Astatic's MobileMax™

Astatic MobileMax Small Photo    

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
MobileMax LED Display "P" For Play.

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 LED Dash No ETS sSgnal. indicates no ETS signal is selected.

Click On The LED Number To Play The Corresponding Beep

Sample Of Reverb

Sample Of Slapback

Front Panel Of The Astatic MobileMax Digital Effects Box



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.


Inside The MobileMax Small Photo


Optimized Audio As Indicated On MobileMax Bar Graph 
MobileMax LED Bar Graph At Optimum Modulation

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

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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