LNB signal problems

[caphook]

Hi Guys hope you can help I have bought a 85cm dish, motor, Lnb set up off ebay and have a 7020 dreambox. I have followed all the install instructions and set up the dish, mount etc but wherever i point the dish the sat finder just makes a noise with no change in pitch. And the signal strength on the dreambox stays at 59-60% no matter where I point the dish, as an outcome of this i cannot setup the dish. Could the LNB be knackered, thanks for any help in solving this.

 

[caphook]

Hi forgot to add when testing the motor with the dish in the front room the signal reading was still 50-60% that is what makes me think I have a dodgy LNB.

 

[guest]

Hi forgot to add when testing the motor with the dish in the front room the signal reading was still 50-60% that is what makes me think I have a dodgy LNB.

You will get a significant "Strength" reading so long as the LNB is actually connected to the cable and powered up - even if it is detached from the Dish or the Dish/LNB is pointing at the floor.

I would be surprised if your problem is anything other than not actually being aligned to any Satellite.

If you are using a simple needle meter, the short stub cable used to connect them is often flimsy and fails to make adequate contact with the LNB F socket.

In that event, the Meter is getting power from the Receiver and will emit a constant whine whatever you do. The Dreambox sees a completed circuit and hence shows a "Strength" reading - even though it's only seeing the Meter and possibly not the LNB.

So check the connections and if you are in any doubt ditch the stub cable and make one up yourself using decent cable and connectors.

 

[caphook]

thanks for that Rai Uno i have made a cable as you suggested with still the same results, even with no meter in just connected to the LNB the signal strength is still 59-60%.

 

[guest]

thanks for that Rai Uno i have made a cable as you suggested with still the same results, even with no meter in just connected to the LNB the signal strength is still 59-60%.

Ok.

That leaves us with misalignment (my favourite) or a duff LNB (as you suggested).

Duff new LNBs are pretty rare beasts, so I suspect your problem is due to alignment.

So, check again:

1. Pole absolutely vertical

2. Motor Latitude scale set to 50 something (they often have a scale either side of the barcket, so make sure you are reading the right one)

3. Dish Elevation set to around 24 degrees (ish)

4. Dish mounted absolutely in line with the front of the motor stub (There should be a faint datum line for you to use.

5. LNB mounted with Zero Skew ie Dead upright with Dish pointing South.

6. Your Lat/Long correctly entered into the Receiver (Common mistake is to leave Longitude as E or +, whereas many UK residents are W or - )

7. Motor sent to Zero/Reference and Thor selected on Receiver (I'm not an adherent to the "South Satellite" philosophy, which is a relic of days gone by, but this Forum seems to abide by it ........... )

8. Alignment optimised by moving the Motor/Dish assembly as one around the Pole (for Azimuth) and by finely adjusting the Dish (not Motor) Elevation for .......... Elevation.

Which one did you forget ................ ?? !

And finally, wise man he always have a spare LNB to hand.

 

[caphook]

1. pole absolutely vertical. CHECK
2. Motor set to 37 deg as in book my latitude is 53.620 CHECK
3. Dish elevation as book 27.4 deg my long is 2.130W CHECK
4. Dish in line CHECK
5. Lnb mounted at Zero CHECK
6. Lat/Long entered correctly CHECK
7. Motor set to Thor and reciever set to thor CHECK
8. Alignment optimised by moving dish not motor CHECK
not got a spare Lnb thou, now you can see my problem. Im stumped as to where i am going wrong.

 

[guest]

1. pole absolutely vertical. CHECK
2. Motor set to 37 deg as in book my latitude is 53.620 CHECK
3. Dish elevation as book 27.4 deg my long is 2.130W CHECK
4. Dish in line CHECK
5. Lnb mounted at Zero CHECK
6. Lat/Long entered correctly CHECK
7. Motor set to Thor and reciever set to thor CHECK
8. Alignment optimised by moving dish not motor CHECK
not got a spare Lnb thou, now you can see my problem. Im stumped as to where i am going wrong.

Your number 8 is worrying me: Only Elevation is adjusted by the Dish alone. Azimuth is achieved by moving the Dish and Motor as one around the Pole ie Once you have fitted the Dish correctly on the Motor stub, DO NOT TOUCH it!

Also, your number 2 is not crystal clear: Your Latitude is roughly 54, but you've set the Motor to 37: If you've set it against the wrong scale (Remember I said there should be two .......) then that isn't exactly going to help.

Set 54 directly on the Latitude scale on the Motor - forget the other scale.

Also, as I am on roughly the same Latitude as you, I think you'll find that you'd be better off using a starting point for fine tuning of 24 degrees on your Dish Elevation scale, not 27. That should now get you close enough to be able to get a signal to optimise.

You see, there comes a point at which calculation/theory become of limited value as the cumulative mechanical errors in setting up the system mean you can do nothing more than use them as very rough indicators for commencing the real work of alignment.

Trust me .....................

 

[caphook]

Right I have taken that onboard will try later and check the scales as you have said I think you could be right im putting to many errors together so ill start from the beginning and get back to you. Thanks again Rai Uno your a gent.

 

[howc]

Caphook. In my experience the Satbeeper is very handy but it only does so much. For example it will change pitch when it finds any sat no matter what the receiver is tuned to. Those sats are pretty close when your hunting for them. Also for me at least, whilst I can use the beeper to position the dish pretty accurately I need to remove the beeper in order for the receiver to actually show any picture. Also final tweeks are best done with someone looking at the TV to tell you when you have maxed the signal so borrow a friend, relative, neighbour or local tramp to help you.

 

[caphook]

Hi I have had a look at the bracket on the motor and both sides are marked as lattitude, here is the table from the motor I used




any suggestions like do I change the motor angle to 53 deg?

Rai Uno when I said move the dish around I ment with the motor as in move the whole thing around the pole the motor is fixed at that angle hope this makes sense.

 

[guest]

Hi I have had a look at the bracket on the motor and both sides are marked as lattitude, here is the table from the motor I used




any suggestions like do I change the motor angle to 53 deg?

Rai Uno when I said move the dish around I ment with the motor as in move the whole thing around the pole the motor is fixed at that angle hope this makes sense.

That table is for the Dish Elevation, not the Motor setting.

Set the Motor to 54 and the Dish Elevation to 27 or so. You'll have to adjust it to get a signal anyway, so it doesn't really matter to within a degree or two what starting point you use.

You table is slightly different to the one my own two Motors uses, so ignore my earlier suggestion of 24 and use 27, as stated.

What Make of Motor is it, by the way?

So, in summary: Motor Latitude = 54; Dish Elevation = 27

Good luck!

 

[caphook]

Thanks its a Super Dark Motor Ill try those settings tomorrow and report back hopefully with good news thanks for the advice

 

[guest]

I'm sure it'll be fine.

There can be few among us who haven't erred in the early days of getting to grips with this stuff - but it all aids the learning process and understanding and is strangely enjoyable.

In retrospect, at least!

 

[caphook]

Hi you where correct Rai Uno there is nothing wrong with my Lnb. I have ended up getting an engineer out of local paper he used to do motorised sysems till his meter blew up, but he has only set my dish to 28.2 East but now cannot get any other satellites any suggestions?

 

[guest]

Yes - DiY!


Lots of self-help guides around the Forum. And you do seem to have got a handle on the general idea.

Setting the Dish to 28E how exactly , I wonder .......................

I can think of many more wrong ways of doing it with a supposedly motorised system than I can think of right ways (cos there's only one!).

But .................. If he aligned to 28E by swinging the lot around the pole, you could try USALS: Alignment of a system for USALS operation requires little more than fixing a single point on the arc and he may have done that, effectively.

If, however, he's done something daft like leave the Motor fixed and slackened the Dish on the stub to swing the Dish around, then 28E is all you will get.

Let's be optimistic and give the guy credit - nothing to lose by selecting USALS, whacking in your Lat and Long and seeing what happens if you select eg Hotbird.

I note, however, upon second reading, that you now can't get any other Satellites, so maybe my optimism is going to be short lived!


Do you actually know what he did?

 

[caphook]

He checked that it was pointing due south then he told me to send the dish to 28.2 East and then he so called "tweaked it". I was inside at the time so dont know exactly how he tweaked it.

 

[guest]

Ah! That sounds vaguely hopefully. You may well be 90% of the way to a successful outcome.

Try Astra 1 and Hotbird in USALS.

Check that your Lat and Long have been correctly entered first.

Report back if the Dish actually moves.

If it does, try sending manual commands from the Box menus to jog the Dish East and West a bit from wherever it lands.

I'm afraid I must go now, but I feel sure others will take up the cudgels and offer sage words of advice