BYONICS MT-AIO User manual

Micro-Trak All-In-One APRS Transmitter
Hardware version 1.3
The MT-AIO is a self-contained, water
resistant APRS transmitter/GPS receiver
designed for portable use. The MT-AIO is
computer –programmable, and frequency
agile over the entire 2 Meter ham band.
Operation beyond 2 Meter bandwidth limits
are not supported, since the device is not
FCC approved for use outside the ham
bands. Agencies exempt from FCC
requirements may contact us about out of
band operations. The device is rugged, and
intended for operation using conventional
AA batteries or other battery packages available locally that do not exceed
13.2 volts. The MT-AIO is not intended for operation on external power
without using a regulated 12 volt power supply, such as the Micro-Volt 12,
available from Byonics. The MT-AIO is not designed to be submerged!
The MT-AIO is a transmitter only, and may send packets coincidentally with
other transmitters. We recommend using the MIC-E format (default) with
this transmitter, since shorter packets tend to have a higher throughput, save
power, and minimize potentially high RF exposure levels.
The MT-AIO is controlled by a special version of the TinyTrack 3 chip, and
retains most, but not all, of the special functionality of the TT3. Features
intended primarily for HF operation have been omitted, for instance. Special
features of the MT-AIO include a power saving mode that switches the GPS
on and waits for a locked GPS position before sending a transmission. Since
the MT-AIO draws only a few milliamperes in the standby mode, battery life
can be extended to days or weeks, depending upon the transmission rate
selected and other parameters, including the type of data packet sent.
Power output of the Micro-Trak AIO is adjustable, and may be dialed down
to a few hundred milliwatts of power or up to as much as 10 Watts. It is
shipped set to maximum power.

The MT-AIO has only one, three position control.
Selector Switch
The selector switch, located near the center of the PC board, is a three
position switch. In the center position, the MT-AIO is off. Even when left
off, the batteries should be removed for extended storage to prevent leakage
and damage to the device.
The other two positions are for selecting one of the two configurations
stored in the TT3 chip’s memory. The two pages of configuration selection
allow you to enter different frequencies, icons, transmission rates, FCC call
signs, tactical call signs, beacons, and all other programmable features.
The MT-AIO will ordinarily be shipped programmed with the
customers requested parameters, allowing instant on-the-air operations;
just add batteries.
On moving the switch to the channel 1 or channel 2 positions, the device
will send a transmission. This data will not include valid GPS data, since the
GPS will not have had time to synchronize. Subsequent transmissions will
wait for the GPS to acquire lock, and this may cause transmissions to be sent
at intervals different than those programmed into the device. For instance, if
you select 2 minute transmission intervals (the default option) and enter a
cave, the GPS will not synch up, preventing a transmission. Immediately
upon the transmission timing cycle requesting a transmission, the device will
verify that the GPS data is valid and hold off transmitting until verified. This
allows a tremendous power savings. A transmission can be forced by
returning the selector switch to center and switching to channel 1 or channel
2, as desired. Note that the device takes a few seconds to complete a
transmission on reset. When the unit is powered off and on, the TT3 PIC re-
flashes the stored frequency parameters into the transmitter. This memory is
non-volatile, and data will be retained even if the unit loses power for long
periods.

Deviation Control
Two small blue trimmer potentiometers are located on the printed circuit
board. One is marked “DEV”. This is the deviation control. The deviation
control is fixed so that at maximum rotation, deviation does not exceed 4
KHZ, which is well within the range of most digipeaters. Commercial
receivers may require a narrower signal, and this control can be used to
allow better decoding in these receivers.
Power Control
The power control is the other blue trimmer potentiometer. It is set fully
clockwise from the factory for maximum power. This trimmer sets the gate
voltage on the amplifier module to allow power control over a wide range,
but it is important to remember that this controls’ range is all within a few
degrees of fully on. Power adjustments are best set using a wattmeter and
dummy load. The power adjustment is used when programming your MT-
AIO with your computer. Turning the power all the way down will minimize
problems in programming caused by RF energy “swamping” your computer
or USB to serial adaptor.
Antennas
The Micro-Trak AIO is shipped with a high quality 2 Meter whip antenna.
For portable use, this is a great option. Take care not to bend the base of the
antenna, as this can result in a cracked enclosure or broken PC board.
External antennas may be utilized, but care should be taken to ensure that
the SWR is within best practices, and that the antenna is not in too close a
proximity to other transmitters or static fields, as this can damage the final
amplifier. Operating without an antenna will destroy the final amplifier. For
this reason, final amplifiers are not covered under warranty, and repairs will
be subject to parts and bench tech costs.

Status LED
A single bi-color LED is used to show the status of the unit. Immediately
upon start up, the LED will flash a pattern of red and green, indicating that
the unit is starting up and internally resetting. If this pattern continues
without stopping, this is an indication that something is wrong, such as a low
battery state or excessive SWR. The single pulse of a red signal indicates
that the unit is sending a transmission. A blinking green indicates that the
unit has switched on the GPS and is waiting for it to lock onto the GPS
satellites. When the GPS locks on solidly, the TT3 brain will allow the
transmitter to send its data out over the air, causing the GPS green indicator
to switch off. In some cases, the GPS LED will remain lit until the next
timing cycle. This is normal, and is an attempt by the TT3 to verify good
GPS data.
Programming
Ordinarily, the MT-AIO is shipped pre-programmed with the user’s
information. In the event that a user needs to reprogram the MT-AIO, this
can be accomplished in several ways. A Kenwood compatible cable is
available through Byonics for this device. Please note that the
programming cable wiring is different than Version 1.1 of the MT-AIO,
and now uses the Kenwood wiring scheme.
To program the device, the power amplifier control should be turned all the
way counter-clockwise (off)
The Micro-Trak AIO software may be downloaded from the Byonics
website. Additional information on programming parameters may be found
in the regular TT3 manual. Note that not all functions are available in the
standard TT3 configuration are available for use on the MT-AIO.
Alternatively, the PIC may be removed and plugged into a regular TT3 for
programming, using a null modem cable and a gender changer. Note that
there is a difference in the chips, and the TT3 should not be connected to a
radio while programming! Use only the programming software designed for
the MT-AIO.

Battery operation
The MT-AIO includes a standard 8 pack AA holder. This connects to the
PCB using a standard 9 volt style battery clip. This clip notwithstanding, the
device will not satisfactorily run on a 9 volt transistor radio battery! Battery
connections are notoriously common points of failure for battery powered
devices. The MT-AIO was designed to allow end-users to replace the battery
clip using nothing more than a small screwdriver. The MT-AIO will run well
from 9 to 13.2 volts DC (do not use unregulated automotive or aircraft
supplies!) This allows a wide variety of options for power if needed,
including ganged 9 volt lithium or alkaline batteries, AA LiPo, NICAD,
NIMH, or alkaline batteries. It is possible that batteries going into the last
segment of their lives will exhibit erratic behavior, and cause the MT-AIO to
continuously recycle. Naturally, these batteries should be removed and
disposed of. (Or recharged) Please note that connecting the battery
connector backwards may damage the MT-AIO. A polarity protection
steering diode has been installed in this transmitter, as opposed to the last
version of the MT-AIO, which had a “crowbar” protection circuit. To
operate the MT-AIO from external power, use a fused line, and a regulated
power supply, like the Micro-Volt 12, available from Byonics. Please be
careful not to install the battery cartridge in a way that allows its snap
connectors to short across the PC Board. This can cause the battery case to
melt and the batteries to explode or leak.
Operation
The internal GPS antenna is horizontally oriented. In general use, this does
not present a problem using the unit in upright operation. It is recommended
that the unit be powered on initially after a long period without being
powered, or after having relocated the unit to a distant location from the last
general area of operation. Allowing the unit to face upright during this time
will allow the GPS to more easily view multiple satellites and locate itself in
the universe quickly.

PCB Layout
Antenna
GPS
Selector
Switch
Programming
Power Control
Deviation Control 12 VDC

MT-AIO Schematic

Specifications
Dimensions 6.37 X 2.62 X 2.06 inches (case dimensions)
Weight 14 ounces, batteries not included
Power supply 8 AA alkaline batteries of equivalent
Antenna 15” 2 Meter whip antenna
Output connector SMA Male
Frequency range 144 to 148 MHz 2 Meter ham band
Output power Maximum 10 Watts at 13.2 volts DC, adjustable
Deviation 3.5 KHz, factory set, adjustable
Estimated operation 8 Days, @ 2min Check-ins using MIC-E Data
Frequency Stability +/- 1.5 KHZ
Operating temperature -20 to +70 Centigrade
Spurious radiations ETSI EN 300 220-3 and ETSI-301 489-3
Adjacent Channel spurs <-40 dBm

GPS Data

A word about using the Smart Beaconing Feature
The MT-AIO was initially designed for portable, hand-held uses. Many
Byonics/VHS customers requested that the Smart Beaconing capabilities
available in other Byonics products be made available in the MT-AIO. The
Smart Beaconing parameters require the GPS to provide a constant source of
data to the processor. This means that when Smart Beaconing is selected, the
GPS will automatically be switched on. Depending upon the battery type
and transmission interval, this will shorten battery life to about 2 days at
best.
Programming Cable Version 1.2

MISUSE
An MT-AIO, carried as rocket payload, after auguring in from 12000 feet.

Using the MT-AIO with External Power
The Micro-Trak AIO was designed primarily for battery powered operation using the
internal battery pack. The Micro-Trak can be operated off an external source of DC
voltage, but care must be taken not to exceed the rated input voltage of 13.2 volts, which
will destroy the amplifier module. For automotive or aircraft operation, a regulated power
supply should be used to run the MT-AIO.
MICRO-VOLT 12
The Micro-Volt is a 12 volt regulated power supply intended for use with Micro-Trak
products. The supply measure 1 X 1 inches, and has a three terminal input/output
connector. The Micro-Volt will supply the short duration 2 Ampere pulses required by 8-
10 Watt Micro-Trak transmitters, and may be used to power any Micro-Trak from
automotive or 24 Volt aircraft power busses. The power supply should be installed on a
fused power bus. Note that the power supply uses a common ground for input and output.
In an automobile with negative ground, the center connection should be connected to
chassis ground. Unlike many power supplies, the voltage regulator tab on the Micro-Volt
is not connected to ground, so use care in your installation not to short the tab to chassis
ground. Do not install a screw through the board to fasten the tab to the board, as this
could cause a short. If required, the voltage regulator may be bent upwards and attached
to an accessory heat sink.