Home |
Search |
Today's Posts |
#7
|
|||
|
|||
" Stephen Cowell" wrote in message . com... "Jimmy" wrote in message . com... In the plan I have for one it calls for a piece of fiberglass rod, others bakelite. to keep the two sections of the J at the right sepration. Are we talking regular J, or Super J here? The antenna you're describing is a Super, a colinear array with the middle phasing section. In a normal J-pole, there is no insulator needed. If a 2 meter J-pole construction is imperfect enough that the short and long vertical portions are not exactly parallel it might require an insulated piece of something to force them to be parallel. If one builds a 6 meter J-pole the long and short vertical parts are sufficiently lengthy and flexible that some kind of insulating brace will probably be required to keep winds from misaligning them. I recently built just such a 6 meter J-pole that used a 102" whip to reduce weight and wind loading on the top of the 1/2 wave radiator side. Even so the original plan called for a pvc brace to keep the vertical tubes aligned. ( the whip portion of the 1/2 wave radiator started about 7 inches above the top of the 1/4 wave matching stub) Both the lower portion of the radiator and all of the matching stub were of 3/4 inch copper pipe. Harold KD5SAK |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Newbie - Studying for Tech & planning station setup - Vertical antennaquestion | Antenna | |||
Low budget in-house cellular repeater project questions | Antenna | |||
BEWARE SPENDING TIME ANSWERING QUESTIONS HERE (WAS Electronic Questions) | Antenna | |||
Two Questions | Antenna | |||
Dipole questions | Antenna |