I've just bought the FT-4X and want to connect to a setup with different radios I have. For that I thought I could use a Motorola M1 cable, but not... The cable have a 2 pin with 2-contact areas each. The problem is when there is something transmitted to the radio it turns of and restarts. Something must be wrong with the M1 connector. When I use a single 3,5mm in the speaker outlet it works fine. I've seen some pictures of earpieces from Yaesu (ssm-512b) that seems to have 3 contact areas per pin. Is there someone who know the pinout diagram for this ht?
Yaesu: FT-4X
- Thread starter ekbacken
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k6cpo
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I assume you are trying to use a headset or earphones with the radio. You need to be more specific about what you're trying to do.
Yes, kind of. I have a radiointerface (this) that is connected to a main flightradio. Then I want to use this FT-4 as a second radio. for that I use a cable that look like this but have a M1 at the radio end. I know it is something with the connector or cable because the problem starts as soon as i connect the cable to the radio and the other end is hanging loose not connected to the interface. As of the M1 specifications the cable seems right. (Ground connected together but that should be ok, or?) (The links go to MicroAvionics in UK)
k6cpo
Member
Here is the pinout for the Yaesu radio. You're going to have to either find or make a cable that has this connection at the FT-4 and the appropriate connection to attach to your interface box at the other end.
k6cpo
Member
OK. That puts the FT-4X into what I call the "Yaefeng" category. These are Yaesu's attempt to capture a share of the Baofeng market by producing a better quality radio, but including similar design elements that would allow using Baofeng accessories. Since Baofeng and Kenwood use the same cable connections, you might search for Kenwood pinout diagrams.
Rather YaeMoFeng… At last I got an answer from Yaesu with the pinout. And it was as I thought a rather strange one. The connector is Motorola-style with 8mm spacing between the pins with speaker on the 3,5mm and mic on 2,5mm. The pins themself have 3 contact areas more like Kennwood/Baofeng.
Even more strange, they call it T2 (which can refer to Kennwood/Boafeng) and T3 (which can refer to a singel-pin Motorola)… And what is P3???
What the #2 area do I don't know but it doesn't like to be grounded, at least on the 2,5mm pin.
| 3.5mm Jack | 2.5mm Jack | |
| 1 | SPK- | Mic GND |
| 2 | ||
| 3 | SPK+ | Mic |
Even more strange, they call it T2 (which can refer to Kennwood/Boafeng) and T3 (which can refer to a singel-pin Motorola)… And what is P3???
What the #2 area do I don't know but it doesn't like to be grounded, at least on the 2,5mm pin.
OK, here's what I found with my FT-4X and the two speaker/mics I have for it.
On my SSM-17B, each pin only has two contacts (TS).
OTOH, on my SSM-512B, both pins have three contacts (TRS).
Both speaker/mics key the radio without issues.
It looks like connecting T to S on the 2.5 mm plug keys the radio. On the SSM-17B, with the PTT unkeyed, those pins are an open circuit, but with PTT keyed, the resistance is about 1400 ohms. On the SSM-512B, PTT unkeyed is open circuit, PTT keyed is about 860 ohms.
On my SSM-17B, each pin only has two contacts (TS).
OTOH, on my SSM-512B, both pins have three contacts (TRS).
Both speaker/mics key the radio without issues.
It looks like connecting T to S on the 2.5 mm plug keys the radio. On the SSM-17B, with the PTT unkeyed, those pins are an open circuit, but with PTT keyed, the resistance is about 1400 ohms. On the SSM-512B, PTT unkeyed is open circuit, PTT keyed is about 860 ohms.
On your M1 cable, check the resistances between all possible combinations of the four contacts. You may find that two of them are shorted. On my SSM-17B, every possible combination is an open circuit, except that T to S on the 2.5 mm plug is 1400 ohms when the PTT switch is closed and T to S on the 3.5 mm plug is about 8 ohms (probably due to the speaker).
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