Bizarre disappearing signal

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Panavision

Panavision

Thread Starter
SatelliteGuys Pro
Jan 23, 2007
282
2
St. Louis Park, Minnesota
Hello. I haven't visited in a while, but it's great to be back!

I'm having this problem where I go to bed listening to music through an ear bud. When I wake up, the music is gone. I'm getting enough signal to rule out day/night outages.

Some background: From my 1.2m dish, I'm running two Norsat Ku LNBs through an ortho. The signal goes through a multiswitch that I've modified to run 18v on both vertical and horizontal. That runs to a Diseqc switch. Then that output goes to my SG2100 and then to a diode-steering splitter where the signal goes to two different receivers. One receiver, a Geosatpro 200c, provides music to my ear bud. The other, goes to my TV in another room through an inline coax amplifier and then 100' of RG-6. That receiver is a MicroHD. The Micro's power gets passed through the splitter, while the 200c is DC blocked so that its power doesn't confuse the motor or otherwise interfere with the polarity signaling.

So, I set the MicroHD to the music TP before going to bed. When I wake up, the receiver shows No Signal. I have to, get this, steer my dish to CNN's TP on SES2 to get the receiver to start seeing a signal again.

You might be thinking that the multiswitch is the culprit, but I bypassed that and had the same problem. I also swapped out the ortho and Norsats and threw in a Geosatpro PLL LNB. Same problem.

I'm getting 77% Q on the music TP day and night, so it's not anything like sun interference.

I've got a few more things I can try, but I just wondered if anyone had a similar experience.

Thanks!
 
migold

migold

SatelliteGuys Pro
Dec 2, 2006
555
71
Pearisburg, Virginia
I had a similar experience. I was losing signal to one receiver fed from a multi-switch, but not to the other. The problem was in the line to the receiver losing signal. I had a 'splice' using an F-81 to join my feed line to a pre-existing line going through the wall. I could clean the connection up, but weeks later, it would be bad again. Finally, I ran a new RG-6 from the multi-switch through the wall to the receiver, eliminating the splice. Now, it works fine, no loss of signal, I have constant reception.
 
radio

radio

"On the Air" in MI
Pub Member / Supporter
Oct 13, 2007
3,711
979
West Central Michigan
I've found most EVERY issue I've ever had is cabling. Either a loop too tight at a connection which "gives" and breaks a conductor inside the jacket, or some other failure via water intrusion, bad connector, or corrosion. I always think I've got my connections just right, pristine, and perfect....but they never are. Good thing we hobbyists like to "tweak" yearly or more often and check things out regularly! (and "play" of course, too.)
 
Panavision

Panavision

Thread Starter
SatelliteGuys Pro
Jan 23, 2007
282
2
St. Louis Park, Minnesota
I've substituted different cables and lengths and I keep coming up with the same problem. It consistently only happens whenever I've got the DiSEqC switch inline. I get 0% Signal and Quality on my vertical transponders, that is until I tune a horizontal transponder. Once I tune horizontal in, I get "access" to vertical transponders. Also, this is a brand new DiSEqC switch- but the old one did the same thing. What am I doing wrong?

UPDATE: I've taken my SG2100 motor out of the equation. Now all my channels come in fine.

Next thing to try: a motor reset.
 
Last edited:
Titanium

Titanium

AI6US
Lifetime Supporter
May 23, 2013
7,427
8,638
Meadow Vista, Northern California
A motor reset will probably not change anything as this will only erase the memorized motor positions and not affect the hardware loop-through circuit.

22KHz and DiSEqC signals require the LNB voltage in order to be distributed. When on a vertical transponder (13Vdc) the 22KHz/DiSEqC signal amplitude will be weaker. Switch to a Horizontal transponder (18Vdc) and the 22KHz/DiSEqC signals will be stronger.

Removing the motor is decreasing the attenuation of the control signals. Place your receiver on a vertical transponder and measure the voltage at the LNB IN port on the back of the receiver. 13Vdc (-/+ 10%)? Now measure at the switch output and inputs with and without the motor in-line. If the vertical transponder voltage measurements remain near 13Vdc then that is not the likely cause. If you have a signal meter with a 22KHz (tone) ON/OFF indicator, the indicator will rapidly flash when DiSEqC signals are detected. If you have a meter with a 22KHz indicator, place it at the DiSEQ switch position and check the indicator on both horizontal and vertical transponders with and without the motor in-line. This would help trouble shoot if the switch position is receding the control signals.

What could cause this to happen? There are several reasons and corroded fittings or damaged coax cable are the most common culprits. If you have ruled out cables and connectors, check out some other possible causes.

Switches are not all the same and some require higher amplitude control signal levels to switch. Aging switches often start going deaf as they fail. What switch are you using? Try a different brand and models switch.Hint: if there are only 2 LNBFs a 22KHz switch will be more reliable than a DiSEqC switch. They typically require lower voltage and lower control amplitude to switch ports.

Another possible cause could be the receiver. Some model STBs output a low amplitude 22KHz/DiSEqC signal to start with. What receiver do you use?

Good luck!
 
Panavision

Panavision

Thread Starter
SatelliteGuys Pro
Jan 23, 2007
282
2
St. Louis Park, Minnesota
Never mind, the vertical channels don't come through whenever I've got my diseqc switch in the chain. Having the motor there or not didn't make a difference. I still can only watch verticals after I tune in a horizontal service first.

I voltage tested all sorts of places. The switch, when I had Port 4 selected on my receiver, was sending 0.25v to Port 4. Port 1 was getting 13v. ???

It's gotta be the switch. This is the second one I've tried- a Pansat. The first one was a GeoSatPro. I'll order another one, but I'm not feeling good about this.

Thanks for troubleshooting with me!
 
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