Disaster!!

[Vipersan]

Hi Joe ..
That part of the big dish re-build is already done and dusted thankfully ..
The steel pipe was eventually filled to roughly 2/3 mtre with oil ..and then filled to the top with expanding foam ..
Finally capping off with a steel plate which was epoxied to the top of the pole.
rgds
VS

 

[Terryl]

Most of the failures in the pipe type mounting that I have forund for the BUD's is the fact that they tend to wobble around in high winds, this causes micro fractures in the pipe where it meets the concrete, this occurs over a long period of time.

Water getting into these micro cracks will cause the rusting and eventual failure at that location, use of salt to melt the ice (if you have that problem) will cause a failure sooner then normal.

Solutions are to coat the exterior of the pipe with a thin layer of auto undercoating or a thin layer of roofing tar to about 200 mm above the level of the concrete base, then filling the mounting pipe with concrete with lessen the wobble.

Other solutions are to not bury the pipe in the concrete but to use a base plate (special made for the pipe) and stainless steel "L" bolts, grout is used to keep junk from getting under the mounting plate.

 

[Terryl]

The nice thing about using the base plate mount is that you can take everything with you if you move, just cut the bolts off if the next guy doesn't want a dish.

 

[Vipersan]

Most of the failures in the pipe type mounting that I have forund for the BUD's is the fact that they tend to wobble around in high winds, this causes micro fractures in the pipe where it meets the concrete, this occurs over a long period of time.

Water getting into these micro cracks will cause the rusting and eventual failure at that location, use of salt to melt the ice (if you have that problem) will cause a failure sooner then normal.

Solutions are to coat the exterior of the pipe with a thin layer of auto undercoating or a thin layer of roofing tar to about 200 mm above the level of the concrete base, then filling the mounting pipe with concrete with lessen the wobble.

Other solutions are to not bury the pipe in the concrete but to use a base plate (special made for the pipe) and stainless steel "L" bolts, grout is used to keep junk from getting under the mounting plate.

Hi Terry ...
Used a very similar method with mine ..
just over 2 feet of pipe where sunk into concrete with a screw cap on the bottom so as to retain the oil..
An anti twist bar was bolted to the pole approx 1 foot from the base ..
4 layers of paint applied 'hammerite' ...
2 layers where red undercoat ..2 layers topcoat ...then the whole of the sunken area of pipe was wrapped in tar backed plastic damp proof material...
This was warmed and bonded to the pipe..
The whole thing was then given a final coat of tar based aquaseal/underseal as used on cars...
before final concrete fill..
The pipe wall is easily 1cm thick ...and bracing to 2 walls will be done later with angled steel bars ..

It ain't going anywhere ..and I expect to outlast me ...

rgds
VS

 

[Huevos]

The steel pipe was eventually filled to roughly 2/3 mtre with oil

I normally just pour my waste engine oil down the drain and reserve my steel pipes for hiding nuclear waste and high explosives.

On the LNB I added one on my 28ºE dish (1.8m) that was close to but not touching the scalar rings of the 28ºE LNB. The LNB was a Multi-Connect for 26ºE. This setup seems to work ok on 2.4m dishes but on the 1.8m dish performance on the central LNB took a hit so I ended up taking it off again.

 

[Vipersan]

Hi Huevos ..
Since the big dish's primary function is fringe C band ...its the 'hit' on the performance of the centre lnb I'm desperately trying to avoid..
Hence the need for such a small physical volume ku lnb ..
Hopefully this stripped down lnb will give me that ..and have a minimal effect on primary function.
Only time and experiment will tell..
Cheers buddy..
VS

 

[Huevos]

Since the big dish's primary function is fringe C band ...its the 'hit' on the performance of the centre lnb I'm desperately trying to avoid

Well it was the central LNB (28ºE) that took the hit for me. I spent a long time adjusting it and it was pretty good on most tranponders, but then I'd come in and have a zap and some transponders would be low or missing. In the end I took it off and added that satellite to the T90 which meant a complete re-think of that dish (another tale of woe).

 

[Vipersan]

Hi friends ..
Found the perfect new enclosure for the 'naked' ALPS ku ..
A short section of 25x40mm upvc box section trunking ..
It has a clip on lid ..and I have on order some blanking ends for the trunking ...which will form a nice oblong box in which the lnb internals can eventually be potted ..using liquid laytex or silicone.
It will make for a very neat job ..and much more functional and easier to mount for my setup.
I'll post pictures when its complete.
rgds
VS

 

[Vipersan]

Still 'testing' this ALPS lnb strapped to the side of the C band scalar plate ..
No focal length adjustment done ..so its all a bit pot luck /heath robinson atm ..
I find Im about 3 > 4 degrees off target for known C band stored positions within the Vbox ..but is so far performing reasonably well ..at least as far as 39East ..
Just pulled in greek orthodox TV on Hellas Sig 90% Qual 71% ..
Not bad I think for a naked LNB held on with rubber bands..
;)
rgds
VS

Just an afterthought ....
Since I know I can't push the Alcoa to see beyond 64 deg East ...I find I can't see TMB on 62 East with the ALPS stapped to the Eastern edge of the C band scalar plate ..
62 + 4 deg making 66 deg ..which of course I can't get the dish to ..
but ..I will try moving the naked ALPS to the western edge of the Scalar plate ..
In theory this _should give me an extra 4 degrees East to play with ..
Making TMB visible ..and maybe 68deg East ???
ya gotta try ...
afterall ..nothing ventured etc..
VS

 

[nelson_b]

hi vipersan --
if you are trying for 68,5 east -- use 12575 V 3378 3/4 Mana sat-
this was the strongest for me when i had a 80.cm fixed dish on this sat a while ago --
other t.p,s used to fade in and out more ---- very low elevation though 2.4 degrees here - probably much the same where you are --

regards nelson.b.

 

[Vipersan]

Hi Nelson ..
I'll give it a go ...just to say I've tried ..
I can just see the transponder carrying TMB...but insufficient to provide a lock with the offset ALPS ...on the opposite side of the scalar plate..
Quite simply it looks like there is insufficient signal when not at the focal point..
I know I can get it just fine with 'the mole'..
Still I had to try..
;)
..and of course ..nothing is yet adjusted for focal length ..so there's stil room for manoever..though not looking hopeful.
rgds
VS

 

[scopus]

Hi friends ..
First ..appologies if there are any typos..
I will correct any I spot.
My hands have been less than useful over the last few days ..making work and play very difficult ..
Hopefully this is only temporary.

OK hands up anyone who has taken apart an ALPS ku lnb..?
Well I bought a couple cheap to 'experiment ' with..
..and was surprised at its construction..
Once opened you realise there is an incredible amount of wasted space ...so closer mounting to the focal point on my pf dish is a definate possibility..
An even smaller hole cut in a C-band scalar plate than expected ....is on the cards
Even better ...
The lnb has a tiny concentric ring feed built onto the lnb feed end ...made of dielectric material..
So ..this is even more useful for prime focus dishes.
I thought the bullet shaped plastic nose of the lnb might be essential to function ..
So I tested a complete unit ..
Then a stripped down unit ..
The difference in gain on my selected test channel BBC NEWS @1West ..
.......NONE...
So ..it can be re-housed in a slimmer package ..and the concentric ring feed but to good use..

Below are the first pics
Which include a picture of the received test channel ..
A complete ALPS and a deconstructed one ..
The lnb internals are currently wrapped in masking tape and an outer layer of aluminium tape ..
..and lashed to the C-band assembly with elastic bands ..
Accuracy is paramount as the focus is critical ..but once on target the gain rises dramaticaly.
More fun to come with this interesting lnb ..and at 6 Euro ...certainly inexpensive enough to carve up and play with.
rgds 2 all
VS

That looks a bit like a Yuri C/Ku LNB setup I used on a 1.2 Precision dish, it worked well, even better when I set it up on 1.8 Precision.
Some pictures attached

 

[Vipersan]

That looks a bit like a Yuri C/Ku LNB setup I used on a 1.2 Precision dish, it worked well, even better when I set it up on 1.8 Precision.
Some pictures attached

Very Impressive Scopus ..
..and is exactly what I'm trying to achieve .
My problem is that the tripod on my setup is home made ..
(The origional was never intended for C band reception...so I had to make a new assembly)
The home made tripod and lnb support has a hard brass retaining ring to provide strength and rigidity ..and this brass ring prevents conventional siamese mounting as with the Yuri..
So ..I'm re-inventing the wheel ..so to speak ..in a desperate attempt to make a very small ku package that _will_ co-exist with the C band head assy..
I do like the Yuri system tho..
Not one I've seen before ..
Who sells it ?
As obviously its unlikely to be available off the shelf in the UK ..
rgds
VS

 

[scopus]

Hi Viperscan,

Been following this thread with great interest, well done on getting your dish back up and running!!
The Yuri came from Australia, a guy on E-Bay was selling them, not anymore though, and I have not seen anyone selling them since, a pity great bit of kit!
I'm now using a 1.8 Channel Master offset and have concocted a C Band setup with that too, using one of those new conical feedhorns available plus the Yuri C Band LNB from that kit just mentioned. Works well very pleased with it so far, needs a bit more tweaking though.
Good Luck!

 

[Vipersan]

Hi friends ..
I've been busy today ..preparing my own version of the Siamese feed..
Pictures include a prepared donar C band feed ..
No way I'm carving up my Corotor feed ;)
The boxed naked ALPS ku lnb ..now considerably smaller..
please ignore the temporary aluminium tape ...as the stop ends for the conduit wont arrive till after the weekend ..
The concentric ring dielectric ku feed is slotted in and detachable ..
Which means I can leave the ku lnb mounted permanently and just pop the 'feedhorn' off and fit the Cband scalar feed for dXing ..
Or..
I can use the modified Cband scalar plate /ku feed combo just swapping the C-plate
..and popping in the ku feed

So as yet untested in its new position ..even closer to the focal point ..but the naked ALPS worked fairly well just strapped wide of the focus ..
Hopefully this will yield better resuts when remounted and complete..
Here are the pics
Might need to occupy anther post ..as I'm not sure of the picture limit per post..
rgds
VS

 

[Vipersan]

and again ..more pics

 

[Huevos]

I'm now using a 1.8 Channel Master offset and have concocted a C Band setup with that too, using one of those new conical feedhorns available plus the Yuri C Band LNB from that kit just mentioned.

What are you doing for elevation control to get you on the C-band LNB? Can you post some pictures of the mount?

 

[Vipersan]

Beautiful sunny day here ..
Just right for attempting to mount the Siamese combo..
here are the pics ..
Improvised a mount clip out of a PC pci card blanking strip..

It will be a prettier and weatherproof job ..once the trunking stop ends arrive..
but...
Now for the testing ..
fingers crossed..
rgds
VS

 

[Vipersan]

Looks very promising ..
obviously not quite as good as placing an lnb at the focus ..but less than a couple of degrees variation ..
Have tested it at 62East ..and briefly got a lock on TMB ..
..which is good since the troublesome tree is starting to leaf..
reasonable results on most broadcast sats between 39 East and 30 west ...
also tested @2 East for feed gathering..
First blind scan pulled over 10 feeds so I suspect it was a worthwhile experiment ...
needless to say the Siamese combo will now become a permanent fixture. as it leaves the Cband focus useable for general use ..and I can still pop on the corotor scalar plate for DXing..
rgds
VS

 

[Vipersan]

..Just for the sake of completeness..
here are the final pics of the previosly naked ALPS siamese ku lnb reclothed now that the upvc blank trunking end caps have arrived ..
The whole of the interior was pre flooded with silcon sealant prior to the endcaps where fitted ..
Not only does this serve as an adhesive to hold the 4 part casing in place ..but also makes the whole thing weathertight..
rgds
VS