[time-nuts] GN-GGB0710 GPS Antenna Mounting Thread

[Skip Withrow]

Hello Time-Nuts,
As I have been playing with some dual-band GPS receivers, I decided to
order a dual-band antenna to replace my permanent L1 antenna that I
use for all the GPSDOs.  I purchased one of the Chinese TOPGNSS model
GN-GGB0710 units.  Much smaller than the choke ring I currently have
up (which uses a 1"-10TPI thread).

However, when I went down to the local hardware emporium to acquire
parts to assemble a mounting bracket I seem to have run into an issue.
A 5/8"-11 bolt appeared to be about right for the mounting threads,
but bound after a turn or two.  So, I went over to the metric section
and found an M16-2 bolt.  It started easily enough, but again bound
after a couple of turns.

Back home I measured the thread pitch and got .08175 inches.  Turns
out this is between the 5/8-11 thread (.0909") and the M16-2 thread
(.0787").

I looked up the Trimble antenna mounting specs and they specify 5/8-11
for their geodetic survey antennas.

Since the 5/8 hardware is a lot cheaper than the M16 I'll probably
just use a 5/8 bolt and just screw it on reasonably tight and call it
a day.  Just wanted to give the list a heads-up.  If there is a secret
mounting thread out there please let me know.

Thanks,
Skip Withrow