Built my own digital antenna but having issues with it

take everything

Hi
I built my own antenna (from a YouTube video) and it worked straight away on the first scan.
I was delighted with myself.

For some dumb reason I switched to a (powered) external antenna (that I remembered i had and dug out) in the last few days and since I've tried to switch back to the built one I can't get anything. The reason I prefer the built one is its simplicity (not powered etc).

I can post the YouTube video to show the setup.
It's basically a piece of wood with an array of bent hangers at regular intervals screwed into it and copper wire crossing at 2 points leading to a transformer jobbie connected to a coaxial cable to my combibox.

Anyone know what might be the problem.
As I say it worked great initially.
Thanks.

Sam Russell

I would say a connection has come loose. Examine it carefully.

winston_1

Aerial design is complicated so you cannot expect a youtube video to work.

Also note there is NO SUCH THING as a digital antenna.

take everything

winston_1 wrote: »

Aerial design is complicated so you cannot expect a youtube video to work.

Also note there is NO SUCH THING as a digital antenna.

I don't know why I put digital in my post tbh. I know there's no such thing.

The antenna worked for weeks without an issue.
I switched to the bought one a couple of days ago (which is powered) and the minute I switched back, nothing.

Thurston?

take everything wrote: »

The antenna worked for weeks without an issue.
I switched to the bought one a couple of days ago (which is powered) and the minute I switched back, nothing.

Have you got your homemade aerial in the same place as when it was working, aligned the same & for the correct polarisation?

take everything

Thurston? wrote: »

Have you got your homemade aerial in the same place as when it was working, aligned the same & for the correct polarisation?

Yeah

Edit:
This is the video

https://www.youtube.com/watch?v=jRW0OCd7LJI

Thurston?

It's a DIY version of this kind of aerial.

I take it you've checked the connections at the balun (the 'transformer jobbie'), & made sure the wires linking the dipoles aren't shorting where they cross?

If you've made a reflector like in the video, maybe it's moved in relation to the dipoles, compared to where it was when the aerial was working?

TAFKAlawhec

Where is the DIY aerial located? If it's in an attic, it's possible that a connection has either gone loose or short-circuited e.g. one of the elements has dropped touching the element below. Also check to see that the plug is not loose at the end of the downlead, or that there is an intermittent loose wire in it.

Aerial design is complicated so you cannot expect a youtube video to work.

It's only as complicated as you want it to be with respect to getting the best gain & directivity you want over certain frequencies. Simple dipole & whip aerials are hardly cases of complicated design, and there are enthusiasts who make and design more complex designs, one example being the Gray Hoverman. Though most high-performance DIY aerial designs tend to originate from North America where unlike most of Europe, broadcasters don't tend to co-locate their transmitter sites and thus reception from more than just one direction is often desired - so the likes of the phased dipoles that the OP has constructed (names over here include Fireguard, Grid and Colour King for this type of aerial) and Gray Hoverman aerials are often used because of their broad forward lobes and reasonable performance over the UHF broadcast band (and if the reflector is removed reception from behind is improved at the expense of some forward gain, giving a figure-8 reception pattern).

Oscarziggy

take everything.
Good on you having a go at constructing an antenna

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I hope you find out what has since gone wrong and have the pleasure of it working again.
I assume that when you switch back again to the "powered one" your pictures are restored?
If not, then you may now have a faulty TV/Set top box.?
Regards

MenloPete

Could it be that you have a setting for Powered/Unpowered on your TV or STB?

take everything

Oscarziggy wrote: »

take everything.
Good on you having a go at constructing an antenna

---

I hope you find out what has since gone wrong and have the pleasure of it working again.
I assume that when you switch back again to the "powered one" your pictures are restored?
If not, then you may now have a faulty TV/Set top box.?
Regards

Aw thanks.
I was chuffed to bits when it worked first time tbh.
I’m using the powered one and it’s working fine.

I never got the diy one to work again. Even after putting a bigger reflective back on it. I also made sure the crossing points weren't touching by replacing the tape between them. I’m pretty sure the balun contacts are fine. I have actually slightly moved two of the screws (maybe 5mm) because they were coming out which may be an issue. Does the geometry have to be exact. The placement of the screws now is slightly less symmetrical I have to say.

Also i’m not sure if the relative placement of screw/hanger/copper wire has to be a certain way. Can anyone advise on this. Because even when it worked the placement wasn’t perfect. And there has been a slight bit of movement since (hangers are always still contacting copper wire though).

Just to answer one of the questions above: I had it in the garden hanging from a rail by twine. It was a bit of a sight so I might go back to the powered.

MBSnr

^^^
I built the below which seems to be the same thing more or less. My mistake was not taking the connection to the TV from the centre. Once I changed that, it worked fine. I did stupidly turn on the powered aerial setting on my combo box..... which with that aerial blew the internal fuse on the motherboard in the unit. Still works ok though. I run 3 devices off it with no amp fine. Mine's in the attic.

http://uhfhdtvantenna.blogspot.ie