Ku Satellite Dish Question

[phlatwound]

..My question is will this affect the elevation now since i'm using a part not designed for the 1.2m Andrew dish? I'll keep the lnb arms and just put my geosat pll lnb. Now i'm trying to figure out if it has to be dead center because the neck is small and it raises the lnb up a little bit. Does it matter if it's the same angle but moved up a little bit? and also the distance? the feedhorn is all the way in the front. Should i move the geosat pll lnb there or can i have it where the neck of the lnb mount is?

I'll try to somehow use the lnb stablizers on the back of the dish once i have my retrofit mount on.

Thanks for all your help guys. Any other ideas or suggestions are welcomed.

My thoughts/wild guesses:

I think if your wood is centered/flush with the dish hole mounting pattern on your dish the elevation/elevation scale reading will not be affected. Even if it is a little off you can still make it work, just have to tweak the angles till it's right.

LNBF/Feed throat placement is critical...any deviation in angle/distance/location could degrade your signal. Need to get it as close as possible to factory spec, the focal point/sweet spot is pretty small.

 

[Grover8]

I got some updates on my dish.

I ordered a second geosat pll lnb and took it apart. Removed the the plastic casing around it and tried to see if it could fit in the neck of the current OMT.

Perfect fit. I was surprised. Below are some pictures.

My question now is I won't have any issues with angle right? and what about distance? Also, since the plastic is off now what can I do to prevent corrosion or rust. There is this new product called Never Wet from rustoleum which is superhydrophobic. Will it work if i spray it?

Getting my other parts Friday and i'll make a trip to the hardware store for a aluminum panel for the back plate.

 

[FaT Air]

Don't know about the Neverwet but I would suppose it wouldn't hurt. Needs reapplication occasionally so maybe WD40 would work as well(?) That's what I've used for that purpose.(BUD's actuator arm) Could also put a 'roof' over the LNBF made out of a 1 or 2 liter soda bottle?
As far as focal point adjustment, going to have to get it on a satellite and see if moving it makes a positive difference. I just have a feelin' that's it's going to be just a little too far from the dish.

 

[primestar31]

WD40 is basically Kerosene, so I really would NOT spray the lnb with that!

It may be good for many things, but I don't know where people get the idea that WD40 makes a good waterproofer for electronics....

 

[SatelliteAV]

No need to worry, corrosion and rust will not occur. I would shade the case from direct sun or paint it white to avoid heat build-up in the case mass.

I agree, that the feedhorn will be too far away from the reflector and will be out of the sweet spot. Probably will need to move it forward so the scalar is in a similar position as the original.

Maybe use a polarity switching LNB such as an original Prime Star dual polarity "pop can" or Invacom SNF-031 / QPF-031 LNBs and attach to the OEM scalar/feedhorn. I am confident that these LNB solutions would provide much better performance.

 

[Pi314]

LNB Shade - WD40

Primestar31,
I do not mean to detract from avenger’s thread; however your interjection that WD40 is kerosene is troubling. I used to know many nursing home residents that used it for their arthritis.


FaT Air,
per your suggestion with a two liter bottle shade; that is a great low tech solution.

 

[avenger]

Just modified a bracket to accept the Invacom SNH-031, it places the LNBF to the face of the dish as close to the original LNB setup...Still don't know if the small PLL LNB can be use for FTA....Took some picture and will post them later on.

Using the non-roof penetrating frame, and intend to locate the 30W satellite. Had to set the dish Elevation to 17.5° so had to put the frame on top of two tier of cement blocks, to keep the dish from being so close to the ground, will play with the setup tomorrow, and still have my doubts on viewing the 30W Satellite from my backyard location.

Took some measurement of the non-penetrating frame, it is a perfect square of 5'3", the mounting tube is 2 13/16" OD.

The yard is not quite level so will have to use something to make the frame as level as possible.

avenger.

 

[Grover8]

I got to work on dish today. I had to go my local hardware store to pickup some parts and also an aluminum panel. See photos below.

It shaved off a lot of weight but the dish is still heavier than most 1.2m. I tried putting on the HH120 and i didn't get a signal. I don't know what to tweak since the dish moves a lot since it's so heavy.

I'm in New York City, so my latitude is 41 degrees and for the HH120 dish elevation is 24 degrees. So far so good? I did a little adjust for the lnb and made it as far possible to replicate the original feedhorn.

Nothing, even on the strongest satellites. Next thing I'm going to do it just make it point it at one satellite on a stationary mount (no rotor/motor). See if i can get a signal.

Moving up to a 1.2m made it so that I have more stuff blocking it. The 90cm could get a signal because the surface area was smaller. Now my dish is being blocked by my tree and other crap in the backyard.

 

[tlzon]

(Andrew / ASCsignal /Global Skyware 1.2m Ku long focal length offset dish) I know this thread is now a little old now, however I have acquired one of these dishes in good condition but without the three main struts (arms) that hold the LNB. It looks like it would make an excellent FTA hobbyist dish. Wondering if there is a forum member that has one of these dishes and would be kind enough to measure and provide the dimensions (length: bold hole to bolt hole) of the left and right arms as well as the arm that connects to the bottom of the dish? I would greatly appreciate it and would allow me to manufacture new arms and get this back into service with minimum of trial and error.

 

[RimaNTSS]

(Andrew / ASCsignal /Global Skyware 1.2m Ku long focal length offset dish)

Could you show couple of pictures, back and front. Instead of trying to replicate original feedarms and LNB-holder, I would find-out exact position of the Focal point of the dish and then make feedarms and LNB-holder in such a way that LNB's Phase center is co-located with antenna's Focal point. I just made new feedarms for Channel Master 1.2m thread is here.