Motor goes back and forth on loss of signal

DJ Rob

SatelliteGuys Pro
Original poster
Sep 8, 2003
1,577
2
Denver, Colorado
So I've noticed tonight with my DG380 motor, when a feed goes dead and I leave it on that channel, the motor starts going east to west by a degree or less every couple of seconds. This is only happening when it had a signal, then lost it. It will do this forever it seems if you don't change to another transponder or turn the MicroHD off. Is this a hidden feature to try to bring a signal back? Or is there some kind of weird bug going on? You would think it could be bad on the life of a motor if it is doing this for a long time.
 
Have not observed this issue. The test bench units and my home unit sit on ended feeds quite regularly without activating the motor.

The microHD will attempt to retune a lost signal and reissue the programmed DiSEqC and 22khz commands, but it does not search switch settings or autoshift the motor.

Please document the system configuation, menu set-up, motor control type and feed information. We will attempt to duplicate
 
I just did a quick check on my two Ku dishes, and couldn't duplicate the issue. I used a large piece of shipping box ( from a geosatPro 90cm , in fact) to block the signal after a move. Neither my DG-380 nor the new SG-2100 did any "micro-moving" in the minutes after losing signal. I think I've run across a similar issue before, but I can't bring the memory out of my foggy brain. :)
 
I have noticed on mine it does keep re-issuing DiSEqC 1.2 commands and USALS. It can get annoying if out at the dish and doing some testing and still have receiver hooked up and turned on....Or even just in the house, and trying to fine tune a signal.

Brian mine is set up with USALS on Ku except for a couple I have fixed dishes on, and DiSEqC 1.2 for C-Band driving a V-Box X. I have the switch set-up for a DiSEqC 1.1 DigiWave 8x1 switch. C-band on port 1 and Ku on port 4. I can not replicate what the op is saying because I just tried it. I went out to the dishes and un-screwed the coax from the switch for Ku and the motor never moved. Here is what mine does and is annoying at times, and it does it on either USALS or the V-Box. Say I have the microHD programmed to go to stored number 10 on the V-Box. Ok so I choose that satellite in the list and the command is issued and the V-Box fires up and moves the dish perfect. Ok but say a certain transponder on that bird wants to be 3 or 4 clicks to the west to get a better signal. Ok I just take the V-Box remote and bump the dish over, great signal. Ok then in about 2 seconds the microHD tells the V-Box to go back to the pro-programmed number. So dish moves 4 clicks back to the east and the picture starts breaking up again..Grrr. Ok the other thing is say I go out to the Ku dish with my meter and hook up the LNBF and want to use the east and west buttons on the motor to try and test if I am on the arc ok. Same happens there if I move dish to test or say while I'm out there I want to move to an adjacent bird just to see what the meter is saying. I push the button and move over and wham the dish moves back to where it was. I could just turn off the microHD before I go out but then I can't move the dish with the buttons.
 
I just did a quick check on my two Ku dishes, and couldn't duplicate the issue. I used a large piece of shipping box ( from a geosatPro 90cm , in fact) to block the signal after a move. Neither my DG-380 nor the new SG-2100 did any "micro-moving" in the minutes after losing signal. I think I've run across a similar issue before, but I can't bring the memory out of my foggy brain. :)

I can't replicate it either, I just tried again with another bird, and the SG9120B didn't move. Strange what DJ Rob is having happen, but I don't know his whole set-up either.
 
Sounds to me like the microHD is just moving the motor back to the previous satellite. I have seen this when you are on a sat, and you delete the only channel loaded for that sat. The microHD will immediately move the dish to the previous satellite in the list with active channels.

Now, if it's actually HUNTING back and forth constantly between two satellites, that beats me. I'd chalk it up to some strange wiring issue or signal "leak" causing his switch to shift it back and forth by itself.
 
Correct, if it loses signal it reissues the switch and motor commands.

You can bump the dish east/west and it will stay unless signal drops below threshold or the transponder/channel is changed.
 
I'm using a Powertech DG380 motor with a GeosatPro 90cm dish with a SL1PLL. There's about 50 ft. of coax between the receiver and the motor.

I'm using USALS on the Micro. I've only seen the dish oscillating only happen on HD feeds so far. And I'm not sure how much time passes after the signal went off the air before it starts moving back and forth.

My wife pointed it out to me the other night that the dish was doing it.

Then, I noticed the dish was going back and forth a few hours after I left the receiver on the NFL feed that was on 105w last night. Once I put it on 97w or where it got signal, it was fine and didn't do it again. I'll try to tune to an HD channel and then cover the lnb and see if it does it again and how long it takes before it does it again.

Maybe a motor issue?
 
Last edited:
Unable to duplicate using an ended HD feed. Using a GEOSATpro HH120 motor, SL1PLL, microHD through 120' quad shield.

Try performing a motor hardware reset. Never used that motor, so unsure if it is USALS compatible or fully implemented. Maybe also use the microHD "recalculate" function as this clears and resets USALS implemented motors.
 
I was unable to duplicate using a 9120 motor. Placed aluminum foil over LNB and showed no signal, but no motor movement. I chose a different TP on same satellite (with foil still installed) - no movement of the 9120.
Bob
 
I threw foil on mine last night and it didn't do it either. The only things I can think of that I might have also been doing which I'll try tomorrow:

1) For sure, I was using the last channel command between a feed on 105w and 103w. So maybe it was going between those two when the feed on 105w went off?

2) I may have also used the "bump" command when I left it on 105w, so then when the feed went off, it kept going between where I "bumped it" and where USALS has 105w. Not totally sure I did that though.
 
I went out today to make sure I had maximum signal. I tuned the MicroHD to Macys at 105W since 105W is my south satellite. When I unplugged the lnb from the motor to hook up to my Acutrac III, the motor again started going back and forth every couple of seconds until I plugged it back in so that the MicroHD could get signal again. I'm using USALS. Any suggestions on what you want me to try next?
 
Since we are unable to replicate this issue with our set-ups, it will be rather difficult. I have connected the microHD to the scope and only observe the typical reissue of the USALS/DiSEqC/22khz commands.

Maybe try a motor hardware reset and also perform a "Recalculate" with the microHD when connected to the motor.

Anyone else using a DG380 motor with the microHD?
 
Since we are unable to replicate this issue with our set-ups, it will be rather difficult. I have connected the microHD to the scope and only observe the typical reissue of the USALS/DiSEqC/22khz commands.

Maybe try a motor hardware reset and also perform a "Recalculate" with the microHD when connected to the motor.

Anyone else using a DG380 motor with the microHD?
I just put my DG-380 on the MicroHD to test this.
1. Put the dish on Aljazeera . Blocked the signal with a big piece of cardboard--no motor movement.
2. With the dish still on Aljazeera, I disconnected both RG-6 cables from the lnbf -- no motor movement.
3. Reconnected both RG-6 cables to lnbf-- motor moved about 5 degrees West, then back to 97W and stable.

It appears that once the lnbf feedback is re-established, the motor movement commences, whether ordered by the MicroHD, or not, I can't tell.

Moving my MicroHD to a SG-2100,

1. Block signal, no change in the motor .
2. remove cable from lnbf, after about 5 seconds, a tiny sound from the motor, like it was being "micro-bumped".
3. Reconnect cable to lnbf, tiny "micro-bump" sound from the motor.
Neither 2 nor 3 resulted in dish movement, just brief motor energization.

Suggest that loss of lnbf feedback triggers some response from the MicroHD. That response signal is interpretted slightly differently, depending upon motor model. :)
 
Doing the same experiment with the Solomend 800 and the DG-380 , I noticed no indication that any motor commands were being issued. No noise, no movement. Different results for probably obvious reason of motor implementation code. :)
In both cases, I'm only getting any motor movement when the lnbf is physically disconnected from the cable, and then only on the MicroHD, with both motors. If the OP is getting motor movement without disconnecting the lnbf, I don't have a suggestion, unless possible bad/loose cable connection. :(
 
Correct, if it loses signal it reissues the switch and motor commands.

You can bump the dish east/west and it will stay unless signal drops below threshold or the transponder/channel is changed.
It appears to me that the different motors respond slightly differently to the reissue of motor commands, when they are already "on target" . The DG-380 actually moves a few degrees and moves back again, the SG-2100 does a "wakeup" and decides that it's already there, and no movement is necessary. I think we're back to wondering why the OP is experiencing sufficient signal loss to trigger the MicroHD commands. I think we're back to cable routing/switches/configuration issues. :)