Thread: A DTV antenna
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Old April 25th 09, 06:31 PM posted to rec.radio.amateur.antenna
K7ITM K7ITM is offline
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Default A DTV antenna

On Apr 24, 10:33*pm, Gordon wrote:
This seems to be the only news group devoted to the topic of antennas.
(and the origins of the universe). *So maybe you guys can help me
with this. *

I have been experimenting with fabricating a decent
indoor DTV antenna. *I have tried several things. *What I have
now is two bowties spaced about 7 inches apart on a wood dowel.
A peanut butter jar with rocks in it makes up the base.

It seems to give pretty good performance. It could be better.
*But I am wondering about a few things.

1) Right now all the digital transmissions are in the UHF band.
*but in 6 weeks, three stations will move back to their VHF
*assignments in the VHF high band.
*How well can I expect my antenna to work in that frequency band?

2) I have not trimmed or dressed the twin lead from the bowties.
* I understand that twin-lead can act as antennas. *So what
is the best way to manage the twinlead? Cut it back? I noticed
that when i laid the leads together, in an attempt to make a
neat assembly, I got signal cancelation.

3) Any suggestions to improve this design?

4) Any suggestions for alternitive DIY designs?

Thanks


If you search for "diy hdtv antenna" or "diy dtv antenna" you will
come up with other ideas. Someone posted a question a while back here
about a design that apparently is pretty forgiving and not too hard to
construct and is claimed to give decent gain; see
http://www.digitalhome.ca/ota/superantenna/.

Dave P's comments are good, though RG-8 is 50 ohm, not 75 ohm. Good
RG-6 type cable should work well for at least short runs, and it is
nominally 75 ohms. I don't know about your TV (or converter box), but
pretty much all the ones I've seen that receive digital TV broadcasts
have 75 ohm F connector inputs anyway, so you may as well go straight
to RG-6 at the source (the antenna).

Cheers,
Tom