V
VK3ZYZ
Guest
I recently, well, a couple of years ago, came into the ownership of an RFI vertical on 88Mhz. It had me wondering what is inside these antennas. So, finally, I thought I'd try to open it up.
After undoing the 2 screws at the base, the 25mm Aluminium tube was held and a spanner used to twist the type N connector back and forward to break the silicone rubber sealing.
At this stage, I could work the antenna out of the tube a short way, but not fully.
So, the next step was to push the socket back into the tube so to allow the tube right at the socket to be gripped in the vice.
Next, the heat shrink seal between the top of the Aluminium and the fiberglass cover was cut off.
Then, a spanner slid over the tube to press against the cover, was "gently" thumped with a hammer and the cover slid off
This was was revealed...
Sorry about the louse pic. It is just a screen grab of the first picture.
It was covered by wide doubled over PVC tape, with some Silicone rubber slopped on.
Detail of the center connection. The Aluminium tube elements are 10mm OD.
It looks like the coax feed from the socket connects to the top tube. There are a couple of screws about 175mm up from the end of the tube that does that.
The top tube is 779mm long.
The bottom 10mm tube sticks out from the 25mm tube around 890mm, while the 25mm tube itself is 832mm long.
The black coax cable runs down the outside of the lower 100 tube 690mm, and the end insulated from the tube with tape.
The lower end of this coax is shorted together.
Here is a detail of the base connection to the 10mm tube.
I hope to work out a mod of this antenna for 6M.
Maybe as below???
After undoing the 2 screws at the base, the 25mm Aluminium tube was held and a spanner used to twist the type N connector back and forward to break the silicone rubber sealing.
At this stage, I could work the antenna out of the tube a short way, but not fully.
So, the next step was to push the socket back into the tube so to allow the tube right at the socket to be gripped in the vice.
Next, the heat shrink seal between the top of the Aluminium and the fiberglass cover was cut off.
Then, a spanner slid over the tube to press against the cover, was "gently" thumped with a hammer and the cover slid off
This was was revealed...
Sorry about the louse pic. It is just a screen grab of the first picture.
It was covered by wide doubled over PVC tape, with some Silicone rubber slopped on.
Detail of the center connection. The Aluminium tube elements are 10mm OD.
It looks like the coax feed from the socket connects to the top tube. There are a couple of screws about 175mm up from the end of the tube that does that.
The top tube is 779mm long.
The bottom 10mm tube sticks out from the 25mm tube around 890mm, while the 25mm tube itself is 832mm long.
The black coax cable runs down the outside of the lower 100 tube 690mm, and the end insulated from the tube with tape.
The lower end of this coax is shorted together.
Here is a detail of the base connection to the 10mm tube.
I hope to work out a mod of this antenna for 6M.
Maybe as below???
Attachments
Last edited by a moderator: