RX sig strength 7 db lower with POTY

EA2ARU · Sep 28th 2020

Ok. But what is the better procedure for search the focus on the offset disc standar 0.6 ? Please send me news .....

DD4YR · Sep 28th 2020

Take a look here:

http://www.hybridpretender.nl/poty.html

especially this drawing:

73 de Robert

HB9SKA · Sep 29th 2020

Quote from EA2ARU

Ok. But what is the better procedure for search the focus on the offset disc standar 0.6 ? Please send me news .....

To search the focus on a dish you can use a laser-pointer if your feeder is flexible. With a POTY Robert answered your question.

DL5CN · Sep 29th 2020

Hallo Jabi,

take 3 very small pieces of a mirror and glew it in the dish at different places. The mirror surfaces must be parallel to the dish. With thin double-sided adhesive tape it will work. Turn the dish to the sun. With a sheet of paper you will see, where the sun beams meet. With this method it can be seen also , if the dish surface and the paraboloid shape are correct still.

Have fun.
73
Andreas

HB9SKA · Sep 29th 2020

Hallo Andreas

That is interesting, can you make us a drawing ?

DL5CN · Sep 30th 2020

Hallo,

here is a picture of a dish with beams (read lines) from the mirrors to the focus point. The mirror pieces are cracked from a bigger mirror. Take care not to get injured.

The reason for this method was a false mounting. The wholes in the dish allowed to mount it wrong, the upper side was at the right side. It didn't work at all, no focus, much frustration. With the mirrors I found my misteake easily. With the top side on top, all is fine.
It is a little bit difficult to hit the sun but with some trials it will be ok. Follow the beams from the mirrors to the focus, the correct position can be found. It can be used also with a dish and unknown focus point.

73
Andreas

HB9SKA · Oct 1st 2020

I see, its a way to find the focus on the LNB or feeder. What I meant is the way to find the focus on the Dish with a laser pointer. On a prime focus Dish its easy, the focus is in the middle of the Dish. This way is also possible with a TV offset Dish. I mounted my helix feeder on top of the LNB and "pointered" it nearly to the focus of the LNB. The point is also in the horizontal center and a little bit over the LNB's point. You need a good eye measure and it works.

IK1IYU · Oct 1st 2020

Please don't break a mirror, or you will have to face seven years of bad luck!!! (as from an italian proverb)

You can use small pieces of kitchen aluminium foil instead.

DM5RM · Oct 1st 2020

Self-adhesive copper or aluminum tape is even slightly better.

DL3HJG · Feb 24th 2024

Hello OMs,

Measured values

Original LNBs (many typs: groove feed, Rocket) Upper Beacon SNR 17. . . 20db

LNB with Poty + dielectric lens (PA) 10dB

without 10dB

http://www.hybridpretender.nl/patch.pdf

Polyamid is a mistake: A Test in microwave stove: the part gets very hot in 1 minute

Polyamid poor: High dissipatipn factor !!

Dissipation Factor (DF) of Plastics - Unit, Formula and Measurement

PA tanδ 0.01 . . 0.06

PE 0.0003 . . 0.002

PTFE 0.0002

Post

RE: RX sig strength 7 db lower with POTY

Hello,
2 questions:

does anyone have information about the f/d ratio for a Kathrein CAS 124. I could not get any info from Kathrein in 2019.

Looking for one long Cylinder lense ( #1, right hand side) to replace the genuine lense supplied with the original poty kit.
73,
Charly DF5VAEforum.amsat-dl.org/cms/index.php?attachment/4140/forum.amsat-dl.org/cms/index.php?attachment/4142/

Charly DF5VAE

Feb 18th 2020

@ DF5VAE: Can you please provide measurements and a sketch for lens '1' and '2'

How is the installation on the LNB?

Post

RE: Montage POTY an Opticum LNB LSP-02G

Hallo Hans,

ich habe hier die "abgesägte und mit 22mm Kupfer Fitting aus dem Baumarkt" Version.
Wer es dicht haben will, kann den Kupfer Fitting mit 1 Tropfen Silikon beim zusammenschieben abdichten.

Gruß
Robert

forum.amsat-dl.org/cms/index.php?attachment/3852/

DD4YR

Jan 5th 2020

Post

RE: Wetterschutz für POTY-Antenne/LNB ?

that is my setup here:
forum.amsat-dl.org/cms/index.php?attachment/3666/

DD0KP

Dec 15th 2019

The high frequency flows on the surface in the pipe
Is a gap of 0.5mm bad? The high frequency can't go any further here
Lengths (transformation!)?

The copper pipe 22 / 20 mm - The diameters don't fit: LNB 19. . 22mm. Each LNB ist diffferent.
Making an adapter on the lathe?
Or the waveguides face to face?

Post

RE: Montage POTY an Opticum LNB LSP-02G

So, nun habe ich die für mich stabile Lösung gefunden. Ich habe das Horn innen ausgedreht und einen 40mm Reduzierring von hinten angeschraubt. Der Hohlleiter selbst wird mittels 3 Madenschrauben im Reduzierring gehalten. Wie man sieht, habe ich soweit es ging mit Langlöchern gearbeitet um den LNB optimal ausrichten zu können. Die Empfangsleistung mit dem POTY ist nahezu vergleichbar mit dem Original-LNB

Kommende Woche müsste der Transverter kommen. Wenn das Ganze gut funktioniert wird alles…

DK1MHW

Jan 11th 2020

73

Hans-Jürgen

RX sig strength 7 db lower with POTY

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