Vertical lines in HDSDR

[dhoover]

I've had these lines (every 8KHz) ever since I've used HDSR. I had them with the rtl dongle and now using an AirSpy with Spyverter. I use HDSDR as a panadapter for an Icom receiver so I've learned to live with them. But I'd like to figure this out. I use shielded USB cables with choke for connection, but I've always assumed it's some form of interference. They are consistent at 8KHz intervals.

Thanks
Dave

 

[dhoover]

Better image, I hope

 

[laddie]

I am new to sdr and use hdsdr as well
tonite I was experimenting with hf using the direct Q method in the exio panel
I also got them and some huge hash about every 50khz
that turned out to be a switching supply
I read on another forum that some guys are making a mod using a separate linear supply
personally I think it is some radiation from a monitor or perhaps the computer.
just a thought, VE3CGA

 

[KC4PSR]

interference spikes at 8KHz intervals

Had the same issue. Traced to USB cable on SDR, and possibly others. I think 8 KHZ is a popular sampling rate for A/D converters. I think I've solved my problem with snap on RF chokes designed for lower frequencies than the usual chokes - look for "mix 75" ferrites. Fair-Rite makes a model that fit most USB and RG-6 cables well. Got 10 of them from Mouser electronics, Mouser part # 623-0475178281. Just tonight I clamped them on every USB cable in/out or near my Elad SDR, and even the RG-6 coming from my mag loop antenna. So far, looks like spikes are gone over entire LF/MF/HF bands.