What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It
needs power but the only manual I can find says it uses the same
voltage as the dish, and doesn't say how much the dish uses.


Thanks for any help on all my questions.

P. S. I also took off the center part, the receiver or whatever, and
sold it for a dollar or two at a hamfest. They sell new for 50
dollars but tha's okay.

On Fri, 17 Jul 2009 18:27:05 -0400, mm
wrote:

What voltage is meant to be used by 18 inch satellite dishes?
AC or DC?

DC. For simple LNB's, 13V for left hand circular polarization. 18V
for right hand. That corresponds to the odd channels and the even
channels (or the reverse in case I got it backwards). If you're using
a DiSEqC switch, there's also a 22KHz control tone to switch outputs.
Life gets really complexicated if you have a 5 LNB dish.

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It
needs power but the only manual I can find says it uses the same
voltage as the dish, and doesn't say how much the dish uses.

Ugh. I don't know how the VHF/UHF antenna is switched.

Thanks for any help on all my questions.

P. S. I also took off the center part, the receiver or whatever, and
sold it for a dollar or two at a hamfest. They sell new for 50
dollars but tha's okay.

You can also build a wi-fi range extender with the dish:
http://www.findmorecollectibles.com/wifi.html
http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/
http://www.qsl.net/ki7cx/wgfeed.htm
http://www.weijand.nl/wifi/

"Jeff Liebermann" wrote in message
...
On Fri, 17 Jul 2009 18:27:05 -0400, mm
wrote:

What voltage is meant to be used by 18 inch satellite dishes?
AC or DC?

DC. For simple LNB's, 13V for left hand circular polarization. 18V
for right hand. That corresponds to the odd channels and the even
channels (or the reverse in case I got it backwards). If you're using
a DiSEqC switch, there's also a 22KHz control tone to switch outputs.
Life gets really complexicated if you have a 5 LNB dish.

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It
needs power but the only manual I can find says it uses the same
voltage as the dish, and doesn't say how much the dish uses.

Ugh. I don't know how the VHF/UHF antenna is switched.

Thanks for any help on all my questions.

P. S. I also took off the center part, the receiver or whatever, and
sold it for a dollar or two at a hamfest. They sell new for 50
dollars but tha's okay.

You can also build a wi-fi range extender with the dish:
http://www.findmorecollectibles.com/wifi.html
http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/
http://www.qsl.net/ki7cx/wgfeed.htm
http://www.weijand.nl/wifi/


Circular polarisation for US DBS, Jeff ? Over this side of the pond, it's
vertical and horizontal polarisation for alternate channels or whatever, but
with the same selection / LNB powering voltages, and additional switching by
22kHz tone, the same.

Arfa

On Sat, 18 Jul 2009 09:54:43 +0100, "Arfa Daily"
wrote:

Circular polarisation for US DBS, Jeff ? Over this side of the pond, it's
vertical and horizontal polarisation for alternate channels or whatever, but
with the same selection / LNB powering voltages, and additional switching by
22kHz tone, the same.

DirecTV and Dish are both circular polarization.
HughesNet internet is linear (vertical or horizontal) polarization.
FTA (free to air) transmissions are all linear polarization.
Broadcast downlinks (FSS) are all linear polarization.

http://en.wikipedia.org/wiki/Low-noise_block_converter
"Most North American DBS signals use circular polarization, instead of
linear polarization, therefore requiring a different LNB type for
proper reception. In this case, the polarization must be adjusted
between clockwise and counterclockwise, rather than horizontal and
vertical."

This explains it in detail:
http://www.abadss.com/forum/102-faq-how/5880-understand-lnbs-standard-linear-circular-universal-lnb-lnbf-stacked.html



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 17 Jul 2009 22:03:07 -0700, Jeff Liebermann
wrote:

On Fri, 17 Jul 2009 18:27:05 -0400, mm
wrote:

What voltage is meant to be used by 18 inch satellite dishes?
AC or DC?

DC. For simple LNB's, 13V for left hand circular polarization. 18V
for right hand.

Wow. That's amazing.

Thanks to everyone. I should be able to get this working, plus I have
3 amplified antennas in my attic. One or two of them are broken, but I
think I have enough for myself and a friend and his landlady, both of
whom have had very little tv since digital.

BTW, I remember now I sold that thing in the center of the dish for
one or two dollars BEFORE I saw it for sale at Radio Shack for 50
dollars, but that's still okay.



That corresponds to the odd channels and the even
channels (or the reverse in case I got it backwards). If you're using
a DiSEqC switch, there's also a 22KHz control tone to switch outputs.
Life gets really complexicated if you have a 5 LNB dish.

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It
needs power but the only manual I can find says it uses the same
voltage as the dish, and doesn't say how much the dish uses.

Ugh. I don't know how the VHF/UHF antenna is switched.

Thanks for any help on all my questions.

P. S. I also took off the center part, the receiver or whatever, and
sold it for a dollar or two at a hamfest. They sell new for 50
dollars but tha's okay.

You can also build a wi-fi range extender with the dish:
http://www.findmorecollectibles.com/wifi.html
http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/
http://www.qsl.net/ki7cx/wgfeed.htm
http://www.weijand.nl/wifi/

On Fri, 17 Jul 2009 18:27:05 -0400, mm wrote:
What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It

Dishes are passive devices; they are not powered by anything but incoming RF
energy.

A good start would be to learn the difference between a dish,
LNB, and receiver.

"Jeff Liebermann" wrote in message
...
On Sat, 18 Jul 2009 09:54:43 +0100, "Arfa Daily"
wrote:

Circular polarisation for US DBS, Jeff ? Over this side of the pond, it's
vertical and horizontal polarisation for alternate channels or whatever,
but
with the same selection / LNB powering voltages, and additional switching
by
22kHz tone, the same.

DirecTV and Dish are both circular polarization.
HughesNet internet is linear (vertical or horizontal) polarization.
FTA (free to air) transmissions are all linear polarization.
Broadcast downlinks (FSS) are all linear polarization.

http://en.wikipedia.org/wiki/Low-noise_block_converter
"Most North American DBS signals use circular polarization, instead of
linear polarization, therefore requiring a different LNB type for
proper reception. In this case, the polarization must be adjusted
between clockwise and counterclockwise, rather than horizontal and
vertical."

This explains it in detail:
http://www.abadss.com/forum/102-faq-how/5880-understand-lnbs-standard-linear-circular-universal-lnb-lnbf-stacked.html



That's interesting. I wonder what the perceived advantage of using circular
over linear polarisation is ? I can see that polarisation twist from passage
of the signal through the atmosphere would be eliminated, and also skew
caused by your E-W position with respect to the bird. Do you think that's
the reason ? I didn't realise that a c.p, LNB was effectively just an l.p
LNB with a signal 'de-spinner' (lump of ferrite ?) in the feed. As long as
DBS has been going in Europe, which is quite a lot of years now if you go
back to the old analogue birds, c.p. has never been used, which is why I'm
not too familiar with it as applied to microwave signals.

Many of the LNBs here are now multis to allow use of receivers with dual
independant tuners, and the multi-room service which allows two dual tuner
receivers to be connected to the same dish. Do you have multis like this
that still work with c,p, ?

Arfa

On Sat, 18 Jul 2009 17:58:10 -0500, AZ Nomad
wrote:

On Fri, 17 Jul 2009 18:27:05 -0400, mm wrote:
What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It

Dishes are passive devices; they are not powered by anything but incoming RF
energy.

Items sold as dishes include amplifers.

A good start would be to learn the difference between a dish,
LNB, and receiver.

A good start on what?

I'm not really interested in an electronics lesson. I just want to
know what voltage would power the amplifier on the VHF/UHF antenna
that surrounds the dish. The manual says it uses the same voltage
that dish does, or something like that. Maybe you can write the
manual's author.

I'll go with one of the helpful answers.

mm wrote:

On Sat, 18 Jul 2009 17:58:10 -0500, AZ Nomad
wrote:

On Fri, 17 Jul 2009 18:27:05 -0400, mm wrote:
What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It

Dishes are passive devices; they are not powered by anything but incoming RF
energy.

Items sold as dishes include amplifers.

A good start would be to learn the difference between a dish,
LNB, and receiver.

A good start on what?

I'm not really interested in an electronics lesson. I just want to
know what voltage would power the amplifier on the VHF/UHF antenna
that surrounds the dish. The manual says it uses the same voltage
that dish does, or something like that. Maybe you can write the
manual's author.

I'll go with one of the helpful answers.


Why don't you just go away? You gave no brand or model number, or
anything else that would let anyone help you.


--
You can't have a sense of humor, if you have no sense!

Arfa Daily wrote:


"Jeff Liebermann" wrote in message
...
On Sat, 18 Jul 2009 09:54:43 +0100, "Arfa Daily"
wrote:

Circular polarisation for US DBS, Jeff ? Over this side of the pond, it's
vertical and horizontal polarisation for alternate channels or whatever,
but
with the same selection / LNB powering voltages, and additional switching
by
22kHz tone, the same.

DirecTV and Dish are both circular polarization.
HughesNet internet is linear (vertical or horizontal) polarization.
FTA (free to air) transmissions are all linear polarization.
Broadcast downlinks (FSS) are all linear polarization.

http://en.wikipedia.org/wiki/Low-noise_block_converter
"Most North American DBS signals use circular polarization, instead of
linear polarization, therefore requiring a different LNB type for
proper reception. In this case, the polarization must be adjusted
between clockwise and counterclockwise, rather than horizontal and
vertical."

This explains it in detail:

http://www.abadss.com/forum/102-faq-how/5880-understand-lnbs-standard-linear-circular-universal-lnb-lnbf-stacked.html



That's interesting. I wonder what the perceived advantage of using
circular over linear polarisation is ? I can see that polarisation twist
from passage of the signal through the atmosphere would be eliminated, and
also skew caused by your E-W position with respect to the bird. Do you
think that's the reason ? I didn't realise that a c.p, LNB was effectively
just an l.p LNB with a signal 'de-spinner' (lump of ferrite ?) in the
feed. As long as DBS has been going in Europe, which is quite a lot of
years now if you go back to the old analogue birds, c.p. has never been
used, which is why I'm not too familiar with it as applied to microwave
signals.

Not completely true - the UK's old BSB satellite service used circular
plolarisation (quoted as right hand circular which I'm assuming means
clockwise) until the system was killed off by SKY's dodgy dealings - they
persuaded the UK government that BSB would need 2 satellites so there would
be a backup and that they'd need to use the more expensive D-MAC standard
to get good enough picture quality.

The result being it cost a fortune to get new box hardware designed and put
2 satellites up just to broadcast 5 channels (which couldn't be expanded
without launching another 2 satellites) when at the same time SKY were
exempt from UK satellite broadcast restrictions due to uplinking from
Luxembourg and were allowed to rent space on an Astra satellite with space
for 16 channels and using cheaper PAL receivers that were already designed
and available.

When BSB closed down (after only 6 months of broadcasting) the 2 satellites
were sold to Scandinavian broadcasters who switched to D2-MAC and used them
until 2003.

"Nigel Feltham" wrote in message
...
Arfa Daily wrote:


"Jeff Liebermann" wrote in message
...
On Sat, 18 Jul 2009 09:54:43 +0100, "Arfa Daily"
wrote:

Circular polarisation for US DBS, Jeff ? Over this side of the pond,
it's
vertical and horizontal polarisation for alternate channels or whatever,
but
with the same selection / LNB powering voltages, and additional
switching
by
22kHz tone, the same.

DirecTV and Dish are both circular polarization.
HughesNet internet is linear (vertical or horizontal) polarization.
FTA (free to air) transmissions are all linear polarization.
Broadcast downlinks (FSS) are all linear polarization.

http://en.wikipedia.org/wiki/Low-noise_block_converter
"Most North American DBS signals use circular polarization, instead of
linear polarization, therefore requiring a different LNB type for
proper reception. In this case, the polarization must be adjusted
between clockwise and counterclockwise, rather than horizontal and
vertical."

This explains it in detail:

http://www.abadss.com/forum/102-faq-how/5880-understand-lnbs-standard-linear-circular-universal-lnb-lnbf-stacked.html



That's interesting. I wonder what the perceived advantage of using
circular over linear polarisation is ? I can see that polarisation twist
from passage of the signal through the atmosphere would be eliminated,
and
also skew caused by your E-W position with respect to the bird. Do you
think that's the reason ? I didn't realise that a c.p, LNB was
effectively
just an l.p LNB with a signal 'de-spinner' (lump of ferrite ?) in the
feed. As long as DBS has been going in Europe, which is quite a lot of
years now if you go back to the old analogue birds, c.p. has never been
used, which is why I'm not too familiar with it as applied to microwave
signals.

Not completely true - the UK's old BSB satellite service used circular
plolarisation (quoted as right hand circular which I'm assuming means
clockwise) until the system was killed off by SKY's dodgy dealings - they
persuaded the UK government that BSB would need 2 satellites so there
would
be a backup and that they'd need to use the more expensive D-MAC standard
to get good enough picture quality.

The result being it cost a fortune to get new box hardware designed and
put
2 satellites up just to broadcast 5 channels (which couldn't be expanded
without launching another 2 satellites) when at the same time SKY were
exempt from UK satellite broadcast restrictions due to uplinking from
Luxembourg and were allowed to rent space on an Astra satellite with space
for 16 channels and using cheaper PAL receivers that were already designed
and available.

When BSB closed down (after only 6 months of broadcasting) the 2
satellites
were sold to Scandinavian broadcasters who switched to D2-MAC and used
them
until 2003.

Yes, all quite true. I'd forgotten about the BSB service, it's active life
being so short ...

And to Jeff. The 'multi' LNBs that I was asking you about are not multiple
singles on a bracket on one dish, but all inside one standard sized LNB
package, so it's one lump with either two or four F connectors on its back.

Arfa

"mm" wrote in message
...
On Sat, 18 Jul 2009 17:58:10 -0500, AZ Nomad
wrote:

On Fri, 17 Jul 2009 18:27:05 -0400, mm wrote:
What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It

Dishes are passive devices; they are not powered by anything but incoming
RF
energy.

Items sold as dishes include amplifers.

A good start would be to learn the difference between a dish,
LNB, and receiver.

A good start on what?

I'm not really interested in an electronics lesson. I just want to
know what voltage would power the amplifier on the VHF/UHF antenna
that surrounds the dish. The manual says it uses the same voltage
that dish does, or something like that. Maybe you can write the
manual's author.

I'll go with one of the helpful answers.

In order to get helpful answers, you first need to have a little respect for
the people who are trying to guide you. Your question doesn't even relate to
any kind of "repair" - read the name of the group, so you are doing well to
elicit any kind of sensible responses at all. If you are not interested in
learning in order to help yourself to arrive at answers, why should we waste
our time doing your research for you ? I would suggest that you try 110v AC
"or something like that". If it works, you won't need to ask any more, and
if it doesn't, you may learn a valuable lesson in both electronics, and life
....

Arfa

On Sun, 19 Jul 2009 10:13:03 -0400, Meat Plow
wrote:

On Sat, 18 Jul 2009 19:56:09 -0700, Jeff Liebermann
wrote:

On Sun, 19 Jul 2009 01:39:38 +0100, "Arfa Daily"
wrote:

That's interesting. I wonder what the perceived advantage of using circular
over linear polarisation is ?

Perception is everything, except in this case.

There are some technical advantages to CP. With a single LNB, it's
possible to install the dish with only elevation and azimuth, and no
consideration for tilt. However, with 2 or more LNB's, it is
necessary to align the dish tilt along the ecliptic.

US DTV HD dishes are now tilted but I don't recall this in the
beginning of their HD offering. Single/dual LNB are not tilted, at
least mine isn't and there is no aiming spec for it. US DISH network
has always tilted even with one LNB IIRC.

Dual LNB is a single LNB with two front end sections. It is aimed at
a single satellite and can feed two receivers, or a dual front end
receiver (i.e. DVR). A dish with two seperate LNB's, each with 2
outputs or 1 output going to a DISEqC switch, is a different animal as
it's designed to hear two satellites. I try to avoid using the term
dual LNB because it's ambiguous.

I've installed a few single LNB dishes. The dish alignment
instructions and web pages didn't have any provisions for tilt. Only
when multiple LNB dishes appeared was there any consideration for
tilt. It might also be useful to note that the single LNB dishes do
not have any mechanism for adjusting tilt.

With HD, one must see more than one satellite. As usual, Europe does
it with a mechanical DISEqC protocol rotator, while the US does it
with multiple LNB's. Each has their benefits and problems. I wasn't
paying much attention when HD first appeared, but I do recall that it
required a new dish because the feed came from a different bird.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 19 Jul 2009 15:42:34 +0100, "Arfa Daily"
wrote:

And to Jeff. The 'multi' LNBs that I was asking you about are not multiple
singles on a bracket on one dish, but all inside one standard sized LNB
package, so it's one lump with either two or four F connectors on its back.

See my comment to Mr Meat Plow about the ambiguous term "dual LNB".

There are dishes with 5 LNB's and a built in switch. For example, the
DirecTV AU9 Slimline dish:
http://www.sadoun.com/Sat/Products/Winegard/DIRECTV-AU9-SLIMLINE-Ku-Ka-Dish.htm
They have 4 outputs, each of which can be switched to one LNB and
pickup a satellite. The assumption is that there will be a maximum of
4 receivers attached, so that there's no need for a 5th output.

I haven't noticed a 5 LNB dish with only 2 outputs.

Things get rather messy with 7 satellites and 4 receivers:
http://www.satpro.tv/ProductImages/wb68instalation22.gif


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 19 Jul 2009 15:49:48 +0100, "Arfa Daily"
wrote:


"mm" wrote in message
.. .
On Sat, 18 Jul 2009 17:58:10 -0500, AZ Nomad
wrote:

On Fri, 17 Jul 2009 18:27:05 -0400, mm wrote:
What voltage is meant to be used by 18 inch satellite dishes?

AC or DC?

I found a satellite antenna in the trash, and I dont have satellite,
but I saved the clip-on VHF/UHF antenna that goes around the edge. It

Dishes are passive devices; they are not powered by anything but incoming
RF
energy.

Items sold as dishes include amplifers.

A good start would be to learn the difference between a dish,
LNB, and receiver.

A good start on what?

I'm not really interested in an electronics lesson. I just want to
know what voltage would power the amplifier on the VHF/UHF antenna
that surrounds the dish. The manual says it uses the same voltage
that dish does, or something like that. Maybe you can write the
manual's author.

I'll go with one of the helpful answers.

In order to get helpful answers, you first need to have a little respect for
the people who are trying to guide you.

I have great respect for and gratitude to the people who are trying to
help or guide me. I don't believe the previous poster was.

OTOH, two posters gave me helpful answers. One was simple, and much of
the other was above me, but it was still quite helpful. Thank you,
both.

Your question doesn't even relate to
any kind of "repair" - read the name of the group, so you are doing well to
elicit any kind of sensible responses at all. If you are not interested in
learning in order to help yourself to arrive at answers, why should we waste
our time doing your research for you ? I would suggest that you try 110v AC
"or something like that".

I don't remember how the manual phrased it, but it said it used the
OTA antenna, that is the amplifier, used the same voltage as the dish,
an 18 inch dish used either for Dish network or Direct TV, probably
the first one.

If it works, you won't need to ask any more, and
if it doesn't, you may learn a valuable lesson in both electronics, and life

I already know that lesson, and I didn't have to burn anything out to
learn it.
...

Arfa

On Mon, 20 Jul 2009 10:02:15 -0400, Meat Plow
wrote:

Thanks for the explanation Jeff. I thought a dual LNB was actually two
LNBs with different polarizations.

Nope. I finally decided to look inside a DBS LNB and see how they
switch from circular polarization. I couldn't find anything on how
the polarization switching works using Google or anything specific
with a patent search. So, I tore an LNB apart.

There are two probes located 90 degrees from each other along the
circular waveguide. There's also what I guess is a 90 degree 12GHz
phase shifter between these two problems. With the RF amp input on
2nd probe, only CP in the direction coming from the first probe to the
2nd probe will pass. The 90 degree rotation of the signal in the
waveguide coincides with the 90 degree phase shift in the phase
shifter. Going the other direction, the 270 degree rotation of the
signal in the waveguide, cancels with the 90 degree phase shift in the
phase shifter. Move the RF input to the first probe, and it will pass
in the other CP direction. (Disclaimer: This was done without a
schematic and might be totally wrong).

While digging, I found some more detail on control voltage for the
newer LNB's, that work with both CP and linear polarization:
www.intersil.com/data/an/an1161.pdf
12V - Horizontal, 18V - Vertical
13V - Circular right-hand, 20V - Circular left-hand
The major use for this arrangement is frequency re-use. The satellite
can transmit simultaneously on all 4 modes.

But as far back as I was paying
attention, the DISH discs were always tilted even before they offered
HD and it's always been a question floating around inside my head as
to why DTV were not tilted and DISH were way before HD. Maybe DISH has
two LNB devices anyway and looks at two different birds? Or is it
linier vs polarization circular at issue?

Bingo, you got it. With linear polarization *AND* a single LNB, you
must have the tilt correct. With circular polarization *AND* a single
LNB, the tilt is not important. Of course, with multiple LNB's, tilt
along the ecliptic is required.

Incidentally, I've seen ads for transparent DBS dishes, but only for
the UK.
http://www.maplin.co.uk/DiscontinuedModule.aspx?ModuleNo=47234
http://www.pulsat.com/satellite/site/details.php?product_id=330
Nothing available across the pond. What inspired transparent dishes
in UK?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 19 Jul 2009 15:42:34 +0100, "Arfa Daily"
wrote:

And to Jeff. The 'multi' LNBs that I was asking you about are not multiple
singles on a bracket on one dish, but all inside one standard sized LNB
package, so it's one lump with either two or four F connectors on its back.

If it's worth doing well, it's also worth overdoing it.
http://www.wavefrontier.us
16 satellites with 16 LNB's on one dish.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

along the ecliptic is required.

Incidentally, I've seen ads for transparent DBS dishes, but only for
the UK.
http://www.maplin.co.uk/DiscontinuedModule.aspx?ModuleNo=47234
http://www.pulsat.com/satellite/site/details.php?product_id=330
Nothing available across the pond. What inspired transparent dishes
in UK?

--
Jeff Liebermann


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
90 deg to one another. There is then a 'steering' transistor, controlled by
the level of the supply voltage, in each probe channel, ahead of the RF amp,
to determine which polarisation is being listened to.

Arfa

On Mon, 20 Jul 2009 10:12:58 -0400, Meat Plow
wrote:

On Sun, 19 Jul 2009 22:12:45 -0400, mm
wrote:


I already know that lesson, and I didn't have to burn anything out to
learn it.

Your free antenna was designed to use the Sat feedline to not only
power it but to also transfer the broadcast signal to either a Multi
Switch with an antenna output or a splitter provided by the antenna
manufacturer. My old Multi Switch had an antenna output IIRC. This
would block standard brodcast frequencies with the downlink, control
signals and voltages from your set.

If you just have the antenna itself and nothing else you may not have
enough of it to work. What brand/model is it?

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.

Meat Plow wrote:
On Mon, 20 Jul 2009 10:04:37 -0700, Jeff Liebermann
wrote:
[...]
Incidentally, I've seen ads for transparent DBS dishes, but only for
the UK.
http://www.maplin.co.uk/DiscontinuedModule.aspx?ModuleNo=47234
http://www.pulsat.com/satellite/site/details.php?product_id=330
Nothing available across the pond. What inspired transparent dishes
in UK?

Wonder what they are coated with to reflect RF?

Tin oxide, presumably.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Tue, 21 Jul 2009 02:28:18 +0100, "Arfa Daily"
wrote:

http://www.maplin.co.uk/DiscontinuedModule.aspx?ModuleNo=47234
http://www.pulsat.com/satellite/site/details.php?product_id=330

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.

We have something similar with "historic buildings".
http://www.nps.gov/nr/
The owner gets a tax break to maintain the building in good condition.
Dishes aren't totally proscribed, but severely limited. For example:
www.concessions.nps.gov/...pp 26 GRCA Housing Policy.pdf
on Page 6 defines what dishes are acceptable.

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.

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

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.

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

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.

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.

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.

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.
http://www.dishpointer.com
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.

In all of the LNBs that I have looked in, the probes are just pcb tracks at
90 deg to one another. There is then a 'steering' transistor, controlled by
the level of the supply voltage, in each probe channel, ahead of the RF amp,
to determine which polarisation is being listened to.

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

Arfa

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Tue, 21 Jul 2009 02:28:18 +0100, "Arfa Daily"
wrote:

http://www.maplin.co.uk/DiscontinuedModule.aspx?ModuleNo=47234
http://www.pulsat.com/satellite/site/details.php?product_id=330

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.

We have something similar with "historic buildings".
http://www.nps.gov/nr/
The owner gets a tax break to maintain the building in good condition.
Dishes aren't totally proscribed, but severely limited. For example:
www.concessions.nps.gov/...pp 26 GRCA Housing Policy.pdf
on Page 6 defines what dishes are acceptable.

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.

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

Jeff Liebermann

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

On Mon, 20 Jul 2009 10:12:58 -0400, Meat Plow
wrote:


If you just have the antenna itself and nothing else you may not have
enough of it to work.

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
44 and sort of an ad for the 42 clip-on and neither gave a voltage,
but one gave a phone number to call for Terk, so I did, and they
didn't keep me waiting more than a minute or two, and the technician
said my thing, the TV-42 you found the picture of, won't work without
a dish. Just like you suspected.

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:
Your free antenna was designed to use the Sat feedline to not only
power it

Okay

but to also transfer the broadcast signal to either a Multi
Switch with an antenna output or a splitter provided by the antenna
manufacturer.

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. )
http://www.audiovox.com/webapp/wcs/s...4170&langId=-1

I downloaded the manual twice. Both copies kept crashing Adobe Reader
9, but I was able instead to display it in a browser window, using PDF
Download, a Firefox Add-on.

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 old Multi Switch had an antenna output IIRC. This
would block standard brodcast frequencies with the downlink, control
signals and voltages from your set.

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.

**I think I have an old power injector, but I suppose I can make one
if I have to.

What brand/model is it?

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


Thanks a lot.

On Wed, 22 Jul 2009 09:50:49 -0400, Meat Plow
wrote:



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.