Signal Loss on C\KU Bands Setup

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Babadem

SatelliteGuys Pro
Original poster
May 21, 2007
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I have a very perplexing problem with my latest C-band and KU setup. Here is how I have my setup. I have a C-Band Mini-Bud (Dual Output) pointed at 99.0°W and connected to Port #3 on 4X1 diseqC (there are two 4X1 DiseqC switches, each connected to a receiver) switch and a KU band Dish (Dual Output) looking at 30.0°W connected to Port #1. Here is the problem, if I'm watching different channels from same satellite on separate receivers there are no issues, but when I have receiver #1(Bedroom) on any C-Band (99.0°W) channels, and then choose a channel on receiver #2(living room) on Transponder 12092 V, 27500SR for example, receiver #2's Quality drops practically to "0". I have swapped the receivers and the same the signal loss keeps happening to any receiver placed in the living room. The C-Band LNB is a "Dual output C-band LNBF GEOSATpro C2", the KU, is an "Eagle Aspen 270 KU" LNB, and the switch is "Chieta" 4X1 DiseqC switch. Any one have any ideas as to why this is happening?
 
Only way I know to test is to wait for signal to drop, then disconnect the cable from the other receiver, and watch to see if signal jumps back up.
 
Only way I know to test is to wait for signal to drop, then disconnect the cable from the other receiver, and watch to see if signal jumps back up.
In that case, I have tested it. As I said in my original post, if either receiver is on the same satellite there are no issues. If receiver #1 is on C-band satellite channel, and receiver #2 is on KU Band and I power off #1 receiver using the remote, the offending receiver #2 works fine (signal quality shoots from 0 to whatever the is the optimal for that channel), but when I power up receiver #1, the quality signal of receiver #2 drops down to absolute "0" :confused:
 
Do you inadvertantly have a 22mhz tone on somewhere causing signal confusion? Just thinking out loud here
 
Sounds like the Switch, 13v / 18v Signals are getting thru the LNBs.
I will try another set of 4X1 switches, or change ports on the switches and see if it makes a difference.
 
Now, I'm really stumped! I just got a new pair of DiseqC 4X1 switch from Sadoun, and the issues still persist. When, I connect the connectors from the C-band to Port 1 and connect the connectors of the KU Band to Port 2 s of the 4X1 DiseqC, (Receiver 1 on C-Band and Receiver 2 on KU Band) all quality signal drop to absolute ZERO when the second receiver on a KU band Channel is turned on and vice. But, When I swap the connectors to C-Band Port 2, and KU Band Port 4 on the DiseqC switches, everything works fine. Remember, it also worked the same way, even with the old Chieta 4X1 switches that I had before. I have changed all F-connector ends on my cable and swapped out KU LNBs, except for the C-band LNB, yet no luck. Apart from replacing the Geo-sat dual output C-band LNB. I really don't know what else could be causing this signal loss issue. :( :confused:
 

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I take it these are fixed dishes - no motors?
Still sounds like there is bleed-thru at the LNBs or Switches.
Try being on the same polarity, one receiver on C, the other on Ku.

What brand Switches did you buy?
 
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I take it these are fixed dishes - no motors?
Still sounds like there is bleed-thru at the LNBs or Switches.
Try being on the same polarity, one receiver on C, the other on Ku.

What brand Switches did you buy?
Yes, both a fixed dishes, and no motors. I will try the suggestion on the last line of your response and get back to you.
 
I take it these are fixed dishes - no motors?
Still sounds like there is bleed-thru at the LNBs or Switches.
Try being on the same polarity, one receiver on C, the other on Ku.

What brand Switches did you buy?
When Receiver 1 is on Horizontal polarity C-Band, and Receiver 2 is on Horizontal polarity C-band the video displays fine on both receivers, but when you change to a Horizontal polarity on KU Band on receiver 2 (Receiver 1 still on C-Band Horizontal polarity) no video is displayed on receiver 2, and vice versa. :(

I have tested with Sadoun, Ecoda, Chieta, SatAV (4X1 and 22khz switches) and no joy.
 
Your 4 port DiSEqC switch drawing looks fine to me and should work.
My suspect is the OpenBox receiver lnb voltage. The OpenBoxs have a little known problem with the lnb voltage regulator, not to be confused with the power supply. Can you substitute another receiver in your setup?
My OpenBox did this while it was still in warranty and was replaced. Now out of warranty it is starting up again after working fine all summer. I'm going to take it apart and fix it myself this time.
I will post the results and possible fix.
There are a few other threads in here with people having mysterious trouble with switches and signal dropping to zero that I suspect are all related to OpenBox lnb voltage.

Edit: Until more is known about this, as a precaution to all OpenBox owners, I would NOT connect ANYTHING to the loop thru. Voltage from the tagged on receiver can damage the OpenBox. Use a power pass splitter with diode protection instead.
 
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I ran it into a variable power resistor for a few hours.
Set for horz. 19 volts held steady with the load drawing 420 ma. which is much above what my system draws and is near the max of the OpenBox.

I even put a 75 watt lamp over the open top and got it quite warm inside, still held steady.

Conclusion: none. Seems everything in the receiver is ok.

Last time I tested an OpenBox with this setup it sagged at a load of 210 ma and went to zero at 260 ma. Some receivers may have this problem my first OpenBox had.
 
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