Silver wire

[Unregistered]

By using silver wire in the RX coil of a concentric would that improve the discrimination of the coil on the account that silver has a different phase angle to copper.

[Max]

By using silver wire in the RX coil of a concentric would that improve the discrimination of the coil on the account that silver has a different phase angle to copper.

Hi,
no, you'll have same discrimination and same initial (no target) phase shift.

Silver wire has lower resistivity than copper wire. You have to match , anyway, inductance and resistance of existing copper rx coil.

What you have , at the end , is just a coil and the phase is unaffected by material composition of wire, but by coil's specs.

One advantage could be an increased Q of coil at same diameter of wire when using silver instead of copper.

I never heard of pure silver made coils... but aluminium ones are about common e.g. in Minelab stuff. The reason why they prefer aluminium is not about phase or something, but mostly weight of finished coils. Now ML coils are BIG... and would be even heavier if made only of copper...
Copper is heavier than aluminium.

Kind regards,
Max

[thedigger]

Max
If you use aluminium they in coils it is only 60% the conductivity of copper,so then you would end up with much big coil,and would that not add to the capacitance of the coil.

[ApBerg]

Alu wire

Hello Friends,

So alu wire is used in coils? I bought some wire , tought it was a bargain at some sort Ebay (Marktplaats).
Thinking that is was copperwire from 0.16mm ....but it is alu wire that looks like copperwire , it has the same sort coating

Can't blame the seller they did not know ... I had to check ...

Can always make some coils for testing, use more wire's in as 1 winding.
But how to solder the connection? any idea's ?


Regards

Ap

[Max]

Max
If you use aluminium they in coils it is only 60% the conductivity of copper,so then you would end up with much big coil,and would that not add to the capacitance of the coil.

Hi,
in things like relic hawk you'll see aluminium coils. Very often, for the reason you mentioned, it's the TX coil that's made of aluminium instead of copper wire.

Also is not uncommon that some PI use aluminium wire in monocoils, reason is always weight.

In RH the TX coil is made of thick wire, not so much turns, and the effect of resistance variation is not relevant.

You must also consider that the gauge used for aluminium wires don't need to match copper gauge: you can find a compromise between gauge, so resistivity and weight of whole coil.

In some cases (e.g. large coils) the difference could be really hi about weight and justify the extra expense and troubles of making the coil using aluminium wire instead of copper.

I saw some proposals of making monocoils using silver wire... for PIs but that's about only the higher conductivity of silver respect to copper: really I don't think there's any real advantage (considering also costs and troubles to get the material at a particular gauge etc) having a PI monocoil made of pure silver.

Kind regards,
Max

[Qiaozhi]

Can always make some coils for testing, use more wire's in as 1 winding.
But how to solder the connection? any idea's ?


Regards

Ap

You will need to buy special solder for soldering aluminium wire. A while ago I had a faulty Garrett 12.5" coil with a dry joint between the TX and nulling coil. It was impossible to get a good solder connection. Then I realized that the TX coil was aluminium, and the nulling coil was copper. A friend gave me some special solder, and this fixed the problem.

[ApBerg]

Alu Solder

Tanks Qiaozhi, I will look for the alu solder.

After removing the isolation I first tought is was copper tinned wire..... so nice to solder ..... no way ! !

Regards.

Ap

[karabuz]

solderin alu

hi, i'm using oil ( hydraulic, or other fine oil) , a clean isolation in isolated area(oil) , because problem with soldering aluminium is a oxidation... if no oxigen - no problem , after cleaning of the oiled wire in isolated area solder it fast with more rosin


sorry for my bad english

[ApBerg]

Hello Karabuz

Thanks for the advice !

Regards.

Ap

[Unregistered]

"hi, i'm using oil ( hydraulic, or other fine oil) , a clean isolation in isolated area(oil) , because problem with soldering aluminium is a oxidation... if no oxigen - no problem , after cleaning of the oiled wire in isolated area solder it fast with more rosin"

I have used WD-40 with good results. I use 60/40 rosen core solder. I read this on line somewhere and did not believe it would work, so I gave it a try and found out that it does.

Jerry

[Max]

"hi, i'm using oil ( hydraulic, or other fine oil) , a clean isolation in isolated area(oil) , because problem with soldering aluminium is a oxidation... if no oxigen - no problem , after cleaning of the oiled wire in isolated area solder it fast with more rosin"

I have used WD-40 with good results. I use 60/40 rosen core solder. I read this on line somewhere and did not believe it would work, so I gave it a try and found out that it does.

Jerry

Hi,
it's not rocket science....apart the WD-40 (maybe you know it was developed for the Atlas stuff in the 50's...)!

Yes, could solder on aluminium if covered with oil but the trick is to "brush" aluminium ...I mean with the soldering iron stuff.... that way you remove the oxide and let solder stay on "clear" metal.

The oil excess you could wash away later....using e.g. solvents. In the case of WD-40 (cause exact formula is unknown....) I don't know if it's safe to heat it really... but I think can stay around 350 °C without ignite, but not sure about.

I remember that old cans where propelled by cfc stuff and were hi flamable !

But all oils are good.... just get one that makes less fumes... or work outside.... kinda crack-house otherwise!

I think some e.g. sint oils are fine cause can resist many hundreds of celsius.... at the end the oil must just prevent the air came in contact with bare aluminium and so the rapid creation of a new (transparent) oxide layer. And the oxide melts at maybe 1400°C so no soldering iron will melt it ever.

It's a trick, actually, in TIG soldering you'll use e.g. Argon to make the trick , no smoke, no pain.... apart the cost!

Kind regards,
Max

[Unregistered]

Soldering Alum

Hello All,

The way Garrett attaches their aluminum windings is by crimping a piece of short copper wire to the aluminum wire. This can then be soldered. Or directly to the coil cable. A small brass or copper sleeve is used and standard crimpers. Hope this helps

Regards
Mark

[nick_f]

Thick multistrand silver plated wire may not be good for PI Coils!

Hi,

I saw some proposals of making monocoils using silver wire... for PIs but that's about only the higher conductivity of silver respect to copper: really I don't think there's any real advantage (considering also costs and troubles to get the material at a particular gauge etc) having a PI monocoil made of pure silver.

Kind regards,
Max

Hi Max,
Please be aware some people don't recommend using silver plated wire for PI coils (it seems a high Q is not desired!). Also, read my results with two almost similar coils built with silver plated wire, http://www.geotech1.com/forums/showthread.php?t=15383 (post #16 and following). It seems that wire diameter and wether is silver plated or tin plated has very significant implications in the speed of the coil.

Regards,
Nicolae

[Matt_Rowe]

How about brass wire, would that work for a coil.

[WM6]

How about brass wire, would that work for a coil.

Do not expect real brass wire.

It should be brass coated steel wire only.

Not suitable for coil windings (except maybe for very HF BFO coils due skin effect) due high resistance.