BH Fast Tracker vs MD5008

[walther24]

Hello ,

I know that the Fast Tracker has 6.6 Khz and a MD5008 has 6.99 Khz.

Is it possible to put a MD5008 coil on the BH Fast Tracker ??.
Fisher F4 has 5.9 Khz ,and they allso fit on a BH.

So can this work and does it hurt the detector ??.

Thanks , Walther from Holland

[Silver Dollar]

It won't hurt it and will probably work just fine. It depends on the design of both detectors
somewhat. A detuned design will most probably work though I'm not sure if the null would still
be valid. If it doesn't work you'll just get poor depth..

[walther24]

The thing is that the Bounty Hunter has a 5 pin plug ,and the MD5008 has a 4 pin plug.
So how do I wire it ???.
And what do you mean with : The null would be valid ??.
What is the null ??.

Please explain this to me.

Thanks Silver Dollar.

[sinclairuser]

the md 5008 probably has its shield connected to one or both of the negative coil wires, while the bounty hunter may have a separate wire for this, or the extra wire ay be unconnected. the only way to know is to open both coils and see.

but that will probably ruin the coils (they never seal up as good as stock), the null is the relationship between the two coils(tx,rx) and the detector its connected to, the null is not a simple matter and is set with a scope when the coil is made.
however the info you need is right here on the forum(no coil hacking required), what you need is wiring diagrams of both coils (both on the forum somewhere), and you can work out where the wires go, it may be as simple as connecting the extra wire to one of the - wires, or even leaving it unconnected.
test the coil wires with a multi meter in conjunction with the wiring diagram, its important that tx+ goes to tx+ tx-to tx- etc and so on, just wire it correctly and give it a try forget the null it will only render your task impossible.
if you are putting the bh coil on the md5008 it should work, the other way round may not be that simple, try it see if the depth of the md5008 improves.

[Silver Dollar]

The null is a balance point where the Receiver sees the transmitted signal the least.

When you build a coil you null it by attaching it to the detector and move the coils
(or add subtract windings) until there is minimal signal from the receiver with no target
present.

An unnulled coil will be much less sensitive. A coil nulled at a different frequency might
not be nulled at the new frequency.

A coil has a transmitter coil and receiver coil and possibly a shield. You need to determine
the coil wires and attach them to a suitable connector to swap the coils. Generally the
resistance will tell you which coil is which. The TX will be less resistance. So you need a
meter to read the coils. The difference might be small (say 6 ohms vs 9 ohms)...

[walther24]

In this picture you see a BH plug.
How do you know what the TX + and - is ; and the RX + and - ??.

[walther24]

Also many thank for the your treads above .
Super , did help me alot.

[Silver Dollar]

"In this picture you see a BH plug.
How do you know what the TX + and - is ; and the RX + and - ??.
BH Pin Layout.jpg "

There is a couple of ways to figure out the polarity. If the coil has a shield you can test from the
shield terminal to the other windings. It might be tied to both TX and RX or just one. If it is tied to
both the side with the lowest resistance to shield is the negative.

If it's not tied you can guess. If it is wrong you will get a double beep then just swap the RX wires...

[sinclairuser]

hope you get it working, i have an md6006.
the coil wiring is very similar on the chinese machines , the 8" bounty hunter coil i put on this machine,is an old one and the 5th wire is not connected, the capacitor can be adjusted to better match the detector(but i did not need to do this it worked fine), and was much improoved with the bh coil.
two versions of this detector exsist some are 7khz and some are 14khz, for the 14khz models plenty of other detectors run at 14khz.
allthough mine and yours are different models there is very little difference between chinese models of this type what diference there is seems to mostly be looks. it may help you.

[walther24]

Dear Silver Dollar ,

I found out that the 5th cabel on the BH is not connected to enything.


The Yellow cabel 5 is not connected .

[walther24]

Sorry ,

So just like a MD5008 , the BH uses just 4 cabels , only has the 5th as a sort of shield.
Can this be correct ??.

[sinclairuser]

how old is that coil in the xray?, the red loop on the tx is probably used to null the coil, my guess is that the yellow wire is conneted to the shield, the way it coils round the buck coil and receive coil may mean its connected to the shield its hard to make out.
the photo i posted of the md6006 coil is a bit deceiving as the black earth wire connects to rx-(on the traces on the board).
if the yellow wire is shield, and your chinese coil has the same 5 wires as mine it should work, but you need to still check rx,tx etc on that chinese coil as they dont allways use the same cables.
as i said before the easiest way to do this is to open both coils and check them manually, but you have to be sure you can seal them up again.
if your 5008md only has 4 wires its shield(it will have one even if its only on rx) maybe connected to rx- wire.

[walther24]

The picture of the open coil is from a BH nugget 4" coil.
It,s about 5 years old and has a 5pin Din plug. ( so not a srew plug. )

The picture of the coil is from a website with all the info.
The yellow wire is not connected.

http://www.whiteriverprep.com/vintag...ch/bhtech.html

[sinclairuser]

then simply ignore it and match the tx and rx wires,
it was not used on the coil i used, my md6006 had it but as the rx- is connected to shield(by a trace on the board) i ignored it.
it works fine better than before with the chinese coil.

[walther24]

Ok , that,s good news.
Can i use any coil between 6.5Khz and 7Khz , with 4 wires then on the MD5008 ??.
Like a Whites 12" or so ??. Or a other brand.
What are my options ?.