The physical world has its limitations—
things can only get so small.
Nowadays, we’re all quite accustomed
to seeing technology pack more
features into smaller packages. Why should
the world of solid-state transmitters be
any different? Evidently that is what the
designers at Harris Broadcast were thinking
when they came up with the Maxiva
UAX Compact Class transmitter. It features
a built-in exciter, drive chain and remote
access/control, all in a 2RU package.
The solid-state Harris Maxiva UAX is
part of the company’s “Compact Class”
of transmitters, with power levels from
5 to 50 watts, and as tested, providing
frequency-agile UHF coverage from 470
to 862 MHz. The unit weighs about 25
pounds, adds less than 65 dBa of acoustic
noise (as measured from one meter in
front of the transmitter), and is air-cooled
via internal fans with a front-to-rear airflow.
It takes AC power between 110 and
230 volts at frequencies between 47 to
63 Hz. Rear panel ports include RF output,
RF input sample for RATC, transport
stream inputs (two, configurable as SPMTE
310M, DVB-ASI or DVB-T2MI). There
are also a couple of ports for DVB-ASI
hierarchical modulation and a 10 MHz
reference input, as well as for a PPS reference,
along with a DHCP-enabled RJ-
45 Ethernet for networking. Front panel ports include a 10 MHz reference output
(SMA, 50 ohms), 1 PPS reference output
(SMA, 50 ohms), RF monitor output
(SMA, 50 ohms) and 1 RJ-45 Ethernet for
The front panel also features an LCD
screen along with Status, Power and Setup
buttons immediately below. To the right of
the screen is a “menu control wheel” and
buttons for remote enable/disable, output
power adjustment and an on/off control.
Seven status LEDs provide a quick status
check of TS input, drive chain, power amplifier,
supply power, output, system and
The transmitter also includes a built-in
GPS option to support single-frequency
network operations, full remote control
capability including Web-based HTML, GUI
interface, SNMP and parallel/monitoring.
As mentioned, the Maxiva has dual
transport stream inputs with manual/auto
switching and Real-Time Adaptive Correction
(RTAC). It supports DVB-T/H, DVB-T2,
ATSC, ATSC-MDTV, ISDB-Tb, CMMB and
As a transposer/translator, the Maxiva
supports all COFDM and ATSC standards
and has a digital, tunable RF input filter. As
a gap filler, its features include powerful
adaptive echo cancellation with up to 15
dB gain margin for exposed stations and
difficult situations and a very low processing
The Maxiva features Harris PowerSmart
Technology inside, and offers high power
and efficiency, utilizing new 50-volt LD-MOS
devices. Its exciter offers the Apex
M2X technology platform.
When the Harris Maxiva arrived, I
mounted it in my test rack and attached the
supplied directional coupler with dummy
load. Next, I connected my station’s SMPTE
310 stream to the input and applied AC
power. The LCD screen was easy to read
and the information was simple and direct.
The display provided forward and reflected
power figures (it indicated “0” and
“0” values for these at power up). I raised
the forward slowly, leveling it off at about
22 watts. At this level, reflected power
measured only about 12 mW. All was well.
However, what channel was I on?
Below the power display was the
menu display list, including On-Air Data,
Digital Signal Path, PFRU (Precise Frequency
Reference Unit), Up/Down Converter,
LPU, Battery Backup, Transmitter
I/O, Revisions, Fault Log, System Settings,
Adaptive, Transmit Power Settings, Remote
Comms and Defaults.
Under the PFRU, I was able to find
“Center Frequency,” and noted the frequency,
582 MHz. This didn’t please me,
as I like transmitting on UHF Channel 36.
Therefore, I killed the RF output (habit),
and using the menu navigation buttons,
I selected the center frequency setup
and changed it to read 605 MHz and then
pressed “enter.” Voila, I was on Channel
36, where my station belongs.
I raised the power and connected a
little consumer DTV to the directional
coupler output (using a paper clip as an
antenna) and there were all three channels
that we regularly broadcast.
After having successfully put this unit
on the air without reading any instructions,
I figured the next order of business
should be to gain remote control via the
I scrolled down the menu to find “Remote
Comms,” and under that menu I
found “Rear IP address.” After connecting
my laptop to the unit using a crossover
cable, I typed the address into my Chrome
browser. A log-on screen appeared, wanting
a pesky “User Name” and “Password.”
There was a box to click as a guest with
“View Only” privileges. When I clicked
there, I was able to pull up the GUI and
look but I needed control!
At this time I took the instructional CD
from the box and loaded it into my desktop
PC. Once the PDF loaded, I searched
“User Name” and once again, I had the
keys to the gate: “admin-admin” were the
magic words. The remote GUI proved to
be slick, simple and intuitive. I was able
to raise and lower power, and all of the
status info I needed for remote control
Over the next few weeks, I let the little
transmitter sit in my office and cook.
I did adjust the power down so that the
dummy load wouldn’t get too hot, but
the unit never missed a beat. The “Output”
LED indicator responded to a low RF
condition when I lowered the drive, and
I checked the TS LED by unplugging the
SMPTE 310 feed.
I next unplugged and powered up the
system several times to see what would
happen in a power bump, and it always
came right back up to normal.
This is a really complete transmission
system in a 2RU package, and one that
you don’t have to go to a training program
to learn how to deploy.
My regret was in not being able to put
it on the air.
Joey Gill is chief engineer at WPSDTV
in Paducah, Ky. and has been with
the station for 30 years. He has worked
in television since 1977. He may be contacted
repeater and gap filler
Compact, solid-state technology,
MSRP as tested, $9,950