7.5' Aluminum dish

[rrob311]

I have a line on a spun aluminum dish of this size. Any ideas on how I should go about transporting it? Its probably 2 hours away from me but I want a solid dish like this for Ku band.

[rrob311]

I am looking to get another dish around this size to put in a spot to get 131w-139w. I just checked the area and I think I can get a clear LOS to these. Should a 7.5' dish be sufficient for these birds or would 10 be better? Probably looking to get 116.8 as well.

[Costactc]

7.5' will be sufficient for most tp Rob but the more difficult mpeg-4 channels might be a bit glitchy. Bigger is always better in our biz.

[rrob311]

The area I plan on putting it is kind of marshy. I was planning on doing an above ground mount for it. I have my SAMI 7.5 on a pallet mount but I use that for 37.5w-83W.

[rrob311]

Scoped it out today. Here are some pictures. I will need to make a new mount and button hook for it. It is a Regency roughly 7.5-8'

[eastof111]

Nice find Rob.... I like the logo imprint too!

[rrob311]

Ya if I get it I am going to stencil in the original logo.

[rrob311]

Well that was a fun trip. I just got back from Greenfield MA picking up the dish. I rented a full size pickup from Uhaul and strapped it down. The dish only stood up on me once. So after that I resecured it and it made it all the way back to NH with no damage.

[eastof111]

Congrats on getting the dish back safely!

[rrob311]

I started designing dish parts for this today. I calculated the f/d ratio to be .28 which is on the far end making this a deep dish. My invacom adf-120 feedhorn is advertised as being adjustable from .32-.43. I found a spec sheet for it which is posted below. Hopefully there is a way to get more adjustment out of the adf so I can use it on this dish. I have a few different lnb's that I can try out on this. In the meantime I am going to try to temporarily mount an lnb on this to see what kind of performance I can expect.

[el bandido]

The side view in post 5 does not look that deep.

[rrob311]

It's 90" in diameter and 20" deep. From what I have gathered the depth is about the same as the Winegard Pinnacle dishes which I have heard good things about.

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[el bandido]

I do not know what the thread pitch or the diameter is on the Invacom piece. You may need to add a few more threads for best reception. Install it and see what you get first. If you screw the scaler ring all the way in and the signal is still climbing then you probably need to add a few more threads.

[rrob311]

I misplaced my feedhorn and have been searching for it today. I don't know if the diameter of the threaded part stays the same to where its not threaded. If it is I can order a die to make more threads. Otherwise I will have to grind it off I suppose. I have a Norsat 4508a I would like to try out along with an Inverto quad

[el bandido]

I just looked at mine. Not much of a way to add more threads to it. It will be a challenge to get lnb parts that are a precise match for a dish that deep.

[rrob311]

It looks like Chaparral sold a "golden ring" which extends the throat of the lnb slightly to allow f/d ratio adjustment from .28-.33. If I can obtain a spacer that fits the front of the adf-120 I should be able to maximize the reception on this dish. I think I only need a few millimeters of extension.

[dr.zin]

I remember the ring from an lna I bought in the 80's but never had a chance to use.
Would that be something I need on a modern lnb/ 8.5' dish?

[rrob311]

If the f/d ratio is less than like .32 you would want to use it. Feeds that support a lower f/d ratio are hard to find. Do you know what the f/d is on your 8.5' dish?

[dr.zin]

I didn't get the dish yet,I was just wondering for when the time comes.
Spun aluminum 8.5'

[rrob311]

Here is a calculator for determining f/d:


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[dr.zin]

I remember the ring from an lna I bought in the 80's but never had a chance to use.
Would that be something I need on a modern lnb/ 8.5' dish?

A moot point,since the original feedhorn diameter is smaller than a modern C/Ku the ring just slides inside a modern lnb all the way.
The original scalar had to be reamed out to fit the new one after looking at it again.