pleasr read this,it's strange

[icu1954]

hi all,i have my 6ft dish with a B1sat stack pointed at 91 west and i was scanning some transponders on c band and all of a sudden up pops fx east and west coming in from galaxy 19 with a transponder frequency of 12711 which is a ku band transponder and 6 degrees away coming in on a c band dish.They are the identical channels as transponder 3720H on 91 west,so what i did to confirm what was happening,i pulled up 97 west lnb configurations and deleted 12711 transponder and the channels went out,so i added the transponder and the signals came back booming and is still booming.Tell me how could this be has this happen to someone else? not complaining just wanted to know.

 

[Stargazer]

I've picked up FX before when I pointed my FTA dish last summer. I think I picked it up off C-Band 91W with a 6 foot dish (mini-BUD). It came in pretty strong. I don't think it is on 97W though. Also nice tuning in History and Biography on 101W.

 

[guacharaca]

Using an all Ku signal system (pure linear ku lnb), I have picked up ku signals using C-band frequencies. It is not a one time thing. I can replicate the situation. It is something in the freq numbers in the STB. However, if you are using a pure C-band LNB, it is something else.

 

[icu1954]

i am using a pure cband B1 eagle aspen stack.

 

[SatelliteAV]

You will not receive KU-band signals with a C-band LNB or C-band signals with a KU-band LNBF. Most likely a setting or a glitch with the receiver. What brand, model and SW version?

You can connect a C-band LNB to your receiver and set the receiver's LO frequency to a Standard KU band LO of 10750. Perform a Blind Scan and the receiver will find all of the C-band frequencies, but assign a KU-band transponder frequencies. Why does this happen? C-band and KU-band LNBFs output in the same IF range between 950 - 2150MHz. The LO frequency setting in your receiver is added to the IF frequency and the result is the displayed transponder frequency that you view in the transponder list.

 

[guacharaca]

Ok. I did some thinking and I believe it is the same situation. You are actually picking up C-band signal, but they are displayed with ku band frequencies. My coolsat 5000 has done the same in the past. What I found was that I accidentally set the wrong frequencies in the STB for the LNB in the set-up and then did a blind-scan. If you do a blind-scan in the wrong frequency range you will likely see the same. The box picks up the C-band signal and puts them in the range of Ku-band freq for which you scanned. The result is that you get some very strange frequency numbers from the Ku range that actually function equally as well as the correct C-band frequency numbers.

I see that SatelliteAV has said the same only seconds before. Great minds think a like.

 

[icu1954]

what i am saying is,to confirm that this ku signal is being received,i went into the lnb setting for galaxy 19 and removed the 12711 transponder and the picture went out,then i went back in and installed the transponder and the picture came back.Like i said c band lnb on 6ft dish aimed at 91 west.

 

[hd fan]

please icu1954 reread satelliteav post, it could not be more explicit. what you just confirmed with your experiment is and only is that you are getting a signal coming in with in the IF or L band , that is 950- 1450 Mhz not necessarily that it is C or Ku band. reread brian's post and you will see why this happens.

your c band lnb has only 1 LO frecuency 5150 therefore as long as you apply voltage to it (probably between 12 to 24 V DC) it will start working oscillating at 5150 and will downconvert everything to 950 to 1450 , therefore it will only work on C band because its waveguide and feedhorn also i think acts as a bandpass filter for c band frecuencies killing anything above or below.

your dumb receiver , pretty much like all mines, has no means to discern or determine whether the incoming signals (all are always between 950 to 1450 Mhz) are either C or Ku or Ka or whatever and they have to rely on our intelligence to tell them (via its dish setup menu) whether the LNB is Cband (5150 or whatever) or Ku (10600, or 10750 or 9750/10600 or whatever).

I hope all this is clear now.

 

[Elchucko]

Conversion chart

Maybe this chart will help