Strange problems with G16@99W C-Band on MicroHD

[TRG]

I hope you get this figured out soon....one of the first things I did when I got mine was go and scan 99W C and all came in fine.

I know, thats what everyone keeps telling me. There are a few things about this that has me ripping my hair out. One is that the same coax coming out of the wall operates an Openbox S9, Coolsat 5000 and a Fortec Star Mercury II just fine. It just wont work properly with the MicroHD. The second thing is that I bought two MicroHD's and they are both doing the same thing! And last but not least is that this seems to be a C Band issue only. Ku Band works as it should.

 

[TRG]

OK, I finally got some time to do what you suggested. The only thing I did different was scan both polarities (auto). Here are my results;

MicroHD LNB power
Blindscan - Detailed

3851 9982 H
3820 25000 H
3900 28000 V
3851 9982 V
3820 25999 V


Openbox Tuned to H. Loop out to MicroHD
Blindscan - Detailed

4000 26400 H
4161 26470 H
3880 30000 H
3848 15030 H
3825 4319 H
3786 4850 H
3776 3255 H
3735 3775 H
4001 26399 V
3880 30000 V
3848 15030 V
3825 4319 V
3805 4939 V
3776 3255 V
3735 3775 V


Openbox Tuned to V. Loop out to MicroHD
Blindscan - Detailed

3925 3679 H
3900 28000 H
3851 9982 H
3820 25999 H
3925 3679 V
3900 28000 V
3851 9982 V
3820 25999 V

Very strange

I really could use some help guys. I'm at wits end trying to figure this out.

In summary.

Latest firmware installed and factory reset performed.

By itself the MicroHD 0nly scans in a couple of transponders. It scans those transponders as H AND V.

Using the Openbox S9 to power the LNB and the MicroHD to display, the rest of the transponders that I normally get light up. However, I get the same echoing of transponders and channels.

Tried eliminating the switch and it does the same thing.

I am going to try and attach a couple of photos showing my setup screen and give an example of the same transponder showing up as H AND V. Sorry for the crummy camera images.

 

[KE4EST]

Have you used both different power supplies or are you hooking the 2 micros up for testing right now still using same PS.

 

[TRG]

Have you used both different power supplies or are you hooking the 2 micros up for testing right now still using same PS.

At first I was using the same power supply. Today I unpacked the second one I have and re-scanned with the same result.

 

[KE4EST]

Do you have another good 12 source you could hook up to one like an Astron Power Supply?

 

[SatelliteAV]

The dual transponders on opposing polarities is caused by scanning the same polarity twice. How does this happen?

Well, the obvious is that when the microHD is directly connected, only vertical transponders are being scanned. This could be a result of one of the following: low voltage output on the microHD, defective or excessive length coax, corroded connector, or most common a voltage switch on the LNBF having a high voltage switch point or failing.

I would measure the loaded voltage at the rear of the microHD and at the dish. Verify on a preprogrammed Horizontal transponder 18vdc (+/- 10%) and on a Vertical transponder 13vdc (+/- 10%).

 

[Mr Tony]

have you tried a different satellite? I'm just throwing stuff out there

 

[TRG]

The dual transponders on opposing polarities is caused by scanning the same polarity twice. How does this happen?

Well, the obvious is that when the microHD is directly connected, only vertical transponders are being scanned. This could be a result of one of the following: low voltage output on the microHD, defective or excessive length coax, corroded connector, or most common a voltage switch on the LNBF having a high voltage switch point or failing.

I would measure the loaded voltage at the rear of the microHD and at the dish. Verify on a preprogrammed Horizontal transponder 18vdc (+/- 10%) and on a Vertical transponder 13vdc (+/- 10%).

Thanks for the reply, Brian. I managed to take some voltage readings before the sky opened up and started pouring rain. Here in the desert thats like nectar from heaven. Its been an awfully dry and hot summer so far.

I'm not sure how to breakout the wires and do a "loaded" check. I assume by that you mean with the LNBF and the MicroHD connected and the receiver being under load. So my reading are going to be with one end or the other disconnected.

Back of MicroHD
14.01v - Vertical
18.57 - Horizontal

At the dish
12.61v - Vertical
17.10v - Horizontal

Within 10 percent, without a load anyway.

You gave me a few ideas to check tomorrow. First I'll check all my connections. This coax was new about a year ago. I use good quality cable and compression fitting and have a proper tool to put them on. Its pretty dry here so I don't think I have a corrosion problem but I'll look anyway. I have a spare LNBF that I can put in the scaler. I did have one of these fail on one polarity before. I kind of ruled out LNBF failure during my troubleshooting because I could get it to work with 3 other receivers. I suppose it could be marginal.

One other thing about the coax. There are two lines running out to the dish farm feeding two rooms in my house. Since the Ku dish/LNBF is operating correctly I can probably assume that the coax is OK. I'm leaning more and more towards a marginal C Band LNBF. Thats one of the easiest things to replace too. I'm afraid it will have to wait till the morning though. There is a lot of lightening out there right now. Its not safe to stand next to a big metal disc at the moment.

 

[SatelliteAV]

Quite a voltage drop with no load at the dish. How long of cable run?

 

[bidaw]

I had the same problem as the OP on all sats on my 12' with Chap Bullseye II Dual Ortho. It was only with the microHD. It perplexed me because I have several other recvrs and not had a problem. So I took last weekend and took a stab in the dark by changing the skew of my feedhorn ever so slightly until I was able to scan without the duplicate H and V transponder scans. Magically, I was able to pickup all the transponders and channels I was supposed to...I did not loose anything with my other recvrs as well. Worth a try at least. Honestly...TRG...I had the EXACT symptoms that you had.

 

[lost_mesa]

TRG,

I agree with what Brain said about the voltage drop. With only a volt meter connected at the LNB end of the cable, you should see the same voltage as at the receiver. This is because without the LNB connected, there is essentially no current flow, so there will be no voltage drop. Something is not right there.

The info you posted clearly indicates that your LNB isn't switching to horizontal with the microHD. Receivers put out about 13 volts for vertical and about 18 volts for horizontal. It is likely that the microHD is putting out slightly less voltage then your other receivers, so your LNB never switches to horizontal. But I don't think this is the fault of the micro HD, the 18.56 volts you measured indicate it is OK.

I think you have one of two problems, perhaps both. Your C band LNB needs a bit more voltage than normal to switch to horizontal. Your other receivers put out a bit more voltage for horizontal than the microHD, so they work OK. The difference could be as little as 1/10 of a volt. Try another LNB to see if this is the problem.

The other possible problem is that you have more voltage loss in your cable than you should. Again, your other receivers are probably putting out a bit more voltage for horizontal than the microHD, so they work. Try another cable to see if this is the problem.

 

[bidaw]

That's a thought too... I have Pico power inserters for my lnbs... Helps immensely for my cable run.