Auroras back in stock

[murphyv310]

Originally Posted by channel405

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

[channel405]

Originally Posted by murphyv310

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

[ppppenguin]

Originally Posted by channel405

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.

[tubesrule]

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

[ianm]

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.....

[ppppenguin]

Originally Posted by tubesrule

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.

[ianm]

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.

[ppppenguin]

Originally Posted by ianm

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.

[garfy]

I agrre also as theres a good chance it will be lost like a lot of things they handle.
Regards,
Garfy.

[Sean Williams]

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

[garfy]

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.

[ppppenguin]

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.

[plumbweiss]

I was charged 5.99 VAT and 13.50 Parcelfarce administration fee.

[Hunts smoothing bomb]

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

[Sean Williams]

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

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

Looking forward to some "proper" television now!

Cheers
Sean

[ppppenguin]

Originally Posted by Sean Williams

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.

[molochkartovski]

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

[ppppenguin]

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.

[tubesrule]

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

[molochkartovski]

Originally Posted by ppppenguin

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