topic Re: HDMI extender over Cat6 issue in Sky Q

HDMI extender over Cat6 issue

NeddyFlanders — Wed, 19 Apr 2023 21:35:35 GMT

Hi everyone, I have my sky q box setup in a comms rack in my house where I have ran cat6 cables to the 3 tv points in my house.

I have a HDMI over Cat 6 Extender (StarTech), but the picture & audio drop out every 5 seconds or so. This is not a cabling issue as I've had all the cat 6 cables tested. The issue seems to be exclusively to the sky Q box as I can stream other HDMI outputs from the same location no problem.

Any help/ideas would be greatly appreciated.

Re: HDMI extender over Cat6 issue

PandJ2020 — Wed, 19 Apr 2023 21:45:54 GMT

What video resolution is the Q box outputting?

Re: HDMI extender over Cat6 issue

NeddyFlanders — Wed, 19 Apr 2023 22:02:15 GMT

It's set to 1080p. But lowering it to 576p only helps slightly.

Re: HDMI extender over Cat6 issue

bob1234 — Thu, 20 Apr 2023 07:35:09 GMT

@NeddyFlandersWhat is the exact model, there seem to be lots, not all have the correct HDCP

This is the main Q box as the mini boxes do not support 4K.

Re: HDMI extender over Cat6 issue

NeddyFlanders — Thu, 20 Apr 2023 11:27:52 GMT

Hi @bob1234

The HDMI By STartech- HDMI Over Cat5e/6 Extender - 4k 30Hz - 130ft(40m)

https://www.startech.com/en-ie/audio-video-products/extend-hdmi-4k40c6p1

The Sky Q Box is Model : ES340A-d8-UKIE

SKY Part Code 16930

Re: HDMI extender over Cat6 issue

PandJ2020 — Thu, 20 Apr 2023 12:22:21 GMT

Q requires HDCP 2.2 (the extender only supports 1.4).

Also bear in mind that 4K signals are 2160p/50 (or 2160p/60).

Re: HDMI extender over Cat6 issue

bob1234 — Thu, 20 Apr 2023 12:31:23 GMT

@NeddyFlandersI believe the Q box output is 50Hz which could be the problem.

Re: HDMI extender over Cat6 issue

StuartMuirhead67 — Thu, 20 Apr 2023 13:15:41 GMT

Hi there, I have also had a sky q box recently installed, replacing a sky + had box. This ran over hdmi and cat 5/6 extenders perfectly but now drops audio and the video jitters every now and then.

I have two tvs with the extender splitting the hdmi. HDMI not running over cat5/6 works fine.

Interested to to know more about HDC and hertz issues. Sky engineer arrives tomorrow but suspect he will say it is the cat 5/6 cable.

Re: HDMI extender over Cat6 issue

NeddyFlanders — Thu, 20 Apr 2023 13:26:38 GMT

Hi @PandJ2020

Thanks for getting back to me.

Could I ask if you could recomment an extender that I could use in this situation?

Kindest Regards

Re: HDMI extender over Cat6 issue

PandJ2020 — Thu, 20 Apr 2023 14:17:48 GMT

@StuartMuirhead67 wrote:
Interested to to know more about HDC and hertz issues. Sky engineer arrives tomorrow but suspect he will say it is the cat 5/6 cable.

The extender needs to be capable of carrying the Q signal - both in terms of resolution and refresh rate (which is generally 50Hz).

Re: HDMI extender over Cat6 issue

PandJ2020 — Thu, 20 Apr 2023 14:18:20 GMT

@NeddyFlanders wrote:
Hi @PandJ2020
Could I ask if you could recomment an extender that I could use in this situation?

Sorry, you'll need to check the specs an ensure they carry HDCP2.2 and up to 2160p/60.

Re: HDMI extender over Cat6 issue

bob1234 — Thu, 20 Apr 2023 16:24:00 GMT

@StuartMuirhead67 wrote:
Hi there, I have also had a sky q box recently installed, replacing a sky + had box. This ran over hdmi and cat 5/6 extenders perfectly but now drops audio and the video jitters every now and then.

I have two tvs with the extender splitting the hdmi. HDMI not running over cat5/6 works fine.

Interested to to know more about HDC and hertz issues. Sky engineer arrives tomorrow but suspect he will say it is the cat 5/6 cable.

Splitters also give problems depending on the type and where they are, everything connected to splitter must be highspeed and HDCP2.2.

Re: HDMI extender over Cat6 issue

SteDC — Tue, 29 Sep 2026 18:49:43 GMT

I'm having similar issues, garbled sound, sometimes out of sych with video and sound. On occasions no sound. This issue appears to only become an issue over the past 12 months. All wiring checked. Normally I need to power down Sky q box to reset. Starts to work fine again for a few hours. HDMI converter details shown below. Is the only solution to swap out all hdmi converters ? I have a fair amount to swap.

Specification: Supports resolutions: 480i@60Hz,480p@60Hz,576i@50Hz, 576p@50Hz,720p@50/60Hz,1080i@50/60Hz, 1080p@50/60Hz Working Temperature: -10¡æ ~60 ¡æ Link Connector(Sender/Receiver): UTP/STP CAT5e/6 Power Consumption: 3W (max) each Relative Humidity: 20%~90% Power Supply: DC 5V/1A Dimensions: 110 x 58 x 26 mm Weight: 239 g Cat5e/6 cable: Follow the standard of IEEE-568B

Re: HDMI extender over Cat6 issue

Chodley — Tue, 29 Sep 2026 19:24:27 GMT

You are outputting 1080p @50 / 60 presumably?

Re: HDMI extender over Cat6 issue

SteDC — Wed, 30 Sep 2026 06:10:43 GMT

Yes, correct, I'm outputting 1080p @50 / 60hz.

Re: HDMI extender over Cat6 issue

Chodley — Wed, 30 Sep 2026 07:29:09 GMT

Have you tested a lower res, just to see what happens?

Re: HDMI extender over Cat6 issue

SteDC — Wed, 30 Sep 2026 17:50:40 GMT

I'll give it a try and monitor. Thank you for the suggestion.

Re: HDMI extender over Cat6 issue

mr.tickle — Wed, 30 Sep 2026 18:35:23 GMT

@SteDC wrote:
Yes, correct, I'm outputting 1080p @50 / 60hz.

You've said cables are ok so my idea of the cable degrading over time may not be it, but you could run ethernet speed checks over that cable without the HDMI adapators in place to check it.

Also remember that there are FOUR components which dictate the bandwidth used, not two:

1. resolution

2. framerate

3. the bit-depth (8, 10, 12)

4. the chroma subsampling. RGB and 4:4:4 both take the same, then 4:2:2 takes less, and 4:2:0 takes less again.

It's a constant frustration to me when manufacturers list only the first 2, since there's an enormous difference in PQ between say 4K50 at 8bit/4:2:0 vs 4:50 at 10bit 4:2:2. (With 8bit you'll get massive banding in HDR for a start).