On 29/01/2021 19:48, charles wrote:
In article , Peter Able wrote:
On 29/01/2021 17:03, charles wrote:
In article , Peter Able
wrote:
On 29/01/2021 10:01, Mark Carver wrote:
On 28/01/2021 16:46, Peter Able wrote:
On 28/01/2021 12:52, Mark Carver wrote:
On 28/01/2021 12:22, Andy Burns wrote:
Peter Able wrote:

Won't a group A aerial - particularly a big one - cripple the
COM7 multiplex?

How long will CH55 be around for? 700MHz auction taking place in
March?

It's on Death Row, Ofcom licence expires next June. Arqiva can pull
it at very short notice before then (as they did with COM 8) BTW
COM 8 licence is still active, also until 30/6/22, not that Arqiva
will ever bring it back

Thanks for that, both. I'd no idea - but have tried to bone up and,
is this right?

All of the re-works have to happen simultaneously for things not to
go wrong?

Using a full HD TV, we'll still get the current quality and quantity
of service?

It'll offer, to Crystal Palace users with a group A aerial, the
benefit of stuff moving from C55 to lower channel numbers?

Once COM 7 on Ch 55 does close, that's it, nowhere in the UK will
anything above UHF Ch 48 be used for TV broadcasts ever again, so
don't go to too much expense to receive Ch 55 for what will only be a
maximum of 17 more months.

There is no 'roadmap' for the conversion of the remaining five DVB-T1
muxes to T2, the government seem to be preoccupied on other matters
at present !

Well, with the HP Spectrum Analyser the only effort was getting the
analyser up and down a loft ladder. I'd already installed a string
crib for the aerial, so moving it in three dimensions was no problem.

Except for all outputs of the distribution amp outputs being
50Hz-modulated. Unbelievable! The Labgear dist amp starts with a
24vAC transformer, a bridge rectifier and then a 25v electrolytic -
which was well bulging! With that replaced by a 40v cap, C55 was no
problem.

I've not been able to find a cct diag for the Labgear, so can't decide
if it was a batch build problem or an original design fault.

Afterall, 24v supply - 25v smoothing cap - what could go wrong?

If it was 25v ac it should have been fine.


Dear, Oh dear! No it would not.

The capacitor will charge up to the peak - which for 24vAC would be well
over 30v.

That's why I said a 30v ac rating. It should cope with 30 x 1.4 volts


What? Firstly, you never said that. Secondly, even if you had, tell me
how many smoothing capacitors in this sort of system would have a "30v
ac rating"? or any other voltage ac rating? None.

PA