Zgemma H7S oddities

[BrianG61UK]

OK, that's expected behavior then. No problem.


No, the BER is consistently 0. Certain combinations of transponders tuned simultaneously seem to cause picture blocking/garbage on one of the channels - for example NHK World HD (11225 V) and Channel 4 HD (12168 V) - though the BER shown in the OSD is 0 when this occurs. I get 863 services on a scan of 28.2E. I'm now suspecting my LNB is the problem and that the two halves of the LNB are interfering with each other, as the corrupted EPG has only occurred when I have been using the box when the OpenTV download has run.

I had the certain combinations of frequencies causing problems thing with my Zgemma H7S.

I assume that an oscillator (VFO) in one tuner leaks into the other tuner a bit and causes problems with weak signals on a certain frequency that depends on what the other tuner is tuned to.

I was able to fix it by using a pair of Labgear CM5220 satellite signal boosters and a pair of short cables with F connectors on the ends.
The CM5220 seems to have been discontinued, but there are other similar ones on eBay like:

https://www.ebay.co.uk/itm/153544214896 or
https://www.ebay.co.uk/itm/270468117287

Shorter or better quality cables from the LNB, or an LNB with a stronger output, might be alternative solutions.

[Knuckx]

I had the certain combinations of frequencies causing problems thing with my Zgemma H7S.

I assume that an oscillator (VFO) in one tuner leaks into the other tuner a bit and causes problems with weak signals on a certain frequency that depends on what the other tuner is tuned to.

Good to know I'm not the only person to have experienced this issue. Hopefully you are correct and this is only a "weak signals" problem.

Shorter or better quality cables from the LNB, or an LNB with a stronger output, might be alternative solutions.

A nicer LNB, and new, good quality cables is probably going to be my first choice of solution. I was planning on getting a new dish anyway, as my existing one looks like crap (it came with the house) and I would like to be able to receive from 19.2E and 13.0E. If that doesn't improve things, then I'll look at getting some amplifiers. Luckily the EPG corruption has only happened a few times, almost all of them when I was fiddling with the box.

[BrianG61UK]

Shorter or better quality cables from the LNB, or an LNB with a stronger output, might be alternative solutions.

Oh, and another possible, maybe, type solution I never looked in to would be to open up the Zgemma H7S and try and fix the problem with the design. Maybe a grounded metal shield fitted between the two tuners would do it. I chickened out of trying it myself though. Also, I hadn't fully formed my idea of what was probably going wrong until I found the booster solution worked well for me. I also have no idea whether my feeds from the dish are unusually weak or not.