Tuesday, October 5, 2010

Rhombic DCTL

Winter and storms arriving, it was time to do something about the wobbly design of the grabber's antenna.

Having had very good results with PE plumbing parts for my weather proof 600m frame antenna, I went to the hardware store today to buy some other material.
Contrary to the 600m stuff, which uses very heavy speaker cable, the DCTL uses lightweight TV twin line and only turn of it. This allows for flimsy 5/8" PE electrical installation tubing. Have a look at the b.o.m.:

My DCTL is 327cm long. An elbow is good for 8.5cm. In order to compensate for the shorter path through the terminal box, the two tubes connected to said box are 2cm longer than the other two.
Consequently, I cut two tubes to the length of 73cm and two to the length of 75cm.

Since today, 1903z, the DCTL is back online, in "tip up" rhombic configuration.

BTW, another reason for selecting this configuration was the wish to lift up the aerial by means of a pole, to improve ground clearance.

Note, the tubes are held together by Duck-Tape. Plumbing glue could be used, I guess, however, tape does not create such a stink ;-)