[time-nuts] Double ovened 10811-60158 on ebay

[Magnus Danielson]

Rick Karlquist wrote:
> We didn't use the epoxy for encapsulation.  We used to in place
> of soldering to see if we could replace solder with epoxy.  Nope.
> 
> Is polyimide or PTFE board less hygroscopic than FR-4?  Anyway,
> we didn't try that (too much trouble).

PTFE is very hydrophobic. Also has good RF properties. I think it would 
handle humidity better than FR4.

Reinforced PTFE is another matter. Tossing glas-fibers into PTFE would 
allow humidity both around the glas fiber as well as asorbed by the glas 
itself. Glas (silica) fibers absorbs a slight amount of humidity and the 
hydroxyl absorbtion separates the 1310 nm and 1550 nm bands we use at 
the higher speeds and lengths.

Cheers,
Magnus