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Introductory Information on the Syntor, Syntor X, Syntor X9000, MCX100, MCX1000 and Mostar Series Compiled by Mike Morris WA6ILQ Maintained by Robert Meister WA1MIK

THERE IS NO SUCH RADIO AS A SYNTOR XX To paraphrase Paul Bennett N7OCS, "The Syntor X, Syntor X9000 and Syntor X9000E radios use a 'drop shadowed' X graphic.   This drop shadow is cosmetic only and there is no such thing as a Syntor XX, Syntor XX 9000 or Syntor XX 9000E radio.   On the other hand, there are Syntor X2 and Syntor X3 trunking radios, so the use of the "XX" can be confusing and should always be avoided." Also there is a space before the "X" and no dash or hyphen between the X and the 9000. In other words, "Syntor X9000" is correct, "Syntor X-9000" is incorrect, as is "Syntor-X9000" and "Syntor-X-9000".

The Syntor line of mobile radios are synthesized 32 channel radios for VHF and UHF. The Syntors were made in the 1980s and were an outgrowth of the crystal controlled MICOR series. The RF frequency information was held in a one-time programmable PROM chip, and the PL tone / DPL code information in a second chip. Paul Benett's web site listed below provides alternatives to the almost-impossible-to-find PROM chips and the methods to program them. The Mike Blenderman K7IC web site, also listed below, is the fount of knowledge on the entire Syntor / Syntor X / Syntor X9000 series.

The Syntor X radios followed the Syntors and were completely different inside (they really should have had a different product name). They offer more options including low band and 32 channels (or more). The programming is held in a plug-in memory module that holds one of several different sized memory chips. The programming information holds separate receive and transmit frequencies, PL or DPL (tone or digital encode/decode), a timeout timer (programmable in 15 second increments to over 7 minutes) and a scan list (up to 32 channels) with two priority channels. There is a mod that provides 64 channels, but it's not as desirable as you first would think (go read Mike Blenderman's page on it to find out why).

Two sources of Syntor or Syntor X memory module programming are:   (offsite links)

The Syntor X9000 followed the Syntor X and is the same radio from an RF standpoint, but the internal controller board was upgraded to expand the number of memory channels up to 255. The control cable connector on the X9000 is the same as the X, but the accessories are not compatible. The X9000 uses Systems 9000 accessories and options that communicate with the radio via a 9600 baud serial bus. The control head(s) are smart heads with their own microprocessor inside. Unlike the Syntor X the X9000 is programmed with RSS (and a slow PC), a RIB and special adapter cable that goes in series with the normal radio cable. The special cable is not an absolute requirement; there are several ways to make your own connection from a radio to a RIB. In other words, the X9000 is a more desirable mobile radio than a Syntor X since you don't need the almost-impossible-to-find suitcase programmer for the plain Syntor or the Syntor X... you just connect a slow PC or a laptop to the X9000 and program it. The RSS package for the X9000 contains two programs, one to program the radio, and one to program the head (you program the radio with the information (frequency, tone, etc) for each mode, you program the head with the text to display for each mode).

One quirk about the 256 channel X9000 radios: the memory chip in the head only has room for about 209 text labels. When you go to any channel above the limit the display changes and displays the word "MODE" plus the channel number. The firmware allocates a fixed number of display memory bytes for each label - in other words using fewer characters in modes 1-209 does not move the switchover threshold. I've found that 209 text labels is sufficient for my needs.

The Syntor X9000E models are actually conventional Syntor X9000 radios with an internal trunking controller board added. The "E" model offers nothing to the non-trunking user and are not any more valuable than a plain X9000. These radios can be easily converted into conventional Syntor X9000 radios (which is not true of trunking Syntor X models).

Note that there are a wide range of Syntor line accessories and that the cable and head are not compatible between the various Syntor, Syntor X Syntor X9000 and Syntor X9000E models. The only accessories that are the same across all radio lines are the speaker, microphone and antenna. If you do not have experience with the Syntor series and decide to buy any Syntor you really need to purchase a complete installation kit - the radio, cable and the head. Mike Blenderman's and Paul Bennett's web sites (linked below) will help sort out the confusion, but it's best NOT to try and mix and match unless you have the full manual that covers your radio(s) and accessories.

Mike Blenderman K7IC has his own very extensive web site on the Syntor, the Syntor X, the Syntor X9000, the Syntor X9000E and the trunking models of the Syntor X and X9000 listed below. There is no point in duplicating his effort here at Repeater-Builder. This web page is only going to cover topics that are not covered at Mike's site. I really suggest that you go to Mike's site first (and bookmark it).

John W1GPO discovered a bad situation dealing with grounds when using Syntor X9000 radios and external power supplies, as in base/repeater installations.

We finally realized why three X9000 radios I recently repaired failed, whereas my personal X9000 radios have never failed over 15 years. Two of the failures happened to X9000 radios used as a base, and one was a mobile, where in this case neither the mounting tray nor the antenna were grounded to the car body (a mag mount antenna was used). None of the failures involved antenna power or SWR circuitry, or a burned out neon bulb coax surge protector, so the problem was not a surge on the antenna. In one radio I had to replace three boards where one component in each went bad (mostly ICs), and in another radio (the hardest to find) a ceramic chip cap on the feed-through wire to ground on the current sense line from the PA became leaky when voltage was applied.

The problem is that the black A- power lead is not grounded to the radio's case, which the coax shield goes to, but half of the interior boards ARE grounded to the coax shield/radio case, and half have a floating ground associated with the black A- lead. Everything is just fine if the radio is installed in a vehicle with the radio tray and antenna shield grounded to the vehicle's body, along with the black A- power lead, as per Motorola's installation guidelines. When an external power supply is used that does not tie A- to the radio case/coax shield, a voltage surge between the antenna and power line ground develops inside the X9000. The radio case/coax shield likewise needs to be connected to A- via vehicle ground or directly to each other in the case of no antenna ground to the vehicle. Note that most Astron power supplies tie the negative lead to chassis (power line) ground.

This situation could affect any radio with a configurable (positive or negative) ground, such as a MICOR.

The Syntor, Syntor X and Syntor x9000 can use 4, 8 or 16 ohm speakers. All use an internal audio output transformer and you don't need to do anything special to do measure quieting, etc. (as opposed to the later Mitreks, MaxTracs, etc that drive both sides of the speaker audio outputs, where you have to use an 8 ohm, 1:1 transformer in line since you can't connect either side of the radio's speaker output to ground).

After Skip Hansen WB6YMH and Lee Dusbabek K7KAJ picked up a fleet of radios that had been sold without the memory modules, they designed, built and now sell a replacement memory module for the Syntor X called the Xcat. It plugs into the Syntor X in place of the original Motorola module and provides complete funtionality plus it is programmable by a PC using a Windows-based program. A Syntor X plus the Xcat is a much more capable base station or remote base radio than an X9000 - and much cheaper! However, if your interest is in a standalone mobile radio then the X9000 is still the way to go as the X9000 came in 32, 64, 128 and 255 modes and offers an 11-character alphanumeric display control head. In contrast, the Xcat provides 32 modes and you can't run some accessories (like a PA-siren) from the Syntor X main control head (when the Syntor X was a current product Moto provided an accessory control box that mounted on top of the radios control head). Click here for a photo of the Xcat board       Click here for a photo of the installed Xcat board. The brown connector at the top of the first photo plugs into the Syntor X in place of the original Motorola module (so if you end up with an eBay Syntor X that was decomissioned by pulling the module you can add the Xcat and turn your doorstop back into a real radio). Again referring to the first photo, the 10-pin header that is visible in the lower left connects to a DE-9 connector that plugs into your PCs serial port (COM port) for programming the Xcat. The 20-pin header at the lower right is for a connection to a repeater controller when used in a remote base application (it's the multicolor ribbon cable in the "installed" photo). The Xcat allows remote selection of RF frequency, PL encode and decode tones, and power level via the Doug Hall "RBI" protocol that is supported by most controllers (and you don't need the Doug Hall box!). The Icom CI-V protocol or the serial protocol can be used by controllers that don't support the Doug Hall protocol. The Xcat module, when plugged in place of the original Moto memory module, provides: Computer control via serial port and a professionally written open source Windows application. Interface to repeater controllers using either the "Doug Hall" or Icom CI-V protocols. Yes, a Syntor X equipped with an Xcat makes an exact and excellent replacement for a Kenwood mobile as a remote base (but it has a real receiver with some decent intermod reistance). The Xcat has been used successfully with RLC3, Pacific Research RI-300s and an Scom - and without the Doug Hall RBI box in the middle. If you interface it to a repeater controller you can use a Syntor-X as a fully frequency and PL tone agile remote base. And you can have multiple Xcats sharing the same controller port (i.e. separate low band, high band and UHF Xcat/Syntor-X remote bases on one repeater controller port). The Xcat was designed to make a Syntor X into a high end remote base radio, with the Xcat cabled to the site controller. However, if installed into a mobile (i.e. in simple standalone operation) you end up with a 32 mode code plug that can be programmed by your home PC without any superfluous hardware (i.e. no RIB, RSS or old 386 computer required). From the point of view of the Syntor the Xcat is an exact replacement for the orignal Motorola-built Syntor X memory module and your radio won't know the difference. The Windows application uploads the information to the Xcat and then the computer is disconnected until the information needs to be changed.

Contact Information:

The author can be contacted at: his-callsign // at // repeater-builder // dot // com.

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Motorola® is a registered trademark of Motorola Inc.   Image used with permission.
Syntor, Syntor X, Syntor X9000, Syntor X2, Syntor X3, the stylized / drop shadowed X, MCX, Mostar, MCX100 and MCX1000 are all registered trademarks of Motorola Inc.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.