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All posts by Justin Eastham

Below are all of Justin Eastham's postings, with the most recent are at the bottom of the page.


Hi,

I'm getting frequent drop-outs in reception, with the PSB-3 MUX at Wenvoe. 5g is now operating from the Wenvoe transmitter; and PSB-3 is on UHF-47 (682MHz). It's possible that my aerial is not aimed DIRECTLY at the transmitter (it might be slightly out of line), or some water ingress has occurred; but rather than go to the hassle of getting the ladders out, and lowering the aerial pole (to access the aerial, and the coax connections); I'd rather see if a 5g or band-pass filter would improve matters. All other (eight) MUXes behave themselves; and for the most part I've got 100/100 reception (where I haven't, it's never lower than 95/100).

When experiencing problems, the signal strength will drop below 30, and will bounce around between 20-something and just over 60-something. Signal quality drops to 91/92.

I'm just wondering whether PSB-3 is particularly susceptible, given that it's 256-QAM modulation, using a 32K carrier, with a much lower guard interval (1/128 versus 1/32). If it IS more susceptible; then why have it so close to 700MHz!?

I welcome any advice; and where to get an (indoor) in-line 5g filter from

Regards



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GB

Hi Chris.SE,

>Firstly, a 5G filter for the 700MHz band will block your reception of COMs 7&8.

I appreciate that. COMs 7&8 are using UHF-55 and UHF-56 (746 and 754 MHz respectively). But for the purposes of testing whether a 5G filter would improve reception of PSB-3 (UHF-47 on 682 MHz), I can live without COMs 7&8 ;-)

>Secondly, AFAIK there are no 700MHz 5G transmissions in Cardiff as they are currently only in the 3.4GHz band at present and what led you to think that there are any 5G transmissions from the Wenvoe mast?

Aaaah, okay. I wasn't aware that 5G operated in anything other that 700MHz. I was led to believe that 5g was operating from Wenvoe, from the Wikipedia page for the Wenvoe Transmitter :

https://en.wikipedia.org/wiki/Wenvoe_transmitting_station

....in particular, "As of 31/05/2019, 5G was launched on the Wenvoe Transmitter on EE"

But I take your point; I've bought 15m of WF100 cable, and am going to replace the cable from the "W" aerial to the Labgear LDA2061LR 6-way Distribution Amplifier; and ensure that the aerial is aimed directly at the transmitter, as best as I can determine.

I was hoping that I could live with the reception problems, until post 700MHz clearance; when I planned on replacing the "W" aerial with a "K" aerial (and replacing the cable run), as COMs 7&8 will have moved to below 700MHz.

Thanks for the advice; my money is on sub-optimal cabling from the aerial, combined with the possibility that the aerial is possibly not bang-on, direction-wise. I could also require an attenuator, given that I'm within 2 miles of the transmitter (I've bought a signal-meter, to measure the "dB").

Cheers


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Hi again Chris.SE

>....which has been allocated for SDL mobile use.

What is SDL, out of interest?


>None of the 700MHz band has yet been auctioned btw, due early next year.

Well that's a sure-fire indication that there is no 5g interference :-)

Cheers

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GB

Hi Chris.SE

>Here's the official definition straight from the OFCOM consultation document -
"Supplemental down link - where a separate spectrum block is used to provide additional downlink resource to support the normal symmetrical arrangement"

Excellent. Many thanks :-)

Justin

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