Best HQDL 414 Plus Quattro LNB for QO-100?

Hello,

I have a Best HQDL 414 plus LNB which is apparently PLL to give better stability on reception , Im not 100% sure about the PLL but it does say "crystal controlled" on the LNB itself.

The LNB has four F outputs marked (V High) (H High) (V low) (H low)

When I tried to get a QO100 signals it did not work even though the dish is correctly aligned and works OK with a unmodified universal single output Lo 9.75 GHz LNB (except it drifts).

I searched through the band with the Best LNB and can see the transponders of the Badr satellite so I know the LNB is working but I cannot find the amateur transponder. I tried all four sockets.

Does anyone know which of the four outputs should be the correct one to use for QO100 reception?

Any ideas what may be the problem? maybe this LNB is not compatible? even though it has the same input and output as the universal LNB 10.7 to 12.75 GHz

And why does my unmodified universal LNB work anyway as supposedly it has an input starting at 10.7 GHz but QO100 is around 10.5 GHz?

Best HQDL 414 plus LNB spec :

Input : 10,7 - 11,7 GHz / 11,7 - 12,75 GHz

* L.O. : 9,75 GHz / 10,6GHz

* Output : 950-1950MHz / 1100 - 2150 MHz

Thanks

Quote from SWL-jsilva

You should use the V Low for the Narrowband Transponder and H Low for the Wideband transponder, assuming you apply the correct skew for your location. If you mess the skew up by 90 degrees, you will need to swap the H/V connectors.

We are kinda working out of spec since QO-100 downlinks outside the official supported range for common COTS LNBs. While most of them work on 10.489, one should not take for granted that every single LNB will work outside of the specified range.

Thanks for the info, so maybe I just got unlucky and this particular LNB doesn't quite get down to 10.489 GHz

I have many LNBs and all the ones I have tested so far tune down to 10.489 but they do drift.

some of the LNBs I have are unmarked, is there any way of knowing if they are PLL type or not without opening them or mounting them on the dish and testing the signal for drift?, lots of them have glued backs without screws so its not easy to look inside. I did open one or two and they appear to be the DRO types. The Best HQDL 414 plus LNB was the only one I have which I thought was PLL as its marked crystal controlled.

Quote from SWL-jsilva

They will drift even if they are of the PLL type. The crystal in there is quite sensitive to temperature. You will need to modify one to inject an external reference signal, from a GPSDO for instance, so that the PLL locks onto it and remains stable. Many also drift quite a bit while warming up, but if the temperature remains reasonably stable after warming up, it will work to an extent.

I am pretty sure all of them will have screws, probably the screws are covered in silicon glue. Do you see some blobs of glue or just a small "line" around the perimeter of the lid? If you can see some blobs, try scraping away and check if there is a screw underneath.

How did you conclude that the LNBs you opened are DRO? Did you see a cavity oscillator or another clue? Beware that some of the PLL LNBs have the crystal on the underside of the PCB, so it may be hidden.

I have no hands-on experience with DRO LNBs, probably because they are very old.

Something you can try with that particular HQDL LNB is to check the noise floor at 10489 MHz (739 MHz IF) while pointing it at the sky, and while pointing it at a warm surface (the ground for example). The noise floor should rise when aimed at a warm object. Check if the noise changes equally when tuned to 739 MHz and when tuned to a frequency that lies inside of the supported band (950-2150 MHz). If the noise changes are practically equal, it should be an indicator that your LNB will work at 10489. If they are very different, then maybe not. That's my guess.

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Many of the LNBs have just glue all around the edges of a plate and are very difficult to open (no screws)

I know the DRO types well as they have 2 ceramic discs and often 2 screws above them for the final tuning at the factory.

I will have another try with the Best LNB to check the noise floor at 10.489 GHz.

Perhaps the first time I just missed the transponder because the V/H skew was off plus the extra complication of the 4 different output sockets.

Thanks

There is an anomaly, when the HQDL LNB is output on LOW horizontal it shows wide transponders from 620 MHz to 900 MHz

but the first BADR transponder starts at 960 MHz? see image..

Quote from dm4im

Hello.

You can try receive the 24th harmonic of 437.075 =10489.8 ( 739.8 if the crystal is 25MHz , or 1105,8 if 24MHz)

Just transmit with your handheld in front of the lnb. Remember any frequency error from your handheld will be multiplied by 24. So you may have to search a bit for the signal depending on the overall accuracy.

73, Martin

Sorry I don't understand, do you mean if I transmit in to the LNB at 437.075 MHz I should see a signal at 10489.8 MHz less the LO of 9750 MHz?

Quote from dm4im

Exactly, you should receive a carrier on 10489.8 -9750 = 739.8MHz .

If you already set up sdr-software like sdr-console or similar, you should see a needle coming out of the noise around that frequency.

This ensures you that your lnb is working.

73, Martin

OK I see now, but I would need to be distant from the SDR otherwise the SDR would be just receiving the transmission directly if too close. Thanks

Quote from dm4im

Exactly, you should receive a carrier on 10489.8 -9750 = 739.8MHz .

If you already set up sdr-software like sdr-console or similar, you should see a needle coming out of the noise around that frequency.

This ensures you that your lnb is working.

73, Martin

Interesting:

Testing the Universal DRO LNB which works OK with OS100

input from walkie 437.075 MHz output 738.80 MHz and 874,40 MHz

Testing the Best PLL LNB which does not work with OS100

input from walkie 437.075 MHz, the output only shows at 874,40 MHz

nothing at 738.80 MHz

still its a mystery when using the Best LNB on LOW H why I can see 30 MHz wide transponders from 620 MHz to 900 MHz from BADR sat when they should start at over 950 MHz

Quote from HB9SKA

Your "Super" LNB is unsuitable for QO-100 I think. There are many other LNB's on the market for little money. If you don't want to modify it, look for Opticum. They are not rock stable but have a clean signal.

Martin described the procedure to test a LNB correct. Would this help you at the moment ? Otherwise tell us your requirements to an LNB.

Thanks for the info, I was just trying to test what I had in the shack and learn along the way but the DRO LNBs are too drifty and yes the Best LNB just doesn't work.

Can you confirm before I buy that the OPTICUM LTP 04H will receive QO-100?

If not which of the OPTICUM LNBs will work?

Thanks

Quote from dm4im

Maybe the LNB uses some other multiplication factor, not 25MHz*390=9750. But anyway, once you found the signals from QO-100 around 874MHz, you can calculate your downconverter offset. 10489.8-874.4 =9615.4 . Now setup your transverter definition in sdr console using 9615.4 - not 9750 - and you are good to go. I beleive the 400kHz after the decimal point is the inaccuracy of the internal crystal, so the offset is either 9615 or 9616 . But i also might be totally wrong. The fact that both lnbs show signals at 874.4 may lead to the conclusion that this really is directly fed into the sdr , not via the lnb. 437,075*2=874,15 .

73, martin

It didnt work, 874,40 MHz was only the output from the walkie. not a peep out of QO-100

Thanks for the tip anyway, it was interesting to try.

Thanks to everyone for the help and suggestions, I will try the OPTICUM LSP-04H. they are ridiculously cheap.

Quote from dm4im

I just googled your lnb. This model is for a multi switch, so only one of four outputs provides the polarisation and band you need. Did you take this into account?

73

Hi, Yes as pointed out by SWL-jsilva to try the Vertical Low socket for the narrow band QO-100, in fact I tried all the sockets and came to the conclusion that this particular LNB doesn't get down to 739MHz, having tested many LNBs *DRO types* they all do cover 739 but drift a lot.

The only PLL LNB I had in the shack was this particular Best model which I assumed would work too but not a peep from QO100.

Anyway in a few days I should have a shiny new OPTICUM LSP-04H.