Freesat: Can only receive Vertical channels.

IanLewis

Standard Member
I have a Humax Foxsat HDR, with 2 feeds from a Quad LNB attached to an old Sky minidish. This has all been installed and working for many years.

Yesterday, I noticed that I can't receive some channels, and after a bit of checking it looks like I can receive all channels with Vertical polarisation; none with Horizontal.

As far as I can tell, this has affected both tuners at the same time.

Does anyone have any suggestions for fixing or further diganosing the problem?

Many thanks,

Ian.
 

grahamlthompson

Distinguished Member
First thing to try is a new lnb. Do not factory reset or retune the box. Without access to the Freesat home transponder (Horizontal) it will not do the postcode check.
 

IanLewis

Standard Member
Do not factory reset or retune the box.
Glad I didn't try this!

Thanks for the answer. Is there any way to tell for (reasonably) sure that it's the LNB? Can I check the DC voltage out of the connectors on the back of the humax? Will the voltage still be there if I unplug the coax cable?

I dislike climbing on roofs only slightly less than paying someone else to do it!

Also, looking at my dish (and trying to remember from ~15 years ago) it's a 'old' style, where the LNB mount is pushed into the arm. Most of the LNBs I see have a different mount, which looks like it sits on top of the arm. There are adaptors, which look a lot like my existing mount. Can I buy a 'new' LNB, and fix it into my existing mount?
 

grahamlthompson

Distinguished Member
Glad I didn't try this!

Thanks for the answer. Is there any way to tell for (reasonably) sure that it's the LNB? Can I check the DC voltage out of the connectors on the back of the humax? Will the voltage still be there if I unplug the coax cable?

I dislike climbing on roofs only slightly less than paying someone else to do it!

Also, looking at my dish (and trying to remember from ~15 years ago) it's a 'old' style, where the LNB mount is pushed into the arm. Most of the LNBs I see have a different mount, which looks like it sits on top of the arm. There are adaptors, which look a lot like my existing mount. Can I buy a 'new' LNB, and fix it into my existing mount?

The voltage should be there. You need a legacy adaptor from e-bay and a new MK4 lnb.


 

grahamlthompson

Distinguished Member
Couldn't see anything, on either connector. <10mV. Reception of Vertical channels still OK, so that's puzzling.
Have you got a cheap satellite meter with a beeper, They take power from the receiver ? If so if your turn up the gain and you get a tone it will have dc output.
Switch to non freesat do a full search. Howc many channels do you get ? Check the polarisation from the internet. On any that work press the opt+ button it should give you the transponder details.
 

IanLewis

Standard Member
Have you got a cheap satellite meter with a beeper,
No, sadly not.
On any that work press the opt+ button it should give you the transponder details.
That's handy - I'd been going back into diagnostics menu to check.

I don't see how the V channels are received with no DC - I thought it was the power source for the LNB. So maybe I've done something wrong measuring it. Or maybe there's a fault in the box, but I still don't see how the V channels work.
I'll try the non-freesat tune, and see what I get.
 

winston2010

Well-known Member
There should (must) be around 13 to 14 volts on the coax for vertical channels and 18 volts for horizontal channels. If you can't read any voltage but receive channels you have not made a good connection.
 

IanLewis

Standard Member
Yeah, I was thinking the same. Turns out my multimeter probes are too fat! With the help of a bent paperclip I can see ~ 13V / 18V. So a new LNB it is. Thanks everyone.
 

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