Thanks for the help, all of them was useful.
I re-read that SDR and VSWR measurement article, it says that an RF bridge or a directional coupler is needed to do that.
So I checked RF bridges and directional couplers, the cheaper ones don't seem to go higher than 3ghz.
Also cheaper VNAs don't...
I think I will start with an SDR like rtl-sdr.
I read that it's possible to do that with an SDR and a configurable signal generator and a directional coupler.
Is this possible?
jasonRF, so this means in the case of -7dB return loss, it is 20% while -28dB would be 0.16% power loss?
OK
Dear forumers,
I would like to do some RF measurements by using a spectrum analyzer or an SDR in the ~ 100mhz-6ghz range.
I'm new to this and to the concepts in general and I would like to hear a few recommendations.
I primarily interested here in how much it is acceptable to use a DIY...
Thanks for the points and the model Baluncore.
- I missed that
This seems very complicated. Should I still include a LISN between the modeled mains wire and the filter?
There are many things I don't understand. Does your simplification (68R resistors) have something to do with LISN? In a...
I need 100-150W.
I was thinking about bringing low voltages (5V, 12V etc.) into the enclosure but it would be a bit complicated to filter all the outputs of a SMPS (AFAI could imagine). I want to power a PC inside the enclosure and I'm planning to do RF/microwave measurements both inside and...
Thanks for the responses, I'll check LISN and the power conditioner in more detail. The filter would feed a SMPS of a computer or maybe a UPS.
I've checked the description of several shielding enclosures and the other types of feedthrough (usb, ethernet etc.) are irrelevant at the moment.
For...
I have a shielding enclosure and I want to keep interference out but I still want to bring the mains voltage into the enclosure. EMI line filters are advertised/described e.g. as "eliminate EM noise from both internal and external sources at the connector interface" and "external noises will not...
But if L1, L2 and L6 are considered as the impedance of the mains wire (Neutral, Active and PE) [correction]:
Actually, I don't know how the mains wires are connected at/after/before the breaker panel so I'm going to look for some information.
OK
I would like to filter incoming noise.
Dear forumers,
I have two high performance AC feedthrough capacitors (47nF, 100A, class Y2, DC-60Hz) which I want to either combine with a general purpose EMC line filter, or build a custom one to filter the mains from of about 100khz to as high as possible (for shielding purposes).
I can see...
This is a great link, thanks. I like the way the panels joined, you're right, this method is excellent.
I meant, what if the space is smaller than 100mm between the walls. 20mm would be a bit small but something like 40-50mm? Is there any rule?
Yes, for power 10*Log(2) = 3dB is the double.
Let's say that an enclosure with a single wall has an SE of 60dB. It seems logic that a nested enclosure (a double walled one) have an SE of 120dB, which is the doubling of dB (that is what I was expecting yes).
We can agree that double walls (the...
I remember reading that in more than one document, those showed that when doing precisely, the 2nd layer improves SE by some (30 or so) dB, but it will be less than double.
"LAMINATED AND NESTED SHIELDS Occasionally, it is assumed that the SE of enclosures can be doubled by doubling the walls...
Is that because of "the futility of trying to reach perfection"? Again, what is the problem by following theory? Papers show that double walls don't double the shielding effectiveness.
Good point actually, and you can see that I told berkeman that I can answer it in private only.
One needs...
OK, but that is just for a specific frequency, cell phones still work in an oven because the frequency is not the same.
The youtube video was about an EMP-proof shielding box (where the frequency is unknown).
There are optical usb cables for 100$. But what if the equipment still transmits...