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I just don’t get it. The dish is grounded with an 8ft ground rod. I have a lnb protector and yet again, I have a blown lnb. Can someone recommend a lnb that can survive lightning strikes in the area? I know it’s not hitting the dish. I have been using Titanium PLL’s.
Can you not add surge protection.
I did. Took that out too. I think it’s the Titanium brand. It doesn’t seem to handle any foreign voltage at all.
Did you use a ground block, or an inline gas dish-charge device???
All a ground block does is ground the coax shield, a gas dish-charge device protects the center conductor, this would protect anything connected to the LNB, but nothing can directly protect the LNB.
An even though you didn't get a direct hit the EMP from a light strike can wipe things out, the only lighting resistant LNB I've seen is one that has an all aluminum casing, but they are hard to find for consumer dishes, most are flange mount for the big commercial dishes.
I used an inline gas protector from amazon. I just ordered some cheap lnb’s out of China. I’m tired of throwing money at this. I’m going to order one out of Toronto too so it will be here in a week but I’ll just stock pile Chinese ones. At least when I come to the cabin, I can swap out one and still have tv. We have bad lightning from May until July here.
How close to you were the hits???? If you blew the in-line gas dish-charge device then it may have been a direct hit.
If within a mile or so the EMP off a big one can wipe out most stuff.
In the broadcast world we used a heavy duty A/B switch on the sensitive stuff, when we got word of thunder storms for our location we would switch over to a direct to ground connection, and post a "Sorry We are experiencing a temporary signal loss" card for the satellite channels affected by the ground out.....It worked most of the time.
A good way to detect lightning is to use an old manual tuned AM radio set to no station, it will tell you that lightning is getting close, when you hear the hit on the radio then count by 1000-1, 1000- 2, ect, until you hear the thunder roll in, then divide that count by 5, this is how many miles it was away from you, if it's instantaneous then it's EMP will affect things.
Do you have a lightning ground rod system protecting your house??? If so you may be getting stray spikes hitting your system, this could cause problems if the satellite system is in any way connected to this ground system, also if you have poor soil conductivity your ground it's self could be causing the problems.
I have intentionally never grounded any of my dishes or coax and have never had a problem and i live in florida. I believe grounding can cause a higher potential to ground and cause an easier path for potential surges to your equipment.................
I might remove the grounding. My dish network and bell both never had a problem and both of those are not grounded. The dish network dish is about 6 feet from the bud. I tried another receiver but it still didn’t work. So now I have a burnt dms one and two Titanium PLL’s. Watch the Chinese ones will work better. Hehehe.
Quote:
Originally Posted by steveOtoo
Well it's very dangerous to not ground an RF system with an antenna outside up on a roof, (or other location) you have been very very lucky.
I've seen what happens to someone who didn't have a grounded a system,(install mistake) they took a hit and it got them from across the room, you could see the smoke trail from the coax leading in from outside, the burnt CATV receiver, pieces of the TV still lying around and the burnt carpet where they where sitting.(carpet was burnt in many place's)
I was called in as a consultant for the arson investigator, the place smelt like a burnt pork sandwich.
I'd rather loose equipment then risk getting BBQ'ed.
The Dish LNB's have internal MOV's on the coax outputs.
I’ll leave the grounding on and hopefully storm season is almost over.
You don't have a lightning rod system do you???
No. The dish is about 100 feet from the cabin. I think it’s lightning in the area.
Well since it's a "C" band setup with the LNB's up inside a cone, can you try this, wrap the LNB in one layer of 1/4 inch foam, (packing stuff), then one layer of aluminum foil, (except for the eye) then a layer of 1/4 inch foam, then one more layer of aluminum foil, do not let the two layers of aluminum touch each other, ground this layer.
This will create somewhat of an EMP shield, I don't know how effective it will be but it has worked on 7 GHz stuff in the past.
I'm going to try that. I was looking in the box that I received my lnb in. What is the fibreglass plate used for? I've never installed it.
it's for a power surge...hmmmQuote:
Originally Posted by dcapper
its to convert linear signals to circular signals....Quote:
Originally Posted by dcapper
it's probably a flat scalar ring and is for maximizing signal quality and attenuating undesired interference
no its a Dielectric plate, Dielectric plates are used to convert linear polarized signals to circularly polarized signals.Quote:
Originally Posted by dnasp002
Dielectric plates are used to convert circularly polarised signals to linear polarisation. They work by utilising the difference in dielectric constant between fibreglass (or teflon) and air.Attachment 28567
use that plate everyday on my 12 footer. works good for a few south american satellite 47W, 40W etc must be used to get signal... here in north america for C band it converts linear to circular....Quote:
Originally Posted by steveOtoo
it's been a long time since I played with a c band dish, wasn't aware that they were even broadcasting circularQuote:
Originally Posted by sonicmario
we used to do the same thing with some linear ku band lnbs but all we used was a piece of plastic
The emp comes from the high nearby voltage generating an emf in your coax that causes a voltage spike at both ends of the cable. I had this same problem but the gas surge suppressors worked for me. I have bought 3 chinese c band lnbs, and all 3 only work on 1 polarity. If your curious about building an emp cage it's called a faraday cage.
I'm going to see if I can build something like posted. My dad just called and he lost Metv at home. But I'm sure it's just the dish is a little out of alignment. All the other channels work. I really need to hire someone to point his dishes.
So I got the new lnb up at the lake but I can’t get some transponders. The ones that don’t work are of course and I the ones I want. 3725, 3733,3744, 3748, and 3764. The lnb manual says it works from 3.7ghz up to 4.2ghz. Low frequency 5150 and high 5750. Any tricks?
seems those are Vertical Transponders, can you confirm you are receiving any Vertical Transponders?Quote:
Originally Posted by dcapper
You are right! I’m not getting any vertical transponders. Do I just need to rotate the lnb?
what kind of lnb is it? does it receive both Horizontal and vertical polarities?Quote:
Originally Posted by dcapper
It’s a cheap Chinese one but it should work.
So I rotated the lnb and now I only get the vertical transponders. I’m using a Freesat V8 super. I either get a high signal on vertical or a high signal on horizontal. Am I missing something?
how many inputs on the lnbf im wondering if you need a switch to separate the 2 polarities?Quote:
Originally Posted by dcapper
There is only the v hookup. The h is capped off. The dish was out a little bit but I think I got it better now but still no horizontal.
hrmm yea that is weird, when u go into the menu on ur reciever do you have your polarity set to auto? and lnb Freq set at 5150?
Yup. My dad has the same problem at home. Only the verticals. It’s a titanium pll at his house and it was the same here until it blew. Now it’s this goldie cheap one. But there must be more to it. I’m at 42 on the focal point. I’m at 30 or so degrees turned.
How does it specify on how to internally switch polarity's, by 13 or 18 volts DC ?? Or by 22 KHz on/off ??
13 volts DC equals vertical transponders, 18 volts DC equal horizontal transponders....You may have too low of a voltage drop out at the LNB that is out of spec, if the DC voltage is too low then all you will get is the vertical channels.
What type coax are you using and how long a run?
he says if he turns the lnb he will get horizontal only? and looking at the box it came in it does not really say much, thinking it may need a switch like you said.Quote:
Originally Posted by Terryl
So get this. I changed the frequency from 5150 to 5750 and I get all the horizontal transponders but none on the vertical. I put it back to 5150 and only the verticals work. It must be the way the Freesat works. I’m going to see if I can add a satellite and then scan. Unless you have another idea?
The run at the lake is pretty long but at my dads it’s maybe 40’. Both satellites have the same problem.
I'd set it to a horizontal channel then go check the DC voltage out at the LNB's input, if under 17 volts DC you have found your problem, most DC switching LNB's have a 2 volt switching window, (horizontal =18 volts DC +- 1 volt) if it cant get above 16.9 volts DC it wont switch to horizontal.
And changing the LO frequency is not a good way to design an LNB as most satellite settings only have the one LO setting, unless its a universal or a dual band.(C and Ku)
The reason I'm asking about the coax is if the coax has a copper coated steel core it could be corroded/rusted somewhere along the line, this would cause a higher then normal voltage drop, I use coax with a pure copper center, less chance of a rust problem.
It’s outdoor rg6 and it’s in a conduit with outdoor connectors. If I set it to 5750 is it going to blow the lnb? It’s a cheap lnb and I really don’t care. But at my dads house, it’s a short run and the same cable and connectors and it’s never worked on horizontal.