PTT problems with Mobilinkd TNC Cable Adapter


I’ve got both the Mobilinkd v3 and Digirig. I can successfully use the Mobilinkd cable on the Anytone 878uv with the Digirig if using the Mobilink3 TNC Adapter (Mobilinkd TNC Cable Adapter – digirig) , but not with the Yaesu FT-5d. The Yaesu cable works with the Mobilinkd directly (w/o the adapter) just fine, so I assume the cable is okay.

With the adapter attached, the standard PTT test by connecting the ring with the nearest sleeve works on the 878uv but not the FT-5d.

Any ideas for troubleshooting this? Is the PTT test supposed to work with the TNC adapter cable?


With FT-5D cable not passing the test we can focus on that area and not worry about the adapter.
This issue is likely to do with the mechanical fit with FT5 having a recessed accessory socket.
Please confirm that the HT side of Digirig cable looks like this:

This is the most recent revision of the cable accommodating the specifics of the socket placement on some of the Yaesu HTs.

Additionally you can confirm the connections using continuity tester/multimeter against the schematic in the product page.

Hi Denis,

The Mobilinkd FT5d cable appears to be straight through when testing continuity. That cable DOES work with the Mobilinkd that I have.

When I add the adapter and measure continuity, the continuity is as shown on the product page, except there is no 2k resistor. R2 goes straight through to R2.

Incidently, the Digirig Yaesu HT cable that I have is wired the same way. No 2k resistor.

I have done more testing. The Digirig Yaesu cable works with both the Digirig and the Mobilinkd v3. Incidentally, it works with the Mobilinkd whether I have the TNC adapter cable connected in-line or not.

The Mobilinkd cable works fine with the Mobilinkd, but not with the Digirig (with the TNC TNC Cable Adapter).

I’m really hoping to use the Mobilinkd cable + TNC Adapter due to size. I have a small kit that all this fits in, and the Digirig cable takes up substantially more room.

I’m going to assume that the Digirig TNC cable adapter doesn’t work with ALL Mobilinkd cables and I’ll just carry both cables with me.

You must have early version of Digirig cable. Currently they have 2K resistor. But with the rings (R1 & R2) shorted there is really no sense to use the Mobilinkd adapter because all it does is crosses over the rings. With your dilemma I would just homebrew the cable to your own specs. These are fairly simple builds.