Search found 118 matches

by F1BJB
Tue Aug 13, 2019 3:58 pm
Forum: General
Topic: Electric Fences
Replies: 4
Views: 763

Re: Electric Fences

LW needs a long aerial the fence in that case.
I would try feeding the fence with a grounded 11 mm coaxial cable with a serial coil on the device side.
The coaxial cable acting as the capacitor of this basic low-pass filter.
Coil could be replaced by a resistor.
by F1BJB
Thu Jul 04, 2019 1:48 pm
Forum: General
Topic: Parting thoughts
Replies: 18
Views: 3488

Re: Parting thoughts

sdrom33 wrote:Thank you, Tech_Support, things had really gone too far. Thanks again for your faultless control of our Forum.

Thomas
+1
I find what is left of this topic quite informative thanks.
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: 3792

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: 744

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: 3003

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: 2627

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: 5775

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: 10949

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: 3569

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: 2572

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.