Dielectric plate ?

[Channel Hopper]

The design of a Ku band depolariser has not advanced much in 20 years, maybe this forum and members can come up with something groundbreaking.

 

[macssam]

is there a Ku / C-Band Feed Horn
which has no servo motor like "chaparral"
and could be hooked up to a DM800

I have problems receiving circular
with my Ku / C-Band all in one lnb
when the Dielectric Plate is inserted
many other signals are gone or very low

 

[macssam]

You can, but you would need to build a simple square wave generator with variable control. About 20 components and two hours work, unless you go for a flip-flop design using an integrated circuit.

A circular depolariser system will always lose some signal when viewing the linear channels, really the only way is to fully remove it between satellites.

+

please provide some building instruction for a
"circular depolariser" system ...

 

[nelson_b]

+

please provide some building instruction for a
"circular depolariser" system ...

hi - macssam -

what -make/model number l.n.b. are you using at the moment - is it a C / Ku combined ? --

have you tried making a plate like the one in the link below --- that " doctorofsat " posted -- or the ones shown in post 65 or post 94 in this thread ---
http://www.satellites.co.uk/satelli...1253355326-doktorofsat-setup-plate-c-band-jpg

you will still probably need to remove the plate to get the best from your existing H and V transponders though

a corotor may be the only way to get all types of transponder ? --
but as you said you will need a different reciever or device to drive it


regards nelson.b .

 

[macssam]

after glueing aluminum strips to the dielectric plate
which came with the Ku/C-Band lnb
as in the instructions I found here
I don't get any signals anymore
with the original dielectric plate most signals cone

 

[Satcom1]

after glueing aluminum strips to the dielectric plate
which came with the Ku/C-Band lnb
as in the instructions I found here
I don't get any signals anymore
with the original dielectric plate most signals cone

Seems like you are getting things confused. The Doktorofsat Dielectric plate was made on a 1 mm piece of plastic. You seem to be using the fiberglas dielectric plate which is about 5 mm thick.

 

[macssam]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

 

[macssam]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

 

[nelson_b]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

nothing that i,m aware of -- macssam --

A bigger dish might override - the signal strength loss on the linear channels caused by the dielectric plate ----
what size dish are you using at the moment -? ----
is it a prime focus or offset dish ?

regards nelson.b.

 

[nelson_b]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

nothing that i,m aware of -- macssam --

A bigger dish might override - the signal strength loss on the linear channels caused by the dielectric plate ----
what size dish are you using at the moment -? ----
is it a prime focus or offset dish ?

regards nelson.b.

 

[Satcom1]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

Sorry ol' Bean, not sure what you are asking.

If you want a Ku/C band circular OR linear lnbf combo, try the DMX741 or the BSC621.

 

[Satcom1]

is there a non servo Ku C-Band feed horn
with all polarity lnb's
which can be hooked up to a DM800

so I can forget about the dielectric plate issue

Sorry ol' Bean, not sure what you are asking.

If you want a Ku/C band circular OR linear lnbf combo, try the DMX741 or the BSC621.

 

[afry]

Hi friends ..
Still experimenting with this dielectric plate ..I was lying in bed last night when it occurred to me that I might be able to part polarize the circular 'signal cloud'/transmission _outside_ the lnbs thoat & just above the scalar rings..

This morning I cut a larger 'T' shaped piece of polythene cutting board ..
and placed this in the open throat of the pauxis..
To my amazement ...the signal/quality improved dramatically ..

ERTU 1 west now showing

Signal 31 %
Quality 45 %
All pictures are now pixel free and totally stable under a cloudy sky ..
Now to find a sheet of PTFE/TEFLON... ;)

rgds
VS

please you know what size dielectric plate you use ? (length, width and thickness)

 

[Vipersan]

Hi Afry..
The large T shaped plate is cut from a single piece of polyethylene cutting board ...
..the kind of thing sold for chopping vegetables or meat in the kitchen...
The section of the T which fits inside the LNB throat is 62mm wide by 85mm long..
The top part of the T which stands outside the lnb and bisects the scalar rings of the feed plate is 62 mm deep by 124 mm wide
The whole plate is approx 7.5 > 8mm in thickness
In my case the surface is slightly rough ...it was made this way to prevent it sliding when used for its origional purpose as a chopping board.
rgds
VS

 

[afry]

Hi Afry..
The large T shaped plate is cut from a single piece of polyethylene cutting board ...
..the kind of thing sold for chopping vegetables or meat in the kitchen...
The section of the T which fits inside the LNB throat is 62mm wide by 85mm long..
The top part of the T which stands outside the lnb and bisects the scalar rings of the feed plate is 62 mm deep by 124 mm wide
The whole plate is approx 7.5 > 8mm in thickness
In my case the surface is slightly rough ...it was made this way to prevent it sliding when used for its origional purpose as a chopping board.
rgds
VS

whether the dielectric plate that measures 85 mm in length in all the LNB? or how many mm that went into the hole of the LNB? (because I see in your picture does not seem to enter the pit LNB all)
thanks

 

[Vipersan]

Hi Afry..here is a diagram I've just made to show how the plate fits ..
You can shorten the 85mm dimension to allow the plate to fit snugg up to the throat/mouth and scalar rings ..
..if your lnbf has not got sufficient depth.
rgds
VS

 

[Satcom1]

Simply by adding a metal object to the flat Scalar claims of 15% SQ improvement.

Doktorofsat or anyone else, can this be confirmed with your testing?

The object must be at the 3 o'clock position, when installed on the lnbf.

 

[doktorofsat]

Hello Satcom1


What kind of metal is there?

I think is Al or something else I see that is welded there !!

I'll made some tests of course but in thede day I had some hadackes only today I fell better

BestRegards
DoktorOfSAT

 

[afry]

more detail please... what is that ?

 

[afry]

Simply by adding a metal object to the flat Scalar claims of 15% SQ improvement.

Doktorofsat or anyone else, can this be confirmed with your testing?

The object must be at the 3 o'clock position, when installed on the lnbf.

more detail please... what is that ?