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Aerial

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wullie    6

We have just bought a Moonraker and can't get a decent signal, picture comes and goes all the time, seems a waste of money unless i am doing something wrong.

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alan_fincher    1,850
On 9/13/2017 at 15:11, dor said:

I've used a wiggly wire Omnimax and it is not often I can't get a decent signal (particularly since the analogue transmitters were shot down), and then I can normally get a good satellite signal.

Seems a bit extreme!

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dor    272
Just now, alan_fincher said:

Seems a bit extreme!

Wishful thinking at the time maybe!

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Dr Bob    61
8 hours ago, wullie said:

We have just bought a Moonraker and can't get a decent signal, picture comes and goes all the time, seems a waste of money unless i am doing something wrong.

It would be useful if you gave some details...otherwise no one can help.

Info such as

What sort of pic are you getting with a yagi? If no yagi (ie first antenna) then where are you. How far from the TV mast? What is the terrain to the mast (ie by the Cape in Wawrick there is no chance of any signal as you are in a deep valley. Are there any other antenna around on houses? Long poles or short poles? Is the tv tuned to the right channels? I would bet my smartguage that you are doing something wrong!

As per my previous post somewhere back a page, we are using a yagi but now fed up with having to take it up and down and point it the right way, so bought a Moonraker last week. I got back to the boat on Friday but we were parked down Saltisford Arm (Wawrick). Last week I had a good signal on the yagi here but friday - parked next to a big tree- the signal was almost non existant on channel 107 (231)- BBC news HD, a weaker channel - No amount of aiming could get it better. Tried the moonraker for 10 mins in pouring rain and got a better signal with the anntena at the gunnel level on its side!!!! but no way to mount it there so went back to the yagi. Promising but not conclusive.

Last night we were parked near the 2 boats on the GU and both the yagi and the mooonraker gave 10/10 signals. I think here we are 47Km from the sutton coldfield mast so I would say a 'reasonable' signal. That means the moonraker will be good for 'general' use - ie mount it low so it goes under bridges and have it mounted all the time. Interesting though is that we are 32 Km from the Lark Stoke mast but no one seems to point it that way. Back to Napton today so will try it there. Signals there are (in my experience) poor to middling so it will be a reasonable test. I will report back tomorrow maybe with some pics.

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WotEver    687
31 minutes ago, Dr Bob said:

Interesting though is that we are 32 Km from the Lark Stoke mast but no one seems to point it that way.

If you compare the SC coverage map:

https://ukfree.tv/transmitters/tv/Sutton_Coldfield

With the Lark Stoke map:

https://ukfree.tv/transmitters/tv/Lark_Stoke/PGSTART110/

You'll see why :)

  • Greenie 1

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Dr Bob    61
8 hours ago, WotEver said:

If you compare the SC coverage map:

https://ukfree.tv/transmitters/tv/Sutton_Coldfield

With the Lark Stoke map:

https://ukfree.tv/transmitters/tv/Lark_Stoke/PGSTART110/

You'll see why :)

Very interesting link. Have a greenie.

.....but not convinced either mast is better if on the Gu between wawrick and Napton (apart from on the wrong side of the hill in Napton). When up at knowle last week it was impossible to get any signal with the yagi other than Lark Stoke which was almost due south and hence 'down the valley'.

Just arrived at Wigrams and got a good signal to SC on the yagi and a good signal on the moonraker when anywhere above the roof line of the boat. Most days here I can get a good picture on ch 107 (BBC news) with the yagi pointed at SC but not always so - the odd day the pic gets pixilated etc.......so that sounds reasonably positive for the moonraker. I think I will mount the moonraker on the pole that supports my 4G and wifi antennas which I put up and down each day but I need a longer cable - so off tomorrow am to buy a few coax connectors - then I can get the moonraker up in the air a bit. Looks like it will be worth the money if I can do it this way.

Any ideas which tv channels are broadcast at lower power - so I can try to compare the moonraker and yagi - its difficult to compare when all signals are good. Freeview ch 107 seems to need a better signal than 001 (HD vs non HD) - but are there any more difficult?

Edit- forget that last question - 'wotevers' link has the powers and ch107 is lower power than 231 (both BBC news). That gives me something to compare.

Edited by Dr Bob

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Dr Bob    61

If anyone is interested, I finally got my Moonraker up in the air and tested it against my yagi. They seem pretty similar in performance in our location today (near the winding hole nr the Folley in Napton). The yagi is pointed NW towards Sutton Coalfield mast 50Kms away. Pic below. The Moonraker got a good signal as soon it was above roof level but it needed to be orientated right - ie N/S/E/W but difficult to say which direction it is 'pointing'. Also seemed to work much better when horizonal as in the first pic (the moonraker is in the centre of the shot on the mast with the 4G and Wifi antenna). The yagi is a tatty old small yagi with one 'half element' missing.  The yagi couldnt get a decent signal on the Lark Stoke transmitter to the south.

The Moonraker seems a bit quirky about how to allign it. It certainly seems directional but less sensitive than the yagi and you have both vertical and horizontal polarisation as variables. I guess with a yagi, if you rotate it 360 deg, you will see a signal for 30 deg of that rotation. With the moonraker, perhaps you are picking up signals for 60 deg - but that maybe as it is picking up other masts that are broadcasting on the same frequency. I need to play with it more. I will try it each day (new location) against the yagi and see which is better. Happy today though that it is working as well as the yagi.

The 4G/wifi antenna are on a pole that just lifts out of a fixed pipe and lays flat on the roof as we cruise along.

The second shot shows that we are beaming over a hill to get the signal so surprised it is so good on either antenna.

IMAG0464.jpg

IMAG0465.jpg

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rusty69    366
27 minutes ago, Dr Bob said:

If anyone is interested, I finally got my Moonraker up in the air and tested it against my yagi. They seem pretty similar in performance in our location today (near the winding hole nr the Folley in Napton). The yagi is pointed NW towards Sutton Coalfield mast 50Kms away. Pic below. The Moonraker got a good signal as soon it was above roof level but it needed to be orientated right - ie N/S/E/W but difficult to say which direction it is 'pointing'. Also seemed to work much better when horizonal as in the first pic (the moonraker is in the centre of the shot on the mast with the 4G and Wifi antenna). The yagi is a tatty old small yagi with one 'half element' missing.  The yagi couldnt get a decent signal on the Lark Stoke transmitter to the south.

The Moonraker seems a bit quirky about how to allign it. It certainly seems directional but less sensitive than the yagi and you have both vertical and horizontal polarisation as variables. I guess with a yagi, if you rotate it 360 deg, you will see a signal for 30 deg of that rotation. With the moonraker, perhaps you are picking up signals for 60 deg - but that maybe as it is picking up other masts that are broadcasting on the same frequency. I need to play with it more. I will try it each day (new location) against the yagi and see which is better. Happy today though that it is working as well as the yagi.

The 4G/wifi antenna are on a pole that just lifts out of a fixed pipe and lays flat on the roof as we cruise along.

The second shot shows that we are beaming over a hill to get the signal so surprised it is so good on either antenna.

IMAG0464.jpg

IMAG0465.jpg

Sounds pretty good.Thanks

 

You could get a job at SETI with that lot.

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reg    62
On 13/09/2017 at 14:01, WotEver said:

It might be pretty and it might be simple to use but it can't possibly be as good as a decent log periodic. 

It's not just swapped my old 'real' ariel for a moonraker not surprised that irs not so good but all told it's a very neat little piece of kit. Easy to put up or remove when you need to. 

Little tip on some teles you can power the ariel via the tv so no need for the supplied 12v booster connector. Check your tv setup for, I think, something like active ariel on. If you do use the supplied connector then the active ariel should set to off in the tv setup. All explained in the supplied manual using the correct terminology unlike me. 

Overall pleased with it but it's not a miracle worker so will not compete with a real ariel. 

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Dr Bob    61

Another update on the Moonraker.

On Tuesday night we parked on the Summit pound (south oxford Br 129) so on the top of the hill. Best signal on the  yagi was Sutton Coalfield (now 60Kms away - a guess). The moonraker was OK but did show a bit of pixilation now and again. No amount of readjustment could get it to be as solid as the yagi. I think this was a marginal signal as SC is not any good further south. It would seem the yagi wins on these marginal signal areas.

Today we got to Croperdy (despite the huge queues with no water in the lock pounds) and Sutton Coalfield no longer available. Looks like we are on the edge of a number of areas with the houses pointed either at Oxford or Lark Stoke. Couldnt get Lark Stoke (same channels as SC) so beamed at oxford with the yagi and re-tuned. Good signal. Set up the moonraker and got very blocky pics apart from one setting where we got a good pic - equiv to the yagi - and that was by pointing the moonraker away from the mast and in a horizonal position! 

I think the summary therefore is that when in a medium to good signal area, the moonraker will work well in any position so can be just mounted permanantly above roof level. However when getting into a marginal area, the moonraker needs a lot of fiddling with - and it is not obvious which way to point it or whether vertical or horizonal is needed. In this case the yagi is better.

The problem though with the moonraker even if you know what transmitters are around - and you buy one for the first time - which way do you point it and do you need to retune?

I think I will use the moonraker as first choice antenna and put the yagi away but know I will need it as I get out of range (if I need the tv) and end up in a marginal signal area. The moonraker is seems a good buy BUT it doesnt have the performance of a yagi at the limits. This excercise has taught me how to look for the transmitters and need to retune.

 

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reg    62
Just now, Glynn said:

Does the Monraker need an electrical supply to work ?.

Yep, all explained in the manual without looking I seem to remember it is only about 5 v and takes very little power, plugs into a 12v socket or mains.I believe its called an active antenna but correct me if i'm wrong. You can get a picture without it in a strong signal area but that appears to a rare occurrence.

Have an ariel splitter installed for over a decade and always wondered what the red line on one of the connections meant, never bothered to find out but now I know its the connection to be used for an active connection.

 

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OldGoat    155
7 minutes ago, Nightwatch said:

yagi? Please.

If you mean "what is it" see post number 32 in this thread.

If something else - then I can't help

To answer Dr. Bob and others - there are Ofcom maps by TV region here (there may be other and better ones - please tell) -

https://www.ofcom.org.uk/spectrum/information/tv-transmitter-maps

All the main transmitters are in capitals and underlined and to receive a transmission from them you orient your Yagi so that the elements are horizontal and the moonraker vertical. There are a number of small local transmitters  which may work if they are very near where you are but for then you have the yagi vertical and moonraker horizontal. Success with these is often quite elusive...

UK Free has great maps but you've got to know which county the transmitter is

https://ukfree.tv/transmitters/locations/Freeview

For best results - even in a strong signal area use an aerial amplifier. I do - but then the yagi is on the bow and the tv at the rear of a 60 ft boat.

 

 

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Dr Bob    61
2 hours ago, WotEver said:

It's a single frequency log periodic. You'd possibly get better results with a log periodic. 

http://www.aerialsandtv.com/touringaerials.html

Coming from a Ham radio background, a yagi was to me a beam antenna with a driven element at right angels to the boom and then a number of shorter elements in front of the driven element and one or two reflectors after it. I would question Wotevers response as I used to use a 7 element yagi for multiple bands (10M, 15M and 20M) - 2 driven elements giving multiband tuning. A TV antenna is not really a yagi - but we always refer to it as it is. To be specific it is a log periodic which has a driven element (or more) and then a set of increasingly shorter elements that enable the antenna to tune to a wide bandwith. Lets just call it a yagi and not split hairs. Havent a clue what the real definition is.

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WotEver    687

log-periodic antenna (LP), also known as a log-periodic array or log-periodic aerial, is a multi-element, directional, antenna designed to operate over a wide band of frequencies. ... Electrically, it simulates a series of two or three-element Yagi antennas connected together, each set tuned to a different frequency.

From here:

https://en.m.wikipedia.org/wiki/Log-periodic_antenna

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reg    62

Now that we have covered the best Aerial subject here's a big, or stupid, question i've sometimes pondered over. Do radio signals ever die?

We can get signals from space craft at the edge of the solar system but how far do they travel.

 

ETA

Just to add thanks to this thread I now know how to spell aerial, been getting it wrong for years

Edited by reg
Cus

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Richard10002    173
18 minutes ago, reg said:

Now that we have covered the best Aerial subject here's a big, or stupid, question i've sometimes pondered over. Do radio signals ever die?

We can get signals from space craft at the edge of the solar system but how far do they travel.

 

ETA

Just to add thanks to this thread I now know how to spell aerial, been getting it wrong for years

The light from stuff that happened at the beginning of the Universe nearly 14 billion years ago is just reaching us today. I'd guess that radio signals have similar longevity, but I'm no expert.

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reg    62

So in 14 billion years time someone will be listening to Ed Grundy talking about turkey farming?

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Richard10002    173
2 hours ago, reg said:

So in 14 billion years time someone will be listening to Ed Grundy talking about turkey farming?

It would seem that Ed Grundy would be out there, but would probably be lost to the signal/noise ratio.

  • Love 1

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