My own construction, 23dB gain, motorized aerial

[iggy]

Hi guys, I wasn't sure if this is right place, but it seems appropriate

My own construction, 23dB gain, motorized aerial. Camera installed underneath to control position.

It is capable of receiving signals from 130 km distant tv transmitters, e.g. Czech transmitter located on Lysa Hora mountain.

 

[rolfw]

Pretty impressive iggy, the windage on that unit must be massive, do you get any movement?.

 

[Analoguesat]

Oh very nice - I used to enjoy terrestrial tv dxing back in the days when the ITV regions carried different programming. My setup want as fancy as that though - it was a battered second hand aerial hung out the bedroom window on washing line!



I managed to get Dutch TV on it once during a lift from north of Birmingham

 

[Hixxy1]

I've heard of people picking up Dutch DTT in Lincoln. It's a bit of a mission as they only use 10kw but are also vertically polarised which helps quite a lot.

Good setup there Iggy. Are you using any amp stages like a masthead amplifier or launch amp?

 

[iggy]

Well, I am always feeling bit concerned when massive winds blow, but luckily my system survives them all. What I do is aligning aerial with wind direction, so that the impact isn’t that destructive.
My record is Berlin Alexanderplatz, more than 529 km Pictures below

Good setup there Iggy. Are you using any amp stages like a masthead amplifier or launch amp?

I am using LNA-177 30dB amplifier, mounted directly on dipole

 

[RimaNTSS]

Great stuff iggy! When I get satisfaction from SAT TV, will probably pay more attention to terrestrial. I like camera you have installed under antenna. What kind of camera is that? And how do you turn your antenna?

 

[iggy]

Great stuff iggy! When I get satisfaction from SAT TV, will probably pay more attention to terrestrial. I like camera you have installed under antenna. What kind of camera is that? And how do you turn your antenna?

Regular VGA camera with IR reflector. System is rotated with manual controller. You can google out some details on it - AR-303

 

[popovp]

Happy New Year!
Some analog & digital(DVB-T2) channels(last 3 photos) receivable in Varna from Ukraine(Simferopol) abb.530 km.
Antenna - remote controlled rotating antenna 20-28 dB gain - modificated(two 5-elements arms up&down added)

 

[mouse3]

This it s my homemade UHF aerials for Bulgarian digital DX-ing.It was one summer project,3 months of hard working.

 

[mouse3]

Reception from Shumen and Russe,channel 26 and 28.

 

[hairybadger]

This it s my homemade UHF aerials for Bulgarian digital DX-ing.It was one summer project,3 months of hard working.

Hi - I understand how you calculate the length of the driven element, but how about the directors and reflectors? Idem for their shape. Is it a matter of educated guess and trial and error?

 

[hexah]

This it s my homemade UHF aerials for Bulgarian digital DX-ing.It was one summer project,3 months of hard working.

That is brilliant. Well done!



I just wish they would bring back Band I transmissions.

 

[mikeisyou]

Interesting stuff guys, is it possible to use a satellite dish as a terrestrial UHF antenna?

 

[hexah]

Interesting stuff guys, is it possible to use a satellite dish as a terrestrial UHF antenna?

It is easier to buy a parabolic uhf antenne like this 120cm AN6111K from Engel Axil.

The principle is the same as a satellite dish except the signal is reflected back to a small log periodic. The feed line goes up the pole and in the back along the feed arm to a connection point where there is a small masthead amplifier built in. It is similar to the barrel types used for the active antenna concept developed by the DVB organization and only really used on the continent.

The f/b ratio iirc has been given at around 30dBi.

This is an old and well proven design. You can stack a pair or make a quad but anything more is unrealistic for most people due to the wind pressure.

They must be installed with free space behind as reflections e.g. from being installed on a wall will interfere with the wanted signal when amplified.

Probably the biggest mistake people could make would be to have too much amplification at the masthead because it will amplify local electrical noise and cause annoying dropouts or hide the weakest signals. The masthead amplifier provided is poor anyway and replacing it with a known good unit from e.g. Vision or Proception would be a great improvement. Antiference still makes grouped mastheads and they can be used to avoid strong out of group signals from interfering within the masthead or receiver (the barn door effect).

 

[peeter3000]

ot:
the best antennas for DX is 4x Triax Unix 100 E21-50 ,stacking together with Triax comb.741 (loss 0,3d +amp.
I have been using this in Tallinn now about 5years.

 

[Channel Hopper]

Interesting stuff guys, is it possible to use a satellite dish as a terrestrial UHF antenna?

The dipole is simply a receiving device which becomes efficient at the VHF and UHF frequencies when the prongs are of the correct length. A parabolic antenna is nothing more than a focusing device. Combining the two will give you something that can be used in much the same way as a yagi, though buying new will cost more than an off the shelf aerial.

If you can source a decent sized dish for pennies then you have the beginnings of a good directional receiving system. The downsides are the cost of changing polarity, susceptibility to winds and with that the potential cost of safe motorising, which is why the military have usually gone down the phased array yagi designs for most frequencies up to L and S band, or 2-4 GHz

http://www.ausairpower.net/APA-Rus-Low-Band-Radars.html

 

[hexah]

the best antennas for DX is 4x Triax Unix 100 E21-50 ,stacking together with Triax comb.741 (loss 0,3d +amp.
I have been using this in Tallinn now about 5years.

The X elements on the Triax Unix can be a problem, they can crack, fall off or catch the wind or snow. They are not popular here anymore.

Here people prefer Antiference or Blake. The X elements are round which deflects the wind much better. Remember we have big wind storms like hurricane bawbag.

Blake uses solid round X elements and their antenna of the same size is heaver than the Antiference which uses hollow X elements (I own both).

Wisi used to make low windage high gain aerials with compact reflectors and round elements. And some good grid antenna with directors for quad stacking.

Kathrein made an excellent combiner. It might be the same as the Triax with a different label.

 

[mouse3]

Hi - I understand how you calculate the length of the driven element, but how about the directors and reflectors? Idem for their shape. Is it a matter of educated guess and trial and error?

I found that atx-91 it s expensive here,so, do it yourself.
So,no problem with calculations,but lots of working and precision it s not the last.

 

[hexah]

The atx-91 would be similar to the JBX21 by Blake but the JBX21 would be many times stronger with thick plastic and solid round X elements.

www.blake-uk.com/jbx-multibeam-freeview-tv-aerial/191-jbx21wb.html

 

[mouse3]

Intresting antenna,jbx21 but very expensive there,one hundred pounds.
Here with post and package atx 91 its little over 40 euros,made in Poland.Hurricane and strong wind are not available in Transilvania.
It s the last think i want, replace each year antenna after storm season.Better i replace wife,it s free.