Simplest Option For Dual Polarity Rx on Prodelin 1244 RxTx ?

[moonbase]

Hi,

I wish to get dual polarity Ku-Band Rx on a Prodelin 1244 antenna that has the 39 degree Ku feedhorn attached to a Prodelin Rx/Tx orthomode.
Is the simplest option to remove the Prodelin Rx/Tx orthomode from the 39 degree feedhorn and replace it with a C120 LNB after drilling some aligned bolt holes at the join?

 

[Channel Hopper]

Two of the bolt holes will line up , which avoids the need for drilling any others.

You will end up with two o rings sitting next to each other, but a good amount of self amalgamating tape should stop any leaks.

 

[s-band]

I drilled and tapped the C120 flange that I bodged on to an Octagon LNB. For the WR75, I drilled and tapped extra holes in the WR75-C120 adapter.

 

[moonbase]

I drilled and tapped the C120 flange that I bodged on to an Octagon LNB. For the WR75, I drilled and tapped extra holes in the WR75-C120 adapter.

Is that a Prodelin 39 degree cone or the 51 degree cone in the pics?

 

[s-band]

Is that a Prodelin 39 degree cone or the 51 degree cone in the pics?

Both 39 deg. My dish is a 3122 Ka VSAT 0.8 f/d

I don't know where I got it from but attached is a table of GD dish dimensions, offset angles and f/d

 

[g host]

Hi @moonbase.
I have same model of antenna.
Here is my dirty hack for use a lnb with c120 flange to Prodelin feedhorn.

 

[moonbase]

Hi @moonbase.
I have same model of antenna.
Here is my dirty hack for use a lnb with c120 flange to Prodelin feedhorn.

View attachment 133326View attachment 133327View attachment 133329View attachment 133330

Thank you for the pictures, they are useful, it looks a nice simple modification and you can always go back to the WR75 setup if you wish.
I see how you have done it, two new bolt holes at top and bottom and expanded the left/right bolt holes.

Did you compare your setup signal levels using a WR75 LNB before the hack with the signal levels from the C120 LNB after the hack?
It would be an interesting comparison.

 

[g host]

Sorry, i do not have other lnb with WR75. Will test when i have lnb and omt.
Btw, do you have omt, could you post some pics ?

 

[moonbase]

Sorry, i do not have other lnb with WR75. Will test when i have lnb and omt.
Btw, do you have omt, could you post some pics ?

Yes sure, here is a pic of the RxTx OMT with the BUC and WR75 LNB removed.

.

 

[g host]

Nice.
I want to find one at affordable price.

 

[moonbase]

Nice.
I want to find one at affordable price.

They sometimes pop up on eBay USA but postage costs to Europe are not cheap.

 

[Channel Hopper]

Nice.
I want to find one at affordable price.

I did ask you if there was anything else required in the last bundle of bits shipped to you.

Give me a few minutes and I'll look back through the archives, I also have a rather nice OMT sitting in the car, which I'll photograph.

 

[g host]

They sometimes pop up on eBay USA but postage costs to Europe are not cheap.

I know. I was hopping to find one in Eu.

 

[Channel Hopper]

Is there something wrong with the one I sent earlier in the year ?

I have one of these, but I cannot guarantee frequency limits or performance as it has no markings anywhere (but it is somewhat lighter than the one you have).

 

[g host]

Is there something wrong with the one I sent earlier in the year ?

I have one of these, but I cannot guarantee frequency limits or performance as it has no markings anywhere (but it is somewhat lighter than the one you have).

It works ok with Andrews/Channel Master feedhorn. Unfortunately, with Prodelin feedhorn, is no match. I have good C/N but, also sone waves on spectrum analyser.

 

[Channel Hopper]

It works ok with Andrews/Channel Master feedhorn. Unfortunately, with Prodelin feedhorn, is no match. I have good C/N but, also sone waves on spectrum analyser.

Can you send images of the interface between the two , bolt hole and -more importantly - port diameter.

 

[g host]

Wich one ? OMT with Prodelin or with Andrews/Channel Master ?

 

[Channel Hopper]

Since you confirm the Andrews combination has no issue, the Prodelin feed.

Are both antennas of yours 0.8 f/d design ?

 

[g host]

Hi. Sorry for late reply.
I have three antennas 1xMabo 1.85(0.6 f/d), 1xProdelin 1194(0.8 f/d) and 1xProdelin 1244(0.8 f/d).
Channel Master/Andrews feedhorn is PN :3040661 OMT PN:3040665-02 with V-plane bend PN:3040668. they work perfectly altoghether.
The problem is: Omt from CH does not work with Prodelin feedhorn PN:0800-1375.
Here is Prodelin feedhorn measurement


My plan was to replicate @beavs2112 work

 

[g host]

Yes sure, here is a pic of the RxTx OMT with the BUC and WR75 LNB removed.

.
View attachment 133332

Hi @moonbase.
Could you make some measurement of your support.
I have tried to make some similar but, i do not know how good are my estimation in reality.
Thank you.