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 > Specific Vintage Equipment > Television Standards Converters, Modulators etc

Notices

Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions.

Closed Thread
 
Thread Tools
Old 27th Oct 2006, 11:07 pm   #101
murphyv310
Dekatron
 
murphyv310's Avatar
 
Join Date: Sep 2006
Location: Kilmarnock, Ayrshire, UK.
Posts: 5,433
Default Re: Auroras back in stock

Quote:
Originally Posted by channel405 View Post
With the lower line rate and therefore reduced bandwidth, 405 line colour would record very well on a component recording system like Beta SP. Because the R-Y and B-Y signals would be less “compressed” the colours would look richer than on 625. So, thus proving the number of lines isn’t everything!
I have tried using the RT Russell test card generator set up for NTSC 405 fed into a standard VHS vcr, this set up records OK even on an older machine switched to monochrome. VHS copes fine with the 2.01mhz chroma signal. If we had stayed with 405 even the video recorders would have been simpler.

Trevor
__________________
Cheers,
Trevor.
MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member
murphyv310 is offline  
Old 27th Oct 2006, 11:56 pm   #102
channel405
Tetrode
 
channel405's Avatar
 
Join Date: Jun 2004
Location: CH3, Blaen Plwyf Transmitter, Aberystwyth, WALES
Posts: 72
Default Re: Auroras back in stock

Quote:
Originally Posted by murphyv310 View Post
I have tried using the RT Russell test card generator set up for NTSC 405 fed into a standard VHS vcr, this set up records OK even on an older machine switched to monochrome. VHS copes fine with the 2.01mhz chroma signal. If we had stayed with 405 even the video recorders would have been simpler.

Trevor
Hi Trevor,
Sorry, excuse my slowness but are you recording 405 colour in NTSC (or should that be color then?!)?

This leads me into pondering if the Aurora would convert to 405 PAL if the subcarrier wasn't removed. Or perhaps at the price of the convertors it would be almost practical to have three convertors for component colour conversion. But then we would have to re-encode it into NTSC/PAL or perhaps, dare I say it MPEGII to be DVB compliant!!

Cheers
__________________
405 line TV, 1936- 1985
2007.........to the present day
channel405 is offline  
Old 28th Oct 2006, 8:25 am   #103
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

Quote:
Originally Posted by channel405 View Post
This leads me into pondering if the Aurora would convert to 405 PAL if the subcarrier wasn't removed.
The immediate answer is no.

Darryl and I had a long discussion about the original multistandard Aurora and reckoned it might be able to produce 405 line NTSC. All the PAL or NTSC colour information is present at the output of the decoder chip and in the special CBS sequential color (note spelling ) version the colour information is stored in the RAM and converted to the output standard. There is conceptually no problem implementing a NTSC (or PAL) coder in the programmable logic, it's just that it's quite a lot of processing to put in a small device and there might not be enough capacity. It got left as one of those interesting ideas that might get implemented one day but not anytime soon. The new Aurora (with modulator) has even less programmable logic available and relies on RAM blocks within the programmable logic. Again there is no conceptual problem, it's just a matter of device capacity.
ppppenguin is offline  
Old 28th Oct 2006, 2:33 pm   #104
tubesrule
Hexode
 
tubesrule's Avatar
 
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
Default Re: Auroras back in stock

I thought about this a little this morning, and I think this could be easily done in the low cost converter. By changing the fpga from a 100e to 250e you gain 2.5 times the logic resources and 3 times the RAM. Only twice the RAM is required to stored the full YUV data versus just the Y, and with 150% more logic, the chroma encoded should fit easily. The difference in cost is only a few dollars for the 250e and a larger EEPROM to support it. A larger image FLASH would also be required if the default image needed to be stored in color. This might be more difficult as I don't believe there is an 8Mb FLASH available in the package used on the board, so it might have to remain monochrome. The other alternative would be to leave the FLASH at 4Mb and change it to half resolution color.

Jeff and I have discussed different aproaches to this over the years, but the main issue has always been the lack of interest for such a device. It would take a substantial amount of engineering to design the chroma encoder, and it's just never seemed worth the effort.

Darryl
tubesrule is offline  
Old 7th Nov 2006, 4:39 pm   #105
ianm
Hexode
 
ianm's Avatar
 
Join Date: Jul 2004
Location: Rickmansworth, Hertfordshire, UK.
Posts: 348
Default Re: Auroras back in stock

My Aurora has just arrived, which is quick to say the least, as I only ordered it on 31st October!

The Parcelforce man asked me to sign for it and went on his way. No mention of any duties to pay, but there's a big HM Revenue & Customs sticker on the side indicating a charge of £34.11, along with the words "THIS PACKAGE CANNOT BE DELIVERED UNTIL THE CHARGES ARE PAID".

An oversight presumably, but I guess that HM Revenue & Customs will catch up with me sooner or later!

Now to try out my great new gadget.....
__________________
Regards

Ian McLaughlin, BVWS member
ianm is offline  
Old 7th Nov 2006, 5:02 pm   #106
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

Quote:
Originally Posted by tubesrule View Post
A larger image FLASH would also be required if the default image needed to be stored in color. This might be more difficult as I don't believe there is an 8Mb FLASH available in the package used on the board, so it might have to remain monochrome. The other alternative would be to leave the FLASH at 4Mb and change it to half resolution color.
The bodge it and run department suggests piggybacking a pair of 4M flash chips, just bringing out the other chip select to a spare pin (what spare pin!) on the Xilinx. That would be a nasty bit of assembly work. The way to do half resolution would be to store just one field of the pair. The final method would be to use some form of simple compression, most likely run length. This would be OK if a digitally derived test signal can be inserted directly into the flash but is likely to fail miserably with real life pictures from the decoder output.

Darryl is right about the amount of effort compared to the reward. A colour coder isn't hugely complex but it still needs a fair bit of designing and neither of us have a design "off the shelf" from our professional work.

Ian, I think you may have got away with it. Parcelfarce should not have delivered the package until you paid. Parcelfarce are acting as agents for HMRC and it's their responsibility to correctly collect any tax.
ppppenguin is offline  
Old 12th Nov 2006, 12:59 pm   #107
ianm
Hexode
 
ianm's Avatar
 
Join Date: Jul 2004
Location: Rickmansworth, Hertfordshire, UK.
Posts: 348
Default Re: Auroras back in stock

Just for the record, HMR&C did catch up with me in the end. Well, sort of.

A day or two after receiving the Aurora, a letter arrived from Parcelforce requesting that I pay the duty, upon receipt of which the package would be delivered.

Guess I'll have to pay up, or I'll have either Parcelforce or HMR&C on my tail, but I certainly won't be in any hurry to do so.
__________________
Regards

Ian McLaughlin, BVWS member
ianm is offline  
Old 12th Nov 2006, 5:13 pm   #108
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

Quote:
Originally Posted by ianm View Post
Guess I'll have to pay up, or I'll have either Parcelforce or HMR&C on my tail, but I certainly won't be in any hurry to do so.
Wait until they ask again. If they ask again.
ppppenguin is offline  
Old 12th Nov 2006, 8:41 pm   #109
garfy
Retired Dormant Member
 
garfy's Avatar
 
Join Date: Mar 2005
Location: Cornwall,UK
Posts: 25
Thumbs up Re: Auroras back in stock

I agrre also as theres a good chance it will be lost like a lot of things they handle.
Regards,
Garfy.
garfy is offline  
Old 19th Dec 2006, 6:24 pm   #110
Sean Williams
Dekatron
 
Sean Williams's Avatar
 
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,524
Default Re: Auroras back in stock

Just ordered my Aurora - A christmas pressie to me!

Looking forward to seeing results in the new year!

Lets see what Parcel Farce charge me.......

Cheers
Sean
__________________
Engineers make things work and have spare bits when finished
Sean Williams is offline  
Old 19th Dec 2006, 8:31 pm   #111
garfy
Retired Dormant Member
 
garfy's Avatar
 
Join Date: Mar 2005
Location: Cornwall,UK
Posts: 25
Unhappy Re: Aurora

Hello,
I have just got a second Aurora from Darryl and this time i was charged £33.61p and out of this Parcelforce charged £13.50p [This the weight of a bar of Cabuarys Fruit and Nut],and the VAT was £20.11,
Looks like they got me this time.
Regards,
Garfy.
garfy is offline  
Old 19th Dec 2006, 9:02 pm   #112
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

I suspect that the VAT charge has gone up since Darryl changed the declaration from "Antique TV stuff" to "Electronics". I can't remember the exact categories he used but there's a possibility that the previous one got a lower rate of VAT.

I still don't understand the VAT charge. £20.11 is 17.5% of £115 which is lower than the declared value.

Last edited by ppppenguin; 19th Dec 2006 at 9:20 pm. Reason: More VAT stuff
ppppenguin is offline  
Old 21st Dec 2006, 12:04 am   #113
plumbweiss
Retired Dormant Member
 
Join Date: Nov 2006
Location: Manchester, UK.
Posts: 157
Default Re: Auroras back in stock

I was charged 5.99 VAT and 13.50 Parcelfarce administration fee.
plumbweiss is offline  
Old 3rd Jan 2007, 6:45 pm   #114
Hunts smoothing bomb
Octode
 
Hunts smoothing bomb's Avatar
 
Join Date: Oct 2005
Location: Wimborne, Dorset, UK.
Posts: 1,410
Default Re: Auroras back in stock

Hi folks,

Just oredrered mine,
Let's see what HM's customs and Parcelfarce charge me!
Also be interesting to see how long it takes to arrive.

Cheers
Lee
__________________
Lee
Hunts smoothing bomb is offline  
Old 4th Jan 2007, 3:37 pm   #115
Sean Williams
Dekatron
 
Sean Williams's Avatar
 
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,524
Default Re: Auroras back in stock

Just been to collect mine - £38.18 in charges.......

Time to play after work........

Looking forward to some "proper" television now!

Cheers
Sean
__________________
Engineers make things work and have spare bits when finished
Sean Williams is offline  
Old 4th Jan 2007, 4:53 pm   #116
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

Quote:
Originally Posted by Sean Williams View Post
Just been to collect mine - £38.18 in charges
That sounds like the highest yet. Looks like the full 17.5% VAT on £141 plus £13.50 Parcelfarce collection charge.

My commiserations. But it's still good value.
ppppenguin is offline  
Old 4th Jan 2007, 6:25 pm   #117
molochkartovski
Tetrode
 
molochkartovski's Avatar
 
Join Date: Jun 2005
Location: Wilton, Salisbury, Wiltshire, UK.
Posts: 66
Default Re: Auroras back in stock

Got my second one today now have channels 1&9

Got stung a bit harder by customs this time though

£10-66 for the last one
£20-55 for this one

I got away lightly though by the sound of it. Doesn't make any sense how they calculate the duty, we're all buying the same thing from the same person we should therefore be paying the same duty

Richard
molochkartovski is offline  
Old 4th Jan 2007, 6:36 pm   #118
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Auroras back in stock

Don't expect sense or consistency from HMG If you were fortunate enough to get delivery via Royal Mail they only charge £3.50 collection fee rather than Parcelfarce's £13.50.

Good luck with your 2 channel setup. Don't forget that you may need some kind of filter to combine the 2 modulators because of the harmonics. You may get away with it because the 3rd and 5th harmonics of Ch1 don't land on Ch9.
ppppenguin is offline  
Old 4th Jan 2007, 6:54 pm   #119
tubesrule
Hexode
 
tubesrule's Avatar
 
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
Default Re: Auroras back in stock

Hi All,
Just a quick note to go along with the name of this thread, but I'm out of stock again. All the parts are here for the next build except the fpga which I expect any day now. I hope to be able to start shipping again towards the end of January.

Darryl
tubesrule is offline  
Old 4th Jan 2007, 6:57 pm   #120
molochkartovski
Tetrode
 
molochkartovski's Avatar
 
Join Date: Jun 2005
Location: Wilton, Salisbury, Wiltshire, UK.
Posts: 66
Default Re: Auroras back in stock

Quote:
Originally Posted by ppppenguin View Post
Good luck with your 2 channel setup. Don't forget that you may need some kind of filter to combine the 2 modulators because of the harmonics. You may get away with it because the 3rd and 5th harmonics of Ch1 don't land on Ch9.
I thought that when I connected them together. All seems to work fine though, I've just got the two outputs going through a bog standard combiner/splitter. As you say I must be lucky the harmonics of ch1 and ch9 seem to miss each other. might be a different story with a different channel combination, but it was London I wanted and london i've got (well sort of anyway )


Richard
molochkartovski is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:58 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 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.