[TowerTalk] Converting CC 215WB to 13B2..de K0FF

[K0FF]

Two Meter antenna conversion....

I purchased a pair of 215WB's for use on FM figuring that an antenna with 3
reflectors would certainly have a better front-to-back ratio than a single
reflector element design.
Not so, as the 13B2 has a 2dB advantage over the 215WB.
Here is the modification to improve the antenna:

 *MOD/215WB to 13B2 *

Remove and discard the tri-reflector outrigging. Keep the 2 ea..  38-3/4
rods.
Cut one of the 38-3/4 rod to 37-7/8 and replace D1 with it.
Cut the other 38-3/4 rod to 36-1/4 and replace D2 with it.
Remove the 40-3/16" reflector from the boom and cut it to 39-3/4.
Return the 39-3/4 rod to the boom, but 4-1/2 inched to the rear of it's
original position.

For practical purposes, that's all that is required. If you are a purist,
you'll have to purchase
new rods for the last 6 directors, but the new rods will only be 1/16th"
longer than the present ones.

Now you have a better performing antenna with fewer parts. I left the TEE
match as is, and have good results. The newer antennas have a UltraMatch
Balun in a plastic box, but the function is the same.

P.S. I've looked into the manuals for the 13B2 (144-148) and the 13B2N
(144-146) and notice no difference in element length or spacing...??

Geo>K0FF



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