View Single Post
  #2   Report Post  
Old February 1st 04, 08:45 PM
Tarmo Tammaru
 
Posts: n/a
Default

If you want to use 300 Ohm twinlead, you should make a folded dipole out of
300 Ohm twinlead, not a straight dipole out of single conductor wire. You
are using 300 Ohm transmission line with a 75 Ohm antenna and losing some
signal.

When using twinlead, you need to keep it away from all metal ( at least a
couple of inches), and twist it about one twist per foot.Do not tape it to,
or run it inside a metal pipe.

Tam/WB2TT
"Caezaar" wrote in message
om...
Trying to pull in TV channel 46 for an afternoon superbowl viewing.
To make a temporary antenna, Here's what I did:

1. figured that Channel 46 is roughly 665mhz
2. Divided 496 by 665 and came up with 8 3/8 inch length
3. Screwed TWO 8 3/8" pieces of electric fence wire to a 2x1x1/2 wood
block
3.5. (Made the wires face away from each other as straight as
possible)
3.6. (The distance between the screws is approx 1/4 inch)
4. Ran 50 feet of 300 ohm coax attached with one pole wire to each
lead
5. stuck a cork in the end of 12 foot electric conduit pipe
6. fixed the assemply to the cork by running a screw through the
middle of the 300 ohm insulation about one inch below the wood block.
7. Attached the pole to the chimeney with a bungee
8. Spun the antenna for best reception (seems to point at repeater)

Noted that reception is marginally better than using a Radio Shack UHF
antenna inside the house. Reception seems to be sensitive to
placement of the 300 ohm coax.

Anything I could have done better? Tips hints?

Thanks all.