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Radio Broadcast Technical Consulting and Sales
10032 Island Drive, Brainerd, MN  56401


Note: These units are sold out.  No more production is planned.  We repair existing units to factory specifications.

      Max-Z front and rear panels
     Click on an image for a more detailed view
In a nutshell:  The Max-Z is a telephone, similar to what you might have at home.  Plug it into an ordinary dial-up phone line.  Push the line button and you will hear a dial tone.  Use the dial pad on the front of the Max-Z to dial the call.  There are four audio inputs for microphones or other audio devices and there are four headset outputs so you can hear your audio and audio from the other end of the phone line, just as you would on a regular telephone.  The difference is the convenience and quality of a microphone mixer and headset amplifier.  The unit is not an ISDN or other digital type device.

The Max-Z is an industry favorite for remote broadcasting of sporting events via standard telephone lines.  It was designed by broadcasters for broadcasters.  This is a rugged and dependable unit.

Wiring for the four microphone/line input connectors:  The Max-Z input is unbalanced.  Use a Switchcraft A3M or equivalent connector.  Pin 1 is shield.  Pin 2 is source -, and is also shield/ground.  Pin 3 is the + input.  Each input is gain adjustable on the rear of the Max-Z from -50 dBm microphone level to +24 dBm line level. 

Outputs: The Max-Z has a dial-up telephone line connection with an RJ11 jack.  This is the same as a telephone you might use at home.  It also has an active balanced output so it can be used to drive a dedicated telephone line at 0 dBm.  This makes it possible to use it as a small studio console.  The connection is an RJ-11 jack.  There is a microphone level (-50 dBm) record output on a 1/8" monaural jack.  

Wiring for the four headset connectors:  There are four 1/4 inch diameter three-circuit headset jacks connected to a two-channel low impedance headset amplifier.  Any headset, 4 ohms and up, can be used with the Max-Z.  There are isolating resistors on each headset jack so that a shorted headset will not prevent audio from being heard on the remaining headset jacks.  The jacks are wired "stereo."  Under normal circumstances, Max-Z program audio and telephone audio are heard in both ears of every headset.  When Channel 1 and/or Channel 4 are put in the "Cue" position, The audio in one ear is switched to the cue audio only while the other headset ear has program audio. 

Size: The Max-Z is 17" wide, 5" high, and 13-1/4" deep.  The unit has an internal 12-volt rechargeable battery that will run for 8 hours.  Included is a carrying case, and a 120 VAC power cord for battery charging and continuous operation.

Frequently requested repair parts that we stock: Price Each
Battery.  This is rechargeable and should last 3 to 5 years. (requires disassembling the unit to install) $29.80
Battery hold-down bracket 5.00
Front panel audio gain, balance, and headphone level knobs with pointer-skirt and cap. 3.98
Front panel audio level controls and headset volume control (A5K) 8.88
Front Panel Balance/Null control (B10K) 8.88
Front panel momentary switch without light.  Used for clock hr/set, min/set, timer start, and timer zero. 16.20
Front panel push-on, push-off switch without light. Used for clock hr/min, and timer on/off 18.58
Front panel push-on, push-off switch with red light. Used for Cue 1, power, tone/pulse, line, and cue 4. 26.80
External wall-mounted power supply with 5-pin DIN plug (used on later production units) Model number A482400400U.  Not available at Radio Shack. (best to buy two so you have a spare on hand when you loose one.)  There is a discount of $2.00 per power supply when purchasing two or more.  Details 22.00
Instruction manual with schematic diagrams 12.00
120 VAC IEC power cord (used on earlier production units) (same as power cords on most computers) 6.00
Rear panel input channel audio gain controls 5.82
Rear panel level knobs 3.00
Rear panel headset jacks 12.00
LCD Bezel and filter for clock and timer displays. 11.00
LCD Displays. 23.20
Piezo buzzer. 17.00
Signetics NE5533N IC's (It is normal for the audio to have hiss when the back panel audio gain is turned all the way up.  Just turn it down 1/8 turn.  This does not indicate a bad IC.) 25.00
Keypad for Touchtone dialer.  Grayhill 86YY3620B-551.  2-11/16" x 2-15/16" sticks through the front panel. (Not all Zercom Max-Z units use this particular one) 28.00
HM9113A Dialer Integrated Circuit 1.00
Telephone line transformer T1 21.82
Telephone cable, 14 feet long. 2.00
Top cover, painted black.  New 40.00
Additional parts available upon request


INQUIRIES:  The best way to get answers to your questions is to e-mail teki@mwpersons.com.  If we are in the office, you will have a reply within an hour.  If we are not in the office, you will have to wait.

SHIPPING:  We normally ship via United Parcel Service.  We DO NOT SHIP INTERNATIONALLY.  If you are an international buyer and have a shipping broker in the United States, we will be glad to ship to them.  We do not ship packages outside of the 50 United States. 

ORDERS:  E-mail your order with a complete street address and telephone number.  We will e-mail you an invoice for the total amount including shipping based on size, weight, and destination.  

PAYMENT:  We now handle VISA credit cardsSend us your credit card information along with your order.  If you would rather not send the credit card data in an e-mail, then give us your telephone number and we will call you to get the number.  You can also pre-pay by cashier's check or money order. 

M. W. Persons and Associates, Inc.
10032 Island Drive
Brainerd, MN  56401

Non-warranty repairs:  Click here

Tech Tips from our Knowledge Base: 
The balance/null is a headset control used to reduce the level of audio mixed by the Max-Z.  It has little or no affect on audio level heard from the phone line.  The goal is to let the announcer on the Max-Z hear himself at the same level as the cues that he might get from the radio station over the phone line.  To adjust this control, place a phone call to the station.  Then speak into a microphone on the Max-Z and adjust the balance/null control so that the audio level is a minimum.  You will normally hear that at about the 2 o'clock position on the control.  Then the headset volume control should be adjusted for the desired level.    
If the Touchtone dialer does not seem reliable, the battery voltage might be below 9 VDC.  The normal battery voltage is 12 VDC.  As battery voltage drops, Touchtone audio drops in level and becomes distorted.    
A good battery will run the unit for 8 hours on a full charge.  When the power cord is plugged into 120 VAC power, the battery will charge regardless of whether the unit is turned on or off.  It takes 24 hours to recharge a dead battery.
On most units, there can be excessive noise in an input channel if the input gain control, at the rear of the unit, is turned to maximum.  Back it off 1/8 of a turn and the noise will go away.
For analog cellular to Zercom Max-Z or Max-ZII, use a "data jack" or "fax Jack." These items are provided by and installed on a cell phone by the people who sell cellular telephones. For Motorola cellular phones, Motorola suggests the " S1936C Cellular Connection Data Jack." The jack provides the equivalent of regular telephone service like fax, computer modem, answering machine, etc. The Zercom unit plugs into the jack on the side of the telephone using it's standard modular telephone cable. The S1936C even accepts rotary dial pulses. Could cost $250 installed.  We recommend you use an analog cell phone rather than digital for the best audio quality.
To connect a Max-Z to cellular telephone service, you might use a Verizon Wireless Home Phone Connect device.  It is a box that looks like a wireless router, but it talks directly to a nearby cell tower and provides a standard RJ-11 telephone jack for plugging an ordinary telephone in or a Zercom Max-Z Remote Broadcast Telephone.  In essence, it is like having a wired telephone line, but it is portable to anywhere.  Just plug it in and you have a telephone line.  Great for sports broadcasts or remote broadcasts of any kind.    Other cell phone providers probably have a similar device.  This is probably your BEST choice.

To connect a Max-Z to a digital cellular telephone, you can use a JK Audio Daptor One.  It converts the 2.5mm headset jack on a wireless cellular phone to a modular RJ-11 jack, the same as a regular telephone line. One small problem: The Max-Z will show a line loss alarm because there is no DC current flowing through its telephone line input.  Audio distortion will be high too.  The alarm can be turned off and the distortion prevented for this kind of connection.  To do this, it is best to send the Max-Z to us for modification.  The cost is $50.00 plus shipping.  This is also an opportunity for you to have the unit repairs made as necessary to keep it in good working condition.  e-mail us

Microphone (Audio Input) Wiring:  The audio inputs are standard A3F jacks.  They are not balanced, but instead have Pin 2 tied to ground, which is the same as Pin 1, which is the shield.  That means the "hot" side of the audio must go to Pin 3.  This configuration is the same as Marti remote pickup transmitters, but is different than the International standard where Pin 2 is the audio input.  If the microphone or other audio source you have is unbalanced and outputs its audio on Pin 2, then you will need to change the connector wiring on that source cable or make an adapter where Pins 2 and 3 are transposed.  We can build and sell you a 6 inch adapter cable to do this for $20.00 plus shipping.   
Hum in Headsets:  Some customers report they would like to reduce the hum that is heard in their headsets.  This hum is heard when the unit is plugged into 120 VAC power.  The hum is not heard in the programming that runs through the unit.  To dramatically reduce the hum, we have an upgraded version of the external wall-mounted power transformer.  The transformers are $30.00 plus shipping and tax.  The change may require swapping two wires inside the Max-Z unit to get the "power" light to come on.  If your unit has a standard computer-type power cord, then the unit will need to be modified to accept an external power supply.  The modification, in our shop, runs $90.00 plus shipping. A new $30.00 power supply is included in the $90.00 price.
Record output level:  The Zercom Max-Z record output was designed to provide unbalanced microphone level audio (-50 dBm).  You can cut one end of resistor R35 (100 ohm) to raise it to -10 dBm, consumer auxiliary level with 10,000 ohm impedance.  To further increase the level, solder a 150 ohm 1/4 watt resistor across R34, (10,000 ohm) resistor.  That should bring the level up to -5 dBm or so.  We do repairs and modifications here in the shop if you need that.
Dedicated Output:  This is about -4 dBm balanced audio on an RJ-11 jack.  The two center conductors are + and - audio.  The two outer conductors are ground. 

Unsolicited e-mail on January 31, 2007:  "Thanks Paula. I got the box today from UPS, just in time to replace the missing power supply and knob on the used Zercom Max-Z unit. I sent it out with our second team for a girls basketball broadcast. It's working fine.  I'm glad you are still providing service and support for the Max-Z's as they are still the best thing out there for those of us who are on a budget and can't afford the new codec systems."

"We are Southwestern Ohio Public Radio (WSWO-LP 97.7)Being an LPFM on a thin budget, I don't see us going to Comrex units anytime soon, so we are doing our sports via cell phone or land lines using the Max-Z.  They are easy for our volunteer announcers to set up and operate even though they may not be very familiar with broadcast technology.Zack Riepenhoff.

   Questions?  Email Mark Persons:  teki@mwpersons.com      

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page last edited 04/28/2016