There are at least 3 models of the ATX Walkabout by Waters & Stanton.
1. Straight BNC base*
2. Right angle PL-259 base*
3. Straight 3/8-24 base
The coil base section of the ATX on both #1 and #2 models actually
have an RCA phono male inside, with adapters from female RCA phono to
BNC or right angle PL-259.
The straight 3/8-24 is much more durable, and can be used in
combination with other types of antenna hardware, such as mast rod
extensions, springs, or mobile mounts.
The 3/8-24 when combined with the Superantennas FT-817 side mount
provides the most stable and strong method for portable or pedestrian
mobile use.
Bonnie KQ6XA