[NLRS] Aluminum tube

[Dr. Gerald N. Johnson]

I found a source of aluminum tube not far from here, but their stock 
isn't as varied as Texas Towers or DX engineering. But a half hour drive 
can beat a week waiting for shipping. I'm working on some compact 2m 
beams and have some 1-1/4" tubing for the ends, wanted 1-3/8 for the 
center section. .058 wall so it would slip over the 1-1/4. No 1-3/8 to 
be had, but they did seem to have 1-1/2" .120 wall. I bought 12' and had 
them cut it to fit in my car.

Today I tried to mate the two boom sections. Not a fit. The supposed 
1-1/2" is really 1-5/8" so the ID is 1-3/8", not a fit on 1-1/4. Since 
its cut into 5 and 7' sections, I probably can't return it. I'm thinking 
of taking it to CSVHF in a couple weeks, probably ask the $2.50 a foot I 
paid. Also plan to have an M2 2m 5WL if I can fit it in the car and an 
imperfect TR-751A.

For my 2m boom which is only 10-1/2 feet long I'll use the 1-1/4 for the 
centers and some 1-1/8 I found in the shed this evening for the ends. 
I'll slip a wooden dowel in the 1-1/4 so I can clamp it securely without 
crushing it and for a bit of bending stiffness. If M2 can run 33 feet of 
boom with .058 wall 1-1/2"aluminum I can do 10 feet with the same wall 
in 1-1/4 for the center section.

73, Jerry, K0CQ