Search found 108 matches

by vk7jj
Sat Jun 16, 2018 3:40 am
Forum: SDRplay related
Topic: SDRPlay and GQRX
Replies: 5
Views: 597

Re: SDRPlay and GQRX

Gqrx has been really great on my Mac for the last few weeks, I've come to like it a lot and use it on Linux and OS-X It was a little flaky though, more often than not after being launched for the first time in a while it would fail to find the RSP hardware. Trying to fix that I downloaded and reinst...
by vk7jj
Sat Jun 16, 2018 2:54 am
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 818

Re: Spectrum Analyser - screen dumps

Here is the return loss at around 52.5MHz of my discone antenna. Many discone antennas use a vertical base loaded whip on the top of them to extend their low frequency response down to 50Mhz. For those who are not familiar with "return loss" the best way to visualise the picture is to cons...
by vk7jj
Sat Jun 16, 2018 2:45 am
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 818

Re: Spectrum Analyser - screen dumps

Here is another showing the FM filter OFF and ON:

1A-FM-0.png
1A-FM-0.png (45.6 KiB) Viewed 482 times

1A-FM-1.png
1A-FM-1.png (43.97 KiB) Viewed 482 times
by vk7jj
Sat Jun 16, 2018 2:43 am
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 818

Re: Spectrum Analyser - screen dumps

I wanted to see the effect of the RSP1A medium wave broadcast band filter as I was not sure how far it intruded into the 160m ham band which starts at 1.8MHz. First picture is with RSP1A with MW filter turned OFF and the second picture is with the filter turn ON. Clearly, the filter works very well,...
by vk7jj
Wed Jun 13, 2018 11:03 am
Forum: SDR Antennas
Topic: Newbie RF frontend protection Qs
Replies: 26
Views: 3224

Re: Newbie RF frontend protection Qs

If we deploy 2 volts over that, is the forward voltage over one diode 1V... or perhaps just plain 0V? Hi Jukka, I'd never have thought of that. http://www.nutsvolts.com/questions-and-answers/diodes-in-series I guess in the case of series RF protection diodes, at any voltage higher than the combined...
by vk7jj
Wed Jun 13, 2018 8:51 am
Forum: SDRplay related
Topic: re. App note on Gain and AGC
Replies: 1
Views: 203

re. App note on Gain and AGC

Thanks for the application note and forgive the naivety of my questions I know nothing about the dynamic range, linearity or overload capability of the mixer, is it useful or possible for you to specify an optimum received signal strength or a range of levels in dBm that the mixer is happiest with? ...
by vk7jj
Wed Jun 13, 2018 8:13 am
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 818

Spectrum Analyser - screen dumps

Thanks to Steve's terrific contribution in extending the useful application of the RSPs we're no doubt going to see some great applications. This is a very humble start as I've been away and busy but busting to try it. One of the nice things about loops is their operation on even harmonics as per th...
by vk7jj
Wed Jun 06, 2018 11:39 pm
Forum: SDRuno
Topic: Set up stumbles
Replies: 4
Views: 375

Re: Set up stumbles

Using a different USB port resolved the problem. I suspect that the port I first used is a USB-3 port that doesn't handle USB-2 well. Similar problem in VMWare Fusion running Windows 10 on a Macintosh with nothing but USB-3, it's very hard to figure out what's causing the problem given it's a virtu...
by vk7jj
Wed Jun 06, 2018 11:02 pm
Forum: General
Topic: CubicSDR Spectrum Range
Replies: 4
Views: 484

Re: CubicSDR Spectrum Range

Have you tried Gqrx instead? http://gqrx.dk/download/gqrx-sdr-for-the-raspberry-pi It offers that ability and more, I've been using it for weak signal work (it's much better suited to that sort of use than stereo FM for example) though I've not had a chance to pop it on a Pi yet I have been using it...
by vk7jj
Wed Jun 06, 2018 8:18 am
Forum: SDR Antennas
Topic: Newbie RF frontend protection Qs
Replies: 26
Views: 3224

Re: Newbie RF frontend protection Qs

Incandescent bulbs take far less than 150 milleseconds to achieve maximum resistance. In 5 milliseconds they are at 1/2 maximum resistance and at 10 milliseconds have reached about 80% of maximum resistance We sure are terriers in search of a resolution aren't we? Have to laugh at us! It looks like...

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