On 30-Oct-02 g3ldo wrote:
I had a similar experience to Mike this afternoon. While running the 72kHz
transmission I noticed that the support insulator support cord near the
loading coil had parted and the antenna was held only by the lead from the
coil to the insulator. I found that the nylon cord had burned through. I
switched off the transmitter and replace the coil with a length of copper
wire to support the insulator.
Nylon is not a good insulator for outdoor use. It's higly higroscopic, moreover
braider cords are like sponges.
Now I use monofilament nylon rope, like fishing line, some 3 mm in diameter
but it's impossible to knot, you must use steel clamps.
For end insulator polycarbonate is not higroscopic and selfextinguish (correct?)
it can be worked like metal and can be bended up to 90 degree using bending
machine.
You can test polycarbonate using a lighter, perspex and polystirene burns
polycarbonate not.
73 de Claudio, IK2PII
----------------------------------------------------------------------
Claudio Pozzi http://www.qsl.net/ik2pii happy Linux user
E-Mail: Claudio Pozzi <[email protected]> <[email protected]>
Date: 31-Oct-02 Time: 17:57:09
This message was sent by XFMail
----------------------------------------------------------------------
| 