RFI

General discussions
Umanyar
Posts: 6
Joined: Sat Mar 26, 2016 1:43 am

RFI

Postby Umanyar » Wed Apr 06, 2016 6:59 am

I was wondering if I could get any suggestions on reducing RFI with the sdrplay. I get tons of RFI when using the sdrplay with a laptop when the power cord is attached, obviously removing the cord helps a lot but reduces the amount of time the system can work. Any suggestions? my ideas so far are:
1. ditch the laptop for a desktop
2. get a lead box, or some other suggested box for the sdrplay
3. keep laptop, just get a larger capacity battery

thank you, just getting started and any suggestions would be very much appreciated.
Last edited by Umanyar on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

Tech_Support
Posts: 199
Joined: Mon Jun 01, 2015 7:00 pm

Re: RFI

Postby Tech_Support » Wed Apr 06, 2016 9:39 am

Dear Umanyar,
The most common causes of RFI are via the USB and antenna cables. If you haven't already done so, try adding clip-on ferrites or ferrite loops at both ends of the USB cable. If your antenna feed is via a coax cable, try adding a ferrite to the coax cable as close to the RSP as possible. If using an unbalance long-wire antenna for HF, try adding a grounded counterpane. Obviously, it is important to keep the antenna away from the sources of interference and so external antenna tends to be best if that is possible.
If you still have problems, some people have reported improvements by covering the case in aluminium or copper foil tape. If done carefully, this can be done on the inside of the case so as not to spoil the external appearance of the unit. Care must be taken to ensure that none of the foil comes into contact with the circuit board. This seems to help primarily at higher frequencies, whereas at the lower frequencies, pickup via cables seems to be the most common cause of problems.

Sincerely

SDRplay Tech_Support
Last edited by Tech_Support on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

dlritter
Posts: 27
Joined: Fri Dec 04, 2015 7:12 pm

Re: RFI

Postby dlritter » Wed Apr 06, 2016 7:25 pm

:D
Ah yes. Such a wonderful noise on my Gateway M535. And then I was in my shop with an Igo universal 120w power unit. NO NOISE!
So yes there are quite power units and there are noisy ones. The project might be just how many must one go thru to find a quiet one.
Last edited by dlritter on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

Umanyar
Posts: 6
Joined: Sat Mar 26, 2016 1:43 am

Re: RFI

Postby Umanyar » Thu Apr 07, 2016 12:59 am

OK great thank you. I will be ordering additional ferrite clips then and some copper tape. I will then assess if I need to do anything on the laptop side. I was amazed in the difference in using the laptop while on battery vs. plugged in. Very much like any SW radio batteries seem to always be better than power supply.
Last edited by Umanyar on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

13dka
Posts: 127
Joined: Sun Feb 14, 2016 8:40 am

Re: RFI

Postby 13dka » Thu Apr 07, 2016 1:44 am

Bought a (too) cheap PSU for my laptop off Amazon and failed to check its RFI output within 30 days. Here's how the punishment for that is looking when I use it in the car, with the antenna 15m away and 5m up.

Crappy_PSU.png
Crappy_PSU.png (184.68 KiB) Viewed 1699 times


:mrgreen:
Last edited by 13dka on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason


Return to “General”

Who is online

Users browsing this forum: Bing [Bot], jonrsp2pro and 2 guests