Syntech I Mobile Information
Do I have a Syntech I or Syntech II ?
Does your radio have a rubber plug about 1 inch x 1 inch on one of the covers? If so, you have a Syntech II. Click here.
Other Syntech I and II Differences
| Feature | Syntech I | Syntech II |
| Trunk mount radio/control head interface connectors | 34 pin | 37 pin |
| Color of buttons on control panel/head | Blue | Gray/White |
| Display | 1/2 inch 2 digit LED | 1 inch 3 digit LED or alphanumeric LCD |
| Programming port covered by rubber plug on cover | NO | YES |
Syntech 1 Lowband Brochure (requires a PDF viewer such as Adobe or Foxit)
The Syntech I radio comes in both dash and trunk mount versions. If the radio has 3 buttons on the control panel, it has scan. If it only has 1 button, then it does not scan. There is a version of the ST1 that is 8 channels. The VHF model is 70-336X and the UHF is 70-526X. The X in the model number refers to the range for the particular band.
ST1 Band Ranges
| Lowband VHF | Midband VHF | Hiband VHF | UHF |
| A = 29-37 mhz | A = 66-80 mhz | A = 136-156 mhz | A = 406-430 mhz |
| B = 35-44 mhz | B = 75-88 mhz | B = 148-174 mhz | B = 450-470 mhz |
| C = 40-54 mhz | C = 470-494 mhz | ||
| D = 494-512 mhz | |||
| E = 430-450 mhz |
The 80 channel radios were offered in several power ranges while the 8 channel radios are only 25-35 watts. On the Repeater Builder website is information about the different models as to power, frequency, and configuration.
The following is one known omission to the Repeater Builder list. If you have any more, please send them to me and I will add them.
| Model | Type | Band | Channels | Power | Configuration |
| 70-066A | ST1 | 66-80 mhz | 80 | 40 watts | Dash Mount |
| 70-066B | ST1 | 75-88mhz | 80 | 40 watts | Dash Mount |
| 70-076A | ST1 | 66-80 mhz | 80 | 40 watts | Trunk Mount |
| 70-076B | ST1 | 75-88mhz | 80 | 40 watts | Trunk Mount |
Power and control cables may be purchased from Bridgeman Communications and they have wiring diagrams available.
Programming Information
The ST1 radio uses a UV erasable EPROM on a custom circuit board. The Midland part # is Z273. Midland made the 70-1000 stand alone programmer to program these modules, and there was also an after-market 70-1000C PC programmer for them. The 70-1000 programmers are no longer available from Midland and you can occasionally find them on Ebay selling for a very high price. The 8 channel ST1 uses a Z383 module which requires a special adaptor and could only be programmed on a Midland 70-1000 programmer - until now.
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| Z273 - 80 Channel | Z383 - From 70-336X and 70-526X 8 Channel |
70-1000 Midland Programmer Alternative
Skyline Engineering of Australia has developed an alternative PC based programmer for the Z273 called the Skyline 70-1000X. Their custom software offers an expanded frequency range that covers the amateur bands. Although some people may have reservations about purchasing from an offshore vender, GCC has been doing business with Skyline for over two years and highly recommends them.
Skyline 70-1000X with Z383X adaptor and Z383 module installed
A review of the programmer is posted at
http://www.greenecountycommunications.com/review.htm.
Skyline has added a custom programming adaptor specifically to program the Z383, which I have also tested and will be adding to the review soon. You can click http://www.radioprogrammers.com (off site link) for more information about their products.
Other Programming Alternatives: Yes there are a few such as using a programming service, schemes to generate the BIN file for the EPROM, and even a replacement module that uses a EEPROM. I can program your Z273 or Z383 module for a small fee. I'll be glad to post alternative programming instructions from a reliable source. Email your suggestions to me.
ST1 Error Codes
Note: These codes are displayed on the radio channel display
| Code | Error | Note |
| 90 | EPROM module faulty or absent | Substitute EPROM module then refer to diagnostics |
| 91 | CPU error | Refer to Manual For Troubleshooting Procedure |
| 92 | CPU error | Refer to Manual For Troubleshooting Procedure |
| 93 | CPU error | Refer to Manual For Troubleshooting Procedure |
| 94 | CPU error | Substitute EPROM module then refer to diagnostics |
| 95 | VCO out of lock | Usually fixed by adjusting VCO. Refer to manual for alignment |
Conversion to Amateur Bands
The 40-54 mhz range radios tune to 6 meters with no modification required. The front end coils and the VCO will require alignment. Radios usually require realignment of the front end coils and VCO no matter what band if you are changing the frequency from commercial to amateur. You should always check the transmitter for frequency, deviation, and spurious emissions.
More info as it is supplied.