Desperetly Need Help Installing Vertex RSI 9.0 m

I suggest you contact Vertex RSI for advice.   They, or their approved installers should be contracted to install it and take the responsibility of adjusting it and getting it though its acceptance testing (far-out and near-in sidelobe patterns, cross pol performance inside -1 dB tx contour, tx gain and receive G/T).  

If it is an old antenna that has been dismantled and moved I would still recommend getting Vertex RSI involved as they will have installation manuals and specialist panel alignment tools, such as theodolite, theodolite mount jig and calibrated steel marker tape, available.  Tell them the model and serial number of the dish.  Panel alignment definitely requires a Vertex RSI qualified installer with access to the master design documentation.  Note that if it is an old dish then Vertex RSI or any other antenna installer may be unwilling to commit to achieving acceptable performance, in which case you retain the financial risk and responsibility of a dud antenna, if it does not pass. You will still have to pay the installer for their efforts.

If the problem is only to do with the subreflector and its position then follow my guide at antenna sub reflector alignment.   You can do this yourself and it should take between one day to one week to do.

Best regards, Eric.

I am not happy to give you any advice as you are likely to permanently distort your antenna and make it useless.

Installing such a dish is a skilled job requiring the Vertex instruction manual and an experienced antenna engineer, theodolite, jigs, tools, test equipment etc.

Sorry,

Best regards, Eric.

Mik is quite right.

Installing any large dish like 9m dia requires great skill.  

A small Ku band dish, like a 1.2m or 1.8m VSAT starts off with a profile accuracy of better than 1.5mm and must not be distorted on installation.  A heavy LNB/BUC can pull the sides of the dish forwards.  Failing to correctly tension the short rear side struts on a 1.2m offset VSAT dish can reduce transmit gain by more than 3 dB. Read about getting a VSAT dish rim flat using fishing line.

A medium sized dish such as 2.4m, 3.7m or 4.5m can sometimes have its panels set up with fishing lines. See parabolic dish panel alignment and sub-reflector alignment

A large dish, like 9m dia, has many panels and with the dish facing upwards you need to set all the panel reference points the same, +/-1mm relative to the assembly reference measurements/angles, during the initial dish assembly and also have the feed axis exactly upright and in the middle.  A theodolite is essential.  Then tilt the dish to its operational angle and remeasure the mm errors up or down all the way round at the panel reference points.  You will find a reasonably smooth curve; the sides of the dish tend to push out a few mm and the top falls down a bit.  Put the dish back upwards and apply reverse adjustments to all points.  Then aim the dish at the wanted satellite and align the subreflector.  

Pay for Mik to come and see what he can do for the subreflector, but be ready to accept that if the dish itself is distorted or the hub and feed not upright in the middle then it will not pass its satellite acceptance tests.  At the hub there will be a machined ring of bolts where the ribs or panel inner ends attach. The plane of this ring must be at right angles to the feed axis and parallel to the planes through all similar panel reference targets (incuding the outer rim of the dish). 

If you have sidelobe patterns please send them to me eric@satsig.net and I will put them here to see.

As I said above I cannot give you advice about your specific dish as without the installation manual and expert help you are likely to permanently distort your antenna and make it useless.  Sorry.  It is not good for my reputation to be associated with a failed large dish assembly !

Best regards. Eric.

hi all,

sorry for late reply.
i'd like to inform you that my 9.0 m antenna is working nicely since the end of 2008.

thank you for your wonderful support.

Best Regards,
Yoyok

Dear Nimrod,

my installers bring down and recheck all the antenna components [since it was a used antenna], including the feedhorn and all the dishes, make sure if they are all ok and then bring them up again for installation and adjusment.
it worked.

i must say that they were a pretty tough installers, they were divided into 2 shifts and worked day and night to solve the problem.

best regards,
yoyok