Coax how long?

ttm

I'd like to set up a simple FTA system so I can primarily receive BBC RADIO 4, currently I pick it up on longwave but don't have broadband (will never happen here) so getting online is not an option.

My problem is that I don't have line of site to the satellite so need to put the dish way out in the garden, so the question is how much coax is too much?

steveon

Its a very hard question to answer, what exactly is blocking direct sight of the dish, have you had it tested???? Very often a dish can be placed on a pole somewhere on the house to help clear trees etc, Sat dishes will often work in some very deep hollows, Ive been amazed at some of the places Ive gotten signals having pulled up thinking not a hope here....

I have used lenghts of over 50metres and after that have encountered problems, I have used Line-Amps to help on very long runs such as 6storey buildings, the best advise is to use a high end graded cable such as CT100 or equivalent.

ttm

A neigbor up the valley was told they could only just see the satellite and I'm 50ft lower and more into the side of the valley. Tried on top of 30ft of scaffolding a while back and no luck. I really need to go across the valley which is about 100yards:( and even them on a telegraph pole (which I have).

I'll go up to the nighbors tomorrow and see what angle he is to the side of the hill in the direction the dish is pointing, then I'll see where I have to be in the garden to get a similar view.

steveon

Sat is up in space, you dont need to see it in order to receive it, U sure your not talking about terrestrial aerial system...

John mac

have you had a look at dishpointer.com ? just enter 28.2E astra and your location.

it will show you the distance and height of an obstacle, also which direction to point,

may help to survey your area and find best place for it.


.

ttm

steveon wrote: »

Sat is up in space, you dont need to see it in order to receive it, U sure your not talking about terrestrial aerial system...

Ah a member of the FLAT EARTH society

But lets make this simple. I live at the bottom of a valley about 2 meters above sea level the valley runs roughly North South, the side of the valley (East) rises to a hill 74m high and astra at 28.2E would be the other side of a 60m contor line when looking at the OS map. With an inclinometer and looking roughtly towards astra at 28.2E I make the angle from the side of the house to the top of the hill 38 degrees, if I go out in the garden that angle goes down to 20degrees but that then means a minimum 50m coax run - hence the question.

afaik to get a signal I need line of site to the satellite which at about 22degrees above the horizon I cannot "see" unless I position the dish in the garden.

Radio 4's fine on good old fashioned LW but the Beeb will eventually discontinue that service and I'd like to keep listening.

ttm

John mac wrote: »

have you had a look at dishpointer.com ? just enter 28.2E astra and your location.

it will show you the distance and height of an obstacle, also which direction to point,

may help to survey your area and find best place for it.


.

Handy site added to favorites but just confirmed that the satellite is where I thought it was - hiding behind a hill

fat-tony

Whereabouts are you located? Any possibility of UK terrestrial TV reception to your North?

ttm

fat-tony wrote: »

Whereabouts are you located? Any possibility of UK TV reception to your North?

I'm down on the coast in Co Waterford.

Don't have any terrestrial TV reception, no mobile reception and this time of year only see the sun in the garden for a couple of hours. Great spot though in the summer only yards from the beach.

I forget which satellites I managed to connect to in the past but they were more to the South than any of the Astra cluster. I managed to look up the angles set up the dish and with very little adjustment get a good signal and hundreds of foreign language programs. But pointing in the direction of Astra 2A,2B,2C,2D from the same mount point gets nothing even after hours of fiddling, you know the way you try even though you really know its not going to work :rolleyes:

Anyway I have a shed out in the garden in a location with a better "view" over the hill so the plan is to run an extension power cable out to it and set up a computer with a TV input, the FTA box and a dish and test it all. Once I know that works I'll either use WiFi to get the signal back to a computer in the house or buy some decent quality coax. Either way I want to see it working before I spend any money on it.

PyeContinental

I'll be interested to hear how your project goes. I would guess that with good quality cable (CT100, or maybe you could try CT125) you could use 100 metres without the need to amplify the signal.

There are inline amplifiers which don't require external power sources available which could overcome attenuation. Haven't tried one myself but worth experimenting with I would think.

You wouldn't need to run any power to the shed for the dish which would be nice. Maybe start with an 80cm or larger dish to help with getting as much signal as possible from the start.

ttm

Been a bad day for the "test" program. Dish I was going to use is damaged so using a tiny LIDL camping one and just managed to reprogram the "box" to display in German only.

So might go and buy a whole new system if I can at least prove to myself it will work.

Anyway same problem as before dispite checking neighbors dish orientation I'm still only getting what I think is Astra 1 which I think is higher in the sky than Astra 2? 25 degrees as opposed to 22 degrees. I know there would be a 5 degree difference in there location but think by now I would have hit Astra 2 as much be luck as judgement.

Plan B (there is a plan B really) is to splash out a whole 8euro on a analogue USB TV card for my laptop so I can test the whole thing out without the need for a mains supply and try across the river and if that works I really might need 100m of coax.

Edit> A new plan just sprung to mind and sunk again without trace:rolleyes:. I Thought I'd check the azimuth with the sun tomorrow LOL, time to check would be 9.21am but the suns elevation is about 4 and a half degees so it too will be hiding on the other side of the hill along with Astra 2 :P

PyeContinental

Yes, you're right about astra1 being at roughly 25.5 degrees above the horizon and astra2 at roughly 22 degrees for the waterford area.
How are you measuring the angle of elevation?

If you really are looking directly at a steep hill towards the south east, you're not giving yourself a sporting chance with the small lidl dish. You might as well make it easy for yourself and get a large 80cm dish or at least a 65mm dish which has elevation markings on it so at least you will be sure what the elevation is and you will only then have to worry about the horizontal plane.

It can get frustrating if you leave too many variables and just keep feeling around in the dark so to speak. I think your enthusiasm is probably making you go a bit too hastily when I think you probably need to go through things a bit more methodologically.

What is this 8 euro usb sat tuner? It could be just something else which adds to the confusion. I may be wrong of course, but it doesn't sound like it's going to be a quality item for the price.

By the way, have you read this thread? I know you probably are aware of everything but it might help to read over it. Try the other satellite maps website on it - you might find it useful in addition to satfinder.com

http://www.boards.ie/vbulletin/showthread.php?t=2055761436

Oh, I was thinking about this while cooking dinner and I realised that I know 100m of cable will work without amplification being needed because I remembered I had tried 100metres myself when first installing my dish - I had a 100m reel and used the entire cable while it was on the reel just to see if it worked at first.

Mike 1972

ttm wrote: »

Radio 4's fine on good old fashioned LW but the Beeb will eventually discontinue that service and I'd like to keep listening.

Not anytime soon

ttm

@PyeContinental

I've been through this all before and very methodically. Last time about 18 months ago I was trying nearer the house and closer into the side of the hill, then a windy night brought down my scafolding I was testing off so I gave up.

This time I thought I'd try again but as far out from the hill as possible and rough calculations seemed to show that I had a better chance this time as top of the hill is at about 20-22degrees elevation.

What happens each time is I set the dish up with a compass (yes I can use one) and then after making very small adjustments around the correct settings I find nothing however if I just keep moving South of East then I find Astra 1, in fact I could find Astra 1 just by pointing a dustbin lid in the sky its that easy to get a signal off it. Now as I can't imagine its anymore difficult to get a signal from Astra 2 (if its there for me to get) then I strongly suspect that the bloody hill is in the way

What I've done once I have a signal off Astra 1 is put a long string line sighting line out below the dish move the dish down 3 degrees then slowly in perhaps 20 or so moves stopping for a few seconds each time move the dish till I'm about 10 degrees more towards the East than my string line. So far moving backwards and forwards off this working mark (getting back to Astra 1 is very easy) I've not got a signal. I've even put the monitor I'm using to check signal strenght on a long vga cable so I can see it as I move the dish and I can't getting anything East of Astra 1. I've tried asuming that the satellite I can see is a number of different ones as that would change my starting point however still makes no differnce as as soon as I get a degree East of my working starting point there is nothing else I can see in the sky. Then just to be sure I went to two neighbors houses and checked the angles they were set at and could exactly duplicate the azimuth on mine and with a few degrees in any direction I get nothing at all.

Now I know I need a better dish (I have a bent 80cm one:() than the little LIDL one but as I said it picks up Astra 1 easily at 75% signal strenght or better if I keep tweaking it and move the LBNA I can just get over 80% signal strength so I can't see why if its available I can't get Astra 2.

Now if Astra 1 has a much stronger signal than Astra 2 a larger dish would be handy but I'm looking for proof of concept before I get another dish as I'm still not sure it will work where I am.

btw the angle is guessed at to start with but as I said easily finds Astra 1 then I use the inclinometer on orienteering compass to measure the 3 degrees down.

Hadn't read your post originally but it sums up much of what I have read online. After trying loads of sites online I've decided to stick with Satellite Antenna Alignment program which does the same as all the websites, only problem was it took me a while to work out my exact latitude and longitude.

Mike 1972 wrote: »

Not anytime soon

Yeh but I can only take sooooo much cricket :cool: and Radio 7 would be nice

John mac

ttm wrote: »

Yeh but I can only take sooooo much cricket :cool:

all day every day if it was on

Apogee

ttm wrote: »

What I've done once I have a signal off Astra 1 is put a long string line sighting line out below the dish move the dish down 3 degrees then slowly in perhaps 20 or so moves stopping for a few seconds each time move the dish till I'm about 10 degrees more towards the East than my string line. So far moving backwards and forwards off this working mark (getting back to Astra 1 is very easy) I've not got a signal.

When you drop the dish by 3 degrees, do the Astra 1 channels disappear?

ttm

Apogee wrote: »

When you drop the dish by 3 degrees, do the Astra 1 channels disappear?

Yes

PyeContinental

ttm, I like your phrase "proof of concept"
I like your method of finding a known position with astra1 and then moving relative to that. However, I think that this method might introduce a little more inaccuracy by moving relative to a point which you may not be exactly aligned to in the first place.

Also, when I checked the beam elevation for waterford city, here:
http://www.satsig.net/maps/satellite-tv-dish-pointing-uk-ireland.htm
astra 1 was 25.5 and astra 2 was 21.9 which is a difference of 3.6 degrees, so you could be out by around 1 degree which would make all the difference.

Regarding the ease with which you pick up astra1 - I have read that its signal is much stronger than astra2, so you are right about that.

I think you should buy a satfinder tool - you can find them cheap on ebay - like this one:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230414888156

If your dish has elevation markings on the back, find out your correct coordinates (look at the "where am I?/current location" page on a satnav or use the method I described about google maps) and put it into the satsig website. Lock off your vertical axis so you only have to worry about the horizontal and astra1 won't be confusing the issue then. Point the dish south and move it back slowly. Use that satfinder tool to listen for the squealing noise.

Apogee

ttm wrote: »

Yes

OK, I was just wondering if your elevation was a little too high, but it appears not. From what you've described, you have been fairly methodical in your approach and it suggests no line-of-sight to 28E.

You could try aligning to 23E using either of the following 2 transponder frequencies and it will give you a new reference point a little closer to 28E:
11914, H, 27500, Tv Noord
11836, H, 29900, SMD01

Alt to double check your LOS, you could use the Sun's azimuth and a homemade inclinometer:
http://bytelive.com/wiki/tiki-index.php?page=How+to+locate+a+satellite+using+the+position+of+the+sun

Or if you know someone with an iPhone 3GS, you can purchase an augmented reality app which maps the position of the satellites across the sky:

https://www.youtube.com/watch?v=5AFtcgYRcu4

fat-tony

ttm - I would agree that you are being absolutely methodical in your approach. The advantage in using a small dish is that it has a wider acceptance angle, so it's not so fussy as regards pointing accuracy. The Lidl camping dish definitely will pick up Astra 2, but the problem is that the signal drops off in rain. I think you should establish that you can see the satellite with the 35cm dish before going bigger. I believe that your calculations are correct and that Astra 2 is obscured, so you need to move the dish away from the house and provide the necessary height so it can see over the top of the hill. Set the receiver to a 2D transponder (one of the BBCs) and see if there is a flicker from the signal strength/quality meters on the box. You may need to invest in 50 - 100 metres of cable, though.

PyeContinental

fat-tony wrote: »

The advantage in using a small dish is that it has a wider acceptance angle, so it's not so fussy as regards pointing accuracy.

Ah, didn't know this.

Apogee, I saw that video on satfinder.com - it looks like such a brilliant invention and what an innovative use of the phone technology! I wonder how well it works in real life.

fat-tony

PyeContinental wrote: »

Ah, didn't know this.

When I went from an 80cm to 1.1m dish the difference was quite noticeable. The slightest nudge and you were off the sat. Obviously, the bigger dish pulls in more signal, so you have a bigger margin at the tuner to deal with rain fade and to pull in those low-power transponders, but the downside is that you need to be much more accurate with setup if you are motorising.

ttm

@ all replies, thanks guys. Current thoughts are that I'll get a sat finder in the new year before I try anything else.

At the same time (and also from HK) I'll get a USB video capture device (about 10euro) so I can have the laptop working as a TV screen and the whole lot in a wheel barrow (with porty II and 12V car battery). Then I can start down near bottom of our field (150yards away) where l'll be at the max distance from the hill, but if I get it all portable then I might as well start off on the beach with no obstuctions at all and if I can't get a signal there I can always give up :rolleyes:

In the mean time if the temperature outside goes up a bit I'll rig up something to make a really good guestimation of the angle of the hill.

fat-tony

Not sure what you mean by a video capture device? Do you mean that you want to capture the composite video from a set top box? Do you have a portable STB - you mentioned a Lidl camping dish? If you have the 12v Lidl STB then you should be on a roll:)
I hope there's no-one on the beach when you are playing around with your wheelbarrow-full of satellite gear:D

ttm

fat-tony wrote: »

Not sure what you mean by a video capture device? Do you mean that you want to capture the composite video from a set top box? Do you have a portable STB - you mentioned a Lidl camping dish? If you have the 12v Lidl STB then you should be on a roll:)
I hope there's no-one on the beach when you are playing around with your wheelbarrow-full of satellite gear:D

Yeh have one of the original Lidl Porty II 12Volt camping sat kits, I said video capture device but its essentially an analog TV to computer adaptor that takes a composite video in via a small box attached to a USB port and displays the "TV Picture" in a Window. You can get them in Maplins at 50 euro or more but I'll wait for the slow boat from China and get one for 10euro or less (inc P&P) from HK on eBay along with a sat finder.

PyeContinental

Yeah the image of you trundling a wheelbarrow with a satellite dish in it along the road down to the beach sounds hilariously surreal! :pac:

Why don't you buy a USB satellite tuner though instead of a USB composite/svideo capture device? That way you would only need the laptop and the dish and wouldn't have to trundle a car battery around with you. :pac: :pac:

ttm

PyeContinental wrote: »

Yeah the image of you trundling a wheelbarrow with a satellite dish in it along the road down to the beach sounds hilariously surreal! :pac:

Why don't you buy a USB satellite tuner though instead of a USB composite/svideo capture device? That way you would only need the laptop and the dish and wouldn't have to trundle a car battery around with you. :pac: :pac:

You can think about it all you like but no one will see me :cool: the odd seagull maybe .

Never thought about a USB sat tuner, found this at just over 20 euro might be worth playing with

But if I have use the wheel barrow it makes a nice soild mounting point for a dish.

ttm

PyeContinental wrote: »

Why don't you buy a USB satellite tuner though instead of a USB composite/svideo capture device? That way you would only need the laptop and the dish and wouldn't have to trundle a car battery around with you. :pac: :pac:

Good idea but suggestion needs a bit more research I'll still need the wheel barrow for the car battery and an invertor to run the 220V Power supply needed for the USB satellite tuner I knew that seemed far to easy an option.

fat-tony

Yes - the current draw at 13v or 18v for the LNB is too much for a standard USB port to supply, so you need an external PSU or at least a high-power DC source:(

ttm

Had a few hours sun this afternoon so I resurveyed everthing and tried a new approach.

I had a location I wanted to try but it wasn't the best looking as it was between two outbuildings and a little nearer the house than I thought would be OK but I had a vague Idea that my problem might be a group of tall pine trees on the top of the hill. So I did (more made up jargon here) what I can best call a man in the middle survey :rolleyes:

I went down to the nearest location with a working satellite connection and standing overlooking the dish took a bearing straight into the focal point of the dish.

I then went back to above our house (the road runs above it along the valley) and found the point where the angle was exactly the same as the one I'd taken from the working dish. So at this point I'm looking down the hill to my potential new dish location. I then looked along the back bearing (orignal + 180 degrees) so I was looking up the hill (this bearing should look straight at Astra 2). The lucky thing here was that half way up the hill is a small oak tree and my bearing took me to exactly to the left of the crown and best of all just to the left of the pines I thought might be the problem (note the oak tree was only half way up the hill and not part of the problem).

Next back to the dish and set up in new location. Gustimate dish inclination and point dish to the left hand side of the crown of the afore mentioned oak tree. Check on screen signal quality and I'm in at 70% without any tweaking. A couple of small movements of the dish and a twist of the LBA and I'm at 75% which is good enough for me, so download channels and low and behold its all working with Radio 4 (BBC R4 FM) comming in loud and clear.

So problem seems to have been that too close to the hill I didn't have line of site to the satellite at all and in the some of the other locations I tested there were Pine trees (on the hill top) in the way. If I'd carried on moving down the field I'd have been well over a 100m from the house before I got a view to Astra2 on the south side of the house but in the end moving back to the north about 12m did the trick.

So one more question? Looks like 30m of coax will do the job but it needs to go across the yard so can I burry it or do I need a special grade for that, it will be burried in a alkathyne water pipe?

fat-tony

Excellent news:)
As regards the cable - the main issue for that type of cable is UV degradation, so burying it in the ground, shielded by an alkathene water pipe should be fine. I've had that type of cable slung over my roof for 10 years without a problem. The worst that can happen if you bury it in the ground is that you perforate it at some time in the future. Even if you short it out, the receiver will handle it without too much fuss.

By the way - Happy Christmas!

ttm

fat-tony wrote: »

Excellent news:)
As regards the cable - the main issue for that type of cable is UV degradation, so burying it in the ground, shielded by an alkathene water pipe should be fine. I've had that type of cable slung over my roof for 10 years without a problem. The worst that can happen if you bury it in the ground is that you perforate it at some time in the future. Even if you short it out, the receiver will handle it without too much fuss.

By the way - Happy Christmas!

Yep, very pleased. In the new year will get a bigger dish, I suspect I only really need 60cm and I can firmly fix it in the gap between two buildings which suits me fine; thats partly because beeing on the coast the wind can be unbelievable and I always think its nice to keep sat dishes out of view as far a possible.

While I'm waiting for the new year and some new cable and new dish I might look into streaming the signal into the house via wireless or an ethernet connection.