USB Line Isolator

Posted Mar 13, 2025

By jason

1 min read

USB Line Isolator

Quick post about Digital Modes and the utter gong show they can be when you get RFI. The Icom IC-705 is quite notorious for locking up and being a royal pain if there is any amount of interference when operating digitally. I would frequently have lock ups, even when using high quality USB cables (micro to USB A). I had to put a million Type 31 ferrites on the cable to get the radio to cooperate. But then I was introduced to USB Isolators.

USB Line isolators break ground loops. I got introduced to them from Vince VE6LK and bought one from him. It worked swimmingly well, but I only had it a couple of days and I broke it! They have a terrible amount of exposed leverage to the board design. That and I’m also a dunce. But that aside, I ordered another one from Amazon. It was $17 bones in 2025.

You want the ADUM 4160 chip. The Amazon ad mentions both 3160 and 4160. But the one I got is branded 4160. I plugged it in right away and viola! You can operate digital modes with just a normal USB cable. No zillion ferrites required. Just make sure you flip the dip switch to 1 for high-speed/blue LED mode.

Case Mod

However, you need to put this thing in a case. Thankfully, there is a 3D Printed version already available. But if you don’t have a 3D printer on hand, you can certainly ghetto-case it with Lego!