Magnetometer by EPE

[golden_greek]

Have anyone make EPE MAGNETOMETER?

I have some questions

[Leto]

John Beckers Magnetometer

I have build two such units..

[golden_greek]

I have build two such units..

i have some problems
first:i connect gps find signal to gps from 6 sat but to magnetometer show "BAD GPS SIGNAL" why?
second: to probe when i disconect the bottom sensor the lcd show 0 to "T" and when i disconect top sensor show 0 to "B"
why?

[Leto]

John Becker's Magnetometer

Hello to you golden_greek:

first:
Make sure you have connected signal out and 0V pin from GPS handset correctly - double check this.
Output protocol should be NMEA 01838 (4800-baud) versions 1.0 to 3.01, this is not the same as NMEA-HS (38.4K-baud).
My advice: GPS handsets are not accurate enough for surveying (maybe not, if corrected from "base station") so I never use it. If you know really interesting place to check, try with old good site grid, it could be very precise - as well you make it and you'll need only pair of long (50m) measuring tapes and some thread.

second:
EPE magnetometer is actually gradiometer and will not work with one sensor disconnected. Text: 0 to "T" and 0 to "B" means Top or Bottom sensor disconnected - I guess.

[golden_greek]

i know what mean 0 to "T" and 0 to "B". But why show 0 to "T" when i disconect bottom and 0 to "B" when i disconect top.
THANKS

[Leto]

Top or Bottom

If the >>top or bottom<< issue bothers you...change positions of FGMs, this will not afect performance in any way.

Some people say that FGM pins pointing down should give better sensitivity - but I can not confirm this.

Better way to improve sensitivity is to space sensors further apart (1m), carefully align FGMs and do not use any metal parts near sensors.

[golden_greek]

If the >>top or bottom<< issue bothers you...change positions of FGMs, this will not afect performance in any way.

Some people say that FGM pins pointing down should give better sensitivity - but I can not confirm this.

Better way to improve sensitivity is to space sensors further apart (1m), carefully align FGMs and do not use any metal parts near sensors.

i send you a mail if you have msn mesenger to talk in chat. take it?
i want ask u some things
thanks

[Lake]

Here is one scan of the EPE article.
http://www.treasurenet.com/f/index.p...=6462.msg88874

[Geophyz]

Bottom is top

i know what mean 0 to "T" and 0 to "B". But why show 0 to "T" when i disconect bottom and 0 to "B" when i disconect top.
THANKS

I think the magazine got it wrong. Mine does the same thing. Top reads bottom and bottom reads top!

And everybody....just go and BUY THE DARN ARTICLE!! :mad: Support this magazine...they are the only ones publishing projects like this.

[Geophyz]

HELLO, HELLO, Anyone there??

By the way, what`s wrong with a cheap gps unit and just taking coords where you are standing at the time??? Sumfin wreely wong wif sum of deez folks now dont it seem.

It does not log that way. It logs data continuously @ one reading a second, but only logs GPS when it is switched on and off (line end points). It is meant as a "walking mag"...not a station mag.

[golden_greek]

Geophyz have you work with epe magnetometer?
what is darn article?
change bottom and top sensor?
work good or have problems?
have you any photo from probe?
use aluminium angle for probe?
have u msn mesenger to ask u some thinks?
THANKS

[Geophyz]

"Geophyz have you work with epe magnetometer?"
YES, I have.


"what is darn article?"
Everyday Popular Electronics (EPE). Go to their website and buy the CDRom.


"change bottom and top sensor?"
I think they got the lines crossed on the schematic.

"work good or have problems?"
Works but with problems. The sensors must be alinged very presise. Stripped data due to directional issues with sensor alingment.

have you any photo from probe?
No. But see the tread on this site "Bobo's Gradiometer" for a nice picture of the probe.

"use aluminium angle for probe?"
Yes

"have u msn mesenger to ask u some thinks?"
No messenger. Sorry.
THANKS

[Carl-NC]

I have deleted all the posts requesting copies of the EPE article.

Please do NOT use these forums to request illegal copies of magazine articles.

EPE sells the magnetometer article on their web site. It is not expensive.
Please buy it from them, instead of passing around illegal copies.

EPE has been VERY generous in allowing me to post most of their older magazine articles on detector projects on Geotech, FOR FREE. If EPE feels this site is being used to encourage copyright infringement, then they may decide to withdraw their support.

Thanks,
Carl