as is, but noise from the unused part of the bandwidth will make the receiver less effective, so it is better to narrow the receive filter as well. The schematics I've seen indicate that radios capable of being narrow-banded have all the required wide and narrow filters installed at the factory on day one, and its just a matter of programming to use the appropriate ones. I have not heard of any voice radios being narrow-banded by changing parts.
What radio? What baud rate?
If you are running at 4800 bps you will see a decrease in battery life.
I'd like to explore this more when we have a chance at the local Trimble dealer.
in the meantime, we have experienced a much greater battery draw in part we think to using high power all the time to get any distance from the new ADL radios.
we bought an Optima for days where the use is long and we're quite a distance away from the base. most days, the smaller Werker group U1, WKDC12-35J works just fine.