Just Sharing This AV-Comm Polariser + Zinwell lnbf

[Trust]

will you be taking orders ??
;)
Nice job mate ..
VS

Its just a start , the barrel should be compaired with a original AV-COM polariser .
And yes , once accepted , I like to make a lot of them .
All the same or with special in and out diameters for the horn and lnb .

 

[Vipersan]

If it would help ...I have a latex cast taked from inside a genuine AVcom polarizer ..
I took the cast from the inside of a polarizer owned by Nelson ..?
The carbonised or burnt end was done when it came time to remove the latex from the mold ...which was not at all easy..
rgds
VS

 

[Lazarus]

BT Crappite?

I think I need new specs.

 

[John]

will you be taking orders ??
;)
Nice job mate ..
VS

The balls rolling VS ;)

 

[John]

View attachment 99052
If it would help ...I have a latex cast taked from inside a genuine AVcom polarizer ..
I took the cast from the inside of a polarizer owned by Nelson ..?
The carbonised or burnt end was done when it came time to remove the latex from the mold ...which was not at all easy..
rgds
VS

Hmmm, nice. I bet there must be someone on here thats into sand casting ? .... Step forward that man

 

[John]

Its just a start , the barrel should be compaired with a original AV-COM polariser .
And yes , once accepted , I like to make a lot of them .
All the same or with special in and out diameters for the horn and lnb .

Struggling to find some 60mm ID x 5mm wall over here Wim, plenty in Germany .
Just checked one of my older AV-Comm barrels from about ten years back and that was 62.5mm ID , can't remember off hand what the new ones are

 

[Vipersan]

Hmmm, nice. I bet there must be someone on here thats into sand casting ? .... Step forward that man

Sort of what I had in mind when I made it John ...but not something I'd be up for these days ...
I considered it a possible future project at the time..
At least this would give me the dimensions 'accessibly'
;)

 

[blademedia]

Struggling to find some 60mm ID x 5mm wall over here Wim, plenty in Germany .
Just checked one of my older AV-Comm barrels from about ten years back and that was 62.5mm ID , can't remember off hand what the new ones are

?
Aluminium Tube - 60mm Diam x 5mm Wall x 250mm Long | eBay

 

[John]

?
Aluminium Tube - 60mm Diam x 5mm Wall x 250mm Long | eBay

Unless i'm reading the ad wrong that link is for 60mm Outside dia

 

[blademedia]

sorry wrong link 60.2 here
Aluminium Round Tube 60mm 63mm 76mm 80mm diameters many walls / various lengths | eBay

 

[John]

sorry wrong link 60.2 here
Aluminium Round Tube 60mm 63mm 76mm 80mm diameters many walls / various lengths | eBay
View attachment 99059

Gotcha .... keeping to Wim's sample dimensions though to achieve an internal dia of 60mm would have to use a tube wall thickness of 1.6mm which is a bit on the thin side

 

[blademedia]

one reason i will be buying a lathe/milling machine you can do what you want then like trust 60.2 3.3 mm wall is near as dam it

 

[Vipersan]

one reason i will be buying a lathe/milling machine you can do what you want then like trust 60.2 3.3 mm wall is near as dam it

Why would a thin wall be such an issue ?
..afterall ...commercial cband lnbfs are thin walled ...and would make the structure much lighter ...thus less leverage at the focus mount point ..

 

[moonbase]

sorry wrong link 60.2 here
Aluminium Round Tube 60mm 63mm 76mm 80mm diameters many walls / various lengths | eBay
View attachment 99059

63.5mm OD with 3.3mm wall is 56.9mm ID, wall has to be counted twice to get ID

 

[Trust]

If you want a Zinwell lnb OD 65 mm , fitting in the tube and a ID 65 mm feedhorn outside the tube , you need certain wall .

 

[blademedia]

Why would a thin wall be such an issue ?
..afterall ...commercial cband lnbfs are thin walled ...and would make the structure much lighter ...thus less leverage at the focus mount point ..

i cant see issue with thin wall who said it was issue ?

63.5mm OD with 3.3mm wall is 56.9mm ID, wall has to be counted twice to get ID

this is true best leave the alone now

 

[John]

63.5mm OD with 3.3mm wall is 56.9mm ID, wall has to be counted twice to get ID

Thankyou

 

[John]

Its just a start , the barrel should be compaired with a original AV-COM polariser .
And yes , once accepted , I like to make a lot of them .
All the same or with special in and out diameters for the horn and lnb .

Regarding internal dimensions Wim, the Guru who i dealt with at AV-Comm did say to me that the barrels are not particularly sharp on frequency response. This was in response to a question to them on how the barrel would perform at extended C-band frequencies ... 4500-4800 GHz, and seeing as the older AV-Comm barrel i have measured something like 62.5mm ID, so it might not be too critical .
Interesting project as well.
Edit: I think our two messages, your PM, my forum, passed each other on the way

 

[John]

... Iv'e now got three motorised polarity changing gadgets spread out over Ku - Ka - Cband lnb's but have just got the one controller in the shack and to change which band i wanted to operate meant going outside to the dish and un-plug which ever and re-plug in another. If it's raining it's a bit of a ba*l ache. So, for a few quid i knocked up this 433MHz 4 way remote switch, located it at the lnb position in a small waterproof hobby box, fitted some led's to indicate what channel is in use, and bobs your uncle. Works a treat.
I'll post some pics when it's daylight..... for the moment here's a schematic

 

[John]

... Iv'e now got three motorised polarity changing gadgets spread out over Ku - Ka - Cband lnb's but have just got the one controller in the shack and to change which band i wanted to operate meant going outside to the dish and un-plug which ever and re-plug in another. If it's raining it's a bit of a ba*l ache. So, for a few quid i knocked up this 433MHz 4 way remote switch, located it at the lnb position in a small waterproof hobby box, fitted some led's to indicate what channel is in use, and bobs your uncle. Works a treat.
I'll post some pics when it's daylight..... for the moment here's a schematic

Just a few pics of the little chap