Frequency drift

K

koansrc

Regular Member
My Satellite Setup
CM 3.0m @ 28.2 w PACE
My Location
Athens-Greece
I'm trying a new invacom quad and I'm finding that all frequencies are off by about +4. For example my sat meter won't lock at 11778V but instead locks at 11774V and it's the same with all frequencies. Is this "drift" normal ? When is it considered a fault ? Should I return the lnb ?
 
yup, L.Osc problem causing the offset, return I would say:)
 
Sounds like local oscilator problem...
This is a common problem with invacoms after couple of years use in extreme temperature conditions such as Cyprus...
I don't remember having this problem on a new invacom tho.....i would return it back.
 
I have this problem with my Horizon meter. On Invacoms over a year old I can only get readings on 2D,
Sometimes on a new Invacom I can't get a reading on 2D. What satmeter do you have?
 
zorba said:
I have this problem with my Horizon meter. On Invacoms over a year old I can only get readings on 2D,
Sometimes on a new Invacom I can't get a reading on 2D. What satmeter do you have?
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was that question for me or koansrc?
 
It's an AD70. Like I said, it will lock but only if I change the freq. The digibox however still manages to work fine (!).

I've used the meter with another invacom twin and an mti with results as expected.

Something is not right with this lnb and so I'm working at getting it replaced.

As for 2D there's no problem for me. No signal, no problem :)
 
iceman said:
was that question for me or koansrc?
Click to expand...

Well,both I suppose. I don't have the option to change frequencies on the Horizon,but I also have a satlook combo and with that I can find the frequency but it doesn't lock too well even when ,for example bbc1 is working okay on the digibox but not a full lock on the satlook.
So, your lnb is not right and maybe you can get another from your supplier just to compare results.
But,although the readings are not right, are you getting the channels on your receiver?
 
I am still using my old UNAOHM EP314...
The last couple of years i have been thinking of upgrading to one of these recent singing-dancing colour TFT screen models,but to be honest with you,the ones i tested were not as responsive as my old meter..
At the moment i am gathering info on some top of the range filed strenght meters by Sefram

http://www.sefram.com/www/np_searchmodel7.asp?lf=Terrestrial+&+Satellite
 
I've been pretty impressed with the RoVer meters although there are some minor issues I have with the slow spec trace. Another good meter I have, and that's the dogs nuts is the prolink 4C or his sister meter the Explorer :)
 
satelliteman said:
I've been pretty impressed with the RoVer meters although there are some minor issues I have with the slow spec trace. Another good meter I have, and that's the dogs nuts is the prolink 4C or his sister meter the Explorer :)
Click to expand...

I have tried couple of Rover's & Explorer (tho the new widescreen model is tempting) but not really impressed with any of them.
If i am going to pay £2000-£2500 on a meter it better impress the hell out of me..;)
I suppose as long as my old meter has life in it i wont spend enough time to get used to another meter to master it.
 
I used to have a rover but I lost it. I have seen a sefram,looks a bit bulky. Is it good for worn out Invacoms?
 
zorba said:
I used to have a rover but I lost it. I have seen a sefram,looks a bit bulky. Is it good for worn out Invacoms?
Click to expand...

bulky??? have another look;)

_http://www.metrix-electronics.com/Specsheets/Cat_TV_Meters_GB0712.pdf
 
You're right. I saw one in Larnaca,it must have been an old model then. These new slim ,LCD lightweights look good ,but as you say expensive. And I would like to try before I buy but thats not possible.
 
zorba said:
So, your lnb is not right and maybe you can get another from your supplier just to compare results.
Click to expand...

yes I'm in the delicate process of requesting another (having bought it on eBay)

zorba said:
But,although the readings are not right, are you getting the channels on your receiver?
Click to expand...

Yes channels on the digibox where ok. If I didn't have the satmeter I wouldn't have noticed the problem. One of the things I've found the AD70 can measure, is "frequency" by which you give it a freq and it will report the "drift" in +/- Mhz from the freq ( I guess ) where the signal actually peaks or tunes.

I tried the same dish, the same satmeter, with a different Invacom LNB and had no problems. Well actually a much smaller drift -0.2 or something.
 
most receiver tuners are built to cope with few Mhz +/-
 
iceman said:
most receiver tuners are built to cope with few Mhz +/-
Click to expand...

do you know if this effects reception ? will eg a weak signal be even harder to get or won't it make any difference being a few mhz off.

I sort of got the feeling that the delay between changing channels was a little more with the quirky lnb. Kinda sluggish response from the digibox. nothing measurable of course.
 
few mhz offset frequency does not make any difference on signal/picture quality...
 
as iceman has said the receiver should have an AFC (automatic frequency control) built into the receiver not unless it drifts out of it range
 
If the drift is small will it matter?

On my scans (take 11200 H for example) it will hopp one (to 11201 H or 11199 H)
Does it matter all the time?
 
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