UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Other Discussions > Forum Announcements and Comments

Notices

Forum Announcements and Comments Announcements about forum changes will be made in this section. All new threads here now require moderator approval.

Closed Thread
 
Thread Tools
Old 25th Jun 2022, 4:42 pm   #21
buggies
Heptode
 
buggies's Avatar
 
Join Date: Jan 2009
Location: West Lothian, UK.
Posts: 677
Default Re: Threads getting more modern?

We want a DAB pantry transmitter design now...
__________________
George
buggies is offline  
Old 25th Jun 2022, 5:53 pm   #22
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 20,197
Default Re: Threads getting more modern?

Here you go then:

The RF side of things is not difficult, you'll need one of the wider bandwidth quadrature digital radio transmitter chips. The fun comes in the encoding and protocol side of things and the digital OFDM modulator. Some parts may be still under patent control by Fraunhofer and others.

ADCs and a rather large FPGA ought to do it.

David
Attached Files
File Type: pdf ma-146r2.pdf (83.3 KB, 36 views)
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 25th Jun 2022, 11:27 pm   #23
Maarten
Dekatron
 
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 3,646
Default Re: Threads getting more modern?

Quote:
Originally Posted by agardiner View Post
Quote:
Originally Posted by Cobaltblue View Post
We also get a lot of users try to classify "vintage looking" radios as vintage even though they are still in production. We try to weed those out and put them in Modern Technology. Maybe by around 2045 they will be "vintage"
By 2045 they will be scrap!
Which would make them extremely rare and desirable
Maarten is offline  
Old 26th Jun 2022, 12:12 am   #24
joebog1
Nonode
 
joebog1's Avatar
 
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,384
Default Re: Threads getting more modern?

David!!, ( Radio Wrangler )

I draw your attention to page 12 of the aforementioned script. The oscilloscope "pictures " look like exactly how digital sounds.

Joe
joebog1 is offline  
Old 26th Jun 2022, 6:35 am   #25
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 20,197
Default Re: Threads getting more modern?

Ah, what you're seeing there is analogue stuff (genuinely random noise) getting into someone's attempt at a nice, clean digital waveform. However hard you try, there is always noise. All clocks have jitter because oscillators are noise-based machines. Right down at the particle physics level, quantum mechanics throws random uncertainty into the mix. You just can't make nice Boolean digital things, the analogue world corrupts them. What you can do is get close enough that you can live with the remaining uncertainty.

Eureka147 was the project which developed DAB. They got two big things wrong. They underestimated progress in microelectronics, that soon improved processors would have allowed them to do a better system, and we are having to live with their compromise. They tried to make a system that would work for all purposes. They tried to keep processing demands down to help battery life in portables, so that you could get at least a few hours listening on a set of batteries.

The nature of the deployment of such a system means that we're stuck with it for at least a few decades. Battery consumption still hasn't been made competitive with a basic old-school FM receiver. Even at the highest data rate options and a clear channel over a short distance, the choices of bit depth, compression and data-rate prevent it being competitive with a good FM receiver within the service range of a transmitter. What Eureka147 has delivered is lots more channels, though many are in the heavily compressed low rent district.

A less obvious effect is that transmission is as a number of multiplexes, each carrying a large number of 'stations'. If you want to transmit your station on DAB, you have to do a deal with the infrastructure operators for a slot on their multiplex. You can no longer get a licence and run your own transmitter. This also means there is likely to be no empty space to sneak a pantry transmitter in.

DAB is already obsolescent, it has been for some time. Radio services over internet are scaleable, different data rates are easily offered and the end user can download new software to handle new formats as they arise. Internet access is becoming mobile with data rates targeted ar movie-watching and fast game-play.

Maybe the frequency space of some multiplexes will become vacant and a pantry transmitter becomes viable for someone to demonstrate radios from this period? However, there is now a lot of DAB radios in cars, where most radio listening happens, and they are built in. This adds a lot of inertia opposing change. But change is inevitable, eventually.

Joe, digital stuff can be done very well, better than the limitations on analogue stuff, but that doesn't mean that it has been done that well. Decisions and choices early on often set the bar disappointingly low... usually for the profit motive.

Cheap and nasty has always beaten the good stuff in terms of both fame and fortune. The public are aware of Clive Sinclair and Alan Sugar. Few have heard of Peter Walker and Arthur Radford.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 26th Jun 2022, 7:20 am   #26
joebog1
Nonode
 
joebog1's Avatar
 
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,384
Default Re: Threads getting more modern?

Once again thankyou for a very eye opening ( for me ) explanation.
People often ask me to listen to their digital setups and all I can hear ( even with my deafness ) is digital power supplies. After all, thats all digital audio is, switching the speakers on at varying bit rates.
I am very far from any DAB stuff here. I have never seen ( nor want to see ) a DAB radio, in a car or anywhere else. If I go out west I use AM around 1 mHz, because it goes the five or six hudred kliks from a city and my car. Actually, my radio in the car ( the ONLY radio I own ) is always on smackdab 100 Mhz FM and every now and then it says ( fully synthesised )
"In 300 metres, turn right "
"In 300 metres, turn right "
If I continue it gets all bitter and twisted and says,
" Turn back "
" Turn back "

The GPS can get hold of 27 satellites, but cant get anything worth listening to.
Thanks again for your education on digital, but alas, I remain highly pessimistic about it. Its expensive, lasts two years and need replacing, there are no "parts " inside that can be changed, there are no "teknishuns " that can work on them,
WHY is it so popular ?

with respect as always

Joe
joebog1 is offline  
Old 26th Jun 2022, 9:13 am   #27
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 5,944
Default Re: Threads getting more modern?

This Thread has gone way off topic, there is only so much you can say so its time to close.

Cheers

Mike T
__________________
Don't care if it was a bargain why's it in my kitchen
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Closed Thread

Thread Tools



All times are GMT. The time now is 12:07 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.