Horn waterproofing

[jefduqth]

Hello all,
Recently , i have acquired a second hand channel master type 183.
The antenna was delivered with a horn feed (REF 3040661) but this piece have a broken waterproofing window (sorry for my approximative english)

What kind of material to use to repair the protection ?
What thickness ?
What kind of glue / silicone to use ?
Any advice is very welcome

PS : Don't worry for the bizzarre assembly, it's only to not loose somes screws and toric joints.
Regards,
Jef.

 

[Channel Hopper]

Find a suitable yoghurt pot (500ml) and cut the base off at the correct diameter for a good friction fit over the cap including the black surround. It will last at least a year and then you simply replace it.

 

[jefduqth]

Hello Channel Hopper,
Thank you for the answer.

So , basicaly to make a short test ,your idea is simple and effective.
A thin sheet of PP or PET suffice and no sealant ( yogourt pot have the good properties to do the job)
But for a longer period how to do that ? The idea is to repair for a long perod.

Normaly when the horn is operationnal, the assembly is completely whaterproof without vent-hole

Using a another material than the original induce two risks :
-Attenuation of the signal
-Distortion of the feed beam ( or the two phenomen combined )

The only info i have about material to use is a thin sheet of Polycarbonat ( plexiglass / actuglass) sealed with clear RTC.
Other material candidates are :
-PTFE ( difficult to glue)
- Mica
- FR4
-Glass ?

Any idea what is the original material ?

Bests Regards,
Jef.

 

[PaulR]

Without checking to be absolutely sure (We're going shopping later today and yoghurts are on the shopping list!) I think that yoghurt pots are made of polystyrene.

 

[Channel Hopper]

Depending on the brand, the pots are made of polypropylene (opaque) , or the more common polyethylene terephthalate (clear).

The clear ones are often thicker and can be cut to shape more accurately. Both are virtually transparent to microwaves.

The shield/cap on the more expensive feeds and LNBF's are (or were acetate of some description with a UV filter to prevent premature demise, these can be fixed with silicone sealant if they split, but remove the water inside before sealing.

OK- best feed cover ? - SatsUK

 

[jefduqth]

Hi,
Thank you for the clear explanations about materials and dessication before assembly.
I will post somes pictures after the repair
PS;
Yoghurts Rules !!!

 

[PaulR]

I rummaged in our bin (going beyond the call of duty there) and out of the three different types of pot two were unmarked (I thought that was illegal?) and one was polypropylene.

 

[Gerry55]

You will find that the top off a Kenko decaffeinated coffee tin will fit perfectly, no cutting required.

The lid is red plastic, a little squirt of silicone and spray with matt black to keep the uv at bay.

 

[jefduqth]

Hi all,

Ok, the repair is done i will leave it drying now...
It's sealed with clear RTC via a syringue without a needle
The thickness is 0.3mm
Btw, i've found a "tip" with the comment of PaulIR : true there is a "mark" on the plastic for recycling , and this is usefull to identify the right material :
Resin identification code - Wikipedia

And the final :


Thank you guys !

 

[Terryl]

I just use the clear 2 liter plastic coke bottles, they last a very long time, some that I have used ave been in service for 15 years, just cut one down the middle from top to bottom and then cut the ends off, remove the label and cut to fit the LNB.....