Hi Ummm …. errrr …. radio transparent plastic. You want to avoid making a lens that distorts the paths over the antenna so it’s not just an issue of transparent. You also want it to be “clear” (non distorting). You need it to be stable in terms of UV, humidity and temperature. The guys who made the antenna didn’t have it quite so tough, they could design the cover as part of what determined the pattern of the antenna.
The short list of what your low cost printer will handle: PLA ABS PETG If it is really low cost, it will only handle the first one. All are a bit of a disaster at 1.5 GHz. PLA likely will not hold up outdoors, let alone do well at RF. The other two are poor at RF. The longer list on a higher priced printer: Nylon Polycarbonate HIPS Flexable’s The last two are out right from the start. One dissolves in water, the other has no structural integrity. Nylon is hydroscopic and not all that great at 1.5 GHz. For what ever reason the polycarbonate that they sell also is a bit hydroscopic. It also is quite challenging to print unless you have a very fancy printer. Certainly not an easy thing to do. Bob > On Nov 23, 2016, at 1:05 AM, Nick Sayer via time-nuts <[email protected]> > wrote: > > >> On Nov 22, 2016, at 9:39 PM, Dennis Lloyd <[email protected]> wrote: >> >> Your problem will be Birds and Debris, it is flat and you will have >> interruptions and phase shifts. >> >> Did you not understand why we use pointed antennas for timing and fixed >> installations. > > No, I guess I didn’t. > > That said, our cats seem to be doing a good job discouraging any birds, and I > can see the antenna mornings when I go out to the car and there’s been no > debris problem I’ve been able to detect. > > If it were required, I’d suspect it would be fairly easy to 3D print a pointy > hat from radio-transparent plastic. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
