Tech help wanted - Multi switch

[DishDick]

Hi,

Hope someone can help. For various reasons I have a problem with my dish and distribution system. But whilst working on a multiswitch I discovered another potential problem. The multi switches I use are modular, and when you open up the plastic case you come to the metal screen (Can). Open that and on each side of the panel is foam/sponge, and that is separated from the board by thick tissue paper (like grease proof paper). Now the paper doesn´t always fit well, and I don´t know what made me do it but I measured the paper - no measurable conductance of electricity. I then measured the foam - its seems to be a good conductor.

What I am therefore worried about, is where the paper doesn´t cover the panel well or if it gets damp will this cause problems? Any idea why they fill the gap between the panel and the screen with paper and foam? Normally I think if the manufacturer puts something in, it must be there for a reason, but I can´t see the logic here. Surely if there was no paper or foam there would be no chance of unintentional flows of electricity and the components would run at a lower temp as there would be plenty of air.


Would welcome people thoughts, as I am thinking of removing the paper and foam from all the multi switches.

 

[ralphmagno]

hello
you never mentioned what is wrong with the multi switch?
the foam and screen is there to protect from shock.
the switch should never be in the rain or snow.
most switches are made for stairwells or basements where it never rains.
if the multiswitch is not working the chances you would be able to fix it unless it has a blown fuse is not likely.
these switches are made and tested to switch to discq tones .
how old is the switch.
how many drops
is it something you set up or did a profesional set it up.
how mant satellites is this picking up.
if this is for a appartment complex and there are 4 flats and it is for 2 sat possions then you should have 8 lines comming from 2 dishes
and 4 drops to 4 flats.
with out knowing all the problems it is not possible to know what the problems are.
ralph

 

[satelliteman]

What's the problem with your multiswitch / system. Why not post up a picture of the switch.

 

[DishDick]

Thanks for the replies. Will post some pics later.

So the foam is only there to prevent against physical shock. I mount in water resistant boxes not prone to any physical shock, so no problem in removing foam then.

I have a whole catalogue of problems, too many to go into. Was just repairing one of the switches where the fourth output had never worked. Turned out to be a bad solder joint from new, when I noticed the conductivity of the foam and thought it could be a potential cause of future problems, especially if the tissue was not fully covering the panel, or for whatever reason the tissue became slightly damp.

Thanks again

 

[satelliteman]

Where are the switched held / installed?

 

[A nonymous]

The brand of switch may also be useful.

I'm taking an educated guess that if its sourced in Gran Canaria that its most probably a Televes switch.

I've worked with Vision, Televes, Fracarro, Spaun, Teldis and Triax IRS equipment so i have come across most failures that can happen.

Let us know whats happening and what equipment it is and we may be able to help you.

Nano

 

[ralphmagno]

Hello,
i don't understand what the problem is with this multiswitch.
how many satellite possions are you trying to set up??
let us say you want 2 possions hotbird at 13 degrees and astra 19 degrees.
then you would need 2 lnb quads with 4 lines each going to a 8 input mulitswitch.
each lnb has a different output because the bands are devided into different bands
H low.H high,V low and V high.
If you put the wrong line into the wrong input it wou't work at all.
then your receiver must have diseq tone to gererate to switch as well as 22 khz tone.
sky uk boxes do not have a diseq tone so this box is out.
you also mention opening several multiswitches ,is it possible that several of these were new and now they are all bad??

so to fix this we need to know the following info
1 what satellite possions are you receiving?
2 who installed this system was it yourself or a pro?
3 what lnb do you have (if it is not a 4 output with all the bands seperate and the proper band going to the proper input it will not work)
4 what size dish are you using in your area?
5 what type of receiver to pick what service??
6 what type of mulitswitch are you using??

if this is a do it your self and you have never installed this type of system the chances are not good you would get it sorted because there are too
many variables involved.
just trying to help
ralph

 

[DishDick]

Hi Nano,

Yes good guess Televes.

Ralph,

It’s a system I put in. All was fine until a few months ago when break up started at night. I ordered a new Sat meter and whilst waiting to get it I thought I would have a look at some of the multi switches that either failed or were faulty from new. Obviously there must have been a bad batch as on a number of multi switches 4th output didn’t work. This looks as if all three of these have bad soldering. Others will only show one band and polarity i.e. only HH. Unlikely that these will be fixable.

No my worry was with the way the units were assembled with a conductive foam placed in the screening can, the same size as the panel separated by a non conducting sheet of tissue, Obviously if the tissue does not cover completely or gets damp it is possible for a shorting to occur. Also there is no room for air to circulate.

Could someone point me in the direction of how I shrink my JPEGs as I can´t post my 2.53mb pics and I can´t remember how I shrink them to under 500KB.

 

[Topper]

Could someone point me in the direction of how I shrink my JPEGs as I can´t post my 2.53mb pics and I can´t remember how I shrink them to under 500KB.

Install pixresizer, available free on the web

 

[ralphmagno]

hello dish dick
thanks for the information.
i was under the impression that someone installed this and it never worked correctly.
what make of multiswitch are you using?
there are some brands that have adjustible line amps in each input.
i would stay away from the brand you are using if there were so many falures.
quality conrtol must be bad there.
ralph

 

[DishDick]

Thanks Topper, excellent bit of software (I used to use paint pad, but this time I could only shrink to 800K.

I attach the pictures

Slightly out of order. Ist one shows top can removed and foam in place, second shows screening can in place,third shows foam removed and paper in place, fourth shows panel.

 

[DishDick]

Well I have my system working well. I opened all my multiswitches (as well as some I had inherited), I took out the foam and paper. I think it was a good idea as in some units had got so hot that components had burnt through the paper! Failure rate very high, out of 12 tested, 6 had various faults! Lucky I had these spares.

 

[A nonymous]

The company i work for have just started using Televes gear to try and cut costs.

Myself and the other engineers i work with are not impressed with the kit at all other than the bright orange makes a refreshing change from the usual dull silver units i'm used to working with

The Televes units don't line power, meaning you have to run another cable through the system to power the damn things up, the power packs keep burning out, and the loss through the terrestrial side of the switch is rediculous. The launch amps are usually run at full power just to get the damn things to work. No wonder the stuff gets so hot.

If it fails again i would seriously consider buying some decent kit to replace it with.

I myslef have a tendency to swing towards Vision kit due to the simplicity. I think it goes by the brand name Terra within Europe.

Spaun and Triax are other brands worth looking at.

Nano