Apache Labs Community Forum

Hi,In my Anan 200D, I had PTT connected to the 25-pin socket (pins 13 and 25). PTT worked with the footswitch. Yesterday, PTT stopped working. I can only turn on TX by pressing MOX or turn on VOX. I checked the cable connections and everything is fine. I can't find an option to disable PTT in the Thetis, and I think the open collector might be damaged. How can I check it to diagnose the problem? In the Thetis HW/Select settings, if I turn on PTT with the mouse, it also works. I'm using a microphone without PTT, so I had to use ACC. Has anyone else had a similar problem?

A common problem on the early designs that used the DB25 connector is that the connector is mounted on the inside surface of the rear panel. Mating connectors often could not be fully seated, thereby leading to intermittent connections. Check to see if that is the issue.

If that is not the problem, then another very simple test is to simply use a paper clip or similar tool to directly connect pin 25 (ground) to pin 13 (PTT input, pulled up to 3.3V internally). If that works, then you know the problem is in the footswitch/cable/connector assembly.

If that still doesn't work, get out a multimeter. Put the multimeter in continuity or resistance mode and make certain there is continuity between pin 25 and the ground lug or an RF connector shell. Then put the meter in DC voltage mode, the positive probe on pin 13, and the negative pin on a grounding point, again the ground lug or connector shell. You should see approximately 3.3VDC with the 200D turned on. If either of those measurements fail, then there is a problem internal to the unit.

Check all that first and report back your results, please.

Hi Scott,As always, you're very helpful. I've already taken measurements. There's a complete short circuit between pin 13 and ground. There's no 3.3V voltage on pin 13, so there's a problem with the circuit. I'd like to fix it, but I don't have a schematic for this circuit. Maybe it's a voltage issue, or maybe the transistor is faulty. I don't know anything more. Is there a schematic for this part of the circuit available somewhere? I'd take measurements and replace the faulty component(s). I'm currently using the spacebar to activate the PTT from the computer keyboard, but I'd like to switch back to the footswitch. Besides that, it works very well.

Slawomir

Look in the schematics section of this forum. The 200D uses the original Orion board. Take careful note that the accessory connector on the schematic is the board connector, so the pinout is completely different than the rear panel connector.

Do you have anything plugged into the mic connector? If so, have you changed it recently? For instance, plugging in a mono (tip and ring) connector into the mic input can short out the entire PTT circuit. It's the same "wire" (or "net") as the rear panel input.

Yesterday I made a new cable to connect an external microphone via a 3.5mm jack plug. In this connection, the ground wire of the plug is shorted to the outer ring of the plug. Without this short circuit, a strong hum is produced. Unplugging the plug from the microphone jack does not restore PTT with the footswitch. I'll look for a schematic. Could I have damaged the PTT circuit with this microphone connection? If I enable PTT on the microphone jack in the Thetis, PTT works, but it can't be disabled.

Rules for mic connections:

1. You must use a TRS connector. Never use a mono connector.

2. Shield is always ground and/or "mic low" (aka "mic minus"), never anything else.

3. Whichever you select in Thetis > Setup for PTT, either tip or ring, must only be connected to a PTT switch, nothing else, and the remaining contact must only be connected to the mic signal, nothing else.

If you are trying to connect a balanced mic to the ANAN unbalanced mic input then see this topic: viewtopic.php?p=5387

If you have unplugged the mic from the front panel, recheck everything on the rear panel as discussed above before doing anything else.

Scott,
I use a 3.5mm stereo plug because that's the microphone jack on the front panel of the Analogue. I don't connect a balanced microphone signal because I have the negative of the micron signal connected to ground. I use this microphone signal to output from the iBOX w2IHY. I just did a test. I plugged the 3.5mm stereo cable into the microphone jack. In the Thetis Hardware Option, PTT is set to ON. I shorted the outer ring to ground, and the PTT works. After unplugging the front microphone cable, the PTT from the rear DB25 jack doesn't work, even though it worked for a month. There's no 3.3V on pin 13.

Now I've unplugged the microphone cable from the mic jack on the front panel. I've enabled the PTT function in the Thetis Hardware Otions, and the foot pedal works. I need to check if I connected the micron cable correctly. I have it connected as shown in the middle diagram in the link you provided.

A key question: Does PTT need to be enabled in Hardware Options for the rear footswitch to work? If it's enabled, PTT with the footswitch works. When I plug in the microphone cable, it transmits continuously. I need to check the connectors for any short circuits.

qst wrote: Sat Dec 06, 2025 5:07 pm A key question: Does PTT need to be enabled in Hardware Options for the rear footswitch to work?

Yes. The PTT connection at the front and the PTT connection at the rear are electrically connected, i.e. they are the same wire. It is not two different circuits.

If it's enabled, PTT with the footswitch works. When I plug in the microphone cable, it transmits continuously. I need to check the connectors for any short circuits.

The mystery is mostly solved, then. It is a problem with how your microphone connection is wired.

Scott,
Everything is resolved and working properly. The microphone plug on the input side of the Anan's microphone jack had a short circuit between the outer ring and ground. After eliminating the short circuit, the PTT works as before. You have to be very careful when soldering the new cable. These plugs are very small, and it's easy to make a mistake. Thank you very much for your support. I'm happy I don't have to repair the radio.

Best regards,
Slawomir