DBSTalk Forum banner
Status
Not open for further replies.
1 - 20 of 20 Posts

·
Hall Of Fame
Joined
·
1,815 Posts
Discussion Starter · #1 ·
as a DirecTV customer, I never heard of it before (which is not to say the phenomenon does not exist with DirecTV LNBs, just that the receivers don't diagnose it to the customer). I saw it noted on my parents' 622 receiver last night.
 

·
Mentor
Joined
·
39 Posts
tkrandall said:
as a DirecTV customer, I never heard of it before (which is not to say the phenomenon does not exist with DirecTV LNBs, just that the receivers don't diagnose it to the customer). I saw it noted on my parents' 622 receiver last night.
I doubt that LNB drift is exclusive to just Dishnetwork. Dish just happens to have software in their receivers that can detect it.

any oscillator in any system can be susceptible to drift. not just in LNB's but all equipment that uses one. it was a common happening in analog music synthesizers in the 70's. Made them sound out of tune all the time.
 

·
Godfather
Joined
·
562 Posts
Yep - it's common to all satellite systems using consumer grade, non-PLL locked LNBs, including most home "big dish" C/Ku-band systems.

Dish's boxes just make the fact that drift was detected available to the end user.
 

·
Hall Of Fame
Joined
·
8,969 Posts
I agree, it happens with DirecTV too. But honestly, it happens a lot less often with DirecTV's LNBs than with Dishes. When we were doing 60 jobs a day with DirecTV, we would replace 1 or 2 LNBs a day. Doing 30 jobs for Dish, we replace 3-4 per day, sometimes more. It even affects DP Duals, which are relatively simple, compared to a Ka/Ku LNB, for example.
 

·
AllStar
Joined
·
92 Posts
dish pro lnb's have two oscillators in them (per orbital slot), think dtv ka/ku only have one oscillator per orbital slot, perhaps this is why you see more dish lnb's suffering from "drifting", it's twice as likely to happen, no?
 

·
Hall Of Fame
Joined
·
2,294 Posts
They replaced mine when it was -6. The older non VIP DVRs, 721 dual tuner SD and a Dishplayer, were losing signal during the heat of the day whereas the VIP622 kept going. It seems that the VIP series can handle more LNB drift than the older legacy boxes. The 721 is a DP series SD DVR and it had problems even though it is new enough to use a separator.

That may have been why there was no quibble about replacing them. I say them as first it was the 61.5 then the 110/119 LNBs.

The system has a DPP44 switch whether or not that made a difference I do not know.
 

·
Hall Of Fame
Joined
·
8,969 Posts
Redwoodman said:
At what point do the LNBs need to be replaced? I'm currently at -8/-9.
Those are bad, and need replacing. Call dish and let them know what your LNB drift is, and they'll schedule a free service call. If your receivers were plugged into a phone line, the receiver's "health check" would have scheduled one automatically once it hit 7 or more. When it hits between 9 and 10, you'll start losing your signal lock to the satellite.
 

·
Hall Of Fame
Joined
·
3,982 Posts
Dish replaced my 129 lnb when it hit -6 and had drop outs. This was ack in the days of the faulty lnb syndrome.
 

·
Mr. FixAnything
Joined
·
27,443 Posts
IIP said:
Those are bad, and need replacing. Call dish and let them know what your LNB drift is, and they'll schedule a free service call. If your receivers were plugged into a phone line, the receiver's "health check" would have scheduled one automatically once it hit 7 or more. When it hits between 9 and 10, you'll start losing your signal lock to the satellite.
'STB_Health' reports sending each week regardless of the drift value.

If your device connected to Internet or/and phone line.
 

·
Godfather
Joined
·
306 Posts
Mine has been bouncing from 7 to 8 and back for some time now for 110 and 119. Despite being internet connected, haven't heard a word from Dish about getting a replacement. I haven't had any noticeable issues, so I wasn't going to make a stink until I consistently read at 8.
 

·
Hall Of Fame
Joined
·
1,340 Posts
Dish settled a lawsuit against CalAmp last year on account that a large number of DishPro Plus and lnb's labeled "Made in USA" by CalAmp has material defective circuit boards in them.

Heat, apparently, was affecting them, and causing "LNB drift."

Higher frequencies create more heat. DishPro lnb's are stacked and generally operate at higher frequencies.

LNB drift is almost unknown in legacy or the older standard DirecTV Phase I lnb's.
 

·
Hall Of Fame
Joined
·
2,294 Posts
Well heat was for sure affecting mine. When we had higher than normal temperatures the LNB drift showed higher and the legacy receivers lost signal until it cooled down again.

So I'll have to say Mike500 hit the nail on the head.

I was switched over to Dishpro LNBs when they set up the 622 for me. They put in a DP34 first but that caused problems with the legacy equipment and not enough feeds, five were needed. So back on the phone and they swapped the DP34 for a DPP44. A seperator on the VIP622 and the older 721 and the legacy device hooked up direct and I was good to go.
 

·
Legend
Joined
·
158 Posts
Is LNB drift the same as the signal strength? I live in the desert southwest and TBS HD the signal strength will go from 22 down to 10 and sometime below as the morning heats up. How do I check stb_health. Ihave the 1000.2 and VIP722
 

·
Hall Of Fame
Joined
·
8,969 Posts
LNBs use "clock"/timing circuitry to help lock on to the signal beamed down from the satellite, similar to you tuning in a radio station. If the circuitry starts to drift, it starts to go "out of tune" with the signal, like when you are using an analog-tuning radio and don't have the station tuned in right. You still get signal, but you also get extra noise and distortion. Eventually it will get bad enough that the signal is "lost" to the noise.

Dish has added a software test to most of their modern receivers that will display LNB drift values of 5 or more. Policy is to replace LNBs with 7 or more drift value, and you can expect to start losing signal if it reaches 9-10.
 

·
Mr. FixAnything
Joined
·
27,443 Posts
LNBF had two local oscillators (LO), eg RF generators; after combining frequencies from LO and sat signal, much lower freq signal coming into your receiver, eg lowering from 12 GHz [Ku] to ~1 GHz[L] IF.
There is no clock/timing circutry inside of LNBF what help lock, the lock happen in sat tuner inside the receiver by tuning to particular IF.
[IIP, stop by at DeAnza college, I'll explain this to you in details :D].
 

·
Godfather
Joined
·
398 Posts
I've had the bad LNB drift for over a year now, connected to a phone line the whole time, and nothing from Dish. Of course. :) I'm moving up to an HD DVR soon anyway, so I figured I'd take care of it then.
 
1 - 20 of 20 Posts
Status
Not open for further replies.
Top