Jan 17, 2010

One step forward means two steps backwards

I was thinking to use one of the many commercial encoder for the IP, but most of the "fairly affordable" encoders available, lacks the ProcAmp controls. Reading a little bit about this things, I remember that in the ETC they are using an "Output Amplifier" by Dave Jones. I don't have enough information about this thing but I realize that is very important to have control in the "TV image construction".

I now got an idea because many people building encoders have troubles; especially people using the AD parts (722, 723, 724 and 725), with these parts one can build an encoder easily, but "easy" means you will sacrifice something. On the other hand, I was seeing some professional encoders built around the MC1377 which was reported by DIY people like a bad option. I think this is because people doesn't care about the things like luma-trap, chroma-filter and B-Y/R-Y clamps, and to keep things simple they use the AD724 for that reason (the few external components). And for that reason the commercial grade equipment using MC1377 (in the past, of course) have those big PCB's. And some other companies was using the (ultra rare) MC13077 and others used the MC1378.

As a side comment, I'm reading about the use of other chips like those of Philips and Sony. About the Sony CXA's are reported as very good image quality, especially the CXA2075. Dave Pietromonaco (designer the chip) say is the best encoder built.

The first thing all this chips do, is create the video TV signal translating the RGB to the YUV colourspace, I've learned this is possible to render outside the chip with more modern chips... hmmm I need to follow this path? recreate the function of the encoder chip with submodules for each function?
I need to read more but I remember when I was working in a TV station that they was using something called the ProcAmp, a little of Google takes me to the GVG3241...

Aha! that is what I need... I think the Dave Jones Output Amplifier is something similar to this big box, at least it seems, have it the knobs one could tweak to create a good video signal.

I know all this is going beyond the Sandin IP color encoder module, but in first place the Sony encoder used it's not available, second I think will be better in some aspects (like the way the sync is added at "brute force"), and third counting with the Proc Amp one can build a very good and stable video image.

As I say on the title, all this makes me think if I build the encoder will be very very slow path, for that reason I think this will be the very last module, until I know how to make it. In the meantime, I will use whatever encoder option only to test the other modules. Looking back the whole IP I think the sync and encoder modules is where the fun is.

Nov 1, 2009

Some truths and some thoughts

Lately I was in contact with Dick Sippel (who built the excellent IP that is now in ETC) and Daniel Sandin. They both gave me their visions on building one IP in nowadays, as many people say, building one classic IP could be difficult because the parts are hard to obtain (which is no true, easily I obtained the chips); otherwise, there is no other impediment to build it.

But what is true, as stated by Sippel and Sandin, building one with modern components is possible to gain better specs with the additional benefit that the chips could be found anywhere.

Dan Sandin suggested me some parts, AD811 in place of the CA3030 and a pair of AD834 to replace the MC1445. Immediately downloaded the datasheets and he was right with this election, at very first sight seems the perfect election. I remember some other chips I was evaluating in the past, some of it maybe doesn't manufactured anymore; élantec, gennum and linear technologies come to my mind now. For those interested in the chips and other parts I will be putting all the datasheets and other info in the esnips folder that you could find in this link.

But what keeps me thinking these days is the encoder; obviously the original encoder can't be built so is necesary find a modern sustitute, in the next posts I will expand the encoder options.

As a side project and as result of all my previous researchs about the Sandin IP, I'm trying to find coincidences and differences between all the IP's built. Until today I was able to (almost) locate 5 IP's, but Mr. Sandin told me he count between 20 and 25 systems built. Seems lots of IP's to find! I think the most complete and expanded is the IP on ETC by Dick Sippel, others systems seems was built with the minimal recommended configuration. At the same time I'm seeking more information, I'm trying to do a online database, probably in Google docs.

My last comment for today is to make one correction, I was reading again an interview to Sandin by Woody Vasulka and found the following statement talking about Phil Morton: "He's completely responsible for the documentation", so what I written in my pdf (original content by Dan Sandin) is not true, of course all the knowledge behind is Sandin's but the content of the original Distribution Religion was written by Phil Morton. I wanted to clarify that, maybe asking Mr. Sandin he could expand on that.

Oct 31, 2009

Parts of the religion

[the name of this post is based on 'Parte de la religión' (=part of the religion) a song by Charly Garcia]

Obviously this is not a cheap project, a quick count of parts easily gives a view of the main groups of expensive parts to buy. As I say it before, I'll trying to build at least one of each modules of the 'classic' IP as previous experience and point of reference on building the new versions. My first fear was that could be impossible locate the old chips and I was wrong, it could be found in many places (prices may vary a lot).

I managed to obtain a good stock of chips, now I have enough to build several 'classic IP' modules. In the quantity order (as stated in the complete part list) the needed chips are: (70ea) CA3030, (35ea) MC1445L, (4ea) ICL8038BC, (4ea) uA715; but that quantities is to build a complete system.

Other semiconductors needed are: (144ea) 2N4123 npn transistor, (90ea) 2N4125 pnp transistor, (53ea) 1N270 germanium diode. Now I'm seeing my options with this parts and also the big quantity of IC sockets needed.
The second big group of parts are: potentiometers, knobs and connectors. For the connectors, I've used an idea I had been thinking around for a while: I bought an empty card cage of a video router on ebay, it requires a little of labor but it only cost me 5 euros! I have not counted yet the potentiometers needed, then I'll see which options I have for this quantity. I think I will left the knobs for the last stage.

Oct 30, 2009

Every religion needs a little of order

I was reading carefully 'Distribution Religion', Criticalartware version, and sometimes I though that I'm missing something, I was right because I've checked other pdf's I've downloaded and found some pages missed and other pages differents.

So, to use only one document as reference manual, I've made a page by page comparation of all the documents about the Sandin IP on the web and finally ensambled one pdf to use in my project. It have the main part coming from the Criticalartware's pdf, in second place it have some pages from the Phil Morton's pdf from the Vasulka website, at last it have one or two pages from others pdf's I don't remember now.

Criticalartware's pdf is almost right, but my main critic is because it is fairly a mess, so I decided give the new pdf a structured layout. Each module is arranged in a group of pages starting by the description, then the front face of module, a block diagrams (if exists), the schematic followed by the pcb mounting and the part list at last.

The modules order I've used is arbitrary, I think it follow a logic order of construction (to me), I left at the final the sync generator and the encoder because it seems to me is possible to found better options (and easier to build) today. And at very last of the pdf I put the 'non classical' modules, I mean those modules not recommended in the construction of a 'Classic Sandin IP' (but could be nice additions) .

Now I think I would have a more productive reading because I use to skip several pages ahead, and again skip pages back very, very often. At least to me, now is easy to follow the directions to build a module in particular. Sometime ago I was thinking about re-write, re-draw and re-assemble the whole document but I guess if I do, I never will start build nothing. I want concentrate my efforts on learning how the IP works, and let this 'documenting impulse' for the IP v2.0 comming next.

I don't know if someone else, other than me, is crazy enough to experiment with 40 years old circuits (it could be possible! there are a bunch of people building Moog clones), so for those people, maybe could find interesting my Distribution Religion re-edition, I put this link below [on the picture] (I couldn't find a good file service than esnips.com)

Oct 12, 2009

(Re)Starting the hardware projects

In last January I was visiting my home-country, Uruguay, and was the opportunity to take me back some of my stuff (magazines, infos, instruments, parts, unfinished stuff). This makes me to re-think one thing: I was keeping me away of all kind of 'old stuff' since long time; but as I am in posessing (again) of parts and info for the Sandin IP that I was collecting for years in Uruguay, maybe is time to finish this.

For the people who don't know a Sandin IP it is... go to Google for this!... well, well, I'll try to explain in the short way: is for video what a modular Moog is for audio. I must admit that I'm more on portable systems but for now I could take advantage of what I have. Maybe in the next future I could build a Jones system; for me this is for video, what a VCS3 is for audio ;)

Lately I was in contact with people already has build a Sandin IP asking some clues, counting the parts and sorting the wide and confusing info available on the web. I think this first part is over (if not, I don't care). To start the building process, I was forced to do some "new" adaptations, so this will not be a "classic IP" as I could wish.

All the IP's I know are in the US, so I can't put my hands on one to see if it's worth all the effort. Judging by some videos processed by the IP on the web I'm positive on that. Hopefully someday I can do an ETC residency where exists the most complete Sandin IP.

Now the advice to others: I will say the exactly the same all people say regarding of building one IP: I don't encourage you to build one... but I will add "ONLY if you have the time AND enough money"

Pressing reset to this blog

I know, has been a long time from the last post, more than a year! My life becomes very complicated lately and this keeps me very busy to persue my internet projects. To make things worse, Googlepages is closing so this means all I have prepared to publish will need some rework, and I have not enough time to do it.

So... I think I will be puting all sort of info on this blog (a little bit messy), I'll cleaning ideas and writings, then (if it doesn't take me much time) publish on the webpage (GoogleSites, GooglePages or whatever). I don't like Google Pages because the url turn a little bit complicated to retain... but... what can I do?... is free.

Anyway, I was checking this blog and nobody come yet, so then it will be a new beginning. The next post will be juicy... I promise

Apr 21, 2008

I'm working...

Yes... I'm working to give this blog a nice face, haven't found yet a good looking template. Also I must put on order the contents to publish.
Be patient and comeback soon.