MFJ sells a 17 foot telescoping steel whip with a 3/8 x 24 fitting for $70 plus sales tax and shipping. Getting one to my door is nearly $90 all-in. I've used one as an option for a very effective "stationary" mobile antenna for the higher bands -- allowing for a true 1/4 lambda radiator for optimal efficiency -- no lossy loading coils or need for cap hats. But the antenna, for what it is, is expensive. I have now found an alternative for half the price of the MFJ that is almost the same and works great. The only catch is that Sonny gets these made as part of a "buddi-pole" type antenna system and for the domestic market - so the mounting is not SAE thread 3/8 x 24 thread but rather metric thread M10 (metric, 10mm). It is fairly easy to modify a typical mobile antenna bracket / mount by replacing the 3/8 x 24 "barrel" with a M10 barrel. To do so, I replaced both the bolt and "barrel" with M10 hardware. The collar washers fit just fine and I am up and running. I don't think you could do this with an SO239 fitted mount, but the "solder lug" style is easy to change. Note that the antenna is an exact same material, same length and diameter and number of sections (14 sections) and probably the same manufacturer as the MFJ variant, except for the brass base screw. The antenna handles 500W PEP no problem with no signs of heating anywhere. It would be pretty easy to take a 3/8x24 collar and weld a M10 nut to one end of it ...which would allow it to be used in a variety of 3/8 x 24 antenna mounts such as a ball mount, etc. Or you could buy an adapter from a car parts shop. Here is a link for those interested: https://www.ebay.com/itm/265087608788 there are a few other cool gadgets from this seller -- an interesting loading coil and a shorter whip that still is over 9 ft long.