Problems with motorized 68 cm Penta on some East satellites

bobbywise · 17-09-2009

Hi there,

I live in Nantes, and have recently installed a Digit 68 CM Penta dish on a motor (upgraded from an oval 60 x 50 optex dish).

I'm pretty much a newbie, but after all the research on the Internet with Dishpointer for true south, Gaaps calculator for motor angle relative to my long/lat, etc ., found it easy to install the dish. I based my initial positioning on Astra 28E, with the motor offset to the angle corresponding to my long/lat.

Here is a list of Sats, with Signal Quality (resolution is only on a 10% granularity level as the Foxsat HDR doesn't show 1% granularity like other STBs):

- 30W 12456V (30,000) - 100%
- 12.5W 12545H (27,500) - 90%
- 8W 10972H (27,500) - 90% to 100%
- 5W 10973V (9000) - 90% to 100%
- 1W 11325H - 90%
- 0.8W forget TPs - 90% - 100%
- 7e 11395 (27,500) - 100%, 11678H (3000) - 80%
- 9e 11823 H - 100%
-10e 11175 - 60% (many weak TPs on this Sat)
-13e typically a weak TP like 12322H (27,500) - 100%
-16e strong TPs 90%, weaker TPs like 11046 (10555) 60% and 10957H (2821) 60%
19e typically a weak YP like 12480V (27,500) - 100%
23.5e typically a weak TP like 10862H (22,000) - 100% (I don't get any TPs on German beam, but this is normal as a 90 cm dish required for my location)
28.2/5e typically a weak TP like 12643V (27,000) - 90% (others 100%)

My problem lies with the following Satellites:

26E - I can only get 12523H (27,500) with 40%, although luckily it doesn't tend to break up. Other frequencies are not available or some of the 12xxx ones are around 30% and drop out. I notice on another post, someone put plastic to raise the lower end of the dish for 26E.

39E - Nothing at all. This is my big concern as according to Dishpointer and other resources, I should get this easily with a 50 cm dish.

40E - Nothing at all. This is also a concern as a according to Dishpointer and other resources, I should get this easily with a 60 cm dish.

On 39E and 40E, I've tried searching on the strong TPs (listed elsewhere in this forum), and moved the dish in "step" mode to "fine tune" find these satellites, but never find them.

Any ideas as to why I cannot find the 39E and 40E satellites ?

I do have a constant array of trees in the entire range where the dish moves, but I am confident they are far enough away not to be in the line of sight for 39E and 40E.

I am wondering whether because the dish is slightly up the pole to pass the chimney, it is tilted slightly lower than needed for 39E and 40E and not perfectly on the "clark belt" arc. However, I think this is unlikely because all other satellites quoted above come in very well as expected. So surely if the dish was slightly to low for 39E and 40E, it would also be for all the other satellites, and this does not seem to be the case.

Do any of you experienced gurus have known examples where all expected satellites come in perfectly as expected, except 39E and 40E ?

Also, I noticed in another posting that someone said the offset on their Penta dish was different to the one they were replacing, and had to lower it by 10°. I have just set the tilt of my dish to 22.8° which is what GAAPS calculator suggests for my location and my motor type. I doubt the tilt of my dish is wrong though, as I am getting all other satellites as expected, but what do other people think ?

Finally, I have the Fracarro 0.5 dB single LNB. I am wondering whether if I get an Inverto 0.2 db single LNB, will it improve my reception on the "borderline" 30% weak TPs that are breaking up on 26E ?

Thanks for all your feedback.

I'll post the layout of the trees in the next couple of days (I am in Paris tonight, returning home tomorrow !).

With Well Wishes,

Rob

**sonnetpete** · 17-09-2009

Hi Rob,

Firstly, I replied to your post on the 'other' forum regarding reception.

I can't get anything off the 'German' transponders from 23.5E, this with a new Gibertini 1M and being a little further East then you. I'll try again and let you know what happens as the dish requires a little fine tuning and I'm waiting for a better meter from the UK to help with this!

Definitely you should get something from 39E and I would suggest you check that your pole is 100% vertical. Is it possible that the weight of the dish is flexing the pole off centre when it moves to those further east sats? How far up the pole is the dish? It sounds a bit precarious mounted near the chimney!

My dish is set at about 25° elevation so your 22.6° sounds a bit low, you cant be that much different to me. From personal experience I would recommend the Inverto Black Ultra LNB, it's proved to be excellent on both the new dish and the now redundant Triax 88.

If you're ever up this way (Lower Normandy/Northern Mayenne) you're welcome to drop by and have look at my set up.

Pete

**nanochickin** · 17-09-2009

Your dish is off the arc mate. Its dropping off past 28.2e by the sounds of it. By past experience if its tracking most of the arc Its usually caused by the dish not being central on the rotor arm

Send the motor to 1w. Move the dish slightly east or west on the rotor arm then adjust the motor back into 1w

I had this problem on a friends setup which kept dropping off the arc at about 20w. This did the trick and it now tracks from 53e to about 45w before it hits the wall

Nano

**sonnetpete** · 17-09-2009

Rob,

Yes, I agree with Nano, it could very well be that your dish isn't central on the motor stub. I'm still confused as to your dish elevation of 22.8°. Unless your motor stub angle is a lot different to mine your dish elevation should be higher than mine (25°), not lower.

Using an information sheet which shows elevation settings for fixed dishes in different departments of France, there is overall a difference of +2° between my location and yours. So, I can only conclude there is a major misalignment issue somewhere in your set up.

Pete

**rolfw** · 17-09-2009

Getting tied up with elevation figures on the dish bracket can be a bit of a red herring.

The main factors which influence motorised arc accuracy are how vertical the mast is (assuming also that dish is mounted straight on the motor arm), the correct latitude or elevation setting on the motor and how well you have aligned the whole rig on your chosen reference satellite, using signal/quality meter.

bobbywise · 17-09-2009

Hi everyone,

Thanks for all your feedback.
I suspect the problem may lie with the fact the dish is slightly up the pole (and lower than required). Also, I used a spirit level and the pole was pretty flush, but I also suspect the weight of this dish is taking it slightly off the plumb line.

My Lat is 47.1884 and my Long is -1.5325. My motor angle is 30°, and I need to deduct the declination angle (which depends on my long/lat) to determine the dish elevation. Gaaps calculator suggest for a 30° motor an antenna elevation of 22.8°, whilst Dishpointer suggest 23° (i.e. declination angle of 7°).

I'm pretty convinced the dish on the motor is bang in the middle - although it's slightly tricky to make sure. It's a shame there are no alignment holes on the dish fixations and the motor pole to ensure you are bang in the middle. I pretty much had the old an new dish visually in the middle of the pole, and never got 39E, so I don't think the problem lies with my ability to get the dish bang in the middle of the motor pole.

It's true I originally found true south using Astra 28, although all the other sats came in at the expected angles on the motor. However, when I re-perform alignment, I'll be sure to use 1W.

For me, 1W corresponds to 0.6E and 0.8W corresponds to 0.8E. It's a shame the Foxsat HDR does not have GOTOX functionality, so I will have to manually move the motor to 0.6E when I align to 1W. This might be a bit tricky without the GOTOX function

Just out of curiosity, the GAPPS calculator gives a change in the direction of the difference, e.g.

45W => 47.5 (diff +2.5)
30W => 31.3W (diff +1.3)
22W => 22.6W (diff +0.6)
15W => 14.9W (diff -0.1)
0.8W=> 0.8E (diff - 1.0)
1W => 0.6E (diff -1.6)
7E => 9.4E (diff -2.4)
10E => 12.7E (diff -2.7)
13E => 16.1E (diff -3.1)
26E => 30.3E (diff -4.3)
39E => 44.3E (diff -5.3)

I remember seeing some info on the net that suggested you simply compensate "constantly" by you Long value, e.g. in my case 1.5325W, 13E would be 16.5325, 1W would be 0.5325E etc. (a constant diff of -1.5325), but I suspect this information to be wrong, and believe the GAAPS calculator more. Do you gurus agree with the GAAP calculator, and how the difference between motor angle and different satellite angles actually varies (i.e. gets bigger toward either E or W extreme like with the values above) ?

For now, the dish install is on the chimney furthest away from the trees, as follows

E S

_____________________

Trees

______________________

______
! !
! !
!______!----- Dish

So you see, this is why I have it up the pole (to not touch chimney)

I will change to the following, so that I can put the motor between the two arms of the bracket.

Dish
!
_______!
! !
! !
!_______!

Before I make any movements, I'll post you up the photos to give me your opinions on the trees.

There is a minute chance the trees are the problem, but my gut feeling from what you all tell me, is that the pole not 100% flush, plus dish up pole (not between two arms, above 2nd arm) is distorting me from the arc on the high Easts.

As a test, I'll also see if I can get 31.5W -- I'm pretty sure I will as I can get 30W.

Cheers,

Rob

**sonnetpete** · 17-09-2009

Rob,

Does sound like the root of the problem might be a 'swaying' pole. Don't get too bound up with all those calculations.

Not sure what you mean about sending the motor to 0.8E. A Humax Foxsat isn't the best receiver to try and align with I guess, but if it were me (and I am not an expert or a guru so take this with a pinch of salt), I would send the motor to Thor and then move the motor and dish on the pole to get the best signal.

I'll look at my Technomate motor manual re the elevation settings as I'm still not convinced about the dish being a lower setting than mine.

Good luck anyway (or should that be 'bon courage')

Pete

**satelliteman** · 17-09-2009

Strange GAAPS differences there, should be a 0.5° difference.

On paper, dish elevation should be at 23° for a motor shaft bend of 30° relative to polar axis. It is said that dish elevation markings are not accurate and wouldn't pay to much attention to this. Without GOTOX, you just need to motorised the motor 0.5° East before alignment (to account for offset), a very very small movement. As said, it would be worth checking the latitude scale on the motor and pole is plumb in al directions.

**sonnetpete** · 17-09-2009

Rob,

According to my Technomate manual there is only .3° difference between your latitude and mine. I don't know how accurate the Penta or indeed the Gibertini elevation scales are but I guess you should concentrate on whether the pole is vertical when the dish is tracking sats towards East and West extremes.

I had similar problems when I changed to a larger dish on an L bend bracket. The weight was bending the bracket out of true. Solution? T & K brackets and a substantial pole (plumb of course)

Pete

bobbywise · 18-09-2009

Thanks again Pete and Paul,

I forgot to mention in my original response that I am confident with the latitude setting on the motor.

Your comments seem to be re-enforcing my initial thoughts of the non-plumb pole, plus the fact the dish is partly up the pole.

I lent my neighbour an old Technomate receiver. Hopefully this supports GOTOX so I can be sure when setting the offset angle on the motor to find true south.

The GAAPS differences (or offsets) are simply those that I plugged into the GAAPS calculator on the Internet for my location and motor type. Like I said in my previous post, I found it strange that according to the offsets seem to get bigger the further E or W you go, and are not constant. However, I have based the calibration of the motor on these 'increasing' offsets (e.g. 30W at 31.5W not 28.5W, 13E at 16.1E not 14.E etc.) and all these satellites are perfect with the increasing (non-constant) offset.

Pete, about sending motor to 0.8E, I was trying to say that next time a I find True South based on Thor 1W signal strength, I'll send my motor to the offset value for my location (e.g. 0.5E if constant, or 0.8 if according to GAAPS calculator).

I'll also check my Technomate 2200 Motor manual tomorrow. But from memory, I remember thinking that the manual approximately corresponded to that given by Gaaps calculator (22.8) and Dishpointer (23°).

I'll keep you updated on my findings.

Really want 39E and 40E and better reception on 26E for the free sports channels

Rob

**satelliteman** · 18-09-2009

Should receive 39°E easily enough, but is a Fracarro 68cm the ideal size dish for motorised. It's big sister the 85cm would certainly give the extra gain, especially for 26°E.

***Vipersan*** · 18-09-2009

Hi Bobby ..
To 100% rule out the trees being a problem ..
Go back to dish pointer ...and use the obstacle marker .
I've had to use this feature recently..
Very useful indeed.
Dont forget _your_ obstacle (tree) height given at the given distance from your dish is relative to the ground so you will have to make allowances for dish height and the height of the tree ..
Its easy enough to work it out .
Only solid obstacles such as buildings are auto calculated.
good luck
VS

bobbywise · 18-09-2009

Ok, a little update.

Dishpointer seems to suggest approximately 1.8 m difference in height tolerance between 28E and 39E. I'm not sure if there is more than 1.8 m difference with the trees at 28E and 39E, but I went on the roof, and took some photos at different angles. It's difficult to get the perspective, and in the photos seem to make the trees more imposing than what they are.

When I look up the arm to the end of the LNB, it seems like maybe the trees are in the way for 39E. What do you think.

***Vipersan*** · 18-09-2009

Hmm ..
Thats a tricky call ..
You _may_ just be clipping the trees at 39E ...
But the only way you can really be sure is to know the height of the tree ..
The distance to the tree is given by dish pointer ...
The height of your dish above ground is also known ..
assuming you are on the same level as the trees base ..
you need to add the height required to see the sat ...given by dishpointer (which assumes ground level) ..to the height of the dish ...
If this is greater than the height of the tree ...then the sat will be visible ..
If its the same or less ..then you can't recive signals from the sat ..
somehow you need to get a rough idea of the height of the trees..
..or just keep trying and hope you have sufficient clearance.
Certainly they look far enough away not to be an issue ....
rgds
VS

Just as an afterthought ..most mature trees around my immediate area are roughly the same height as my old terraced house
ie 2 floors and the roof to the apex
as a guestimation ..you could assume this to be 9 > 10 mtres.

**sonnetpete** · 18-09-2009

Rob,

I don't think you should have line of sight problems with 39°E as your trees look about the same distance away from your dish as mine are.

However, I can try and take a couple of pics from a similar angle to yours, pointing at relevant sats. Perhaps then you can get an idea how far above the dish trees can appear to be without blocking the signal.

Pete

**satelliteman** · 18-09-2009

Yes, you might just be ok for 39Hellas.

bobbywise · 18-09-2009

Yes, it's a tricky borderline one I think !

The trees are quite close, and according to dish pointer (although I am guessing the distance from the chimney is about 14m - 15m), the height needed is 5.8m for 39E and 7.8m for 28E.

I've never had problems with 28E, even when I had a Multytenne 45 cm fixed dish, so it's sure the trees are ok for 28E.

39E is a tricky one. Not sure if the trees are 13.5, 14.5, 15, 16 m away

I'm starting to think (contrary to my original thoughts), that maybe the trees are in the way, and my alignment is pretty much on the arc. Having said that, I still have doubts about potential pole flexing, so I might buy a scaffold pole.

If the trees are an issue, I don't want to move the dish lower (between two arms on bracket) and closer to the trees.

Winter is around the corner, and those leaves with fall (I'll be getting the rake out

).

I'm now contemplating leaving the dish alignment as it is, and searching for 39E and 40E when only the branches are left. Since 39E only needs a 50 cm dish where I am located, with bare branches I'll probably pick it up.

I'll keep you all posted, and look forward to Pete's photos of his trees

BTW, it was cloudy today and the 26E 12523H TP I usually get at 40% was gone. Maybe I knocked the dish while taking those photos, or the clouds had an impact

26E needs a 70/90 cm dish anyway, so I guess I'll always have problems with that.

***Vipersan*** · 18-09-2009

I share your pain Rob...
Like you I have been after the elusive Hellas for some weeks now ...
and like you I have a tree in close proximity ..
Close enough in fact such that it obscures everything from 36E to 65 East...
I absolutely know my problem is the height of the tree ...
..but I'm lucky in that my Dads house is about 18 mtres away to the west ...
and he has a prime spot on his rear south facing wall on which I have fitted an 80 cm motorised dish just this afternoon ..
I'll effectively be able to look _behind_ the tree..
I haven't aligned it yet ...but hopefully this will complement my motorised triax 1.1 on my back wall thus filling in the the missing section of arc ..with a tiny overlap
From his location he also has a tree which blocks everything west of 28 deg East..
I have 2 HD tuners in my recently added IP9000HD ...and Im hoping I wont even notice as the receiver swaps from one dish to the other.
..This also has the bonus of freeing up my Humax HDCI2000 for exclusive C Band use on the 1.8 m PF dish..which Sadly is located below the Triax ...and so suffers from the same Eastward blind spot.
rgds
VS

**sonnetpete** · 19-09-2009

Rob,

I popped up the stepladder this morning and between moving the dish I took a few photos looking out towards the LNB.

It proved a couple of things, (a) always check the camera isn't set to macro before taking a shot and (b) you might have line of site above the trees, so don't go shooting your mouth off about the dish appearing to be blocked!!

However, camera reset, I got a couple of images which show my West and East limits at the moment. They do show the lnb pointing at the trees and any further along the arc may be attainable when the leaves fall or I can 'trim' the top of the offending trees.

Sorry if this isn't as useful as I thought it would be. I have a little further height on the pole and may try and raise the motor up to try and clear the eastern tree as I used to get 57°E before the summer.

Pete

bobbywise · 20-09-2009

Hi Pete,

Your trees at 57E look further away than my trees at 39E.
So if you can no longer get 57E, I think there's no chance for me at 39E.
I'm tempted to raise my dish up the pole, but if I go for this option I'll probably change my pole for a scaffold one !

Cheers,

Rob

**sonnetpete** · 20-09-2009

Rob,

Just to clarify, first photo shows dish pointing at 53°E, which I do receive. The trees are considerably further away than the ones in the second photo, but less 'suitable' for trimming as they are cider pear, cider apple and walnut. I guess I'll just have to wait till Autumn

Perhaps you may have to do the same, unless you know a good 'elegagiste'. At least I think thats what the French call a tree surgeon!!

Pete

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Problems with motorized 68 cm Penta on some East satellites Information exchange on LNBs, Single satellite, motorised and multi-satellite systems. DiSEqC switches, positioners, motors, actuators, dish-alignment etc.