Troy X5: Where to connect coil shielding ?

[Naildiggerdigger]

Hello all,

I built a DD-Coil for my X5. I shielded it with Graphite and connected the shielding of the coil to the shielding of the wire. So far so good, but I did not yet find out where to connect it to the detector.... That might sound stupid, but If you open the X5 Connector, you will realize that there are only 4 wires connected to the machine ! I measured them, and found out, that these are only the two coils (How surprising). But where is the shielding connected to ? None of the Pins seems to be connected to ground (Minus Pole of the Battery).

Any Ideas or Suggestions ?

Best Regards,

Manuel; DL2MAN

[bbsailor]

Re: Troy X5: Where to connect coil shielding ?

Can you provide details of the sonstruction?
Coil shell size? Looks like a Hays 11" but confirm.
Winding details. (1) Coil diameter to fit each side, (2) wire size for each coil (3)number of turns for each coil. Also tell us how you nulled the coils and secured the wires inside the coil shell?

Thanks

bbsailor

[Beachcomber]

Re: Troy X5: Where to connect coil shielding ?

Since the X-5 uses two individually shielded wires my best guess would be to attach it the recieve winding coil cable shield. I think most coils have the shield wire attached inside the coil rather than at the coil connector.

HH

Beachcomber

[Naildiggerdigger]

Re: Troy X5: Where to connect coil shielding ?

Hello,

I planned to connect it in the shell, but since I didn´t obtain double shielded wire in the desiered quality here in germany, I used a 4 wire cable with common shield.

I will try to connect it to the RX-Ground, and then test it.

Thank you so far.

Best Regards,

Manuel; DL2MAN

[Naildiggerdigger]

Re: Troy X5: Where to connect coil shielding ?

Hello,

The size of the shell is 29cm x 26cm. I designed it myself, and let the mold be milled.
I don´t have Winding Details, since I wind and measure until I match the Inductance. Actually I sawed 3 D-Shaped Boards, put them together and used them as coil-winding-aid. The size of that coils are the base of my shell construction.
I nulled them with my Oszi, by connecting them to the detector, and measuring the RX Coil Signal. Then I moved them until the scope shows a straight line. Then I glued it to the graphite-sprayed shell, and filled it with epoxy resin.

Best Regards,

Manuel; DL2MAN

[Carl-NC]

Re: Troy X5: Where to connect coil shielding ?

Many detectors that have a 5-pin connector only use 4 of them, 2 for RX & 2 for TX.

It's possible that the TX coil is part of a +V-referenced Colpitts oscillator (common in White's I believe) and the RX coax feeds a fully differential receiver amp, so that neither shield connects to ground.

- Carl

[KT315]

in whites

in whites are 2 for RX & 2 for TX & 1 wire for shield. 'GREEN' TX one is connected to -V on PCB side, not to +V. 'WHITE' is connected to oscillator output on PCB side. 'RED' RX one is connected to the OPAMP input, 'BLACK' RX one is connected to GROUND on PCB side (there is not full differential receiver amp).

the shield cable ONE wire is connected BY TWO wires to coil COVERS. on PCB side this one is connected to GROUND. accordingly all wires with zero potential are connected IN ONE GENERAL POINT NEAR RX OP-AMP'S INPUT, that is the main criterion/way to drop down a noise in the schematic.

[Beachcomber]

Re: Troy X5: Where to connect coil shielding ?




One of the wires on the X-5 does go to ground. But it is internal. I think is was pin 1 but I don't remember for sure anymore. I don't have an X-5 to take apart to find out anymore as I rebuilt mine into a waterproof housing for use in lake hunting. But there is a way to find out if you have an ohm meter. The wire that goes to ground is connected to pin 5 (the center pin) as well as I believe to pin 1 and to the outer metal part of the connector on the X-5. If you measure from pin 5 to the metal I believe you will get a zero reading on your meter. If my memory is correct you should also get a zero reading between pin 1, pin 5, and the metal of the connector. If all this proves true then Pin 1 should be the ground side of the receive winding and the location to attach your shield wire. Or if this all correct you can just connect your shield wire to the unused pin 5 of the coil connector. Hope this helps!

HH

Beachcomber

[Naildigger]

Re: Troy X5: Where to connect coil shielding ?




Hello again,

Pin 1 and 5 are connected, Pin 1 is the shield wire of RX.
Pin 4 and the metal threading are connected.
Pin 4 is the shield-wire of TX-Coil.

When connecting my coil shielding to theb threading, nothing changes. When connecting ist to pin 1/5 it´s getting a lot more quiet. But still not satisfying.... It seems, that I made a mistake at my coil-shielding...

Next one will be better....

Thank you so far.

Manuel ; DL2MAN

[Beachcomber]

Re: Troy X5: Where to connect coil shielding ?

Your coil looks great!!!! Hope the next one works out the way you want it to!!!!

HH

Beachcomber