Coil noise

[billr]

After grounding a coil using copper tape there is no longer any noise when I place my hand on or near it but if I wave the coil about in the air or bounce it up and down it causes a huge amount of interference.
What's causing this and how do I stop it?

[waltr]

That could be caused by a number of things.

Is all the coil windings bound tightly and secured to the shell so they do not move?
Connections good and not moving when moving the coil?
Detector circuit properly cancels EF (Earth Field)?

Any Metal near where you 'wave' the coil? My detectors pick up paint can in my basement shop from greater than a meter away.

[billr]

I went outside all was good. I chickened out doing that initially cuz it was too darn cold. Must be underfloor cables or piping. Keep forgetting these things have a substantial side range as well as depth.
Thanks for the reply.

[waltr]

Ah, good it didn't have issues outside.
Yes these detectors we build are quite sensitive.

[dbanner]

Wait until you get over wet grass, then you'll find out something peculiar. The ground connection is never made at the search coil end. It's made in the chassis box, behind the connector.

[39cents]

Wait until you get over wet grass, then you'll find out something peculiar. The ground connection is never made at the search coil end. It's made in the chassis box, behind the connector.

Hi could you please explain this a little for me? I do not understand thank you

[kt315]

After grounding a coil using copper tape
--
who told you to use copper tape? the source?

[39cents]

After grounding a coil using copper tape
--
who told you to use copper tape? the source?

"Inside the metal detector" mentions using metal tape (aluminum in this case) on page 138

[Qiaozhi]

"Inside the metal detector" mentions using metal tape (aluminum in this case) on page 138

You can use sticky-backed aluminium tape (typically 20um thick) for the shield. Don't use cooking foil as it's too thick.
Eric recommends using woven copper fabric tape ->
https://www.geotech1.com/forums/show...per#post254821

[kt315]

do you do VLF detector/coil?

[Gwil]

I'd appreciate it if people posting would say whether they are talking about PI or VLF IB coils, because they often don't, and it makes a difference. Thanks.

[kt315]

I'd appreciate it if people posting would say whether they are talking about PI or VLF IB coils, because they often don't, and it makes a difference. Thanks.

main problem of people they do not want write the question in thread header with full name of detector.
thats hardly obstruct the search in forum after time considering we are here from 2002 years.

[green]

You can use sticky-backed aluminium tape (typically 20um thick) for the shield. Don't use cooking foil as it's too thick.
Eric recommends using woven copper fabric tape ->
https://www.geotech1.com/forums/show...per#post254821

What am I doing wrong? Standard Reynolds foil 16um, less than (typically 20um thick).

[kt315]

What am I doing wrong? Standard Reynolds foil 16um, less than (typically 20um thick).

where, in which comment, i suggested you to use foil? either it 16um or 20um?

[6666]

You can use sticky-backed aluminium tape (typically 20um thick) for the shield. Don't use cooking foil as it's too thick.
Eric recommends using woven copper fabric tape ->
https://www.geotech1.com/forums/show...per#post254821

I just checked the ebay company that Eric used and it appears to have closed
If you search on Conductive Fabric Cloth Tape, OR Adhesive Silver Conductive Cloth Tape
others show up.