TenTec used hot melt glue in the VCO modules of the Paragon transceiver, so
this glue probably has good RF characteristics (hopefully). The expansion
and contraction of this glue over varying temperatures did cause the solder
joints to fracture over the years............this was the downfall of the
Paragon.
I have used epoxy over the years, with good results. That is the direction I
would go.

Pete

"MarkAren" wrote in message
...
Hi All,

Has anyone attempted to use good old fashioned hot melt glue as an
encapsulant for modules ?

Probably needs melting in a pot over a flame (with appropriate care).

A mould could me made out of Plexiglass with appropriate draft
(angles) and high temperature release agent.

A second thought is to use standard two part fiberglass mix, obviously
a lot more rigid, but potting boxes are likely to be needed also.

I guess I could use thin walled pipe to house a long rectifier stack
and associated capacitors.

Both of these options seem significantly less expensive than standard
epoxy potting compound...

Any thoughts ?

Mark

Pete KE9OA wrote:

TenTec used hot melt glue in the VCO modules of the Paragon transceiver,
so this glue probably has good RF characteristics (hopefully). The
expansion and contraction of this glue over varying temperatures did cause
the solder joints to fracture over the years............this was the
downfall of the Paragon.
======================
In 1991 I bought a second hand TenTec Paragon trx ....still going strong as
my main HF transceiver. But tnx for the above .........if VCO ever
fails I know what the reason could be.

Frank KN6WH / GM0CSZ

Pete KE9OA wrote:

TenTec used hot melt glue in the VCO modules of the Paragon transceiver, so
this glue probably has good RF characteristics (hopefully).

A way to test hot melt glue would be to place a small piece on a paper
plate in the microwave oven, along with a cup of coffee to the side (as
a dummy load to keep the oven happy). See if it gets warm.

Has anyone attempted to use good old fashioned hot melt glue as an
encapsulant for modules ?

Probably needs melting in a pot over a flame (with appropriate care).

A double boiler set up may be better for that.




Both of these options seem significantly less expensive than standard
epoxy potting compound...

I suppose an advantage of hot melt glue is that you could de-encapsulate
stuff easier if you ever needed to.