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+--- Thread: shield the E-field ? (/showthread.php?tid=1374)
RE: shield the E-field ? - Knickohr - 2015-06-27
This is the same situation as with my ferrite !
I cannot trigger on h-field because of heavy disturbers. But maybe you can trigger on e-field channel C.
Try :
Go to the settings tab
- manual mode
- set alternate channel mapping off, yes really off !
- set auto adapt to noise on
- set auto ampl. filter on
Go to the signal tab
click on amplifier 2
- set threshold for channel A and B to 0
- set threshold for channel C to 35mV
- set gains for channels to about 16x10
OK, watch channel C for gains. Gains will now change. If the system have found a good gain, then go again to the settings of amplifier 2. Now set gains for Channel A and B manually. But be carefull, the first number must be the same as the automatic found for channel C. Now play with the gains (middle number) of channel A and B for good and strong singals, but do not overtune it, do not override or clip singals.
P:S: your friend means that : https://en.wikipedia.org/wiki/Isolation_transformer
(but I'm nor sure if this really works !)
Thomas
RE: shield the E-field ? - cutty - 2015-06-27
(2015-06-27, 14:07)Knickohr Wrote: P:S: your friend means that : https://en.wikipedia.org/wiki/Isolation_transformer
(but I'm nor sure if this really works !)
Thomas
Now, that is sort of cute, and a good one on me...
English is my language, and I have to do a lot of Google translate...Gert spelled it, for me, as "govanis trova" in his email... so playing around awhile I came up with something like
"Galvanic Detector".. possibly meaning an EMI meter..
These language things can be confusing....
I Think the display runs backwards, at times, in Gert's movie, because of the different frame rates in Gert's SWF, and the frame rate of the Signals display... and means little other than the frequencies of the noise may also vary in addition... resulting in that effect.
RE: shield the E-field ? - Knickohr - 2015-06-27
(2015-06-27, 14:28)Cutty Wrote: "Galvanic Detector".. possibly meaning an EMI meter..
These language things can be confusing....
Thomas
RE: shield the E-field ? - Rothuize - 2015-06-27
hi Thomas and Mike
I made a abc error its Galvanic trafo oeps
but it works the same like this page http://www.epanorama.net/circuits/antenna_isolator.html
Only I don't need it between the antenna cable but between the 230v power line !
it will stop the noise from the input to the output to my 230v cable
next week I will go again to that friend and hope he can deliver it ?
I have google it but can not find it here .. only the pro stuff and that is to much money !
hope to know next week more
thanks for al the help
greetings Gert
RE: shield the E-field ? - Knickohr - 2015-06-27
Where do you want to install this isolator-transformer ?
What powersupply do you use for your station ?
Thomas
RE: shield the E-field ? - Rothuize - 2015-06-27
(2015-06-27, 17:19)Knickohr Wrote: Where do you want to install this isolator-transformer ?
What powersupply do you use for your station ?
Thomas
between the power socket and the socket( 1 in and 6 sockets out ) to the computer and Blitzortung board
powersupply board = the power socket from Blitzortung 230 to 5 V
RE: shield the E-field ? - Steph - 2015-06-27
Isolation transformers can (depending on type) transduce several 100kHz, so this probably won't work very well and is expensive.
I'd recommend putting a choke between the PSU and the controller. Make as much as possible windings on a Epcos T37 ring core, or N30. This will help, if the noise is coming from the power line.
I made some measurements on that:
But as i said earlier, a clean grounding is most important for e-field. Vertical ground rods don't work well, because the current is seperating at earth surface due skin effect, leaving a big ground resistance.
Ideally large expanses of vertical wires just below earth surface are used. the more and the longer, the better.
But a direct wire to the water supply pipe will be enough for our purpose in most cases, as long the pipe is of metal and not PVC.
RE: shield the E-field ? - Knickohr - 2015-06-27
Yes, what type, model, brand of the 5V power supply do you use ?
Thomas
RE: shield the E-field ? - Rothuize - 2015-06-27
(2015-06-27, 17:42)Knickohr Wrote: Yes, what type, model, brand of the 5V power supply do you use ?
Thomas
GooBay model 44005 input 100-240VAC 50/60Hz Output 5V DC 1A
and I know what you are thinking
But this is not the noise maker on this moment I run the power from the PC ( USB) to the Board
but all is still the same
RE: shield the E-field ? - Rothuize - 2015-06-27
(2015-06-27, 17:41)Steph Wrote: Isolation transformers can (depending on type) transduce several 100kHz, so this probably won't work very well and is expensive.
I'd recommend putting a choke between the PSU and the controller. Make as much as possible windings on a Epcos T37 ring core, or N30. This will help, if the noise is coming from the power line.
I made some measurements on that:
But as i said earlier, a clean grounding is most important for e-field. Vertical ground rods don't work well, because the current is seperating at earth surface due skin effect, leaving a big ground resistance.
Ideally large expanses of vertical wires just below earth surface are used. the more and the longer, the better.
But a direct wire to the water supply pipe will be enough for our purpose in most cases, as long the pipe is of metal and not PVC.
that's a nice setup only this is not possible here
I don't live free
and thanks for the info .... choke will keep it in mind
my ground is coming from my second grounding punt
not in this house but this one is outside no powerline on this one
ground from water pipe not possible its PVC