Friday 18 January 2019

USB Isolators.

Some days ago, Bas, PE4BAS, told me about USB isolators.  This was in response to a problem with RFI emitted by the Raspberry Pi 3B+ and associated 7" touchscreen under certain circumstances.

I had never before heard of USB isolators so, at just £6.36, I bought one from Ebay.  If you really want to, you can pay as much as £35 (or, if you are really stupid, a lot more).

A few days later, the isolator arrived direct from China.  First, I tested it as a fairly high transfer-rate isolator on the family Windows 7 PC's external backup hard drive.  Apart from the tiny, yet blindlingly-bright on-board LED, no problems there at all!

USB isolator in action.  To relieve stress on the laptop's USB port, support from underneath the board is advisable.

This morning, I decided to risk sticking it in my main station laptop (the Raspberry Pi operates my remote shack).

Result?  Well, it didn't cause Windows 10 to crash, or the computer to burn up - a good start!

Using it with FT8, the isolator doesn't cause any problems at all in either direction.

BUT!  A problem!  Connecting the RSP1a SDR via the isolator leads to the RSP1a not being detected!  So, I will have to consult others to see if there is a resolution to this issue.

This video is a good with/without comparison using other SDR software:

1 comment:

PE4BAS, Bas said...

A lot of difference in the video. I hope you will get it working. Strange that the SDR is not detected anymore. Have you tried another USB port? In theory this will also help with other receivers of course resulting in even better weak signal receive. One condition, of course, is that you need to be in a low noise area otherwise you will not have better results. 73, Bas