What voltage for 18 inch satellite dishes?

However with a true single DTV LNB I don't recall a dish tilt (emphasis upon if I recall seeing any DTV before they went dual.) This would mean that the polarization is linear.

From the very begining of their existance that I know of DISH have always tilted indicating circular polarization unless they started out with two LNBs.

Somewhere in the thread I thought I read all US sats are circular polarized. If I'm correct then this isn't true.

Wonder what they are coated with to reflect RF?

If it's worth doing well, it's also worth overdoing it.

Planning laws and building covenants can be very odd here. Many old buildings in towns and villages are protected by a National Trust 'listing'. Depending on the level of the listing, all sorts of provisions are made about protecting the exterior appearance, and with high level listings, even the internal features, down to decor in some cases. On buildings like this, and indeed on some new buildings, the likes of satellite dishes are expressly forbidden, particularly if they impact on the 'public' face of the building. As far as I know, transparent dishes were developed to try to get around this, and I believe some planners and listing inspectors, were sympathetic to their use. I don't know how successful DBS has been over there, but here, probably 60% or more of houses in any given street, have a dish bolted on them, so disguise is quite a big issue in some areas. To that end, I believe that there were some 'microwave friendly' paints developed as well, to allow the dish to 'disappear' chameleon-fashion.

The coating on these transparent dishes is just a very thin vapour deposited metalic coat as far as I recall reading somewhere long ago. I guess that it's just the same sort of thing as the 'transparent' electrodes on LCD and plasma screens.

As to the rotation of the LNB for linearly polarised skew correction, all of the DBS dishes here are offset eliptical types, and have a fixed horizontal attitude. Adjustment for azimuth and elevation is carried out by the X - Y mounting bracket, but skew is carried out by rotating the LNB itself in its clamp, which is a split circle around the waveguide throat, with a screw to pinch it up. A right hand twist (looking from the front) of around 10 deg is about right for the UK, but I guess with the USA being rather wider than us, your range of required skew correction could be a lot more than that, and even in both directions if your birds are located centrally.

In all of the LNBs that I have looked in, the probes are just pcb tracks at

Arfa

It's a Terk, but I can't find a model number. There's a ragged piece of paper glued to it that might have been a label.

It has a circular plastic box in the middle with 4 coaxial connectors, marked 1, 2, 4, and 4. The first two are also marked IN and the second two are marked OUT.

Tin oxide, presumably.

We have something similar with "historic buildings".

The owner gets a tax break to maintain the building in good condition. Dishes aren't totally proscribed, but severely limited. For example:

on Page 6 defines what dishes are acceptable.

About half the UK density. Satellite 30 million (about 31% of US homes passed) CATV 60 million (about 62% of US homes passed)

Yeah, that sounds reasonable. They could probably also have used a thick transparent plastic pipe for the mount, but didn't.

Rotating the LNB works just fine for a single LNB. However, the dish tilt (skew) is intended for multiple LNB arrangements, where the LNB's need to be line to to be parallel to the satellite belt (ecliptic). Also, if you look at the photos of the multiple LNB dishes, you'll probably note that the LNB has a large overhang and are jammed together. Therefore they cannot be rotated.

Well, let's see. From my house on the left coast, I get 105.5 degrees skew for the 3 DirecTV birds (101, 110, 119). Moving to the east coast, I get 53.3 degrees for the same birds. Yeah it varies.

However, for a single location anywhere, the variations in skew are minor over a 121-101 = 20 degree window. However, if the dish were trying to see birds from horizon to horizon, the variations in skew would need to be considered.

Yep. That's the way it works for linear polarization. I was wondering how it works for circular polarization switching.

I saw a "This Old House" programme with Steve and Norm where they were working on an old place up Nantucket way somewhere as I recall. On an island anyway. This place had an historic buildings listing, and the owners were made to jump through hoops to keep everything about it original. But at least over there, you are encouraged to do so with tax breaks. Over here, there is no such thing - just a potential bunch of heartache, if you take on one of these buildings which, although it might have a grade one listing, has been left by National Heritage or the National Trust, to decay into a pile of rubble.

We have a programme here called "Grand Designs". I'm sure that one of your cable DIY channels probably carries it. In the last series, one of the programmes followed a guy who had bought what was literally a pile of stones on a remote hillside, with a view to restoring it to the small castle that it originally was. Despite this place being grade one listed, and having been left to decay for decades, he was offered no help financially or otherwise, to do the work. However, once he had started, then the listing body kicked in at full power, starting archeological digs on the site, and insisting that everything was restored exactly as per the records that existed before the building had crumbled to nothing - and I mean nothing. No roof, no floors, almost no internal walls, and full of plants and trees. It cracks me up that they are prepared to watch the place decay to nothing, but as soon as someone shows an interest in restoring it, suddenly, they care, but have no practical or financial help to offer.

Anyway, this guy was an architect by trade, and slowly managed to win grudging admiration from the inspectors for his efforts, to the point where he managed to successfully argue the case that buildings were 'living' records and testaments to the times that they had survived through, and that this particular building had been altered and modified and extended by every owner since it was first built, and that as a consequence, he should be allowed to add his own personalisation. They eventually agreed that he could add a pitched slate roof to the top, where it was originally flat, and that he could build the side of that roof which faced the nice view across the hills, fully in glass.

This he did, leaving a flat area in front, to provide an 'attic' room with a terrace in front of a fully glass wall, which opened right up. Being right on the top - I would guess 60 or more feet up - the view was magnificent, as you might imagine. The Heritage people were so impressed with the sympathetic restoration work that he did on the place, and the modifications that he made which fitted in seamlessly, that they offered him either a job or a consultancy position - I can't remember which now. I was glad to see this realistic and sensible attitude, but it often doesn't prevail. We have another programme called "Property Ladder" which follows first time property developers, who often make the mistake of buying a listed building at auction for pennies, hoping to turn a huge profit. They will do things like fit an entire set of home entertainment wiring, only to then find that they are not allowed to put a sat dish or antenna on the outside of the building ...

We have a lot of cable here now, providing similar huge amounts of programming as the sat service. In fact the biggest provider, Virgin, carry a number of the sat programmes as well, when they are not falling out with each other. A few years ago, there was a big push by the government to get the whole country cabled up, probably to shove a pair of fingers up Mr Maxwell's nose, as there is a long and historic animosity between he and they, but that seems to have stalled now, probably due to financial constraints, so in the meantime, Sky satellite services continue to flourish, particularly now that they are the largest carrier of HD services, allbeit for an additional subscription ...

Arfa

Does it look similar to this?

It turns out you're right on. And thank you for posting the .jpg file for the TV-42 in another post.

To make a long story short, I found printed matter, a manual for the

I asked him if there was a way around it and he seemed truly sorry to tell me no. So I guess there isn't. But now that I've had 4 hours to think about it, I don't understand why not.

I re-ordered your post:

Okay

A multi-switch with an antenna output? Can't I just use one or the other of the two connectors labeled Output, and connect that to a digital tv or a digital converter box?

Does the power for the amp come in through one of the Input connectors? If so, I could run a second co-ax line to power the amp.

In addition to the TV-44 and TV-42, I found the HD-TVo, (which is a stand-alone antenna, that looks like the other two but it has a sword-like or Xmas-tree-like looking thing in the center. )

I downloaded the manual twice. Both copies kept crashing Adobe Reader

The HD-TVo comes with a "Power Injector with 110v AC to DC power adapter"; but it doesn't say what the DC voltage is. That's when I decided to call Terk. He said 12 volts, center pin positive, which was in the range you gave. But then I asked about the TV-42, and he said it won't work alone.

BTW, somewhere I came across instructions for the whole dish including the power supply, and just like you said, Jeff, it was 13v for one half and 18v for the other half. That's so strange to me, but please don't anyone waste his time trying to explain it to me.

My tv set? If I'm not using, don't need a Multi Switch, would there be anything to block the standard broadcast frequencies?

I could spend 80 dollars and buy a new one, complete with a bracket and a power supply and that thing they call the power injector**, but that's not the point. I love trying to make things work.

Terk TV-42. There is also a TV-44 but it has 4 pairs of In and Out coax connectors.

Thanks a lot.

Anything will do, the dish is just for mounting and I would think the Terk would work as good on a mockup dish built from anything metallic or not.

Doesn't have anything to do with your situation.

If you truly want to use that antenna you need to mount it on a mock dish. Then you need to apply voltage to it through one of the coaxial connectors. With a real dish you would use diplexors on both ends. How you separate the DC from TV signal is up to your ingenuity.

Remember this antenna is omni directional and its performance will depend on how well/high its mounted and distance from transmitter. If you actually get it working in some semblance of normalcy I would expect it to have a range of no more than 60 kilometers.

Can't add anything else so good luck.

I plan to give it a try. Not right away though. I'll try to post back any results. Thanks a lot.