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Review of the New NCE Radio Base Station and Repeater
by Don Fiehmann
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Don's NCE Radio Tips
NCE Radio Users Guide
This new upgrade, according to Don Fiehmann, provides
much faster response times.
There was a great improvement in model railroad operation
when we went from stationary throttles to walk-around control. But
the walk-around had one minor problem. The attachment cord was either
too short or got tangled up if it was long! The answer to this was
wireless connections. But the radio wireless had problems of its
own. Here is a history of the development of the latest big improvement
with the second generation wireless system from NCE.
WIRELESS HISTORY
The NCE wireless cabs work in the ISM (Industrial
Scientific Medical) radio band at 916.5 MHz. All wireless devices
that use radio waves must be approved by the FCC. The FCC controls
both the frequency and the amount of power the device can emit.
Extensive testing is require for final FCC approval. When NCE started
to design the wireless system the amount of power allowed was greater
than was allowed in the final product. Some where along the way
the power was reduced to 0.00035 watts (350µ watts). The NCE
wireless uses two way or duplex transmission. The handheld cabs
both transmit and receive data so commands can be sent to the command
station and the system send back the change in status to the display.
You know the signal got to the command station when the display
is updated. Many DCC systems use simplex or one-way transmission
and only send out the commands from handheld throttles. The only
way to tell the signal was received is by the response of the locomotive
or accessory decoder.
The FCC rules are different for simplex and duplex
transmission. The rule is based on the average amount of power emitted
by a transmitter. With simplex the only time there is a signal transmitted
is when a signal is sent from throttle or cab. With duplex the signal
is transmitted almost constantly. Thereby the amount of power that
can be emitted from a duplex system is far less than a simplex system.
For NCE this meant great reduction of the output power compared
to simplex systems. Reduced power meant reduced range of operation.
One of the first improvements was the change from
a 1/4 wave to a 1/2 wave (longer) antenna. Other improvements were
using an aluminum pie tin for a ground plane under the antenna.
Changing antenna locations also helped. But all of these improvements
still left holes in coverage in some layouts. Some of these holes
were caused by multi-path reception. This is the same type of problem
that causes TV ghosts and flicker when a plane flies overhead. Even
when the system checked out OK there could be dropouts when added
people soaked up the RF energy between the handheld and the base
station. Another complaint about the wireless system was the response
was much slower than when operating wired.
THE SOLUTION
If multiple transmitters and receivers could be placed
around a layout the coverage would improve. The solution was the
combination of RB02 base station and the RPT1 repeater. The connections
on the RB02 master allow it to communicate with the RPT1(s) repeaters.
Up to 30 RPT1s can be added. Each RPT1 has one output connection
and two (A & B) Inputs. The RPT1s to expand up to four levels,
five levels if your start with the RB02. Each RPT1 can be wired
to two RPT1s. The cables from unit to unit can be up to 40 feet.
This would allow a run of 160 feet with RPT1s every 40 feet. If
the RB02 is in the center you could cover an area of over 300 feet.
The power requirement from the Cab Bus is 70ma for the RB02 and
only 35ma for each PRT1. Adding more than 10 RPT1s may require added
power to the Cab Bus. (Check the manual for power requirements when
expanding with a many of PRT1s.) Three LEDs on the top of both units
are used to indicate which input (A or B) is active and one for
local activity.
A significant change in the RB02 was the improvement
in response time. The difference between wireless and wired has
been reduced to the point where they are almost the same, that is
fast!
Both the RB02 and RPT1 are the same size case and
come with the 1/2 wave antenna. A 7 foot cab bus cable comes with
the RB02 and a 40 foot cable is supplied with each RPT1. The cable
has both power and signal wires. The Cab Bus and the Radio Expansion
cables are the same type cables. But the expansion cables from the
PRT1s must be connected thru an RB02 to connected to the Cab Bus.
The new BR02 supports the setting of the Layout ID
number. The ID number allows more than one NCE system to operate
in an area and keep the commands separated for each NCE system.
See the manual for instructions for the RB02. The wireless cabs
must be set to a corresponding layout number.
There have been a few complaints about the length
of the longer 1/2 wave antenna in a crowded layout room. With the
improved coverage you might try using the 1/4 wave antenna. The
receivers in both the RB02 and PRT1 are very sensitive and can be
overloaded when the Cab is too close. When placing these units make
sure they are at least 2 feet or more space between the unit and
area where wireless cabs are used.
TESTING
I started my testing by putting the new RB02 in place
of my old RB01. I used a wireless ProCab and a wireless CAB-04e
for the tests. Signal strength can be observed by watching the LED
pulse on the top of the cab. Another way to check the system response
is to watch the display change on the ProCab after you enter a command.
The RB02 alone worked as well as the older RB01 in my first tests
with one big exception. The response of the new RB02 was very close
to a cab that was plugged in! It put the fun back into running wireless.
The fast response and ability to operating DCC controlled turnouts
made switching movements very workable. With the RB01 switching
was best done when plugged in to the Cab Bus. The faster response
makes operating new sound systems with added sound functions more
controllable. I’ll have to admit that I avoided using the older
wireless due to the slow response. Now I grab the wireless when
running the layout. No more stretching the cord to get to an area
almost out of reach.
My layout is in an area about the size of a two car
garage. The RB02 is near one corner of the room. The PRT1 was installed
at the opposite corner. The 40 foot cable was run along the wall
and just fit. I replaced the 1/2 wave antennas on both cabs with
1/4 wave antennas. I tired to find a location in the layout room
where the signal was weak .I even held the cab flat which puts the
antennas at right angles. This should reduce the signal strength
between the cab and the RB02/RPT1. The signal stayed solid and response
fast in all locations in the layout room and most of the rest of
the house.
The location of the LEDs have been moved to the top
of the RB02 from the side on the RB01. My base station is at about
eye level. At eye level it was easier to see the LEDs on the side
than the new location the top. I put both new units at a slight
angle for better visibility while testing.
When the system was turned on the RB02 would startup
each time until the RPT1 was plugged into Bus A. The RB02 would
then fail to startup on power up. Plugging the RPT1 into Bus B of
the RB02 solved the problem. NEC found a bug in the software that
affects some RB02s. This problem has been fixed. If you have this
startup problem with RB02 contact NEC for this fix.
UPGRADE
If you have an older NCE RB01 base station the improvement
in response it is worth the money to replace it with the new RB02.
There is a coupon that comes with the RB02 for a free repeater upgrade
of your old RB01. Only charge is $5.00 for S&H. Adding the RB02
and upgrading RB01 the would give you both a base and a repeater
for much better coverage.
We welcome
comments or suggestions from readers; please write
or call.
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