Roger Hayter wrote:
wrote:

Irv Finkleman wrote:
Here's a situation I haven't encountered before
and which I know little about.

I am building a magnetic loop antenna and have
an assembly which includes a capacitor and drive motor ideally suited
for the antenna. My problem is that the assembly is welded to an
aluminum mount. I want to attach a copper tubing loop to the mount
which will connect the loop to the motor driven capacitor.

My concern is the matter of dissimilar metals i.e. copper and aluminum
being joined. I would prefer to be able to bolt the assembly to the
copper tubing using star washers to reduce the joint resistance.

Here are my concerns:
1. What about rectification at the dissimilar metals joint? Is it going
to cause problems? Is it of any real concern?

3. Can the copper be welded to the aluminum mount for better joint
conduction? This is a last resort for me as it would mean taking the
assembly to a place where the welding, if possible, could be done.

Thanks in advance for any comments or suggestions which would be greatly
welcomed.

Irv, VE6BP
RADIATE OR DIE TRYING!!

Yes, there is a problem with aluminum to copper connections.

There are various "greases" to solve the problem.

This is just one of them:

http://www.dxengineering.com/search/...plies/product-
line/jet-lube-ss-30-pure-copper-anti-seize?autoview=SKU&N=4294952247&sortb
y=Default&sortorder=Ascending

Here are some mo

http://ecat.burndy.com/Comergent/burndy/cat/602945

There is something to be said for using aluminium[1] tubing instead, and
any increased losses might be oounteracted by using larger tubing. The
skill and equipment to weld aluminium to aluminium is widely available.


[1] as spelled here

Not on this side of the Atlantic.

https://en.wikipedia.org/wiki/Alumin...ferent_endings


--
Jim Pennino