Home Made Dipole

[hdtv4dummies]

I need some advice on a home made Dipole antenna for the following reasons:

I am in 21054, Gambrills MD. Several years ago, before HDTV, I installed a rather large antenna in my attic pointed towards Baltimore. It did a bang up lob of receiving Baltimore stations and the major Washington DC stations. It also did well at receiving digital after I got my converter boxes.

However there was one station, WNVC, 30.1 thru 30.5, 32 miles away in Merrifield VA that was marginal upstairs and did not get thru at all downstairs.

There is a splitter in the attic. One legs goes 25 feet to an upstairs to analog tv with a Zenith converter. The other leg goes downstairs 60 feet with another splitter for a digital tv and another analog with a Zenith converter. I used RG6 quad coax everywhere.

To get a stronger signal on ch 30, I replaced the splitter in the attic with an ancient Radio Shack dual output signal amplifier. Channel 30 went away completely. I took it out and put the splitter back, fed with newer 12 db booster, made by Phillips I think.

Same problem. I replaced the Phillips booster with a brand new 10 db RCA booster from Lowes, with the same results.

I noticed at times ch 30 would come in briefly with no direct between the coax and the antenna. A pretty strong signal was being picked up by the wiring alone. I deduced that a stong signal from a UHF station 5 miles away was overloading the el cheapo signal amplifiers.

I scrounged around in my junk and found an old freebie type dipole antenna traditionally made from 300 ohm twinlead like this one: http://www.wfu.edu/~matthews/misc/dipole/dipole.gif
The length was 65", probably made for an FM receiver.

I stretched out dipole, taped it to a board and temporaily stuck it in the attic. I hooked a balun coil to the downleads and fed it into the splitter after disconnecting the existing antenna.

Now I get chanel 30 fine both upstairs and down, on the old analog TVs and the Aquos digital TV.

I can "almost" receive WNVT, ch 30.6 to 30.10, which is 50.3 miles away at nearly the same heading as it's sister station, WNVC. With a little more oomph I could pull it in.

My question is how can I improve on this antenna a tad to get the weak WNVT signal?

I was thinking of doubling up on the T shape arrangement and making it like an H shape to double the signal.

Or just double the length hopefully double the signal.

Or make it in the H shape with the second loop shortened to the WNVT 704 frequency length, which would be 16.77" for a full wave length or 33.5" for a double wavelength.

I am not too sure of the WNVT frequency, Another source says it is ch 24, 566 - 572 mhz,
20.75" wavelength.

In any event, I am removing that monster in the attic to make room for the dipole. Maybe I can unload it on Craigslist.

Gramps

[tigerbangs]

Yours is a classic case of trying to amplify your way out of a reception issue. An antenna fixed in an attic, aimed in one direction, can't be expected to pick up from all directions, and, as we have learned from countless experience, attics and antennas are highly incompatible partners. Had you chosen a roof-mounted antenna along with a rotator and a small distribution amplifier, you would have gotten the station that you were looking for and a lot more. I'm glad that your kludge worked for you, however.