Frequently Asked Questions
When does
the FCC require us to migrate to 700 MHz P25?
There seem to be quite a bit of misinformation
floating around on this subject. The FCC is NOT requiring a
migration to Project 25 digital or to 700 MHz. While it is true that
P25 Phase 1, in any frequency band, meets the FCC’s narrowbanding
requirements, this can be accomplished by using 12.5 KHz bandwidth
analog mode on the same 25 KHz channel(s) you are presently using.
It is also true, that in most cases if you are using grant money to
fund radio purchases, you are required to purchase P25 “capable”
radios. But…you are not required to operate in P25 mode. See our
Narrowbanding
page.
We use
Motorola Smart-Net trunking. My present radio supplier has said,
“Ours are the only units that will work on your system.”
Wrong, EF Johnson produces Smart-Net trunking
protocol radios under license from Motorola that will work on your
system. Many of your XTS-2500 and XTS-5000 accessories such as
batteries and speaker / microphones will work on both units.
What are
the differences in batteries (chemistries)?
Nickel Cadmium (NiCad): Oldest
type. Used on two-way radios for decades, most economical, suffers
from “memory” effect. It has the lowest weight to energy density.
They are heavy for a given capacity.
Nickel Metal
Hydride (NiMH): Higher capacity than NiCad’s, looses its ability to
operate equipment rapidly when cold. They have a shorter lifespan
than NiCad. Memory isn’t as much of a problem as NiCads. Still
heavy.
Lithium Ion (Li-Ion): One of the newest
chemistries, along with Li-Polymer. It is the most expensive, but is
the lightest. It has the highest weight to energy density. Some old
NiCad batteries weighed as much as the radio or more! Li-Ion can
significantly reduce the overall weight of the radio/battery
package.
How long will my battery last? (Or, when
will I have to replace it?)
That depends on how the battery is used, how
often it is charged, how deeply it is discharged, and what chemistry
it is. Ni-Cads have a life expectancy of around 700-800 charge /
discharge cycles, NiMH usually wear out around 300-400 cycles and
tend to fail rather abruptly. Li-Ion will deteriorate about 20% of
its capacity per year of use if charged / discharged ever day.
What is
the duty cycle of my battery?
The duty cycle (Daily use) of a battery depends
on how much capacity the battery has. This is usually rated in
MilliAmp Hours (MAH). One MAH is one thousandth of an amp. It takes
1000 MAHs to equal 1 AH. To put this in prospective, a common car
battery might be 100 AHs. A 100 AH battery will provide 100 Amps for
1 Hour or 1 Amp for 100 hours. Most radio manufacturers rate their
products based on a 5-5-90 duty cycle, which means 5% of the time
transmit, 5% receive, and 90% standby (squelched receiver).
Obviously the more you talk, the shorter time the battery will
operate the radio. Most modern batteries will give in excess of 8
hours use before needing to be recharged, based on the industry
5-5-90 standard.
Can I
start using a new battery as soon as I get it?
You should fully charge a new battery before you
start using it. If at all possible, leave it in a charger for 24
hours, even if the charger is a “fast” charger. The first charge is
important to help “form” the cells.
Will my
rechargeable battery get a “memory”?
The condition of rechargeable nickel cadmium and nickel metal hydride batteries in which it continues to hold less of a charge over time is commonly called “memory.” The technical term for “memory” is voltage depression. It is said to "remember" how full it was when last charged because it will not charge past that point the next time. This is why you should completely drain nickel-based batteries every month or so. This memory effect is caused by a combination of chemical reactions; however, the cadmium in a nickel cadmium battery is the bigger problem and why nickel metal hydride batteries fare somewhat better. In a fresh battery, the anode's cadmium crystals are approximately one micron across. If the battery sits in the charger too long or is not fully discharged, over time, the crystals grow too as much as 100 microns. This conceals more of the active material to the electrolyte and reduces battery life. For an exhaustive look into the world of rechargeable batteries, visit http://www.batteryuniversity.com/ . Modern NiCad batteries, thanks to manufacturing improvements, don’t have as severe of a problem as early NiCad’s with memory. NiCad and NiMH both can get “memories”. NiMH exhibits this phenomenon less than NiCad’s. Modern NiCad’s if used properly will significantly outlast NiMH type batteries. If you have a NiCad or a NiHM battery pack that has developed a memory, KC Wireless has the necessary analyzers and conditioners to remove any memory.
I
am using Li-Ion batteries should I purchase a battery
analyzer/conditioner?
Because Li-Ion
batteries don’t have a memory problem, and can be ‘opportunity”
charged any time before the battery is fully discharged. An analyzer
will only tell you what the absolute capacity of the battery is.
There is no way to “condition” a Li-Ion battery. Once it is worn
out, replace it. If you have NiCads, a battery analyzer/conditioner
can pay for itself rapidly if you have a large fleet of radios
If
I fully charge a new battery and store it, will it have a full
charge when I decide to use it?
All batteries exhibit “self-discharge”. Some battery chemistries discharge faster than others. A fully charged NiMH will self-discharge at about 1% per day, NiCad’s slightly less. So, if you retrieve your battery after 2 months, expect it to be only about 40% charged. Li-ion batteries fare much better, at about 10% per month. If you need to store your radios and batteries for prolonged periods of time for “emergency” use, consider purchasing a battery holder that uses standard alkaline single use batteries. If stored properly, these can have a shelf life of several years, with negligible effect on capacity.
Can I
leave my portable radio turned on in the charger?
It’s not a good idea to do this. Most chargers
won’t properly charge a battery if the radio is left turned on while
in the charger. If the “trickle” charge rate is less than that
demanded by the radio, once the charger switches to that mode, the
battery will eventually discharge due to the radio using more out
than the charger is putting in!
How long will my radios last?
Now that’s a tough one…. How durable or well
built is the radio you are using, how are they being treated? They
won’t last as long if they’re doubling as a tire chock or a hammer.
If you are using it for two 8 hr shifts, then it effectively gets
double the use…. Expect half the life, For example, if you are using
a radio for all 3 shifts it ages 3 years for every year of life.
What if my
radio gets wet?
First thing, turn the unit OFF and REMOVE the
battery if it’s a portable. If it’s a mounted mobile, turn the unit
OFF and if possible disconnect the power to the radio. Bring it to
us ASAP, especially if it’s a soft drink or coffee, due to the
acidic content. Make sure to tell us it’s been wet. This greatly
improves the chances of us saving it. Ideally, we should look at it
before it completely dries out. Once corrosion on the circuit board
and components starts, it is difficult to completely repair this
damage.
How far will my radios talk?
Now that’s a good one… There is not just one
answer for that question, there are just too many factors
influencing how far you will be able to communicate. Typically,
portable radios, not using a repeater (unit to unit operation), you
can expect somewhere between 1 to 1.5 miles in an outside urban
area. If you are trying to operate in a building, all bets are off.
Again too many factors can interfere with clear communication,
building construction, (steel, concrete, etc.) and the contents of
the building. An open building works much different than a warehouse
full of metal cans of green beans. Don’t believe advertisements
claiming many multiples of miles. Remember, radios operate
“line-of-sight”. If one end is on a building top, or a high hill,
your range will increase. If there are obstacles you can expect much
less.
Can my scanner pick up P25 transmissions?
Not unless your scanner is specifically designed
for P25 digital. These
are the newest ones on the market and are the most expensive of all
scanners.
Can a scanner pick up trunked conversations?
Some scanners like the
“Uniden Bearcat Trunk Tracker” family are designed to “follow”
trunked conversations such as Motorola Smart-Net, Ericsson (now
Harris) Edacs, and EF Johnson’s LTR protocol.
Can a
scanner pick up PassPort conversations?
Currently no one makes a scanner to follow
PassPort conversations.
Can I
scramble my PassPort radios?
Yes, some radios have scrambling built-in, while
others require a small board to be installed in the radios you would
like to be protected.