Radtel RT880/G cable

1

I have a Radtel RT880G unit, and I’m wanting to try and work VaraFM and packet modes, but the unit has the Motorola M3 (the smaller gp328plus) on the side instead of the Kenwood K1.

I haven’t been able to find any adapter cables, or documentation on the side connector, so I emailed Radtel and received a response.

image
image1009×824 92.3 KB

So now I’m on the hunt for parts, does anyone know where I could source the M3 connector? I can buy TRRS breakouts on Amazon, or I may have 1 from a previous project.

2

Here’s the pinout info if you are willing to homebrew a cable. I used a cable from the cheap headset in this case:

Motorola 13 pin connector cable - Digirig Forum

I need to look in the storage, but I ordered some of Motorola cables some time ago and can see if those are M3s. Email or PM me if you are interested.

3

I’m ordering a TRRS Terminal block cable, and a Motorola GP328plus ear piece/microphone. I’ll work on splicing those together.

Based on the images of the Radtel handmic, they use pins:

  • 1 EXT-SPK+
  • 2 EXT-SPK-
  • 4 EXT-MIC+
  • 5 EXT-PTT
  • 6 SELC
  • 7 GND

And Digirig TRRS being:

  • T RX_Audio
  • R1 TX_Audio
  • R2 PTT
  • S GND

should mean:

  • 2 ↔ T (your linked post only used pin 2, not pin 1)
  • 4 ↔ R1
  • 5 ↔ R2
  • 6+7 ↔ S

Does that all seem correct?

4

This looks ok. Please report your results when you have a chance to try this out.

5

The mic/earphone adapter I purchased only had 5 cables inside it, not 6. It appears to be missing PIN6/SELC. And PIN7/GND does not test for continuity to the pin, but does to the back of the PCB. I need to test further, but I might have a faulty product.

Updated post, missed bolded word.

6

Some pins can share the functionality. E.g. SPK- or MIC- can be grounded. See which line rings to the radio’s chassis.