Search found 116 matches

by F1BJB
Thu Apr 18, 2019 8:51 pm
Forum: General
Topic: FM BROADCAST BAND SUPPRESSION CHEBYSHEV N=5 BAND-STOP FILTER
Replies: 14
Views: 2331

Re: FM BROADCAST BAND SUPPRESSION CHEBYSHEV N=5 BAND-STOP FILTER

Very nice post. Another useful trick in low pass filters is to replace part of the capacitors to ground by open quarter wave stubs of coaxial cable. You cut the cable to notch out a strong local signal . Normally there is not enough capacity so you add a real one to compensate. Or you add another op...
by F1BJB
Thu Apr 18, 2019 8:22 pm
Forum: General
Topic: Broadcast AM station carrier disappears in certain bandwidths
Replies: 2
Views: 360

Re: Broadcast AM station carrier disappears in certain bandwidths

Hi and welcome This behavior is normal with a zero-if receiver. You cannot receive correctly AM or FM when perfectly centered. This can be useful if for example you have an interfering signal on 1411Khz just use 1411 as center frequency and you have a free notch filter. :) Also if there is a very st...
by F1BJB
Thu Dec 20, 2018 8:39 pm
Forum: General
Topic: Sdr
Replies: 8
Views: 2238

Re: Sdr

Very few SDR softwares allow direct decoding of digital modes.
Most of the time you have to link the audio output of an analog SDR software to another software dedicated to the digital mode you require.
I use my SDRplay for DAB and DRM with no problems.
by F1BJB
Sun Dec 02, 2018 1:59 am
Forum: General
Topic: Is Windows 10 ok now?
Replies: 3
Views: 2092

Re: Is Windows 10 ok now?

Mikesimpson wrote:There have never been any problems with Windows 10 with SDRs.

Same thing for me.
by F1BJB
Thu May 24, 2018 7:59 am
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 4965

Re: Cheap broadband planar elliptical dipole antenna

Thanks Phil, I have made some other small/simple improvements to other antennas. One was adding an extra square plate Reflector to a 15 Element yagi for L-Band Aero signals. Which in turn gave an extra 6dbi (One S point) increase in signal strength. Hi Most Yagi design have only a single reflector....
by F1BJB
Thu May 17, 2018 12:25 pm
Forum: General
Topic: Clear Recommended Computer requirements (for RSP on a Laptop)
Replies: 10
Views: 9863

Re: Clear Recommended Computer requirements (for RSP on a Laptop)

Hi I too think that it totally depends of what you want to do with the RSP and the software you intend to run. Receiving NDB and DVBT2 HEVC signals have very little in common. Neglected important features of the computer used are: It's power consumption. It's EMC performance. Performance of it's USB...
by F1BJB
Wed Dec 27, 2017 11:00 am
Forum: SDR Antennas
Topic: Degaussing Coil as a Loop style Antenna
Replies: 2
Views: 3191

Re: Degaussing Coil as a Loop style Antenna

Those multi turn loops have a drawback: parasitic capacitance.
It is very hard to get a decent tuning range with current variable capacitors.
by F1BJB
Sat Dec 23, 2017 7:06 am
Forum: SDRplay related
Topic: Ethernet
Replies: 2
Views: 2323

Re: Ethernet

Only gigabit Ethernet is better than USB2 and the difference is not very big.
And if you have to use POE it gets complicated.
by F1BJB
Tue Oct 10, 2017 2:43 am
Forum: SDRuno
Topic: Excessive CPU usage
Replies: 4
Views: 3959

Re: Excessive CPU usage

I had this problem with windows 7 and many audio/video related software's. It is not related to SDRuno I tried a lot of tips from various sources with no effect. It seems that the problem mysteriously vanished and I don't know if it was due to an update from Microsoft or the installation of a softwa...
by F1BJB
Wed Oct 04, 2017 3:14 pm
Forum: New Users' experiences
Topic: PC (laptop) power induces significant noise
Replies: 16
Views: 15794

Re: PC (laptop) power induces significant noise

PC monitors or their cables can also produce interference A trick is to start a recording then switch off and disconnect everything from your PC : keyboard, mouse, monitor,speakers , etc Then play back the recording. Of course for a laptop you are limited :) I also found that sometimes interference ...

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