Jurassic Duck Mk III & PRC-26

From that last post, you could probably tell that I've been up to something.  Following up on last month's Three Days In The Woods, it was painfully clear that we needed serious radio power in a backpack-able format.  Some discussion of updating the old AN/PRC-25/77 radio concept was batted around.  Starting with the Jurassic Duck Mk II as a prototype antenna and building up a backpack frame with a TYT-9000D 2m radio and a 20 AH LiFePO4 batt, we took the original DoD realization from 42 pounds and 2 watts for $5000 (inflation adjusted) to a much improved 14 pounds and 60 watts for $300.  Of course, that's 60 watts on 2m, which for the typical 40 MHz used with the PRC-25/77 series, has about the same punch as 5 watts at that frequency.  OK, so a third the weight and two and a half times the power for a sixteenth the cost.  Wrap it up, I'll take it.  Also, this being 2026, we dubbed it the "PRC-26."  Picture on the right.

Of course, any project such as this one will naturally bring in a few refinements and construction notes.  Here they are for this iteration:

• We used a cam-lock lever to allow the antenna pole to pivot over to half-size for storage and transport.  This has caused all kinds of havoc, and I don't recommend it.  First, it necessitated bringing the coax out through the side of the PVC pipe above the pivot, which makes slipping things in and out during adjustment a bear.  Also, it necessitates a longer lower segment, which makes the whole thing wobbly.
• Recommended for next iteration: Two glue-on male threaded adapters with a female threaded coupler to join them.  Note, the UHF plug connector can slip through all of these and come out through the bottom of the lower pipe.  Much simpler, more rugged, and easier to construct.
• Be damned sure to get thin-walled PVC!  Bring a section of 450 ohm window line to the hardware store with you and try slip-fitting it in.  It'll be snug, but make sure it fits fairly easily.
• Revised lengths for the j-pole internals: 
• main radiator = 38" with an inch or so of loop-over (cut it a little long and tune down 1/4" at a time)
• 450 ohm segment = 17" total length, remembering to leave enough to solder the bottom legs together and an extension on the hot side for the main radiator wire attachment
• tap 1.75" from the bottom of the window line

And that's it!  I'll be building up my own personal copy of this revised version in the near future.