Bill - I'm really certain that the fitting is 3/8" thread, and if you find PE fittings in 3/8" size it will have the correct thread to fit the Andrew (and other) EIA gas pass/barrier flange connectors. My local hardware stock fits, yours should as well. Best to you on your project!
Jim "Turbo" Turvaville
SBE Certified Radio Engineer
Turbo Technical Services
From: Bill Hurne <firstname.lastname@example.org>
To: CRTech <email@example.com>
Sent: Friday, May 26, 2017 2:44 PM
Subject: [CRTech] Pressure fitting?
What is the gas pressure fitting size to screw on Andrew coax connectors? Is it 1/8 inch NPT male pipe thread? Or ¼ inch NPT male pipe thread?
The Pilgrim Radio Network
Western Inspirational Broadcasters, Inc