Close

The Yagi, is a flag.

A project log for BIRTHA - Pneumatic RV antenna mast

Telescopic cellular antenna mast, extended and retracted with air using a collapsible garden hose.

Daren SchwenkeDaren Schwenke 04/25/2018 at 05:180 Comments

For the purpose of aerodynamics and my engineering sanity, I designed the Yagi to point backwards while the RV was in motion.  Pointing it forwards would have meant the rotation mechanism would have needed to survive 120 mph wind loading (70 mph RV speed plus perhaps up to 50mph wind gusts).  

There was about 4 inches of clearance back there between the inside panels and the outer valence so unless I wanted an 8 foot pole hanging off the back or going through the inside of the living area, that is where it had to go.

This left the Yagi hanging out over the back of Birtha, and before this shot:

It looked like this:

Chris said it was ugly, and I had to agree with her.  

Then she had the brilliant idea of making it into a flag.

So I did.. the same day.

Memorial day made it very easy to find cheap flags.  I bought two for $2 total, made some marks for alignment, and spray glued them on with some headliner adhesive (doesn't degrade with heat).  That was probably good enough really, but the surface texture was that of a cheap flag still and I imagined 5k miles down the road it would be pretty grimey.

I gave it about 5 coats of clear lacquer, sanded it, and then gave it one more coat.  That got rid of about 90% of the surface texture which is about when I ran out of patience for watching paint dry and put it on the RV.  The lacquer loosened the adhesive though, so be careful.

It looks great.  Thank you Chris.

Discussions