Newsnet on Ka Band A

[John]

Right now with CM 1.8 and SL3K 12.0 dB

Forgot to say Wim, picked up the bits from Chris earlier on today and have to say they were spot on. Thanks very much for your efforts and time.

 

[John]

Just a thought John ..
My XMW bought from Jin ...but for KaD coverage did once get wet inside due to excessive rain and a hairline crack in the Aluminium casting...
Rather than send it back I opened it up ...dried it out an re-sealed everything with silicon grease..
Worked fine afterwards and that was a couple of years back..

I opened it up th other day Ewan hoping to find something along those lines but alas no.
It's still drawing the right amount of current for a pll and it didn't die instantly either, it just went low on output gain firstly and now down to no output at all but still drawing correct current. I don't want to make it too obvious to see that it has been taken apart or Jin will tell me to do one, but i am tempted to have one last look

 

[Archive-8]

 

[John]

View attachment 91533 View attachment 91534

Keep going keep going .... your in the ball park for sure. A non deformed metal 1.5 Gib with lnb at focus should belt in tho Chris, i would expect the nag feed to be up around 15 - 16 dB or so for you. Iv'e found at Ka on bigger dishes can be a bit of a faffy job to hit the absolute sweet spot and keep it there whilst you tighten up your nuts. (made me titter that did)

 

[Vipersan]

I opened it up th other day Ewan hoping to find something along those lines but alas no.
It's still drawing the right amount of current for a pll and it didn't die instantly either, it just went low on output gain firstly and now down to no output at all but still drawing correct current. I don't want to make it too obvious to see that it has been taken apart or Jin will tell me to do one, but i am tempted to have one last look

Look with a jewellers eyeglass or good magnifying glass for _any_ signs of corrosion ..and gently toast both sides of the opened lnb ...with a hardryer set on low to medium ..
DONT overheat anything..
good luck..

 

[Archive-8]

Had a mate watch the signal meter, while I was on the mobile to him, I went out side to move the lnb, left, right, up and down.

And nudged the lnb arm up and down a bit, and I have made a slight .3db improvement.

But now I have an idea as to what is wrong!

I will go and have a play with it tomorrow!

But feeling well chuffed:-) as the lnb is still alive.

 

[John]

Look with a jewellers eyeglass or good magnifying glass for _any_ signs of corrosion ..and gently toast both sides of the opened lnb ...with a hardryer set on low to medium ..
DONT overheat anything..
good luck..

Update..... following your lead ;) and applying gentle heat all round .... upon very close inspection of casing & pcb both sides a few things caught my eye. On both lids there was microscopic droplets present, not water marks .... actual micro droplets. Two places on the pcb were suspect. A soldering iron burn on what looks like an inductor ? has been added at factory, see pic, Performance degrade ??. Three pins on pcb with one pin possibly making the finest contact to the other ??. No signs of casing cracks, F connector from outside to inside seems to be watertight. After approx 30 mins and re-applying 18v supply, gain has risen to around 58.4 dBuV which is higher than it was yesterday. it's on soak now drawing a steady 235mA. Hmmmmmm

 

[Vipersan]

Update..... following your lead ;) and applying gentle heat all round .... upon very close inspection of casing & pcb both sides a few things caught my eye. On both lids there was microscopic droplets present, not water marks .... actual micro droplets. Two places on the pcb were suspect. A soldering iron burn on what looks like an inductor ? has been added at factory, see pic, Performance degrade ??. Three pins on pcb with one pin possibly making the finest contact to the other ??. No signs of casing cracks, F connector from outside to inside seems to be watertight. After approx 30 mins and re-applying 18v supply, gain has risen to around 58.4 dBuV which is higher than it was yesterday. it's on soak now drawing a steady 235mA. Hmmmmmm

Looking at the photos it is difficult to say if that is actually burnt material or some sort of glue or resin..
Certainly there should not have been microscopic water droplets inside the casting ...so let it sit on a radiator overnight ...casing open both sides ..
put a towel under it if need be in case the radiator gets too hot..

If drying out does indeed fix the problem ...I'd recommend buying some silicon grease to smear over all gaskets and seals before reassembly ..
Check also the lnb waveguide entrance where the feedhorn joins ..
this is a weak point and a failed seal here will cause some condensation internally..

 

[John]

Looking at the photos it is difficult to say if that is actually burnt material or some sort of glue or resin..
Certainly there should not have been microscopic water droplets inside the casting ...so let it sit on a radiator overnight ...casing open both sides ..
put a towel under it if need be in case the radiator gets too hot..

If drying out does indeed fix the problem ...I'd recommend buying some silicon grease to smear over all gaskets and seals before reassembly ..
Check also the lnb waveguide entrance where the feedhorn joins ..
this is a weak point and a failed seal here will cause some condensation internally..

Will do .......
Iv'e enlarged the pic a bit more but it's difficult to get close enough with the camera ..... it's definitely a soldering tip burn.
Been on soak now for over an hour and holding, radiator tonight and then hopefully a re-fit tomorrow.
Thanks again for the tips.

 

[scopus]

Not good considering how much they cost!!

 

[John]

Update from ICU:
After acting on the consultants advice from the previous night where the situation was looking for the worse, the patient has shown a remarkable recovery as shown on the before and after ECG's and is expected to leave it's recovery position and re-enter outdoor service with the Newsnet Ladies very soon.

 

[scopus]

This really doesn't surprise me as both of those XMW feeds I had from France, not Feedsat or his friends shop fault I hasten to add..both of the caps on the feeds caps came straight off as I noticed condensation appearing behind the cap with little to no sealent holding them. I re-sealed them with silicone glue, spot on now.

 

[Vipersan]

Looks like my advice comes in useful occasionally..
;)

 

[John]

Looks like my advice comes in useful occasionally..
;)

Ohhh Yes.

 

[scopus]

Has the patient recovered John? Are the Newsnet ladies coming in nice and strong??

 

[John]

Has the patient recovered John? Are the Newsnet ladies coming in nice and strong??

Yes, she 's stable and looking good at the moment. She's got a Newsnet temparature of 14.2 dB at the moment & I'll check on her later to see if i can improve her condition.

 

[Vipersan]

Yes, she 's stable and looking good at the moment. She's got a Newsnet temparature of 14.2 dB at the moment & I'll check on her later to see if i can improve her condition.

Dont forget to re-seal with silicon grease...

 

[scopus]

Dont forget to re-seal with silicon grease...

lol, I just about to say the same VS...

 

[John]

Dont forget to re-seal with silicon grease...

Done that Doctor, she passes on her regards and says if it wasn't for your intervention she wouldn't be here today. ---------- she would have been on her way to S/Korea!.

 

[scopus]

Done that Doctor, she passes on her regards and says if it wasn't for your intervention she wouldn't be here today. ---------- she would have been on her way to S/Korea!.

Let's hope she appreciates your TLC dear....;)