Hi all , could you have a look at these aerials and tell me which is the better one of the two for performance , as i can't work it out . aerial_1aerial_2
looks like 6 and half a dozen to me, the 1st one has bigger prongs so would probably pick up better. the one I have is like the 2nd one and does a good job
Don't get the first one.If you scratch yourself on the prongs, and it goes septic,It could be the worst case of vanaireal disease you ever caught Sorry couldn't resist it .
------------- Corpogreen esq
dead horse
and
donkey buyer
I would suggest you would be better off with a standard yagi than either of those. The difference between them is the way they quote the gain figure. dBi means decibels isotropic. An isotropic aerial is a theoretic device as it can't exist in reality. The 28db gain aerial is claiming an unrealistic gain figure. To be meaningful they should quote gain compared to a standard 1/4wave dipole.
Go for a good standard yagi like you'd put on the house. There really is so much waffle talked about aerials for digital tv these days and most of it is in an effort to sell people things they don't need and profiteer from the digital switchover.
If you happen to live miles from a transmitter in a poor signal area you may need some extra hi gain monster of an aerial but for much of the UK a piece of damp string will usually do! Also remember that aerial amplifiers amplify signal which is wanted but they amplify noise too and this is definately not wanted.
I'm actual in the trade, these aerials are fine if you live / camping in a good signal area. For all areas I use a Fracarro Sigma HD aerial which is good but are expense for non trade in-excess of £48.
To try to explain aerial gain I refer to the aerial in the picture in digisatmans post.
The actual dipole aerial (the bit that does the work) is the bit with the wire coming out of it. The V shaped bit behind it(nearest the pole mountng) it is called the reflector. The 5 elements in front of this are called 'directors'
The more directors you have the better the gain of the aerial. The 5 element Yagi in the picture will have less gain than a 12 element yagi. By adding more directors and thus increasing the gain of the aerial you also make it much more directional because there is no such thing in life as a free lunch. This means it has to be pointed at the transmitter more accurately to take advantage of the extra gain.
The Sigma has 17db gain which equals a aerial twice it's size, 4.1db more than one you quote & 14db more in the Front-to-back ratio ( stops unwanted signal come in from the side)
Quote
By adding more directors and thus increasing the gain,
In this case the directors are designed as a circle check out the link below
Fracarro code 213201
Elements n° 6
Band UHF
Channel E21 – E69
Technical characteristics
Bandwidth MHz 470 – 862
Maximum gain dBi 17
Front-to-back ratio dB 32
Return loss dB -18
Beamwidth (-3dB) ° +/- 18
Impedance Ohm 75
Mechanical characteristics
Dimensions (L. x W.) mm 920 x 625
Maximum mast diameter mm 60
Wind load at 120 Km/h (720 N/m2) kg (N) 23 (225.4)
Connector Type F Link
PS
And as a laugh I actually showed the Fracarro Marketing manger from Italy the photo from above only last week at one of there Dinners He loved it & asked for me to forward him the said photo.
its 17dBi!! dBi gain means better than an isotropic radiator - a meaningless technical figure! this is also quoted as the maximum gain. It states bandwidth of 470 to 862Mhz. At what frequency is the maximum gain figure achieved? Channel E21 to E69 is just another way of quoting the bandwidth as each channel number equates to a spot frequency. If it didn't have a reasonably high front to back ratio it wouldn't be a yagi (this means if you point a signal at it from the wrong end where its supposed to be bad) its something like a hundred times worse than if you send it to the front (where its supposed to be good) All tv antennas are 75ohm and the rest of the figures are about how much it weighs and stuff!
Sorry mate i wouldn't pay 40 odd quid for that when something costing 8 quid would give similar results.
Peak gain is at 840Mhz. It has reasonable gain over quite a wide bandwidth too. Doesn't look a bad aerial. Thanks for the info.
Not sure whether I'd be willing to pay 48 quid for it though. Given that you can get a satellite kit from Aldi for under 60 quid including dish, dish finder, satellite reciever, scart lead, cables and a carrying case. Once you have that you can forget whether the area is digital or not and forget constant re-tuning as you travel about - just point your dish at 28.2 and go!
Hi. I'm not getting into the technical arguments about dbs and all the rest of it. I would just mention that the 20 element one is, it states, amplified. If you read the advert, it says that you will very probably need a power supply for it = more money.
Hi Dave8858 and Digisatman , thanks for your input , it's most interesting to read both your views and it helps to know your in the trade , although i don't fully understand these aerials , i now have a few options to look at . I do have a suitcase satellite from Aldi , but it has a flaw , if it's windy the plastic dish gets blown about causing picture loss, no matter how tight i have it done up .
I usually stick Aldi dish to the car roof Wizard. It has a perfectly stable suction mount. I have an iphone app which gives the rough heading for the satellite ( a compass will do) and then use a satellite finder to get the best signal. It can all be done in under 5 minutes.
I'm going to France in September and for that I have a tripod arrangement on which I can mount a bigger dish (needed if you go further south than northern france) but same drill point it at the satellite and go. No tedious re-tuning of the TV once you've found the satellite you've won.
Then again you could use the internet. Glad you found digisatmans and my views on this subject informative.
Hi Dave , i have my dish pole mounted on the side of my caravan , the problem is with the ball socket that connects the dish arm to the pole . If i tighten the socket up tight it bends the plastic arm , and even with it pretty tight the dish still gets blown off position if windy .
Lining the dish up wise , i'd say it takes me about 60 seconds or less , i use a compass to give me a rough idea where to point the dish , then with the sat box on i select one of my channels from my favorites and press the info button , this then shows me the signal quality and strength , it's just a matter of turning the dish till the percentage goes to it's highest .
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Topic: Caravan aerial which one ?
