Search found 118 matches

by F1BJB
Fri Jun 30, 2017 8:03 am
Forum: General
Topic: Computer specification suggestions?
Replies: 3
Views: 12627

Re: Computer specification suggestions?

In fact the annoying dropouts in the sound are not impairing too much the spectrum display. And displaying a wide range means sharing the dynamic range with many signals that can impair demodulation of the wanted one even with big computing power. The main case I miss it is on the 118/136 MHZ air band
by F1BJB
Mon Mar 20, 2017 8:21 am
Forum: General
Topic: Exercise Blue Ham?
Replies: 2
Views: 9228

Re: Exercise Blue Ham?

Hi
Thanks for the link.
It seems a good idea ,in shared bands, to use the amateur community to get an estimation of the efficiency ,or lack of it,
of a commercial/military installation.
by F1BJB
Tue Jan 17, 2017 8:57 pm
Forum: General
Topic: dump1090 - 2 vs. 8MHz and RSSI
Replies: 2
Views: 10594

Re: dump1090 - 2 vs. 8MHz and RSSI

If you use more than 2 MHz bandwidth you will pick up interference
Mainly DME signals.
by F1BJB
Fri Jan 13, 2017 8:56 pm
Forum: SDRuno
Topic: What is "Decimation"?
Replies: 10
Views: 45523

Re: What is "Decimation"?

How would I effectively use Decimation in my situation. I believe there is very little gain to use decimation with a 5 MHz bandwidth. It would require a sampling frequency of 10MHz and this is pretty close to the 480 Mbps limit of USB2 10MHz x 32 bits(I/Q) =320Mbps and USB2 is half duplex and there...
by F1BJB
Fri Jan 13, 2017 8:29 pm
Forum: SDRuno
Topic: What is "Decimation"?
Replies: 10
Views: 45523

Re: What is "Decimation"?

You're saying Decimation causes multiple successive samples to be added/averaged, I get that, but samples of... What, exactly? l In fact SDR is a mix of analog and digital technology. The bridge between those two worlds is the Shannon theorem https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sa...
by F1BJB
Thu Jan 12, 2017 10:21 am
Forum: SDRuno
Topic: Initial Frequency On Startup Distorted
Replies: 7
Views: 21828

Re: Initial Frequency On Startup Distorted

Hi In fact I found that the zero IF notch can be quite useful. With a sound card it is hard to use because you pickup a lot of hum noises due to ground loops around it. Two examples: In Europe if you want to receive Boston on 1510 KHz you get a 2KHz tone due to European stations on 1512. putting 151...
by F1BJB
Thu Jan 12, 2017 9:42 am
Forum: SDRuno
Topic: What is "Decimation"?
Replies: 10
Views: 45523

Re: What is "Decimation"?

Hi Decimation is a way to reduce the number of samples delivered to the software. I believe that the minimum sample rate of the hardware is 2M samples per second witch is huge for a software designed to use a top grade sound card limited to 192 KHz sampling but with at least 16 bits resolution. Here...
by F1BJB
Tue Jan 03, 2017 2:26 pm
Forum: SDRplay related
Topic: SDRplay RSP1 gain control
Replies: 8
Views: 21880

Re: SDRplay RSP1 gain control

Yes there is a strange thing with the LNA button on RSP1
It works definitely better with it on Long and Medium Wave .
That is rather unexpected but once you know it that is OK.
On VHF /UHF it improves SNR as expected.
On a crowded FM band it introduce intermodulation but that is normal too.
by F1BJB
Fri Dec 30, 2016 1:09 pm
Forum: General
Topic: DAB with SDRplay
Replies: 3
Views: 12819

Re: DAB with SDRplay

Hi I believe the software is included somewhere in the drivers of the RSP1. It is not user friendly but quite sensitive. There is one for DVBT too but it is very CPU intensive due to every thing being done by software . It could be useful with a big computer anyway. May be ATSC is supported too ? On...
by F1BJB
Thu Dec 29, 2016 1:05 pm
Forum: General
Topic: DAB with SDRplay
Replies: 3
Views: 12819

DAB with SDRplay

It works:
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gold.gif (34.37 KiB) Viewed 12815 times
But a more user friendly software would be great :)