iMidland XTR 8 Channel

Models 70-1336x and 70-1526x

This page is currently under construction and revision - 1-30-10

The Midland XTR 8 channel radio looks different than the standard XTR series.  It has a single digit display and does not have an external squelch adjustment.  It uses the standard 4 pin Midland mic. 

The main radio chassis is a little thinner than the XTR series and the heat sink for the PA is on top of the radio.  The ribbed part of the top in front of the heat sink is where the internal speaker is located.  You can faintly see the round outline of it.

Programming is through the flap on the side and uses the same programmer as the standard XTR radio as well as the same software. You can purchase a programmer here. You can see the squelch disable switch beside the programming port.  Turning this off opens the squelch on the radio. The squelch is adjusted internally and there is no external squelch adjustment.  If you need more than 8 channels, the radio can be programmed for up to 22  frequencies using the DOS software but the display will only read 1 to 0, repeat, and then 1 to 2 when stepping through the channels.

The power connector used is the same as the Bantam/Titan series.  This is a 10 pin connector.  External/internal speaker selection is made by jumping wires or connecting an external speaker and there is also 2 wires for a hang up box for the mic.  For CTCSS to be enabled on RX or scan to work, the hang up box wires must be shorted together if you are not using a hang up box. .

Bridgeman Communications has the pin out for this plug and sells an excellent pre-wired cable. The plug and pins are also available from Digikey and Mouser Electronics.

Hacked Power Connector For Bantam, XTR 8 channel,  and Titan

WARNING!!! I assume no responsibility if you decide to make your own power cable and damage your radio by wiring or connecting it wrong. Please refer to the site above for proper connections to the radio. 

You can make a connector by robbing the main connector off a bad ATX computer power supply and cutting off the molex connector so it will plug into the radio .  Using a very small jewelers screw driver, you can press the tabs on the pins and remove the wires.  Rearrange them so you don't get the power leads mixed up with the other wires.  The tab on the computer connector won't match up when you cut it down but the connector seats well and won't come out that easily.  Pins must be jumpered to enable internal/external speaker and scan.  .

Service Manuals

These are required for any adjustments to the radio.

http://www.scribd.com/doc/2575945/701336-xtr for VHF

http://www.scribd.com/doc/2471046/Service-Manual-701526-A-B-70152600 for UHF 

Conversion to 2 meter or 70 centimeter Amateur Bands

These radios can be converted to the amateur bands usually with minimal realignment. Retune the RX and TX VCO's, adjust the power output to around 10 to 15 watts, and adjust the internal squelch control to your liking. 

If converting to 2 meters, the model number can be changed to 1336A and that range will cover 2 meters.  UHF radios do not have a band range that covers 440-450 mhz. If the software being used has been hacked,  amateur frequencies in the 144-148 and 440-450 ranges can be programmed regardless of the band range.. If your DOS software will not let you enter frequencies in those ranges, open the xtr.chl file in Notepad and edit the band ranges.  The first column is an unmodified CHL file, the second has the changes in red to change the band ranges for amateur frequencies. This only has to be done once and opens your software to work on all amateur bands.

Usually after programming amateur frequencies the display will flash 3 and the radio will beep.  This indicates the VCO is out of lock and it will have to be adjusted for both transmit and receive. Refer to the procedure in the service manual.   The RX front end is factory aligned and should not require alignment. 

Make sure you turn the power down to 10-15 watts because the duty cycle of most commercial radios is about 5% TX time otherwise the PA could be overheated and become damaged by long transmissions in ragchews.