On 2/24/19 5:01 PM, djl wrote:
Probably tapped for 1/2" pipe thread.
Don
I don't know.. 1/2" NPT is 0.840" which a lot bigger than 5/8" 0.625"
3/8" NPT is 0.675, which would be pretty loose on a 5/8" bolt. 3/8" is
18 TPI. Not til you get up to the 1" and bigger do you get down to 11.5 TPI.
I have seen antennas with pipe thread - the idea is that you are
bringing the cable down through rigid metallic conduit - but it was 3/4"
NPT pipe. 1.050" OD, 14 TPI.
An interesting question - how many turns of mismatched thread pitch do
you get before it binds?
Maybe it's a somewhat non-standard tapered 5/8-11? - as others have
noted, 5/8-11 is a standard surveying tripod thread. I'll also note that
on a tripod typically you have the bolt and often has a tightening nut,
so you can deal with both shallow and deep holes in the instrument
you're putting on top. You thread the bolt up into the instrument, then
spin the nut up against the bottom of the mounting surface to pull the
instrument snug on the top surface.
(or a poorly manufactured 5/8-11?)
On 2019-02-24 12:40, Ben Hall wrote:
Good evening all,
After almost a month in transit, my GN-GGB0710 GNSS antenna arrived
from the auction site "we all know and love." ;)
Unit was not tapped to a proper 5/8"-11 TPI thread. A standard 5/8-11
bolt went in maybe two full threads. I modified an old tap I had in
the drawer into a 5/8"-11 bottom tap and cleaned it up. Best I can
tell, the thread cut by the manufacturer was slightly tapered.
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