SSB transmission disabling AIS reception

[jcorsican]

When I transmit via SSB, my AIS reception goes away for several hours. I have the AIS transceiver mounted right next to the SSB auto tuner, which is PROBABLY the reason this is happening. Anyone else experience this phenomenon?

Thanks!

[Brian.D]

AIS, or VHF for that matter, and SSB can coexist side by side without ever interacting with each other. That is, if the grounds are proper. There is the possibility of a ground loop existing in your vessel that is causing RF to leak into the AIS system.

You will need to run a simple test using a DVM, if you have one. You are going to check for resistance between the SSB tuner's ground and the AIS radio ground. There should be 0Ω of resistance. That tells you that the two grounds are common. Any value other than 0Ω is resistance and when a voltage is applied then current will flow within the ground. It is possible that the AIS rig is being mildly shocked.

There is another possibility. That the ground wire of the AIS is no longer connected (physically or by corrosion) and the ground wire is acting like an antenna. This too would cause the AIS receiver to go bonkers with a high dose of RF. Remember that point where the RF wire for the SSB exits the tuner, that is the beginning of the antenna and contains the highest levels of voltage or current.

These are just some of the possibilities, there may be others. JMHO

[smac999]

I can understand the ais stoping while the ssb is transmitting. Because ssb transmissions cause havoc. Ie I have seen ssb transmissions cause dock office printers to start printing random letters.

But the 2 hour thing makes no sense. If you turn the ais power off and back on. Does it start back up? Or still take 2 hours.

Plug a laptop into it to see what it’s doing. Ie maybe it’s losing gps for 2 hours. Or what exactly is stoping.

[jcorsican]

It isn't always 2 hours, but it just about NEVER comes back immediately.

[kev_rm]

How close is your VHF/AIS antenna to your HF antenna?

[Brian.D]

Common Mode Currents

[Paul L]

What is the connection between AIS and the device that is displaying the AIS info, 0183, nmea2k, usb, WiFi?
What device is displaying the AIS data?

[ohgary]

IF you power on/off the AIS tranceiver does the issue reset immediately? 2hrs is odd. Desense would go away after the SSB transmitter turns off. What might be happening is your handing the transceiver and or other network devies and that times out after 2 hours.