Has anyone made a 300 ohm twin lead antenna?
Has anyone made one of these antennas for a single channel from 300 ohm twin lead? How well did it work? I want to get channel 3.
http://users.wfu.edu/matthews/misc/dipole.html |
They work well enough, but how will you mount it? They need to be "aimed" at the tower so it works best up on the roof and getting it on some kind of non-metal mount will be tricky.
One of these for real channel 3 will be just over 6 feet long. You can buy a low VHF, (assuming you mean real channel 3), antenna very cheaply, BTW. |
I have seen some people have supported them in a PVC tune and was thinking about doing that and suspending it in the attic where size wouldn't matter.
I currently have a Antennas Direct High VHF antenna and it picks up real channel 3 (~50 miles away) in the winter only. I pointed it at channel 11 (5 deg mag ~50 miles away) thinking I couldn't get 3 (260 deg mag) but after the leaves fell I could. So I am expecting to loose it again come spring. My zip code is 24503. What VHF Low antenna do you recommend? I have been looking at the Winegard HD7000R but it's only rated for 30 miles. |
Quote:
If you do add in a low-band VHF antenna, you'll still need to score an HLSJ in order to readily combine it with the rest of your setup and they're getting very scarce. I did find a listing on ebay, do a search for "CABLETRONIX HLSJ". I've not tested that particular one, but it should work based on the manufacturer's spec sheet. Quote:
If you have a suitable length of 2-conductor heavy electrical wire 12-14 ga, insulated or not) and a common matching transformer (https://www.lowes.com/pd/RCA-Outdoor...former/3724168), you can easily fabricate a simple dipole without trying to find twin-lead. Use two 4'3" sections of wire attached to a simple frame of wood or PVC with a 1-2" gap between them and attach each leg of the transformer to the inside ends of the gap with a simple sheet metal screws. Aim it broadside in the direction of WBRA, then adjust for best results. |
I have a DB8E with a VHF-1 retrofit kit.
Found a 100 feet of twin lead online at Fry's, ~10$ delivered. Would the twin lead or electrical wire be better? |
If you have a matching transformer (which you're going to need anyway) and some wire, why buy twin-lead? There won't be any difference in performance if executed properly.
|
What is the range on the Antennas Direct V4? I see two places that say 25 miles and the link ADTech sent says 55 miles.
|
It is my personal opinion that range numbers are an irrelevant but a necessary evil. At best, they're only a wild-a$$ guess. There are too many other variables that are actually more important than the antenna itself that are involved in determining if any given antenna is suitable for any given situation They're pretty much a lowest common denominator for folks for whom a mile is the only thing they can relate to.
|
2 Attachment(s)
I agree; mileage figures are only useful to compare different models of the same brand. What counts is how strong the signals are at your location, and putting it in the attic makes them even weaker. What good is a 55 mile antenna if you happen to have a hill five miles away that blocks the signals?
Quote:
Many years ago I was located between Richmond and Norfolk. In my attic I had a folded dipole or a 5 element single channel yagi cut for each channel. I had a 2-pole, 12 position ceramic switch with its shaft extended below so that I could select which antenna I needed. It worked very well. All the feed lines were 300 ohm twin lead, which is why I used a 2-pole rotary switch. At my next location, I only used the Norfolk channels. I had a 4-bay UHF antenna and a folded dipole for 13 connected to the original 7777 preamp that had separate inputs for UHF and VHF. The antennas were only 5 feet AGL, but reception was satisfactory. The UHF and VHF channels were about the same strength on my report, but 13 was weaker for me because of the lower gain of the folded dipole. At my present location I am closer to Norfolk and am able to use a GE 34792 Attic Antenna indoors at ground level. Channel 13 is again weaker because the GE antenna only has a single element folded dipole for VHF-High. The UHF section has more gain, so I can get PBS on 16 which has Create, one of my favorites. http://forum.tvfool.com/attachment.p...1&d=1486828373 You can suspend a twin lead folded dipole for channel 3 in your attic to see how it works. http://forum.tvfool.com/attachment.p...1&d=1486829832 Channel 3, 60 to 66 MHZ, center frequency 63 MHz 5540/63 = 87.9 inches length for a folded dipole antenna |
1 Attachment(s)
To convert the dipole antenna into a 3 element beam for more gain, add a reflector and a director:
Wire Reflector, 92.3 inches, Wire Director, 83.5 inches, dipole to reflector spacing is 37.49 inches dipole to director spacing is 28.12 inches http://forum.tvfool.com/attachment.p...1&d=1486848071 |
On channel real 3 I got 4 out of 10 signal strength with the twin lead and matching transformer mounted on a piece of wood in my den, in a brick house looking out a window. I am assuming it will drop some in the attic and summer with leafs also.
Is it almost certain that something like the AD V4 will work better? ADTech, you mentioned the V4 is a cut to channel antenna, do you trim all three components? What is the difference between the V4 and Winegard HD7000R? Is there an advantage to a full wavelength vs 1/2 wavelength antenna? I found a well priced VHF High and Low combiner. https://www.solidsignal.com/m/product.aspx?p=zhlsj |
1 Attachment(s)
Quote:
Quote:
Quote:
Quote:
http://i496.photobucket.com/albums/r...psrxqzi62s.jpg http://i496.photobucket.com/albums/r...psfnpknksg.jpg http://i496.photobucket.com/albums/r...urrentFlow.jpg We also see fullwave elements in UHF and VHF loop antennas. Think of it as a folded dipole that has been opened up to form a circle, rectangle, or square. The folded dipole has two halfwave wires connected at the ends. The most interesting fullwave loop antenna is the element used in Antennas Direct UHF antennas. Think of it as a fullwave dipole that has fat ends to increase the bandwidth, the way that whiskers increase the bandwidth in the bowtie antenna. Then, imagine that the ends are bent up to meet each other and join. This creates a tapered loop. Don't make one to sell, Antennas Direct holds the patent. http://forum.tvfool.com/attachment.p...1&d=1488153777 Instead of a 3 element ch 3 yagi, you could make a 3 element quad antenna, with 3 fullwave loops, 1/4 wave on each side, about 45 inches. The director loop would be a little smaller and the reflector loop a little larger. |
Quote:
I see that you have a previous thread. It would have been better to add your question to that thread instead of starting a new one, which would give us the background information, making it easier to help you. Reception Help http://forum.tvfool.com/showthread.php?t=16134 and the report http://www.tvfool.com/?option=com_wr...dfaf2e0205f846 It was suggested that you try for WVPT PBS on channel 11 with a VHF-High antenna that has more gain than the VHF dipole kit for your DB8e. Did you try that idea? |
Since then I have found out they have different programming and decided to go for both. Sorry this went from a a question about the twin lead to a lot more.
|
Quote:
Quote:
WBRA http://www.rabbitears.info/market.ph...&callsign=wbra WVPT (my favorite; Create with travel and This Old House) http://www.rabbitears.info/market.ph...&callsign=wvpt Please let us know how it works out, on this thread. |
All times are GMT. The time now is 5:41 PM. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © TV Fool, LLC