C-Band LNB Frequency shifted

[qwert1515]

About two weeks ago my C-Band LNB was working in the night and the next morning it stopped working. I checked the LNB again after about a week and it was still not working.

A few minutes ago I wanted to triple check the LNB to be sure that it was dead and this time I decided to use my BLSA (Broad Logic Spectrum Analyser) and I noticed that the signals were there but shifted 13 MHz higher than normal. (Example. A transponder that was at 3700 MHz before, is now at 3713 MHz) (A Blind Scan shows this too)

So the only way I can fix this is to change the LO frequency to 5137 (instead of 5150) but then my LNB's frequency range is changed to: 3387 - 4187 instead of the correct: 3400 - 4200. (I can change the LO on my Pansat but I don't think my Coolsat lets me specify an exact LO (The closest it gives me is 5150)) When I get an analog receiver I am sure this will be an issue........

What should I do, the LNB is still under warranty, should / will the manufacturer do anything about this?

Thanks.

EDIT - Should this be in the C-Band Section or is it "Technical enough" to be in the FTA Section ?

 

[gabshere]

the coolsat will allow you to set the Freq range in the blind scan menu area and leave the LO set at 5150


if the lnb is still under warranty, i would e-mail them and find out about replacement.

 

[Mr Tony]

I've seen that happen but that was due to the cold (what we Minnesotans call cold)

My C-Band LNB had a lot of float when it would get below 10 above

 

[qwert1515]

Thanks Gabshere and Iceberg, I will email the company (They are a site sponsor so I think everything will work out, I hope )

It is 46 above zero right now (Cold in Southern California ), Does your LNB's "float" return to normal when the temperature rises or is it a permanent change?

About changing the frequency scan range (Coolsat), is there a way to make that permanent, or do you have to set the frequency for every satellite you want to scan every time you run a scan?

Thanks.

 

[Mr Tony]

It is 46 above zero right now (Cold in Southern California ), Does your LNB's "float" return to normal when the temperature rises or is it a permanent change?

it goes back to normal.....its interesting

+15 or so everything is fine
0 or below it seizes up completelly and wont work on H

between those two it floats big time......I think the LNB is shot but it survives most of the year

The 621 I had on I thought was doing the same thing as the temp is now -9 out but that wasn't it...the satellite I was aimed it had issues with signal

 

[gabshere]

it resets each time like Ice said.

but i will have to check tomorrow if you can use a editor and set the LO to 5137
it should be possible i just can't check until tomorrow.also i don't know on the coolsat acts like the pansat if the LO is set to 5137 if it will change the scanning range ( this i suspect won't change even though the LO is set differently) but won't know until tried.

 

[qwert1515]

the coolsat will allow you to set the Freq range in the blind scan menu area

This resets every time, is there a permanent way to change this?

 

[Mr Tony]

if you change the LNB LO it should change the blind scan range. When I had a stacked LNB on my 5000 it reset the parameters. Also on my Universal it resets those when I say 10600 22k yes

 

[gabshere]

it might be worth a try then

 

[Mr Tony]

when I mean reset I mean the Coolsat will take the IF frequency range of 950-2150 and add it to the LNB LO

Standard 10750 defaults to 11700-12200

 

[qwert1515]

Thanks, what I meant for the frequency range is for my other LNB (Universal 10600/9750) the Coolsat defaults to 10700 - 12750 MHz is there a way to permanently change it to 11700 - 12200 or do I have to change the scan range every time I scan?

Thanks.

 

[truckracer]

I lost Horizontal channels last night when it got cold. It started by shifting frequency quite a bit. After everything warmed up to the 30's degrees F, all is normal again

 

[Mr Tony]

Thanks, what I meant for the frequency range is for my other LNB (Universal 10600/9750) the Coolsat defaults to 10700 - 12750 MHz is there a way to permanently change it to 11700 - 12200 or do I have to change the scan range every time I scan?

Thanks.

no way to change it permanently unless the LNB LO is at 10750. As soon as you pick a LO other than 10750 it defaults to the 950-2150 IF frequency range

 

[qwert1515]

Thanks,

Iceberg - T minus 21 posts and counting I wonder what time tomorrow and what the post will be about.

 

[qwert1515]

I found out that the Coolsat does let you change the LO to an exact frequency.

It is in the "Dish Setting" menu and under the "LNB Freq" if you select the first LO frequency in the menu it allows you to specify an exact frequency.

Also my LNB's frequency is still off by 13 MHz and it is 60 degrees right now, so I think it has permanently shifted, so I will have to call for warranty information tomorrow or Tuesday depending if they are closed for tomorrows holiday.

 

[photoman76]

I have a dbs lnbf that shifted permanently. I have to set the lo to 11257 instead of 11250. I think water got into it from a crack in the plastic cover. Other than the lo shift, it works fine.

 

[gabshere]

ok i used a channel editor on my coolsat 5000 and edited the LO from 5150 to 5137 ( for one satellite only all others remained 5150) and it automatically changed the scan range in the blind scan area to adjust for this change. and then scanned in the channels and it worked . none of the other satellites were affected with this change. so it does work.

 

[gabshere]

Thanks, what I meant for the frequency range is for my other LNB (Universal 10600/9750) the Coolsat defaults to 10700 - 12750 MHz is there a way to permanently change it to 11700 - 12200 or do I have to change the scan range every time I scan?

Thanks.

i would have to do some more checking with the editor to see if this can be changed , i suspect its a software programming thing and the editor will only allow you to change the LO which would changes the range ( only from what the default is )

 

[Larry1]

What should I do, the LNB is still under warranty, should / will the manufacturer do anything about this?

The LNB should be stable over a vast temperature range.
the following is for a Cal Amp LNB from their web site

Specifications*

Input Frequency 3.4 to 4.2 GHz
Output Frequency 950 - 1750 MHz
Noise Temperature 20°K to 35°K @ 25°C
Gain 63 dB Typical, 60 dB Min
Gain Flatness ± 2.0 dB Max
Image Rejection 55 dBc Min
Output VSWR 2.0:1 Typical, 75 ohm
1-dB Compression Point +10 dBm Min
3rd Order Intercept Point +20 dBm Min
LO Frequency Stability 5.15 GHz, ± 125 KHz Max
@ -40°C to +60°C
Phase Noise -69 dBc/Hz @ 100 Hz
-85 dBc/Hz @ 1 KHz
-88 dBc/Hz @ 10 KHz
-92 dBc/Hz @ 100 KHz
-105 dBc/Hz @ 1 MHz
DC Input +15 to +24 VDC
Current 275 mA Typ, 300 mA Max
Operating Temperature
-40°C to +60°C
Input Interface
Flange, WR 229G
Output Interface 75 Ohm, Type "F" Female
Finish Powder Coat
Physical Size 3.86 x 3.0 x 7.0 in
Weight 20 oz



Note the temperature range of -40°C to +60°C with a LO Frequency Stability 5.15 GHz, ± 125 KHz Max over that temperature range. Your might not be rated for quite the stability of the above example, but it should not drift 13Mhz. The manufacturer should repalce it with no questions for a drift of that much.