Double Channels???

[pontic79]

I recently received my new microHD receiver and I scanned in Galaxy 19 and others and it worked fine. I switched out my LNBF with a newer one and all my scanned channels lost their signal. I did a factory reset and blind scanned Galaxy 19. The scan produced double channels. Those channels are also on different transponders, according to Lygsat. What is interesting is that it will scan all of the channels form G19 on the Vertical frequencies, then it scans all of the same channels, but on the Horizontal frequencies. The transponder frequencies match on both of the double channels. One is on H whereas the other one is on V. Why is this happening? Could it be a LNB problem?

I also reinstalled the latest firmware and it still does the same thing.

 

[SatelliteAV]

What happens if you switch back to the original LNBF?

What is the brand and model of the new LNBF? Is it a bandstacked LNBF? What is the LO frequency of the old and new LNBFs?

 

[pontic79]

I haven't tried switching it back to the original LNBF. The origional LNBF was an Invacom Quad Polar LNB; LO:10.750/11.250. The new LNBF is a Captive Works CW-200L; LO:10.750.

 

[rv1pop]

~~~~~~Sound like ~~~~ one LNB skewed 90 degrees from the other ~~~~~ ????

 

[pontic79]

I have a motorized system; the LNB is inline with the dish, it is not skewed.

 

[SatelliteAV]

Sounds like a bad LNBF.

Swap back to the original LNBF and give us a report.

 

[pontic79]

Before I swapped back to the original LNBF, I decided to troubleshoot the system to see if it was actually an LNBF problem or if it was a receiver problem.

I hooked up my old Fortec-star Mercury 2 to the CW LNBF and performed a blind scan of G19. It successfully scanned in the G19 FTA channels. It did not produce double channels. The transponder frequencies were still off, according to Lyngsat.

After swapping out the CW LNBF with the original, Invacom, LNBF I performed a blind scan with both the Mercury 2 receiver and the MicroHD receiver. The MicroHD successfully captured all of the G19 FTA channels with no doubles. The transponder frequencies were also correct. The mercury 2 also successfully captured the FTA channels with correct transponder frequencies.

How was the mercury 2 able to successfully blind scan with the CW LNBF and not the microHD? Are the incorrect transponder frequencies an LNBF problem? How does that work?

When I say incorrect LNBF frequencies this is what I mean:
On lyngsat, the channels on the transponder freq. 12177v23000 appear on different frequencies depending on the LNBF I use. On the CW LNBF, those channels are on the transponder frequency 12194v22999. On the Invacom, LNBF those channels appear on the transponder freq. 12180v22999. This is the same on both of the receivers that I have tested.

 

[SatelliteAV]

Both LNBFs have off frequency LOs. This is usually found on older DRO LNBFs that drift off of the factory setting over time. I usually replace LNBFs that are drifted more than 3MHz.

The Invacom LNBF has drifted 3MHz (and this is normal as Invacoms age), but the CW has probably been tuned incorrectly at the factory as it is a whooping 17mhz. Since the CW LNBF already has a problem with the off-frequency LO, I would just replace it with a properly functioning LNBF.

The CW LNBF may not be switching between horizontal and vertical polarities when using the microHD. Check the voltage output of the microHD abd the Mercury II at the dish with a load (LNBF connected). The Horizontal voltage should be 18vdc and Vertical voltage 13vdc (+/- 10%). Some LNBFs have specific voltage requirements in order to switch between horizontal and vertical polarities. Possibly the Mercury II is putting out the voltages at the range that the CW LNBF requires, but the microHD may not put out the voltages that the CW LNBF switching requires.