Wanted c band waveguide polarizer

[Spiff]

Wanted a C band waveguide polarizer or DIY design : )

Something to improve on my dielectric plate.

God Bless Spiff

 

[Channel Hopper]

What is on the front of your dish at the moment ?

You sold me something a while ago.

Do you want it back ?

 

[moonbase]

Spiff,

Unless you can source a C-Band polariser second hand from this forum or another forum your options to buy new would probably need the item to be imported.
The three suppliers I know of are AV-COMM, Prodelin and one in Brazil.

The Brazil supplier sells the pin pipe at low cost but you get hit by postage, if there was enough interest in a mini group buy it might help with postage costs.
I think the supplier will ship to the UK.

Pin Pipe

Tubo Prolongador Para Lnbf Banda C Circular - R$ 79,56

Encontre mais produtos no Mercado Livre

produto.mercadolivre.com.br

AV-COMM

C Band Waveguide Polariser - Av-Comm

Our C Band Waveguide Polariser is the highest performance method of converting circularly polarised C band signals to linear polarisation.

www.avcomm.com.au

C Band Dual Polarity Circular Polarisation Kit

Our C Band Dual Polarity Circular Polarisation Kit is designed to provide an economic yet high performance solution for the reception of circularly polarised C Band satellite signals.

www.avcomm.com.au

Prodelin Rib Tickler
The C-Band polariser from Prodelin is very well made, quite heavy and has stepped ridges in a square pipe with adapter flanges at the ends
You can sometimes find them on eBay (USA) but again there is shipping to the UK.







Good luck in your search.

 

[s-band]

C Band Dual Polarity Circular Polarisation Kit

Our C Band Dual Polarity Circular Polarisation Kit is designed to provide an economic yet high performance solution for the reception of circularly polarised C Band satellite signals.

www.avcomm.com.au

I've got one of these that I have only ever used briefly and don't really need. PM if interested.

 

[Spiff]

What is on the front of your dish at the moment ?

You sold me something a while ago.

Do you want it back ?

Good morning Channel Hopper,

I am using a dielectric plate in the shape of a T, I think the design was on this Forum some time back.

From test I did at the time, it showed an improvement on a standard size dielectric plate.

I like C band, a recent scan of which produce the Reuters news channel, which I often watch on KU band.

Something like attached image is the way I wish to go.

God Bless Spiff

 

[Spiff]

Spiff,

Unless you can source a C-Band polariser second hand from this forum or another forum your options to buy new would probably need the item to be imported.
The three suppliers I know of are AV-COMM, Prodelin and one in Brazil.

The Brazil supplier sells the pin pipe at low cost but you get hit by postage, if there was enough interest in a mini group buy it might help with postage costs.
I think the supplier will ship to the UK.

Pin Pipe

Tubo Prolongador Para Lnbf Banda C Circular - R$ 79,56

Encontre mais produtos no Mercado Livre

produto.mercadolivre.com.br

AV-COMM

C Band Waveguide Polariser - Av-Comm

Our C Band Waveguide Polariser is the highest performance method of converting circularly polarised C band signals to linear polarisation.

www.avcomm.com.au

C Band Dual Polarity Circular Polarisation Kit

Our C Band Dual Polarity Circular Polarisation Kit is designed to provide an economic yet high performance solution for the reception of circularly polarised C Band satellite signals.

www.avcomm.com.au

Prodelin Rib Tickler
The C-Band polariser from Prodelin is very well made, quite heavy and has stepped ridges in a square pipe with adapter flanges at the ends
You can sometimes find them on eBay (USA) but again there is shipping to the UK.



View attachment 138164 View attachment 138165



Good luck in your search.

Good Morning Moon Base,

Thank you for the information, that is the way I wish to go.

I have just sent a PM to a member, but other wise a group purchase would be of interest.

I shall have a look at the cost of that one after my run when my head is clear.

A late night in the radio workshop and a lay in does little for clarity of thought : )

God Bless Spiff

 

[Channel Hopper]

Good morning Channel Hopper,

I am using a dielectric plate in the shape of a T, I think the design was on this Forum some time back.

From test I did at the time, it showed an improvement on a standard size dielectric plate.

I like C band, a recent scan of which produce the Reuters news channel, which I often watch on KU band.

Something like attached image is the way I wish to go.

God Bless Spiff

Ah, I meant the whole caboodle up front, and how it is attached to the refector.

For anything depolarising in a mechanical fashion you will need two C-band LNBs , or a motor driven system to convert each of the circular polarities to single linear.

 

[moonbase]

Spiff,

If you buy the AV-COMM polo pipe that was offered to you earlier, all you need to do is to shove a twin probe LNBF into the end of it, stick the scalar on the other end and job done, both Left and Right circular polarity from the twin probe LNBF. Depending on the receiver, you might be able to select L/R as the scan output, otherwise it will be H/V as the scan output. E2 receivers and EBS Pro allow nomination of the scan output to be registered as L/R.

I think the polo pipe offered earlier in the topic might come with a Zinwell LNBF, if it does not any twin probe LNBF can be used subject to the O/D of the LNBF being capable of being shoved into the polo pipe.

Orientate the twin probes in the LNBF so that they are bisected by an imaginary line between the internal steps on opposite sides of the polo pipe and scan with your receiver. It will pick up both polarities if both are selected for the scan.

I have attached below a picture of a mockup that I prepared for a client for use on an offset dish.
For a prime focus dish the hooded scalar is changed for a flat scalar.

.

 

[Spiff]

Spiff,

If you buy the AV-COMM polo pipe that was offered to you earlier, all you need to do is to shove a twin probe LNBF into the end of it, stick the scalar on the other end and job done, both Left and Right circular polarity from the twin probe LNBF. Depending on the receiver, you might be able to select L/R as the scan output, otherwise it will be H/V as the scan output. E2 receivers and EBS Pro allow nomination of the scan output to be registered as L/R.

I think the polo pipe offered earlier in the topic might come with a Zinwell LNBF, if it does not any twin probe LNBF can be used subject to the O/D of the LNBF being capable of being shoved into the polo pipe.

Orientate the twin probes in the LNBF so that they are bisected by an imaginary line between the internal steps on opposite sides of the polo pipe and scan with your receiver. It will pick up both polarities if both are selected for the scan.

I have attached below a picture of a mockup that I prepared for a client for use on an offset dish.
For a prime focus dish the hooded scalar is changed for a flat scalar.

.
View attachment 138192

Hallo Moonbase,

Ah, I meant the whole caboodle up front, and how it is attached to the refector.

For anything depolarising in a mechanical fashion you will need two C-band LNBs , or a motor driven system to convert each of the circular polarities to single linear.

Hallo Channel Hopper,

I cannot understand why you say I will need two LNBs or a motor driven system ?

The C Band LNB I have has horizontal / vertical.

The dielectric strip that I use at the moment, as far as I know changes the left / right circular polarization to horizontal / vertical.

With the polarizer the same thing will happen ?

Is that not the case.

 

[Spiff]

Spiff,

If you buy the AV-COMM polo pipe that was offered to you earlier, all you need to do is to shove a twin probe LNBF into the end of it, stick the scalar on the other end and job done, both Left and Right circular polarity from the twin probe LNBF. Depending on the receiver, you might be able to select L/R as the scan output, otherwise it will be H/V as the scan output. E2 receivers and EBS Pro allow nomination of the scan output to be registered as L/R.

I think the polo pipe offered earlier in the topic might come with a Zinwell LNBF, if it does not any twin probe LNBF can be used subject to the O/D of the LNBF being capable of being shoved into the polo pipe.

Orientate the twin probes in the LNBF so that they are bisected by an imaginary line between the internal steps on opposite sides of the polo pipe and scan with your receiver. It will pick up both polarities if both are selected for the scan.

I have attached below a picture of a mockup that I prepared for a client for use on an offset dish.
For a prime focus dish the hooded scalar is changed for a flat scalar.

.
View attachment 138192

Hallo Moon Base,

That is the way I understand it will work, I have just replied to Channel Hopper as I cannot understand why as he said I would require two LNBs or a motor drive.

The C Band LNB I have has horizontal / vertical.

The dielectric strip that I use at the moment, as far as I know changes the left / right circular polarization to horizontal / vertical.

With the polarizer the same thing will happen ?

 

[moonbase]

Spiff,

Yes, the polo pipe is an alternative to the dielectric plate
From one twin probe LNBF you will receive both polarities and the signals should be stronger with the polo pipe compared to the dielectric plate.

 

[Channel Hopper]

Hallo Moonbase,

Hallo Channel Hopper,

I cannot understand why you say I will need two LNBs or a motor driven system ?

The C Band LNB I have has horizontal / vertical.

The dielectric strip that I use at the moment, as far as I know changes the left / right circular polarization to horizontal / vertical.

With the polarizer the same thing will happen ?

Is that not the case.

The mechanical depolariser - manufactured by Prodelin - is a rectangular waveguide terminated in a CPR229 flange which is fixed in one of two positions depending on the polarisation required.

John spent time assessing the improvements over the circular pipe style systems, modifying the shorter version with bearing groves. and a servo motor drive to eke out the maximum signal from his system, though I cannot find the link on the forum atm. I recall him using parts of a telescope eyepiece though.

 

[Channel Hopper]

An auction sale that illustrates the complexity of plumbing required to obtain performance approaching that of John's setup.

Dual C Band Circular Satellite Feed w/WR-229 WR-137 Waveguide ERA Tech | eBay

5-7 GHz, using WR137 flange and 3-5 GHz using WR229. LHCP and RHCP in/out for port 1 via built-in waveguide switch, and selectable LHCP RHCP for C band receive port 2. Mounted on rotatable base.

www.ebay.co.uk

 

[moonbase]

Spiff,

If you use an AV-COMM polo pipe as an alternative to a dielectric plate all you need to do is to shove the LNBF in the end of the polo pipe and orientate the twin probes of the LNBF as illustrated in a couple of pictures below. Clamp the polo pipe in your feed holder at the correct distance from the dish face, fix the scalar onto the pipe and job done, get scanning, both polarities should be receivable.

I have attached two pairs of pictures below that illustrate the principle, one pair for a Zinwwell twin probe LNBF, the other pair for a Titanium twin probe LNBF.
The LNBF is held in its correct orientation by a small grub screw in the polo pipe.


Zinwell Twin Probe LNBF



Titanium Twin Probe LNBF



As you can see from the internal pictures, the LNBF twin probes are orientated so that they are bisected by an imaginary line between the internal steps on opposite sides of the polo pipe.
This setup should improve your signal levels compared to a dielectric plate setup.

 

[John]

The mechanical depolariser - manufactured by Prodelin - is a rectangular waveguide terminated in a CPR229 flange which is fixed in one of two positions depending on the polarisation required.

John spent time assessing the improvements over the circular pipe style systems, modifying the shorter version with bearing groves. and a servo motor drive to eke out the maximum signal from his system, though I cannot find the link on the forum atm. I recall him using parts of a telescope eyepiece though.

>>"I recall him using parts of a telescope eyepiece though."<< - as part of an experiment i needed a small rack and pinion device to attach my scalar ring to on my 2.2mtr - i then fitted a motor to the focusing knob to remotely control scalar position for optimum dish performance from the shack whilst monitoring signals.
Re: the Prodelin rib tickler i use - a really quality bit of kit and a fair bit of work to mod it but it performs better than any other method ive tried to obtain L/R/H/V polarity. The one thing that was very close to it was a Zinwell lnbf into the AVComm poloriser tube.... rotating the Zinwell within the tube will give L/R/H/V pol when needed.
** - MB, you slipped your illustration in whilst i was typing lol

 

[s-band]

An auction sale that illustrates the complexity of plumbing required to obtain performance approaching that of John's setup.

Dual C Band Circular Satellite Feed w/WR-229 WR-137 Waveguide ERA Tech | eBay

5-7 GHz, using WR137 flange and 3-5 GHz using WR229. LHCP and RHCP in/out for port 1 via built-in waveguide switch, and selectable LHCP RHCP for C band receive port 2. Mounted on rotatable base.

www.ebay.co.uk

The TX side will be fairly loss loss but the RX will have 1-2dB+ in those hybrids and cables. John's set-up is much better for RX as it doesn't have anything very lossy in the signal path. For a really nice set-up, do the same as the Allen Array; V & H feeds to separate SDRs and sort out the polarisation in software. Just a few lines of code

Voyager-1 single dish detection at Allen Telescope Array – Daniel Estévez

destevez.net

 

[scopus]

Spiff,

Unless you can get around to 55,58W for linear reception then most C Band satellites for Europe are circular, or want extended C Band reception like John the AV Comm pipe is the way to go. I have spent many an hour experimenting with various C Band LNB's OMT's etc...and by far the best performance comes from the AV Comm barrel with a dual polarity, single output LNB like Moonbase has pictured. I recently had a slightly different C Band LNB with one output at 18V and the other 13V to feed my multiswitch, and this works for me extremely well..

 

[moonbase]

Spiff,

Unless you can get around to 55,58W for linear reception then most C Band satellites for Europe are circular, or want extended C Band reception like John the AV Comm pipe is the way to go. I have spent many an hour experimenting with various C Band LNB's OMT's etc...and by far the best performance comes from the AV Comm barrel with a dual polarity, single output LNB like Moonbase has pictured. I recently had a slightly different C Band LNB with one output at 18V and the other 13V to feed my multiswitch, and this works for me extremely well..

@scopus

Totally agree, for the best bang per buck in terms of signal gain, simplicity and ease of setup, the AV-COMM polo pipe with an LNBF shoved in the end is the way to go if the 3400-4200MHz C-Band range is required. For the ultimate performance and inclusion of the 4500-4800MHz C-Band range the modding route taken by John is the way to go.

 

[Channel Hopper]

Ah, here it is.

Calculating waveguide size

i am studying av-comm polarizer and "polopipe" (from brazil) (device for convert circular to linear) i have found some calculation about wavelenght in pipe but i have two variant of the same equation : LG = L / (racine (1 - ( L / (2.d))^ 2)) LG = L / (racine (1 - ( L / (1.6406.d))^ 2)) lg...

satellites.co.uk

Just Sharing This - Adapting a Prodelin Polariser.

Heavy rain at the moment (Sunday) so no outdoor work today but the forecast for the next three days or so is rain free. Here's a few pics of the lnb to servo motor bracket during construction...

satellites.co.uk

 

[Spiff]

What a fantastic lot of information

The mechanical depolariser - manufactured by Prodelin - is a rectangular waveguide terminated in a CPR229 flange which is fixed in one of two positions depending on the polarisation required.

John spent time assessing the improvements over the circular pipe style systems, modifying the shorter version with bearing groves. and a servo motor drive to eke out the maximum signal from his system, though I cannot find the link on the forum atm. I recall him using parts of a telescope eyepiece though.

Thank you Channel Hopper I understand what you were referring to now.