What's New At Skyvision?

[mikekohl]

As many of you know, I have been burning the candles at both ends in recent weeks, commuting between Fergus Falls, Minnesota and Plain, Wisconsin, racking up about a thousand miles of driving a week.

Please click on the following link to see the monster that I have just created for Skyvision: Skyvision Free To-Air Free TV

This is a 1.8 meter commercial Prodelin transmit/receive Ku-band offset antenna that has been Frankensteined for 12 satellite reception. In this case, I had simultaneous reception from 79, 83, 87, 89, 91, 93, 95, 97, 99, 101, 103 & 107.3 West satellites on the same antenna.

Main support beam is 3/4 inch conduit, which is far superior to the usual 1/2 inch material, with a new twist: separate elevation sub-brackets to coincide with the center of the arc, and minimize the length of LNBF adjusters.

In normal situations, it appears that I have the proper mix of beamwidth and gain to supply usable signals over a 35 degree east-west azimuth span at temperate latitudes similar to the 40 to 50 degree north locations that I have been working in. Using a 1.8 meter antenna, I find that I can do 2 degree equatorial spacing on most Ku-band satellites, with the occasional persuasion required at times, by playing with the in and out distance and squeezing another LNBF in between existing devices.

Those to the extreme south will find a smaller number of satellites available due to the greater than 35 degree local azimuth differences encountered as you get closer and deeper into the tropical latitudes closer to the equator. But in any case, it beats using lots of smaller antennas. And you can throw in the odd C-band offset conical adapter near the center of the dish for extra fun. But much better results with that mix will happen if you use a 2.4 meter offset.

Mike Kohl
globalcm@mhtc.net

Global Communications Plain, Wisconsin
AND
Skyvision Fergus Falls, Minnesota

 

[skysurfer]

What's the point of all this effort other than hopefully putting a good bunch of money in your bank account?

Skyvision is for typical installation stuff, not advanced/experiemental hobbyist things. I don't know any advanced hobbyist that obtains things from Skyvision unless the item needed is rare enough that Skyvision is about the only source for it.

Did Skyvision have you do this so they can more readily create FTA charts for their website?

 

[mikekohl]

Everyone's entitled to their opinion, but I hope that your negative thoughts are in the minority! Truth be told, I can dream about possibly getting some commercial referral installations from exposure on the Skyvision website. There are lots of people out there, even broadcasters and other users of multiple Ku band antennas, who can recognize value and quality. A single 1.8 meter offset antenna can cover 35 degrees of local azimuth with at least a dozen LNBFs in the system pictured. Two such antennas could cover the entire domestic Ku-band arc from 72 to 129 West in many parts of the country. The extreme southern U.S. may be an exception, because azimuth differences change dramatically as one approaches the equator.

Skyvision has been doing retail sales since 1983, to a customer base that numbers many thousands. Many of these customers no longer have a dealer that they can trust for local service, so they turn to Skyvision for advice, parts, and sometimes even moral support. Not every dish owner may have the time and experience that you and I possess in this industry, but rather than belittle these folks as an exception, they should be encouraged to continue in this hobby, or in some cases...their business, which needs the tools and facilities described. Not every member of these forums is technically able to put together their own system. Many or most are....but there are a lot of dreamers that need more encouragement to show them what is possible. A picture is said to be a thousand words, so what better example than a refurbished commercial transmit-receive reflector that has seen a rebirth through the addition of 12 LNBFs, some hardware, and cleverly bent electrical conduit. It may have resulted from rocket science, but does not necessarily have to be that complicated.

If someone wants to have the finished product, we are showing how to be contacted for questions, advice and more. I look forward to other comments from anyone genuinely interested in using heavy duty hardware to replace a collection of smaller antennas.

 

[PopcornNMore]

Very nice work Mike! The Channel Master 1.8m commercial offset antenna that I have stored in my garage looks very similar to the Prodelin. Perhaps i'll try multiple LNBF's on it someday.

 

[turbosat]

That is a thing of beauty Mr Kohl! No waiting on tha motor to move the dish.

 

[SatelliteAV]

A photograph is worth a thousand words.... Very Nice Demo Install!

 

[tdti1]

Skyvision has been around for a while, and I'm sure nearly every big dish user that is still using there dish has had dealings with them at least once.

Nice job Mike.

 

[dfergie]

Thats way cool Mike ... I've ordered from Skyvision myself once or twice

 

[Cadsulfide]

Mike;

Nice setup! Any signal strength problems at the periphery ?

 

[tvropro]

Skyvision is great. I ordered from them a few times. I also ordered from Mike direct, he is great too. Skyvision and Mike Kohl of Global Communications are a very important part of the satellite industry. They want to see it move forward. I just wish Skyvision had the clout to get a new receiver built to replace the 4DTV for HD, megapipe etc. Maybe some day they may get that to happen. That's whats needed to keep subscription tv on the bud around for the long run.

Good job Mike on another fine design in American ingenuity.

 

[linuxman]

Very Nice Job!!!

You have proven it can be done.

I didn't do that well on my Prodelin, but of course, I'm not a pro, and don't have professional meters to do the tuning.

Can you give us some signal readings on your various LNBFs especially on the outer edges.

Also how about some detailed close-up pictures either on Skyvision's website, or post them here?

 

[Scott Greczkowski]

Mike I love it when you frankenstein stuff.

The Skyvision folks are good people, please tell Del that I said hello.

 

[dougbrown]

Mike, your work is very interesting for me. I recently obtained an old Hughes Earth Station dish that is at least a 1M maybe larger ( I have not been able to measure it yet), offset elliptical. My first desire was to motorize the beast, but is soon became obvious that that would not work. When I saw what you are doing I thought to myself "aha, thats just what I need". So thank you for the inspiration.

 

[Corrado]

Excellent work Mike. Projects like these keep it interesting for all of us. It's a good pastime to work with for the advanced hobbyist.

I have a second Prodelin with my name on it on a 2 story building and this might be a fun thing to do with it. I started thinking about it when Linuxman was working with his. Those dishes can be had for free at many auto dealerships that no longer use them.

I have been dealing with Skyvision for over 20 years. Personally purchased 4 receivers and repair parts from them over the time. I remember watching their TV programs years ago. I think their catalogs introduced many to what FTA was intended to be.

 

[Frenchophile]

This is the kind of thing that would appeal to someone with limited technical expertise but who REALLY wants FTA. it's like FTA made easy. aesthetically and logistically, having two largish antennae beats having multiple small ones.

Mike: could you swap out any LNBs for dual Ku/C? from what I've read, people have gotten some success getting C with the 1.2 m.

 

[mikekohl]

Thank you everyone for the kind comments, questions, and suggestions.
Let me attempt to address the questions:

I have calculated roughly a 35 degree azimuth range at our latitude of 46 degrees North, without major dropoff...then it falls like a rock.

79 West was a major challenge, with slight dropoff...but I get Telemundo from NM quite reliably. Trying 74 West for ONN is doable, but quality readings struggle to get into the low 50s. The antenna is boresighted at 93 West in our situation.
On the west end, 107.3 is quite strong...giving me reliable reception of those 4:2:2 and other encoded video signals. But going only four more degrees to the west in search of 111.1 (Anik F2) is almost like looking for a needle in a haystack. Not enough signal to register a usable picture.

Every geographical location is different, but my calculations tell me that one antenna centered on 87 West should cover 72 to 101 West in most areas, and a second antenna centered on 116.8 West should work for 103 to 129 West.

Calculations for Fergus Falls:
Satellite Elevation Azimuth

129 West 27.8 221.9
116.8 33.0 207.6 Spans azimuth of 32.4 degrees
103 36.3 189.5

101 36.6 186.8
087 36.0 167.5 Spans azimuth of 38.5 degrees
072 31.7 148.3

It becomes a balancing act, whether you want to favor the west or east part of the arc, and will vary greatly between the northern and southern U.S. states.

Try same numbers for New Orleans, at 29.9 North:

129 West 35.3 238.3 Spans azimuth of 33.6 degrees,
116.8 44.6 225.3 but over a range of 17.1 in elevation.
103 52.4 204.7

101 53.1 201.1 Spans azimuth of 54.4 degrees,
087 55.0 173.8 but over a range of only 5.1 in elevation.
072 49.9 146.7

Clearly a New Orleans installation would mean shifting the western dish a few degrees to the East, and a major elevation bracket modification...but an eastern dish will simply not cover the over 50 degree swing in azimuth range.
Locations in the south may actually need 3 antennas to properly cover 72-129, as compared to their cousins north of the Mason-Dixon line. It all about math, and must be considered individually in each location, as no two places are the same.

The conical scalar feed adapter will allow use of one of these antennas with a C band or even a C/Ku feedhorn. May be a tricky adjustment, but it should work well within five degrees of the center of the reflector. Would recommend using a 2.4 meter offset however, for less disappointment in C band results. But the improvements in dB readings versus a prime focus with conventional feed are significant. One other thing to mention is that the conical scalar adapter takes a lot of physical space, so you will limit the number of other LNBFs of any type that can fit within the usable space. Choose your placements wisely after doing some experiments near center to see the full gain potential of the contraption. Also...one trick with the conical adapter is to FIRST find the signal's focal point hotspot WITHOUT the conical device. It will be reduced, but you will be rewarded when the conical device is slipped onto the feed assembly. There will be a dramatic shift upwards in signal almost like magic, when you find it. Trying to both find the focal point and perfectly adjust the conical ring can result in completely missing the best location due to inadvertently setting that ring near a null point on the feed. It's trial and error, so be patient and organized.

End of tonight's lesson from Professor Mike

 

[Sadoun]

Mike, nice work and beautiful setup. If anyone has a 1.8m dish, this would be a nice way to go to capture 35 degrees of the KU ARC. BTW, the T90 toroidal dish also achieves similar results within the same arc range.

We have attempted to stock the 1.5 and 1.8m offset dishes in the past, but the shipping to customers is way to expensive.

 

[Anole]

Very clever:

The following is just my opinion from examining a few very small pictures.


Mike's had similar designs on his site, using the 6' Prodeln, and other dishes like a Primestar 84e.
In the past, LNBs were mounted onto that big sweeping "square-U" shaped arm.
As long as it followed the correct path, all was well.

This latest creation seems to improve greatly on old ideas. -
The big "U" is no longer a critical part of the LNB path. It's just a general mounting guide.
That short, somewhat "V" shaped sub-bracket, flies above the "U", and takes the LNB holders.
Now, you have a smaller, simpler, mounting arm, which is easier to rebuild if you need to optimize it.

Also, note the screw adjustments at each end of the "V" bar.
That gives both stability and fine tuning ability to the entire LNB support line.
It also lets you locate the dish east/west across the country, or aim it far from your TS bird, and not have to fabricate so many custom pieces.

The angle or curve of the (not really) V-shaped piece can be tweaked for north/south dish locations, to optimize LNB placement.
One thought I had, that may or may not be implimented, is that the "V" may be rolled about its axis to optimize LNB locations when the dish is used far north or far south.
Otherwise, just that one "V" structure needs to be custom-built for a given site.

Something not supported by the pictures, the flying V could be put an inch closer to the dish than the bottom of the U.
This would allow the line of LNBs to cross from above to below the central mount point.

For a guy who wants to make this work anywhere, it's a brilliant collection of new and old ideas! -
A home builder, who just needs to get his one dish working, might want to simplify to a custom one-of.
However, following Mike's plan would sure get ya there in style! -

Kudos, Mike!