More Hellas 39E problems

[Vipersan]

Hi friends..
Finally completed the setup of my second motorised dish today ..
This is an 80 cm offset mounted on my old SG2100 motor ...and is specifically aimed at 28 deg East > 60 East .
..The main target being Hellas at 39 East
The dish is tracking the arc and is finding all the sats I'm pointing it at.
There are some losses in the long cable run ...and the sg2100 will probably suck out a couple more db.
However I'm still having probs with Hellas
I can get all the transponders related to Bulsat ...but one ...
The one carrying the HD transmissions on 11012V
Strangly I did manage to get this ..but just once ....
In the morning ....but was gone by 3pm afternoon ..
Looking at lyngsat the footprint transponder is the much same as the others although I suspect this isn't the case.
Has anyone else noticed any differences on the various transponders or can explain whats going on ?
.Ideally I could do with a report sig strength report from someone in my neck of the woods (Manchester).
As I said ..the long cable run could be contributing ...but I can't understand getting nothing at all from this transponder.
rgds
VS

 

[Robbo]

I'm getting a massive signal on that TP, VS, better then some of the others like RIKSat.

It could be a cable issue. What cable are you using and how long is it?

A kink or squash could cause a problem like that I would have thought.


Can you stick you receiver at the dish to eliminate a cable problem?

 

[Vipersan]

Hi Robbo ...
I'm fairly convinced myself that the cable is the issue ..
I have a small overlap where both dishes ...my triax and the the new 80cm dish can see the same sat (33 deg East)
Comparing 2 signals from the same transponder Eurobird 3 (11596V)
Shows around half as much signal on the same receiver ..coming from the 80cm dish on the long cable run.
I must be losing quite a few db over the distance ...which I may well have underestimated at around 30mtrs total length ..
..It could indeed be closer to 35 >38 mtrs
Its good quality double screened with a solid copper outer layer ...but that obviously is insufficient to compensate for the length of the run .
It was an ambitious project ...and I was well aware of the possible failings before I took it on .
For the most part it is useable ...but I'm going to have to try experimenting with line amplifiers I think ....assuming they will pass the motor control information ok..

Can you quote any figures at me regarding this setup ..
For example db losses per 10mtre of cable ..
and effectiveness and placing of line amplifiers etc..
rgds
VS

 

[Robbo]

35 to 38 metres of decent non damaged cable should not be causing any problems at all.

I have had 50m on Nilesat, no problems, and that is weak to start off with.
I have tested up to 60m with loads of joins in it, on 28E, that was OK too.

I think my current cable is about 35m too, with a couple of joins.


For wf100, the attenuation per 100m at the highest IF frequency is 32 odd dBs maximum, as it is for any cable in that class:-

_http://www.cai.org.uk/

Check it with a short Length I would suggest.

I would suspect that the cable has been mishandled, an amp is not necessary for such a short length.

 

[Channel Hopper]

A badly installed F-connector and certain LNBs in a batch can stop one particular frequency dead.

Try another LNB first.

(I also know of one install where the receiver was at fault.)

 

[Vipersan]

Thanks for you input guys...
much appreciated
Since the signal level is down accross the whole spectrum ...and the lnb is a brand new inverto ..
I'm inclined to go with the cable theory ..
Not least because a section of the run has been there for some time...
The section under my floor
I'll recheck the joints etc ...but I'm more or less resigned to replacing at least that section.

Incidentally ...I love the way I can seemlessly switch between the 2 dishes on my IPbox9000HD ...
Thats definately a plus.
If only it had a built in spectrum analyser...lol
rgds
VS

 

[crewey]

Hi VS, Sorry to open this thread up as it's back from Sept but did you solve the issue with TP 11012V on 39e ?
I appear to be having the same issue on my dm800

Thanks

 

[Vipersan]

Hi Crewey...
I never totally solved this one .
I did get some improvement on the HD transponder 11012V ...by putting a line amplifier about 30 mtrs from the dish ...
This did overcome some losses in the long cable run ..but I still remain convinced that this transponder broadcasts at a lower power that the rest of the bulsat mux.
I suspect that upgrading the 80cm dish to 1m would solve the problem totally ..
Firstly due to the increased surface area ..
..but also because the beam would be tighter ..and less prone to external interferance.

At my location ..and with the relatively low elevation ..I'm convinced I'm getting some unwanted signal ..
I have a mobile phone repeater and Manchester Airport ....roughly along that trajectory..
rgds
VS

 

[hexah]

Airports are famous for noise and interference in the microwave spectrum, extending for at least a mile around it. Usually, the bigger the dish, the more noise and interference it collects.

If it is the problem, the only thing you can do is to build a wall as high as the dish face, or block it in some similar way.

 

[satelliteman]

Re-siting the dish or inverting would be the first move I'd say.

 

[crewey]

Thanks guys, there is a tree in the garden which "may" be causing some issue but all the other transponders on 39e are OK even in wind and heavy rain.
I just get 0% signal all the time on 11012v
When I had this problem on 1w with a single transponder I re-installed my channel list and all was fine again, this didn't work for this transponder.