Advice with Loss of Mux 1

Paspatout

Standard Member
Hello,

This relates to a block of seven flats in Watford, Herts with a shared aerial pointing toward the Crystal Palace transmitter. There is a basic mains powered Philex aerial amplifier in the loft followed by a splitter with a cable emanating to each flat.
For more than 5 years we've had no problems with Freeview reception until about four weeks ago since when we have periodically lost Mux 1 every day for periods anything from a few minutes to a few hours at a time. When it returns, it returns with a strong signal. All of the other Mux's are receiving a high strength signal all the time. There's nothing online to indicate that it's periodoc maintenance related.
Without any technical knowledge of the subject, I'm making an assumption that the strong signal on all other Mux's indicates that aerial and cabling is all functional. The only other thing I can think is that the aerial needs directional tweeking, but that doesn't explain the all or nothing reception on one Mux only. I need to call an Aerial Engineer out, but it troubles me that someone may come out and be inclined to replace equipment that doesn't need replacing.

TIA for any advice.
 

kjhskj75

Novice Member
It looks to me that you're getting interference from some electrical equipment in your vicinity, that kills your signal whenever it's switched on. Is there any time-pattern to your loss of signal ?
 

Rodders53

Distinguished Member
Mux1=BBC1,2 mux = ch25. BBC1 analogue=ch26.

When you have problems with Mux1 what is analogue BBC1 like? (and is that different to when things are OK with Mux1?)

Does the issue affect all 7 dwellings, or is it only some? {HDMI-connected equipment has been know to cause digital reception issues, so it may be worth disconnecting hdmi cables and using scart temporarily to eliminate this}.

Where is the block of flats (I know Watford quite well) as many parts are better served from the Hemel Hempstead transmitter (aka Bedmond or BT Pimlico)?
 

Paspatout

Standard Member
It looks to me that you're getting interference from some electrical equipment in your vicinity, that kills your signal whenever it's switched on. Is there any time-pattern to your loss of signal ?
There's no pattern that I can determine it seems to be pretty random in frequency and duration.
 

Paspatout

Standard Member
Mux1=BBC1,2 mux = ch25. BBC1 analogue=ch26.

When you have problems with Mux1 what is analogue BBC1 like? (and is that different to when things are OK with Mux1?)

Does the issue affect all 7 dwellings, or is it only some? {HDMI-connected equipment has been know to cause digital reception issues, so it may be worth disconnecting hdmi cables and using scart temporarily to eliminate this}.

Where is the block of flats (I know Watford quite well) as many parts are better served from the Hemel Hempstead transmitter (aka Bedmond or BT Pimlico)?
The analogue signal for BBC1 and 2 is perefectly watchable though not as pin sharp as digital. The analogue quality doesn't seem to change with the loss and return of the digital reception. I've spoken to 4 of the 7 residents and everyone is experiencing the same. We are located in Central Watford and it seems all our neighbours aerials point south easterly, including one neighbour who had a new aerial installed about a month ago, and who isn't having reception problems.

Thanks for the responses
 

Rodders53

Distinguished Member
The analogue signal for BBC1 and 2 is perefectly watchable though not as pin sharp as digital. The analogue quality doesn't seem to change with the loss and return of the digital reception. I've spoken to 4 of the 7 residents and everyone is experiencing the same. We are located in Central Watford and it seems all our neighbours aerials point south easterly, including one neighbour who had a new aerial installed about a month ago, and who isn't having reception problems.
Thanks for that - you've done a lot there. Very helpful.
This is pointing to a 'very local' interference issue - probably something getting into that amplifier from a very nearby source: the dwellings immediately adjacent to it being the most likely culprits...
Have you spoken to those who are just under the area of the loft with the amplifier and splitters?
It could be anything from mobile phones, cordless phones, baby alarms, to computers and electronic lighting (led or fluorescent) or their controls - especially if they share the same electrical circuit as the amplifier (e.g. communal area lighting?).
Turning things off and on when the problem is occurring may find the device that is the culprit. Relocating or repairing the faulty device should cure it.

None of that will be easy though! So good luck - you'll be needing it.
 

Paspatout

Standard Member
A eureka moment in this matter today. I asked my neighbour, who's loft space the roof aerial first passes through, if I could inspect the cable where it enters the roof void. I didn't really know what I was going to be looking for but good job I did because I immediately spotted a suspicious bit of insulating tape, which on removal revealed that the cable had been cut and then the braid twisted together. A metre further along the cable it passed beneath some suspiciously new looking insulated paipework. A bit more investigation revealed that the new pipework related to a new radiator which had been fitted about a month previously, about the same time our problem started. I can only imagine that they needed the cable temporarily out of the way and so they cut through it and hoped it wouldn't be discovered.
I've now spliced the cable using coax connectors and I'm hoping that will resolve the problem. Thing is the act of that tradesman could have cost us hundreds of pounds, so wherever you are *^!!!*%$+!!:censored:
 

Rodders53

Distinguished Member
I can only imagine that they needed the cable temporarily out of the way and so they cut through it and hoped it wouldn't be discovered.
More likely accidentally caught it drilling up from below? :clown: Why not own up to it rather than bodge the job? Impossible to prove of course - otherwise you could present them with a plumbers rates bill for investigation and fixing it.

Anyway, well found! Let's hope it fixes the problem for you all! :arty:

I think you deserve a :beer:
 

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