Plastic Antenna Molding

Sounds like it was an epoxy mix of some sorts.

Check your local epoxy/adhesive suppliers like Dupont, Araldite, Loktite or similar.

Make sure they understand it's for an antenna, will have exposed metal parts in it, will be exposed to weather, must NOT conduct electricity and so on.

I suspect that the black colour was the available method of UV protection for the material from that era.

thanks

can2new hello, You could try the company called

Master Bond

they have potting and encapsulation compounds and just about any other

epoxies for about any job.

btw is this antenna ham related? Because your description sounds like something I remember hearing about some time back. The antennas this person built were very good and reliable but I don't remember the name or brand.

Anyhow I hope the link helps there people should be able to help you find what you need.

An no I don't have any connections with the company other than using a couple of

there epoxies in a past job.

Charles

Hi

plastics can be conductive by covering wit palladium chloride, and then you may apply electroless copper plating.

Bino

thanks

Thanks, I will look into the product.

It could have come from that original application, but it is not for that. It is for a geotechnical application.

Thanks

What happened to the original antenna? Can the pieces be put back together? What sort of radio is it for? Is this antenna flexible or rigid? Does it need to be weatherproof? Is the entire antenna assembly enclosed? Must it be a particular color? Do you know if the inner conductor is single? Multiple? Straight? U-shaped? J-shaped? Coiled? Is it connected with a resistor? With a loading coil?

Unless you are trying to conceal the fact that the original antenna was lost or broken, connecting a piece of wire to a connector that will fit the socket on the radio and trimming it shorter will give you some idea of how long the wire should be. If you know what frequency or band of frequencies this device employs, you can consult tables or use formulas to determine how long to make the wire before you begin trimming. It may take several tries, but the materials won't be very costly. This wire can also serve as a temporary antenna while you create a more exact replacement.

For higher frequencies, the diameter of the antenna element and the presence (or absence) of insulated cladding over this element may also need to be considered. The dielectric constant of this insulation will make a difference as well. Good luck.

I still have the original. It is for a geotechnical application. Yes it is rigid. It would be great if it was waterproof, currently it is not water friendly. Yes the assembly is enclosed. (The only exposure is the fitting that connects the internal wire to the connector that is exposed ) Color is not a big deal. I believe the answer is conductor is single. The shape is circular - coiled.

I need a back up in the event this one ever breaks. I have been in the field with it and it got wet and it shut down. It is a prototype of antenna. As far as the wire and how many wraps to make I have that information. I just do not have the make and type of mis for the plastic shell for the antenna. Always wanting to improve the process, like making it waterproof etc.

All great questions. Thanks for your help.

You probably want to use a 2 part urethane used for casting. In order to do this properly, form without air bubbles, the entire mold, with the casting material should be vacuum degassed. This is not necessary but well advised to do.

You can buy material from:

http://www.smooth-on.com/liqplas.htm

http://www.lumicast.com/links.html

One of the industry experts in this process is Paramount and they may be willing to cast this for you (for a price) in your mold.

http://www.paramountind.com/urethane-castings.html

Thanks for all these sites and info! I will look into these options

Flexible "rubber duck" antennae can be re-waterproofed using domestic roof repair mastic compound!

could be Texin 950U ?

thanks I will look into this

thanks