An interface lead for the Moonraker MT-270M

The interface lead for the MT-270 being impossible to obtain, I began to research to try and find out the connections required. The interface which was shown on the Moonraker website indicated that it used a four pole 3.5 mm jack plug. The other end had a usb connection.

I could not find any info for the MT-270, but what I did find out was that it was a clone of the QYT KT-8900. I found info on the interface for that radio, which showed only three connections were required and that it used an ordinary 3.5 mm stereo jack to connect to the radio. To do the USB to serial conversion I had a ZLP interface which I examined and found had three output connections which I presumed where tx, rx and screen. I made up a lead and tried to connect to the radio using the freely available programming software Chirp. Unfortunately this did not work. I presumed that the reason for this was that a four pole jack was required.

These are quite easy to obtain but I was given one already mounted on a lead by Graham, G8ZNK. When checking the connections with a meter, I found that the screen was on the third pole of the plug. A new lead was made up, using the following connections. Tip tx. Second ring rx. Third ring, screen. Fourth ring, no connection. This then worked!

I tried it with Chirp and the software that is available from the Moonraker website, and both worked.

If you haven't got a suitable usb to serial cable to modify, they can be obtained from Ebay or Amazon for a couple of pounds. You need to look for a USB to RS232 converter. One tip. If it does not work after you have made up the lead, don't panic! Try swapping the tx and the rx connections and try again!

Good Luck. 73. Martin. G7RQD.

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