[time-nuts] GPS Timing Antenna Failure - Long
lmcdavid at lmceng.com
Sat May 12 20:38:59 EDT 2018
Thanks, Dave, for reporting your failed GPS antenna; at least, I am not
alone in having this failure.
It will be interesting to understand what you find when you open your
failed 58532A. Removing the radome is very easy, just 4 screws and some
wiggling or gentle prying. If yours does not have the metal shield-can
over the coax termination, a quick look at the coax solder joints for
old flux will confirm or refute that as the likely failure cause. If
your antenna has the shield-can and you see no flux around its soldered
tabs, there likely is no flux problem.
Perhaps 1-2 years ago Symmetricom offered here a deep discount on this
antenna, clearing their stock; presumably they have something newer. The
antennas with the shield-can are from my purchase from Symmetricom of
several of these antennas. The 58532A that failed is at least 10 years
old so they must have made an in-line design change without changing the
If you do remove the PWB, you will find the RF circuit rather obvious
and even rectilinear in layout. All the parts are SMT. Two of the three
amplifier chips are the same, as are two of the three bandpass filters.
The first amplifier and the first bandpass filter are unique.
My primary goal in writing this narrative was to help someone who also
had a similar antenna failure. I've heard now from several who have. If
the fix is as simple as old flux removal, the antennas can probably be
When I first tested the repaired antenna, I used a 5 vdc GPS device and
that was successful. Later, I used another GPS device that puts only 3.3
vdc to the antenna and that worked ok also, with no noticeable
difference in performance. Note that the Symmetricom spec rates the
antenna at 5 vdc input.
On 5/12/2018 3:17 PM, Artek Manuals wrote:
> Thanks for the analysis... I too have a failed 58532A which died a year
> ago . which I had not bothered to disassemble yet..The weather guessers
> are predicting rain all week net week so maybe I will find an
> opportunity to comp[are my findings to yours
> Do you have a schematic for the board or is the layout so simple that it
> is self evident once you look at the board?
> Stay tuned for film at 11
> de NR1DX
> manuals at artekmanuals.com
> On 5/12/2018 4:07 PM, Larry McDavid wrote:
>> I recently had an unexpected failure of a white-conical-dome
>> HP/Symmetricom 58532A GPS antenna......
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
More information about the time-nuts