[Aavso-sid-list] Re: 20' Vertical Antenna "First Light"

[ChrisAtUpw at aol.com]

In a message dated 14/02/2006, samouce2 at netscape.com writes:

Yesterday I  replaced the inside loop antenna with a free standing, 20 foot 
vertical  antenna connected to the Stanford SID Monitor.  
To construct the 20' Vertical Antenna the following  materials were used:
1 each 20' length, 1", schedule 40 PVC  (white)(cut off flare and make cutout 
to expose conduit)
1 each 1" cap for  above
2 each 10' length 1/2" metal electrical  conduit (the antenna)
Hi Dusty,
 
    You would probably do much better to buy copper  water pipe. You can get 
it in straight lengths and in soft coils. If you can  only get coils, you can 
'unroll' the coil nearly straight. You  then clamp one end, pull and twist the 
other end to straighten and  harden the copper. It may be an advantage to 
varnish the copper before  use.

1 each coupler for conduit (after clamping cut off excess screw and  nipples 
so that it fits inside PVC)
1 each 10' length, 1 1/4" plastic  conduit (gray) (cut off flare and make 
cutout to expose  conduit)
    You need to protect the joint from the  weather.

1 each 4' ground rod (Radio Shack # 15-530)
1 each grounding block  (Radio Shack # 15-909)
couple feet aluminum ground wire (Radio Shack #  15-035)(between rod and 
block)
    Consult ham radio recommendations. This doesn't  sound long enough to me. 
You can use PVC covered copper cable in a X.

silicone tape (orange)(Radio Shack # 64-2336, a discontinued item so  buy it 
if you can find it)
    You can buy self amalgamating black rubber tape. It  is very good for 
external use.

Pix one shows closeup of antenna base where lead attaches (note  cutout).
    You need two right angle connectors and a straight  connector to give an 
inverted U to keep rain out of the vertical connecting  pipe.
 
Time will tell if it can stand up to an ice storm without guy  wires.
 
    I would not wait for a disaster! Use three guy  cords attached at about 
2/3 full height. This will prevent the pole from  oscillating in the wind.
 
    Regards,
 
    Chris  Chapman
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