Fortec Star antenna

[altadata]

I have problems with my Fortec 90 cm ( 36 inch ) antenna ( U bolt style ).
The problem is that I'm getting a good signal on one of the transponders ( 12090 ) but nothing on the others.

I did some experimenting by removing the LNB from the enclosure and keeping it with my hand ( taking care I don't get in the way ).

If I move it higher and to the right I get good signal on one of the transponders I want ( 1.5-2 inch higher and about 1.5-2 inch to the right ).
If I move it higher and to the left I get a good signal on another transponder that I want ( and 0 on the previous one ).

What is wrong? How am I supposed to get signal on all the transponders?


Thanks.

 

[Anole]

You are moving it how far?
I'd say you are seeing different satellites.

What are your LNB and satellite of interest?

What is your city/state (or zip code) - enter either into this program and it'll give you aiming info for all the satellites.
Re-mount the LNB, and then aim the dish using a compass and the magnetic alignment info on the print-out, adjust the elevation by the readings on your antenna mount, and the skew as shown on the web site.
THEN tweak a little left-right or up-down from there to find your satellite.

Aiming is somewhat touchy and precise.
You have to do it in tiny increments (fraction of an inch), see where you are, and then adjust.
If you land on the wrong satellite, that's okay.
We can figure out which one, and adjust to get you to the correct one.

 

[starman345]

Stringline youir dish to check if its warped, some will warp so bad symptoms like you describe will happen. If its bad you should be able to tell just by looking side on to the dish, sight edge to edge, the edges should line up perfectly. What satellite are you pointed at when you are getting 12090?

 

[altadata]

Stringline youir dish to check if its warped, some will warp so bad symptoms like you describe will happen. If its bad you should be able to tell just by looking side on to the dish, sight edge to edge, the edges should line up perfectly. What satellite are you pointed at when you are getting 12090?

I was pointing to IA5 ( 97W ).
The reflector is good ( I just checked it by turning it upside down on a flat surface and the edge is touching the flat surface all around ). The reflector also looks good ( there are no bends, the surface looks good ).
I had only troubles with this antenna.

The thing that I'm not sure is the LNB holding arm - it could be out of shape or maybe they shipped me the arm from the 80 cm antenna? Can somebody take a picture of a good LNB arm for the Fortec Star 90 cm, while the arm is on a flat surface so that I can compare the shape ( angle ) ? Maybe also could provide some measurements of the arm ( lengh )?

My location is Ottawa Canada and according to the footprint , a 90 cm antenna is more than enough.
I set the azimuth according to the website, and is good since I'm getting a strong transponder ( 45% ).
I set the elevation lower than what the website says ( it says 33.7 and I have to set it to 31 to get anything ).
I set the LNBF skew to +19 ( approx ).
It is in this position that I find that by moving the LNBF up and to the left or right I get signal.

I really hate this antenna.

Thanks.

 

[concord]

The Fortec dishes have been known to be up to 5 degrees off in dish elevation, I had to increase my elevation from 39 to 43 degrees on my 31".

On www.fortecstar.com 's website, it states that the focus length is 492cm (31") vs 510cm (36")....

 

[colbec]

I have one of these and it too does not perform as well as a smaller Digiwave dish. One of the details is that the lnb arm seems to be off the focus of the dish. If I measure from the side of the dish (there is a hole in the edge of the dish where it looks as if there might be a strut) to the screw that holds down the lnb on that side, and then do the same on the other side I get a difference of about 3/4". I have tried halfheartedly to shim the dish out on one side with washers to push the dish over but with no great success so far since I ran out of washers and will probably need a longer bolt.

My longer term goal is to make up some struts that will ensure the lnb is on centre before tightening down the dish to the supporting bracket. This size of dish should really come with these struts.

 

[altadata]

The Fortec dishes have been known to be up to 5 degrees off in dish elevation, I had to increase my elevation from 39 to 43 degrees on my 31".

On www.fortecstar.com 's website, it states that the focus length is 492cm (31") vs 510cm (36")....

How do you measure the "focus length" of an offset antenna?
It is the distance from the Focal point to where?

Thanks.

 

[altadata]

Colbec of anyone else with a Fortec90 cm,
is it possible for you to measure the distance from the left hole on the edge of the reflector to the screw of the lnbf holder ( the distance you mention ),
and to provide the "good" value? This way I can set my distance to be the same.
By "good value" I mean that it should be equal to the left as to the right.
Also what signal quality to you usually get on various tp on IA5?
Thanks.

 

[concord]

How do you measure the "focus length" of an offset antenna?
It is the distance from the Focal point to where?

Thanks.

Oops, I meant mm, not cm: "On www.fortecstar.com 's website, it states that the focus length is 492mm (31") vs 510mm (36")...." Therefore 19.3" and 20.08" respectively.

I believe on an offset dish, focal length is measured as the shortest distance from the dish to the end of LNB arm. Since the bottom of the dish is closer to the LNB, measure from the bottom of the dish to the end on the LNB arm. To double check this, I measured mine 31" and it was around 19.4".

Also colbec mentions "holes" on the left and right. On the 31", my holes are on the top and bottom (long axis). I assumed that these were for moisture venting for the rim.

Question: Do you have the LNB arm mounted and aligned with the long axis? If ever seen a primestar or direcway dish, it's the opposite, with the LNB arm aligned on the short axis....

 

[altadata]

Question: Do you have the LNB arm mounted and aligned with the long axis? If ever seen a primestar or direcway dish, it's the opposite, with the LNB arm aligned on the short axis....

Sure it is aligned with the long axis.
What about somebody with a 36" ( 90 mm ) Fortec that has good signal, can they provide some measurements?

Thanks.

 

[concord]

Sure it is aligned with the long axis.
What about somebody with a 36" ( 90 mm ) Fortec that has good signal, can they provide some measurements?

Thanks.

Curious, did you resolved your problem, was it a bent LNB arm, etc.?

 

[patmos]

The Fortec dishes have been known to be up to 5 degrees off in dish elevation, I had to increase my elevation from 39 to 43 degrees on my 31".

On www.fortecstar.com 's website, it states that the focus length is 492cm (31") vs 510cm (36")....

Does this mean the reading on the scale(dish) that is wrong or the inclinometer also will show that increase?

 

[jayelem]

I'm wondering if maybe this is not just a big deal about nothing , I hope at least you're enjoying FTA instead of being annoyed by these TP's , I'll explain Why .....

What type of LNB are you using ?

What Satellite is this occuring on , is it a Circular or Linear signal ?

You know I believe I experienced the same results as you , but left good enough alone.
It all happened one day while I was on the motor control on my CS 5000 , I was fine tuning a particular TP that had low quality signal , after saving my position I went to my channels on other TP's only to find I had lost signal strength on them, after doing this back and forth several times I decided to leave it on USALS that I had originally for motor control, I found that I was dead on for 99% of birds on the ARC and that my adjustments could not correct what I thought was unnatural.

In fact I once posted a Wild Feed Find ( long ago ) SBS 6, and remember members here not being able to get it , until one member posted he made an adjustment and it came in fine , I also remember playing around with IA-6 and making an adjustment east and blind scanning , I found a Soccer Feed that seemed out of place , I don't know what happened but it was as if the signal coming down was so wide that my dish was just missing it , but short of being from another bird.

I hope you can enjoy your FTA setup and not lose sleep over warped dishes or Focal Distance , because even with all the right answers it might just be something that may seem unnatural but isn't.

 

[sksatellite]

It could be the tension problem if is clamp type, at least my last couple trouble shooting on two customers are related to tension or the clamp is too tight to the pole. Same quality reading on both frequency, one tp good but other is breaking video, releast the nut a bit on one side of the clamp and problem solved.