Advice Needed Is a 4 degree separation on a 60cm dish possible?

[Scubadan77]

At last some pictures!!!

 

[sonnetpete]

First thought after looking at the photos.....have you tried the monoblock fully forward and fully back in relation to the dish face?

 

[a33]

thanks guy for your advice, i did have a 80cm but have lent out for a while.
I can get my hands on 1m so will try that also try setting up the diseqc.

As the feedhorns of your monoblock-LNB are about 55 mm apart (I reckon from your photoos), a 100 cm dish will be too big. That won't work, either.

For this LNB I guess a 75 cm broadth dish would be best, in your area in Spain. So 80 cm would also be OK.

You could try if you can get reception on both satellites with this LNB on this 60 cm dish if you align both feedhorns sub-optimal, i.e. about 5 mm off of their focal point. Though I am not really hopefull that that would give stable reception on both satellites in all weather conditions.

-To test it: define 23east as diseqc B in your receiver (or 2/4, or AB, or whatever it is called in your receiver).
-Align your dish for optimal reception of 23 east.
-Check that you receive 23east at the proper head, by holding your hand in front of the 23east head of the LNB. Signal should diminish to zero.
-The monoblock should then be put about 19 degrees diagonal (as you have it, on your photoos)
-Then turn the whole dish further to the east; as far as you can to just keep reception on 23east.
-Then try if you can receive 19east, on diseqc A (or AA or 1/4, or whatever it is called in your receiver).

If you then have reception on both satellites, you can try to find the best compromise in signal quality between the two.

Greetz,
A33

 

[Archive4]

View attachment 87977 View attachment 87978 View attachment 87979 At last some pictures!!!

Your lnb is roughly level, judging by the pics, 19.2 needs to come down by about 16 degrees. Not sure how good, or bad, the M dish is.
Either way, measure its girth! that will give us a better chance of advice.
Intending to go to Leroy Merlin next Teusday at La Zenia, it you ain´t fixed it by then, let me know!

 

[Scubadan77]

First thought after looking at the photos.....have you tried the monoblock fully forward and fully back in relation to the dish face?

I tried the Lnb forward and back , up and down but it was one or the other .. think the dish is to small .....

As the feedhorns of your monoblock-LNB are about 55 mm apart (I reckon from your photoos), a 100 cm dish will be too big. That won't work, either.

For this LNB I guess a 75 cm broadth dish would be best, in your area in Spain. So 80 cm would also be OK.

a33 , you say 100cm dish will be to0 big, why??
I thought bigger dish would give you a stronger signal???

Your lnb is roughly level, judging by the pics, 19.2 needs to come down by about 16 degrees. Not sure how good, or bad, the M dish is.
Either way, measure its girth! that will give us a better chance of advice.
Intending to go to Leroy Merlin next Teusday at La Zenia, it you ain´t fixed it by then, let me know!

I now have a 100cm high and 90cm wide dish to try but don't know when i will be able to mess with
as busy with work but thank you for the offer Milamber , your a star!!!!

 

[timo_w2s]

a33 , you say 100cm dish will be to0 big, why??
I thought bigger dish would give you a stronger signal???

That's true if you use the correct LNB but the LNB is probably optimised for an 80cm dish. The distance between the two heads needs to change depending on the size of the dish.

 

[a33]

a33 , you say 100cm dish will be to0 big, why??
I thought bigger dish would give you a stronger signal???

That's true if you use the correct LNB but the LNB is probably optimised for an 80cm dish. The distance between the two heads needs to change depending on the size of the dish.

That's right, the distance between the heads is the one thing that is relevant with monoblock LNBs.
Manufacturers advertise for them saying it is a x-degree (arc-)separation for a q cm dish, but that is only true for a specific region, and doesn't give much information.
Relevant is the 'focal distance' of the actual dish (with a offset-dish: the 'adapted' focal distance), and the azimuth difference between the two satellites at your location.
From these two the needed distance between the center of the heads of the monoblock for your location can be calculated.
(The focal distance of an offset dish is dependent on the width of the dish, that's why they usually mention the width. For calculation of focal distance you need the f/D-ratio of the (offset) dish, to get the proper f.)

So: your 90 cm dish gives stronger signal, yes! But the heads in your monoblock are probably not far enough apart for problem-free reception of both 19e and 23e on a 100cm dish in Spain; you need a dishsize fit for your monoblock. Or you have to buy a monoblock with correct distance for the 90cm dish. Or, even better adjustable, two LNBs on a multifeed-rail in combination with a diseqc switch.

greetz,
A33

 

[Scubadan77]

thank you a33 for explaining it , there's me thinking it was as easy as aligning a single Lnb!!!
this is new to me using a monoblock for 2 satellites. I think i will ask the suppliers what size
it should be used with and go from there but i will get there!!!!

 

[Archive4]

Finally got round to running the tests with the two 4.3 monoblock lnb´s I have. As suspected had problems getting a good balance on a 60 cm dish. Managed to get a trade off receiving both at about 9 dB, but a nudge either way gives great improvement on one with a big loss on the other. Didn´t have a true 80 cm dish, so jumped straight to the Laminas 100 cm dish. Got both satellites in excess of 12 dB with no problem. The sharp eyed amongst us will spot the LNB skew is a bit too much, caused by the holder design not allowing me to drop it any more. Probably would have got a slightly higher reading.



Either way, it proves the 4.3 monoblock will work happily on a 100 cm dish, even though it is designed for an 80 cm

 

[timo_w2s]

Finally got round to running the tests with the two 4.3 monoblock lnb´s I have. As suspected had problems getting a good balance on a 60 cm dish. Managed to get a trade off receiving both at about 9 dB, but a nudge either way gives great improvement on one with a big loss on the other. Didn´t have a true 80 cm dish, so jumped straight to the Laminas 100 cm dish. Got both satellites in excess of 12 dB with no problem. The sharp eyed amongst us will stop the LNB skew is a bit too much, caused by the holder design not allowing me to drop it any more. Probably would have got a slightly higher reading.

Either way, it proves the 4.3 monoblock will work happily on a 100 cm dish, even though it is designed for an 80 cm

Interesting. I guess it's probably working closer to an 80cm equivalent as the LNB is not optimised correctly for a 100cm. So you'll be using a much bigger dish with no real gain (gain - see what I did there ).

 

[a33]

Good testing, Milander!

So, scubadan77 is in luck, assuming his monoblock has the same dimensions as Milanders. And scubans dish is 90cm, so that would be even 'better'.... ??

Greetz, A33

 

[Scubadan77]

Either way, it proves the 4.3 monoblock will work happily on a 100 cm dish, even though it is designed for an 80 cm

thank you Milamber, so there might be hope for me using this W90cm x H100cm dish.




I see you have clamped the right side (19,2E) , did this make a difference???
I am waiting to hear from the suppliers what size needed for the monoblock .

 

[Archive4]

thank you Milamber, so there might be hope for me using this W90cm x H100cm dish.

View attachment 88185


I see you have clamped the right side (19,2E) , did this make a difference???
I am waiting to hear from the suppliers what size needed for the monoblock .

I mounted it on 19.2 E because the " holder " on the Laminas would mean I have to strip the dish down to get the LNB in place correctly. Using a Triax or similar dish I would recommend using 23.5 E as the focal point, 19.2 E being much easier to receive. ( Also, most HD ch´s are on 23.5 E and need more SNR than the SD on 19.2 )
I am sure the LNB you have will work well on the 90 cm dish without any problem, most are designed for an 80 cm dish, so 90 will work, as proved. I agree with A33 and Timo , bit of " overkill " but should give better rain margin!

 

[Archive4]

Good testing, Milander!

So, scubadan77 is in luck, assuming his monoblock has the same dimensions as Milanders. And scubans dish is 90cm, so that would be even 'better'.... ??

Greetz, A33

I have no doubt it will work, and work well on that dish. Just wish I had a Duo or Smart 4.3, designed for a 60 cm dish to run the same tests. May have to beg, borrow, or steal one!
( Or contact a fellow forum member who has one! )

 

[a33]

I have no doubt it will work, and work well on that dish. Just wish I had a Duo or Smart 4.3, designed for a 60 cm dish to run the same tests. May have to beg, borrow, or steal one!
( Or contact a fellow forum member who has one! )

Well, I have one, but I am living in the Netherlands...

After reading your testresult a memory came back to me, that I've read somewhere that it is better to have too small a monoblock on a bigger dish, than too wide a monoblock on a smaller dish (as Scubadan77 had originally -- sorry, I wrote his(her) name incorrectly above), even if the distance between the feedhorns is the same millimeters off of what it should be.
I believe it had to do with the way the two feedhorns separate the signalbeams of the two satellites in the middle, and the signalbeams arriving more at the outsides of the feedhorns giving more signalstrength to the LNB. But I'm not quite sure if I recollect this correctly.

By the way: the triple LNB for 19-23-28e, designed for a Triax64 (60cm) dish, gives (in Holland) even better reception on a Triax78 (70cm) than on a Triax64, it seems. Though the aligning must be done with much much more precision than on a Triax64, as all the feedhorns are a bit out of focus; and you must find the best compromise between the three satellites. But, if you succeed in doing that, you get better results!
For a Triax88 the triple LNB is worthless in the Netherlands, however.

Greetz,
A33

 

[Archive4]

Well, I have one, but I am living in the Netherlands...


Greetz,
A33

Thanks for the offer, but I´m sourcing one through another forum member, will advise results when it arrives.

 

[Scubadan77]

I only gone and done it !!!!

I had a go over the weekend, got to say it wasn't straight forward,
it took a bit of tweeking and patience !!!.

I aligned the dish to 23.5e on a single lnb,
I then change to the monoblock and clamped it on the left what is
23.5e but couldn't get 19.2e. I then swapped and clamped it on 19.2e
and had the same problem. it was frustrating it was like they needed
to be further apart . I couldn't think which way to move to get them both to work.
anyway i loosened the dish and keeped going between the 2 sat untill i got both.
i think it must have been pure fluke!!!
also i have a new meter what i don't fully understand and i need to learn ..

this is a great forum full of knowlegeable people who are happy to pass it on!!!

thanks

 

[4wd]

I only gone and done it !!!!

I had a go over the weekend, got to say it wasn't straight forward,
it took a bit of tweeking and patience !!!.

That's the way to do it. Spending time & experimenting = results. Congrats.

 

[Archive4]

I only gone and done it !!!!

I had a go over the weekend, got to say it wasn't straight forward,
it took a bit of tweeking and patience !!!.

I aligned the dish to 23.5e on a single lnb,
I then change to the monoblock and clamped it on the left what is
23.5e but couldn't get 19.2e. I then swapped and clamped it on 19.2e
and had the same problem. it was frustrating it was like they needed
to be further apart . I couldn't think which way to move to get them both to work.
anyway i loosened the dish and keeped going between the 2 sat untill i got both.
i think it must have been pure fluke!!!
also i have a new meter what i don't fully understand and i need to learn ..

this is a great forum full of knowlegeable people who are happy to pass it on!!!

thanks

View attachment 88397

Well done you!

Out of interest, what is the new meter? Good chance if you have problems driving it one of us may know the type and be able to help out.

 

[Scubadan77]

Satlink WS-7009 SE HD Combo DVB-S/S2 + DVB-T/2 Spectrum.

i have a basic satlink meter already and wanted something better and cope with all situations but
i need to learn what i'm looking at and understand what they mean, was going to start another post.