FWIW I just poked around my shop and found something that fit perfectly. It was a 5/8 inch plumbing 'barb'. So I just went to to a big-box hardware store (Lowes) and went to the plumbing section. The sales person agreed with me that it seemed to be tapered and I found a nice 8 inch length of brass extension threaded on both ends. It fit snugly and seems well suited for attachment to a larger pole using a couple of hose clamps. Dave Witten

3/8" (nominal bore) NPT thread has an outer diameter near 5/8" and has 18 threads/inch somewhat finer than the 5/8 11 TPI used for most surveying antennae Bruce > On 23 February 2019 at 11:06 David Witten <wittend@wwrinc.com> wrote: > > > FWIW > > I just poked around my shop and found something that fit perfectly. It was > a 5/8 inch plumbing 'barb'. So I just went to to a big-box hardware store > (Lowes) and went to the plumbing section. The sales person agreed with me > that it seemed to be tapered and I found a nice 8 inch length of brass > extension threaded on both ends. It fit snugly and seems well suited for > attachment to a larger pole using a couple of hose clamps. > > Dave Witten > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.