Televes or fracarro?

[Red alert]

So you want to receive 30 West as your most westerly satellite now, and not 7 West, as stated in your opening post?

Maybe you could also setup motorized til 7W, and add a separate dish for 30W at a suitable location?

What part of the house and the (garden) ground in the picture are actually yours?
Must the dish be on ground level, or can you fix a pole to front or back of your house (high up the wall? Or maybe at the roof)?
(For 30W you need about 24 degrees elevation, according to the dishpointer LOS calculation.)
I'm thinking if there might be alternatives for a >2.5 meters pole, which would not be ideal if not fixed to a wall I guess.

Greetz,
A33

I would like to receive upto 30 West but probably pushing it. If i can get upto 15 west that is fine also. The dishpointer screenshot where i have added the point is the closest I can put the pole to my neighbours garden. From that point I am approx 1.5m away from my neighbours fence. Initially I thought I could have it installed on the wall at the front of the house lower on the wall but the neighbours wont be very pleased. I'm not good with heights so cant do above gutter or roof installation. I hope if the pole is 1m below ground and sticking above the ground by 2.1m I can see the western sats upto 15 West, which I dont mind. If I had a south facing garden I would have no issue putting the dish on the wall as wont have to go so high.

 

[jeallen01]

@Red alert
Rember you can "legally" (IIRC!) have both a 1m dish "anywhere" and also another much smaller (someone please remind me of the max dimensions!) - so you could possibly have a 1m steerable dish on the front wall and that "smaller" dish for 30W "somewhere"(all the major and strong transponders can be received on a Zone 2/60cm, and a Zone 1 dish would probably still get most of those).

 

[Red alert]

@Red alert
Rember you can "legally" (IIRC!) have both a 1m dish "anywhere" and also another much smaller (someone please remind me of the max dimensions!) - so you could possibly have a 1m steerable dish on the front wall and that "smaller" dish for 30W "somewhere"(all the major and strong transponders can be received on a Zone 2/60cm, and a Zone 1 dish would probably still get most of those).

The other thing is my missus dont want 1m dish at front of house, says will look ugly so garden only option. I could probably enforce it with a brace to the fence post. We have a sky dish at front of house so I can move that to 30 west. We will probably have the dish at 13 east most of the time so hopefully height of pole wont be a problem.

 

[jeallen01]

@Red alert
... and also another much smaller (someone please remind me of the max dimensions!) - ....

"Reminded myself" - this is what the planning regs used to say about dishes:
"if you are installing two antennas, one is not more than 100 centimetres in any linear dimension, and the other is not more
than 60 centimetres in any linear dimension (not including any projecting feed element, reinforcing rim, mounting and
brackets)"

Don't think that has since changed, and it would mean that the dish on the front of the house could legally be a Zone 2 dish.

 

[Channel Hopper]

Every Zone 2 dish I have installed has been larger than 60cms wide.

 

[jeallen01]

"Oh deary, deary me"! - "silly old Sky" then

Not that I think that anyone (else!) has ever taken that into account when installing both Zone 1 and Zone 2 dishes near each other on street-facing walls (and certainly not around "here"!)

 

[Red alert]

Just measured upto the gutter of the house and its approx 5.2m high. Does the angle of the roof mean that it has less effect on blocking the signal going to the dish, or will it have same effect as a hypothetical wall going straight up from the gutter?

 

[jeallen01]

Just measured upto the gutter of the house and its approx 5.2m high. Does the angle of the roof mean that it has less effect on blocking the signal going to the dish, or will it have same effect as a hypothetical wall going straight up from the gutter?

A) When at the central position (of the arc for a motorised dish) most offset dishes will be roughly "horizontal", but the received beam will be coming in from angle of around 22-24 degrees above that (before it is reflected to the LNB on the feedarm).

B ) Assuming that the "pitch" of that roof is effectively a straight sloping line then the actual effect will be dependent on the height of the ridge tiles on the top, and they will be slightly further from the dish than the wall, but it is whichever of the gutter or the top of the ridge that first intercepts it that will determine how "high" that house is in this context.

That effect gets more significant as a motorised dish swings towards the edges of the arc because sats in those positions are progressively lower in the sky - I have this issue with the sats to the East as as the roof of a new house stops anything beyond about 53E being received, and even 53E is very iffy and weather dependent - whereas a previous smaller dish used to get to around 56E before that house was built. Maybe that's a diffraction/signal loss effect as the beam is close to "clipping" the highest point?
PS: you can see that house in the 1st & 3rd images in my "We see no dishes!" thread posted on Christmas Day.

 

[Red alert]

A) When at the central position (of the arc for a motorised dish) most offset dishes will be roughly "horizontal", but the received beam will be coming in from angle of around 22-24 degrees above that (before it is reflected to the LNB on the feedarm).

B ) Assuming that the "pitch" of that roof is effectively a straight sloping line then the actual effect will be dependent on the height of the ridge tiles on the top, and they will be slightly further from the dish than the wall, but it is whichever of the gutter or the top of the ridge that first intercepts it that will determine how "high" that house is in this context.

That effect gets more significant as a motorised dish swings towards the edges of the arc because sats in those positions are progressively lower in the sky - I have this issue with the sats to the East as as the roof of a new house stops anything beyond about 53E being received, and even 53E is very iffy and weather dependent - whereas a previous smaller dish used to get to around 56E before that house was built. Maybe that's a diffraction/signal loss effect as the beam is close to "clipping" the highest point?
PS: you can see that house in the 1st & 3rd images in my "We see no dishes!" thread posted on Christmas Day.

Thats interesting, thanks for the explanation. Not sure if I should be worried about the gutter as the pole will be 2.2m from the ground. At 15 West the dish should see above the gutter at 5.4m (2.2m + 3.2m). Dishpointer states 3.2m as the maximum the obstacle can have at 15 West at the gutter line (see attached). Does that mean I will have only 20cm clearance from the top of the dish or that the entire dish will see 20cm above the gutter line of 5.2m??

I should have no obstacles from 13 east as that is when my neighbours house ends. So I am not worried about eastern sats. Anything west of 5 east thats when I start to get problems with line of sight.

Seems you have hidden your dishes well. If i could hide them I would put up a 1.5m.

 

[a33]

BTW You could also check Line of Sight at sun outage; for 53.3N that would be about Febr 29, 2020.
(see Satellite Look Angle Calculator )

At sun outage, the sun is rotating exactly behind the clarke belt, so you can judge places (or heights) where you might put your dish, by where the sunshine is received at certain moments of the day. (You need a sunny day for that!)

Greetz,
A33

BTW2: line of sight is about the bottom of the dish, when you have an obstacle near the ground. See #65.

 

[Red alert]

BTW You could also check Line of Sight at sun outage; for 53.3N that would be about Febr 29, 2020.
(see Satellite Look Angle Calculator )

At sun outage, the sun is rotating exactly behind the clarke belt, so you can judge places (or heights) where you might put your dish, by where the sunshine is received at certain moments of the day. (You need a sunny day for that!)

Greetz,
A33

BTW2: line of sight is about the bottom of the dish, when you have an obstacle near the ground. See #65.

So does that mean I would need to install the pole 3.2m high from the ground, since the dish is 1m offset dish??

 

[a33]

You'd need to measure the height from the bottom of the dish to the brackets of the motor.
That is because the motor brackets need to be on the pole (and not above the pole ),
and the bottom of the dish needs to be at a certain height, as dispointer LOS indicates.

A little bit of common sense, I would say?

greetz,
A33

 

[Channel Hopper]

An inverted offset dish will provide additional clearance, meaning the post could be slightly lower than the one proposed.

I bought the Gibertini 1m. Would I get away with having 2m pole?


Missed this post - answer is yes, possibly.

 

[jeallen01]

I bought the Gibertini 1m. Would I get away with having 2m pole?
Missed this post - answer is yes, possibly.

@Channel Hopper
Could you possibly point us towards some websites/threads that explain how to set up an inverted dish on a motor??

 

[a33]

I don't see it being advantageous, an upside down dish here.

The bottom of the dish is near the pole, with 'normal' dish position.

When upside down, the new 'bottom' position is further from the pole, and must therefore be HIGHER, to be in the bottom edge of the beam!

For upside down dish placement advantadges, I learned to think primarily in visualisations of the BEAM, and how you can place a dish in that beam. My conclusion is that upside down placement is advantageous in only very few situations.
(See e.g. (my post on) a german forum: Offsetspiegel hinter Balkongeländer verstecken )


What would make a difference for pole height, is if the arm of the motor is above, or under the motor (STAB motor versus SG2100 motor).
But the dish hight would still need to be the same; so it would just affect the pole height a bit.


Greetz,
A33

 

[Red alert]

You'd need to measure the height from the bottom of the dish to the brackets of the motor.
That is because the motor brackets need to be on the pole (and not above the pole ),
and the bottom of the dish needs to be at a certain height, as dispointer LOS indicates.

A little bit of common sense, I would say?

greetz,
A33

So if I have this correct I would need to have a 2.5m pole coming out of the ground and install the motor brackets 20cm down on the pole, so the base of this dish will be 2.2m above the ground? I'm probably just confusing myself.

 

[jeallen01]

@a33
Sorry to be a linguistic ignoramus (which you are obviously NOT ) but that linked website is in German, and so is there any chance you (or anyone else?) could provide us with a rough "english" version?

 

[a33]

To show the 'thinking primarily in visualisations of the BEAM' principle, I made the following drawing.



There are some interesting examples of inverted dishes on the internet that I've seen. Google will be your friend?

greetz,
A33

 

[PaulR]

There are photographs of inverted dishes here as well.

Another Afghanistan Thread

hello AFN installers, i have been reading some of these postes. ok first alignment. look at other working dishes in your area and see the general direction they are pointing. this will give you a general idea where it has to point. next lnb your scew may be off i don't know what 4 o'clock might...

www.satellites.co.uk

 

[Channel Hopper]

To show the 'thinking primarily in visualisations of the BEAM' principle, I made the following drawing.

View attachment 127605

There are some interesting examples of inverted dishes on the internet that I've seen. Google will be your friend?

greetz,
A33

Now redraw it with the actuator approximately where it would be, near the middle point of the reflector.