Thread: A DTV antenna
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Old May 1st 09, 01:23 AM posted to rec.radio.amateur.antenna
[email protected] dfinn1@nc.rr.com is offline
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First recorded activity by RadioBanter: Dec 2007
Posts: 136
Default A DTV antenna

On Apr 25, 1:33*am, 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


Gordon, I installed a large radio shack "tagi" type TV receiving
antenna in my attic 10 years since the house came wired for it. I
pointed the antenna in the general direction of the transmitting
antennae in my area and received excellent analog reception even with
the 5-10dB attenuation that occurs with VHF and UHF from the wooden
roof with asphalt shingles. I even have a rotor but never had to
really use it.

Now, with DTV, the exact same antenna gives me excellent reception as
well, just as good as analog (but of course "better" due to the nature
of DTV broadcasts).

I think for DTV that uses both UHF and VHF, you should be able to use
the same antenna that you used with the analog system that used UHF
and VHF and (as you know) you will probably find that the digital
signal is better in any case. Whatever their technology, these are all
multiband receiving antennas and the spectra for DTV and analog TV are
much the same. There are no technical aspects that need to be covered
here because there really is no problem.

Regards,

73 de AI4QJ