Aurora converter suggestions

[tubesrule]

I'll be needing to have some more raw pcb's fabricated in in the next month or two and I want to incorporate any additions into the art work, so this is the time to make suggestions.

One thing I will add is the ability to generate a 1KHz test tone along with the default image. This tone will be mixed with the regular audio input and controllable by the audio gain control, but will nominally be set to -12dB. I'm not sure if I'll make this defeatable on the option switch or not.

I would have liked to add more FLASH to allow for more stored images, but there just isn't a part available in the size required. Jeff mentioned in another thread that two parts could be piggybacked on one another, and while this can be done, it does make assembly a bit of a problem. I think this one will have to remain as is.

That's all I have for now.

Darryl

[ppppenguin]

How are you going to make the 1kHz tone? PWM "DAC" running from 1 pin of the Xilinx? That sounds like an interesting bit of design.

The only problem I can see with this is if a user wants to have the default test pattern and their own audio input at the same time. Then you really need a switch for the tone.

I suppose you could use some spare space in the flash for an arbitrary audio test signal but capturing it could be tricky. Readout would be done in line blanking when the flash is otherwise idle and buffered to give continuous audio.

[tubesrule]

That's exactly correct Jeff. I can PWM out of one pin and mix it into the audio op-amp. I thought of the same issue that sometimes I want my own audio with the default image, so you really need to be able to defeat this tone. Assuming this gets into the option switch, you would be able to defeat the tone to use your own audio. Of course if the tone is enabled and external audio is present, they would just get mixed. I think this would be acceptable.

Darryl

[Ghostuser]

Hi Darryl,
It is a great idea to have a test tone alongside the default test card. In the absence of that I have been using a DVD of Test Card C and others, with accompanying sound, supplied by a member of the Forum. The only snag with the latter is that the card is recorded with a rather low peak white, so I go back to your default card to set up brightness and contrast. Thanks for all you efforts with the Aurora box. It is proving to be an extremely useful piece of kit. As to future changes, I would suggest that if it helps, you could reduce the number of available output channels. I guess that most people would be happy with Channel 1 plus one Band III channel.
Regards
Nigel

[Duke_Nukem]

I guess that most people would be happy with Channel 1 plus one Band III channel.

You guess wrongly matey ! There are a lot of brummy-only non-tuneable ch4 sets about for starters.

If all 5 Band I channels are supported then you can run _any_ 405 line set, Band III just isn't needed at all (a nice luxury though).

By the time places like Holme Moss came on line most sets were tuneable so could be retuned to Ch1 or Ch4,but TBH theres no substitute for covering all five - especially when you deal with a set and initially have no idea which channel it is tuned to !

TTFN,
Jon

[ppppenguin]

Picking up Jon's theme, the channel changes are a real fiddle if you routinely use more than 1 channel. A hex switch, accessible through a hole in the case, would be a great idea.

[chipp1968]

Yes I agree with jeffrey , although I havnt yet needed to change channels , access without having to dismantle would be the best mod i can see ,if only one mod is to be chosen . A tone added to test card is also a nice idea . I must admit of being a little weary of dismantaling the aurora to adjust anything as I would be worried about damage to something , also if I had sets that workd on diffrerent channels , then it looks like id be dismantaling it to much or avoiding using certain sets !
Paul

[tubesrule]

That little dip switch is fairly robust, and you don't need to treat it extremely delicately. I have flipped the one on my development unit litteraly hundreds of times with no problems using anything from paper clips to screwdrivers but you certainly do have to open the unit which some people may not be comfortable with. It might be posible to get a 16 position switch into the unit somewhere, probably poking out the side where the dip switch is now. I would still need the dip switch for the other options, so the hex switch would be just for the channel. It would need to be the screwdriver adjustable type since the ones with the little knob just aren't available anymore.

Darryl

[ppppenguin]

If I start doing much channel switching on mine I might even butcher it by fitting a switch on the case. Then just wire it to the relevant 4 poles of the DIP switch and leave the DIP switches set to off. I know that when I was reviewing the product I went up the band from ch1-13 quite a few times and got rather sick of it.

[tubesrule]

It's definetly a pain if you need to switch the channel a lot like I do during development, but I just wasn't sure if it was worth the extra cost of having an external switch if most people were going to set it to a single channel and forget it. For the ones I actually have connected to my sets, I have never changed the channel after the initial setup.

For now I first need to make sure I can squeeze this in and what cost is associated with it, and then we can evaluate if it's worth while. I'll try mocking up a unit so I can get a picture of what it might look like. One thing I want to avoid is having to put a square hole in the box which is what these switches usually require. It is difficult and expensive to make square holes. I'm thinking that with a large round hole that exposed the slot and numbers, a square might not be needed.

Darryl

[Duke_Nukem]

Just a though but you I wonder if an idea could be nicked from some late 50's sets. Instead of layings switches out in order ch1,ch2...ch13 they were jumbled up such that there was a chance that wherever you were in the country there was a good chance that the appropriate band III ITV channel was next to the relevent BBC band I channel.

Applied to this instance, a switch order of Ch4, ch1, Ch3 would minimise the distance you'd need to switch it by since the first most of the time sets would be covered by teh first two switch settings.

Or maybe thats just overly complex. But just an idea.

TTFN,
Jon

[DoctorWho]

The Aurora is a magnificent converter, I never thought such a compact and versatile unit would be possible.

My only suggestion would be th ability to transmit on 2 channels at once, perhaps Channel 1 and Channel 4 on Band I, so as to allow the use of London and Midlands sets without the need to adjust the unit or use a second unit, or perhaps a Band I and a Band III channel?

That's my only suggestion.

All the best,

Peter.

[Danny]

I now use two converters on both ch1 and ch4 with diffrent programs on each i have fed them down the one feeder and can change channels on sets with turret tuners . as for mods to be able to select channels without opening the unit is probrably the best mod you could do apart from adding a few KWs to the output!

[tubesrule]

I've done a first look at getting a external channel switch in the unit, and it's looking like it should fit. If I move the main regulator somewhere else, a switch might fit on the back panel inbetween the RF and video connectors. Otherwise it could possibly fit right where the option switch is now and poke out the side of hte unit. I don't like this as much a it requires tooling of a hole in the side of the case that straddles the split in the case. Routing to the switch is another matter, but usually some soultion can be found without adding layers to the PCB.
As for the KW output option, a socket on the top of the box where a nice xmtr valve could plug into would be really cool! Maybe on the next unit ;-)

[chipp1968]

Im definately beginning to think that ease of channal switching is definately the best mod you can do at the moment if nothing else !

[Derek]

What an informative lot you are I was just about to add a question about the slightly awkward nature of channel changing on this unit, and I find it has already been discussed! Bearing in mind how the units are at the moment, has anyone worked out which is the best tool to use to change/set the switches without it slipping and risking any damage to anything else? Fingers are good but obviously too large to just set one switch. I hope this is not seen too much as a criticism of this unit, as has been pointed out, the price clearly is very good value, and, personally speaking, it means I can use sets I haven't been able to use for years. I am almost tempted to buy a different unit for each set, but even at this price that might be a little extravagant

[ALANS ANITAS]

The tip of a ball point pen has traditionally been suggested to operate DIP switches.


ALAN

[Derek]

Thank you, personally I find that part more awkward than dismantling the unit.