Search found 39 matches

by Stromeko
Wed Apr 14, 2021 8:19 am
Forum: RTL-SDR Discussion
Topic: New L-Band Patch Antenna Question
Replies: 2
Views: 243

Re: New L-Band Patch Antenna Question

If you head on over to the introduction page for this antenna you'll find the bandwidth plot towards the end of the page. 1770MHz looks possible, but already about 10dB down:
https://www.rtl-sdr.com/preorder-sale-a ... for-44-95/
by Stromeko
Wed Apr 07, 2021 4:57 pm
Forum: Troubleshooting Help
Topic: Signal not received when receiver too close to transmitting device?
Replies: 2
Views: 353

Re: Signal not received when receiver too close to transmitting device?

It appears that it does not receive signals when they are "too strong"? Does anyone know why this happens and what can be done to mitigate the issue? Yes, if you overload the RF frontend you will not be able to pick out and decode the signal. I would start off with switching the AGC off, it works a...
by Stromeko
Mon Oct 19, 2020 6:13 pm
Forum: KerberosSDR
Topic: 9 RTL-SDRs USB connection for phased array
Replies: 1
Views: 891

Re: 9 RTL-SDRs USB connection for phased array

I am apart of a university satellite team implementing 9 RTL-SDRs with 9 patch antennas in a 3X3 layout to determine a direction of arrival from above satellites. Our flight computer only has two USB ports and my team and I are having trouble trying to figure out how we can connect to our computer....
by Stromeko
Mon Oct 12, 2020 7:34 pm
Forum: RTL-SDR Discussion
Topic: Help understanding use of "Upconverter"
Replies: 5
Views: 1407

Re: Help understanding use of "Upconverter"

going by the manufacturer's description, passthrough mode is for frequencies between 300 Hz and 6 GHz - that's well beyond the range achievable using the dongle on it's own. Well, it says those frequencies make it through the upconverter in bypass mode (if they were present in the input to start wi...
by Stromeko
Wed Sep 09, 2020 8:02 am
Forum: KerberosSDR
Topic: KerberosSDR Developments in 2020
Replies: 43
Views: 34245

Re: KerberosSDR Developments in 2020

Can the Kerberos 4 channel board accept a clock input signal? At least the first batch has a clock input next to channel 4, you also need to jumper the board to act as a secondary (otherwise this acts as a clock output). This functionality was/is meant for daisy-chaining two KSDR for an 8-channel s...
by Stromeko
Fri Aug 28, 2020 11:07 am
Forum: KerberosSDR
Topic: Please help with start-up issues with KerberosSDR
Replies: 7
Views: 2187

Re: Please help with start-up issues with KerberosSDR

Thanks for the research you've done. I'll have to get a 8GB model and test it. Bit of a shame if image files aren't compatible between the different RAM sizes though. AFAIK, the way the memory used to get mapped between VPU and ARM side can not work past 4GB total memory size (mapping 16MiB pages o...
by Stromeko
Sat Jul 25, 2020 7:47 am
Forum: RTL-SDR Discussion
Topic: RTL-SDR for Iridium
Replies: 6
Views: 2360

Re: RTL-SDR for Iridium

I am not using the recommended 30x30cm copper mounting plate since my intuition is that it would improve performance but not be necessary. Would it be necessary? Intuition and RF don't mix well unless you are one of very few gifted individuals. If an antenna is designed to work with a ground plane ...
by Stromeko
Fri Jul 17, 2020 4:34 am
Forum: KerberosSDR
Topic: KerberosSDR Interface to Gnu Radio Companion (GRC)
Replies: 15
Views: 8541

Re: KerberosSDR Interface to Gnu Radio Companion (GRC)

BUT phase coherency/sync is still not achieved by that stage. The reason is that when the R820T2's start up their initial phase is completely random. Hmm. From what I've read it's the mixer PLL that arrives at a slightly different tuning each time, so you end up with a drifting phase difference bef...
by Stromeko
Mon Jul 13, 2020 4:30 pm
Forum: KerberosSDR
Topic: KerberosSDR Interface to Gnu Radio Companion (GRC)
Replies: 15
Views: 8541

Re: KerberosSDR Interface to Gnu Radio Companion (GRC)

Kerberos is not coherent by itself, the sample and phase sync comes from the software. So in GNU Radio you'd have to build a flowchart to do the coherency for you - not that simple or maybe not even possible, which is why we do it in the C code. That doesn't sound right... :) My current understandi...
by Stromeko
Sat Jul 11, 2020 8:34 am
Forum: Signal Identification Help
Topic: Contineous signal at 148.5MHz - Identification help
Replies: 3
Views: 2236

Re: Contineous signal at 148.5MHz - Identification help

Well, 148.5MHz is the pixel clock frequency for FullHD...