[time-nuts] EOL Motorola Oncore Remote Antenna

[Art Sepin]

> To me it looks more like water ingress through micro-cracks in the
>  plastic-dome, and the O-ring did its job and kept that water in.

Interesting. That's the first we've heard about micro-cracks in the Radome but that's certainly a likely possibility with such a long exposure to U/V. The more common failure mode reported was moisture ingress due to "breathing;" the uptake of moisture laden air past the O-Ring, due to a small pressure differential. But, once the moisture was inside, it was also trapped internally by the O-Ring. This condition was reported more often in geographic areas that experienced a wide variation in barometric pressures.  

Art

-----Original Message-----
From: Poul-Henning Kamp <phk at phk.freebsd.dk> 
Sent: Sunday, November 29, 2020 11:19 PM
To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>; Art Sepin <art at synergy-gps.com>
Subject: Re: [time-nuts] EOL Motorola Oncore Remote Antenna

--------

> It's obvious from the photo that the O-Ring seal failed its purpose 
> over its many years of service. Has the unit totally failed or does the electronic portion still function?

No, the electronics is stone dead.

To me it looks more like water ingress through micro-cracks in the plastic-dome, and the O-ring did its job and kept that water in.

The microcracks are uniform and seem to follow the molding flow, and that is probably to be expected in our climate:  We have a lot of humid freeze-thaw cycles.

I wonder if buffing the radomes with car-wax would help ?

> I said lucky because I found some GSynQ parts here in an engineering 
> storage cabinet that we  can send to you at no charge to revive your unit.

Thanks for the offer, but dont bother: I had a spare on hand, and I may still have third one lying around somewhere.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.