Astatic's MobileMax™
It’s been a while since we’ve seen a new echo
box. I think RF Limited up until this one was the only company still
making an echo box. The problem with these ad-on boxes has been RF
feedback. RF Limited units seemed immune to this type of problem in most
installations. They did quite a bit of engineering in filtering and
tracking down ground loops in these products before their release. Believe
me, there was extensive testing on many radio and antenna combinations,
because on some units I helped in the testing.
Remember the RF Limited/Road Noise VC-100. This box
had a voice scrambler, echo, roger beeps, compressor and talkback in one.
Or how about the VC-200, with it’s melodies, roger beeps, echo,
compressor, and talkback in one. The ice cream truck melody seemed
everyone’s favorite. They sure sold a ton of these, and when they were
discontinued, the demand went up. Some of these boxes sold for over
$200.00 each.
Now Astatic has entered the market. This box is a
descendent of the EchoMax 2000. It has the same echo and slapback effects
as the mic. In addition, it has 9 ETS (End of Transmission Signal) or
plainly put, roger beeps. And if that wasn’t enough, it has a 6 second
digital recorder. A 20 second recorder is more desirable though. Unlike
the VC-100 and 200, the MobileMax doesn’t have and internal speaker for
talkback, it requires an external speaker for the talkback feature to
work. There is an input jack on the rear of the unit for the receiver
speaker output to be directed to the external speaker through the
MobileMax. A horizontal LED bar graph displays the modulation level.
The sound quality is superb. This is the truest form
of digital echo. They incorporate a analog to digital converter, produce
the effects digitally and convert the digital back to analog. This is the
same process used in studio equipment. The digital echo will repeat a up
to a count of 7 at the maximum delay setting and will repeat several times
with the effect volume at maximum. The slapback effect is the same as the
echo, except the word or phrase is repeated only once. Setting the
slapback delay very short gives an effect that sound like two people
talking simultaneously. Setting the effects delay is a little tricky at
first. This isn't your usual echo delay control. With the control in the
12 O'clock position there are no effects. Turning the control
counter-clockwise produces an echo effect, the more the control is turned
in that direction, the longer the delay. Turning the control in the
clockwise direction produces a slapback echo effect, the more the control
is turned in this direction, the longer the delay.
The digital recorder is high resolution with very
natural reproductive sound. I find the six seconds a little short, but
this is probably due to the high quality audio. Because the radio
doesn’t transmit during the recording process, a received signal can be
recorded by holding the mic up to the speaker and then played back by just
pressing the play/record button momentarily. This can be good for
returning a modulation check, or to let an operator know how stupid they
sound. The playback is sound activated. If a recorded sound is
shorter that the 6 second interval, the radio is un-keyed on the sounds
completion.
| Click
on the LED "P" to hear the test recording that comes with
the MobileMax |
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The 9 ETS signals have 10 settings. ETS 0-8 are nine
different roger beeps. ETS 9 plays one of the nine roger beeps at random
every time the mic is un-keyed. Clicking below on number
nine demonstrates how the beeps are randomly played. The beep could be the
same a couple of times and then different every time for a number of
un-keys.
The dash
indicates no ETS signal is selected.
| Click
On The LED Number To Play The Corresponding Beep
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Sample
Of Reverb
Sample
Of Slapback
| Front
Panel Of The Astatic MobileMax Digital Effects Box |
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Inside the MobileMax, the circuit board and wiring
are first class. This is a professional job all the way. The computer
generated double-sided glass epoxy boards are what you won’t find in
other CB products. Broken solder connections shouldn’t be a problem with
these units. The relays look like over kill too. They’ve added an audio
transformer to isolate the audio ground from the PTT common, but they are
tied together at the mike connector. This would only have a purpose on the
5-pin sideband radios like the Cobra 148 GTL types. However, to date,
Astatic hasn’t offered a 5-pin version. But conversion is simple because
the mic cord coming out of the back of the unit is a 5-wire cord and they
have 5 wires available to the mike jack on the front panel. It’s just a
mater of changing the mic jack and mic connector to the 5-pin type. I have
changed one over to a 6-pin RCI version. The UP/DN mic buttons weren't of
a concern to the customer, so the 5-wire mic cord wasn't replaced. This
installation worked fine, with no sign of RF getting back into the unit.
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| Optimized
Audio As Indicated On MobileMax Bar Graph |
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Very clean reproduction is accomplished with this type of
digital echo. However, it doesn't have the same effects when the effects
delay knob is rotated as the conventional echo boards. Conventional boards
warp the audio as the clock speed is changed with the delay control potentiometer.
The pitch changes as well as the speed, giving a multitude of effects
depending on the direction of the delay control and were it was at the
time of audio input. In this type of echo changing the delay control
causes what is in the echo memory to become choppy or jerky sounding and
giving a Max Headroom effect. Someone described this echo as an antiseptic
echo, meaning clean sound and no way to warp it out of control. Back 5
years ago, this would have been less desirable, but now more radio
operators are using echo to enhance the sound of their station, not as an
agitator.
| Over-Driven
Audio As Indicated On The MobileMax Bar Graph |
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To
sum it all up, the MobileMax is a well designed, well made, scaled down
version of studio type sound processing equipment with some toys thrown
in. The sound reproduction is terrific. The LED bar graph display is
accurate, while recording I tested how far into the red I could push the
envelope. Once the second red LED lit, a slight distortion was present in
the playback. By the time the forth red LED lit, the output was quite
distorted. So the LED bar graph is a functional tool, not just glitz.
Now...there are some issues that Astatic could have avoided if they just
put more thought into the product development. The time required to hold
the play/rec. button before it locks into the record mod is too long. It
seems to be 3 seconds, and I found myself pressing the button in harder as
I waited for the "R" to flash. It didn't matter how hard the
button was pushed, a light touch worked just as well. However, after
waiting a second or two, its human nature to think there is something
wrong and you compensate. This could be frustrating to some operators that
try to make a quick recording, or could be a cause of premature switch
failure. A better talkback circuit could have been incorporated the
talkback isn't very loud. More record storage time would be better, but I
understand that the six-second limit is probably due to the limits of
the chipset inside. In addition, my final gripe is when you open the box
and inspect everything and read the manual, you realize that Astatic
doesn't supply a cable to connect the external speaker jack of the radio
to the MobileMax. Without this cable, you can't run the radio through the
external speaker plugged into the MobileMax. The radio internal speaker or
a second external speaker would be required, all for the sake of a cable
that would cost them pennies. This is the true meaning of "penny wise
and pound foolish”. Despite these few shortcomings, I highly recommend
the MobileMax as an audio enhancer, tool, and toy. I enjoyed testing it
(playing with it) and talking on-air with a slight amount of slapback. Bob
F
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