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Spectrum Analyzer?

Seek assistance with all types of tech. - computer, phone, TV, heating controls etc.
XFool
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Re: Spectrum Analyzer?

#404741

Postby XFool » April 16th, 2021, 3:02 pm

Thanks for all comments and help.

I'm now moving to the position of thinking the fault could possibly be in my decoder box. Perhaps it is having a problem with QPSK decoding? Fact is, I already know it has progressively lost function - fairly recently stopped decoding the station ident page on radio channels - due perhaps to that 'firmware rot' which seems to me to afflict various digital devices. Of course the manufacturer has already ceased issuing firmware updates.

AleisterCrowley
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Re: Spectrum Analyzer?

#404746

Postby AleisterCrowley » April 16th, 2021, 3:49 pm

(shudder) happy memories of my LTE (4G) course
LTE channels go up and down QPSK/16QAM/64QAM depending on channel conditions (and phase of the moon, current weather forecast, winner of the 4.15 at Newmarket etc) -changing per millisecond, per user!
Horrible feeling 256QAM may be in later releases...
I have forgotten most of that stuff, for my sanity's sake

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Re: Spectrum Analyzer?

#404754

Postby Breelander » April 16th, 2021, 4:03 pm

XFool wrote:Programme channel 'London Live' is transmitted from Crystal Palace. It is on the local service multiplex (LCN 8) for London, the LTVMux L-LON or MuxLW - London (take yer pick!) transmitted at 30kW on RF channel 35 at 586 MHz.

I remember a while ago now watching the old 60s/70s series 'Callan' on it. Not recently though, it pixelated all over the place. Before the aerial guy did his work I had noticed this (relatively lower power) channel/Mux was indicated by my box as having a somewhat weak signal (~13 dB ?) but with a zero error rate. Thinks: So why is it pixelating?


XFool wrote:...I'm now moving to the position of thinking the fault could possibly be in my decoder box. Perhaps it is having a problem with QPSK decoding? Fact is, I already know it has progressively lost function - fairly recently stopped decoding the station ident page on radio channels - due perhaps to that 'firmware rot' which seems to me to afflict various digital devices. Of course the manufacturer has already ceased issuing firmware updates.


FWIW, my PVR is long out of support too. I'm on the outer reaches of Crystal Palace coverage. Signal strength for London Live on channel 35 is around 90%, with 'signal quality' shown as 98% and a C/N (carrier to noise) ratio of 24dB.

I've not seen Callan for years, so I recorded (and enjoyed - thanks ;)) an episode on London Live - not a single sign of any pixelation. Does sound like your decoder is past it's 'best before' date :(

XFool
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Re: Spectrum Analyzer?

#448262

Postby XFool » October 6th, 2021, 11:40 am

XFool wrote:
AleisterCrowley wrote:I haven't used any decent test equipment for years (as I now seem to be an acccountant) All the good stuff was from the likes of HP/Agilent, Rohde&Schwarz, Marconi etc

Ah! All the 'old' names. :)

Who was it made those old UK make of impedance bridge testers.

Wayne-Kerr - Just came to me out of the blue! (Boris is making a speech on the radio - surely no connection?)

They still exist, too: http://www.waynekerr.com/site_us/

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Re: Spectrum Analyzer?

#448282

Postby servodude » October 6th, 2021, 1:05 pm

XFool wrote:
XFool wrote:
AleisterCrowley wrote:I haven't used any decent test equipment for years (as I now seem to be an acccountant) All the good stuff was from the likes of HP/Agilent, Rohde&Schwarz, Marconi etc

Ah! All the 'old' names. :)

Who was it made those old UK make of impedance bridge testers.

Wayne-Kerr - Just came to me out of the blue! (Boris is making a speech on the radio - surely no connection?)

They still exist, too: http://www.waynekerr.com/site_us/


Ooh yes they used to raise a snigger for some reason
Useful things though
- less so with 0402 surface mount caps :(

-sd

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Re: Spectrum Analyzer?

#448309

Postby AleisterCrowley » October 6th, 2021, 3:05 pm

Ah , that brought back a few memories...!
Also, slaving over a Racal LCR bridge testing samples from a reel ...yawn...filling out QC report ...yawn

XFool
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Re: Spectrum Analyzer?

#448972

Postby XFool » October 9th, 2021, 4:00 pm

Aerial guy ("a different one to last time, but he knows all the details") coming again on Wednesday! (viewtopic.php?p=448281#p448281)

Everything working AOK at present - apart from landline :lol: (viewtopic.php?p=448948#p448948) - so I reckon there's going to have to be a LOT of explaining...

If anything digital keeps going for more than 6 months does it get a Meritorious Service award?

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Re: Spectrum Analyzer?

#449784

Postby XFool » October 13th, 2021, 11:33 am

Aerial guy been and gone. Tweeked signal level down.

Interference on VHF gone (for now?). DTV COM 6 working OK (for now?). Will have to "wait and see", showed me all the "mush" on his analyzer, before and after. He blamed "all the transmitters going up around here", 5 G etc.

I think I'm going to start blaming coronavirus...

Meanwhile, landline is working again - those bots don't lie. :lol:

But... now have to try and get broadband back to 'normal'. Damn that DLM! :evil:


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