Imagine a meshtastic network of devices across a city or country, broadcasting a set of rotating teletext pages with no ability to censor it. That would be something.
aprs is basically here
Reviving Teletext for Ham Radio
31–40 of 46 posts
Re: Reviving Teletext for Ham Radio
#32Earlier quoted context omitted.
I love learning about pre-internet ways of transferring data on the back of other things. I once worked for a radio station that made 90% of its revenue from carrying data feeds on subcarriers, and not from main music programs. Because of the geographic location and size of the signal, it was a vital link between two major cities before planting fiber optic lines became cheap.
I’m looking forward to cell phones un-shackling themselves from telecom oligopolies through a mix of repurposed satellite uplink and where available: some FM spectrum downlink utilization. Just stream me the weather, traffic, text msgs & some news stories that a TTS can read out to me. Won’t work well for streaming a video but for most of us generally on wifi except out-of-doors, I can live with it.
Just stream me the weather, traffic, text msgs & some news stories that a TTS can read out to me.
SiriusXM is half way there. It supplies weather and traffic as a data service.
I knew about traffic from way back when the service was new, and found out Sirius Marine Weather a few years ago, but recently rented a car that also had Sirius-delivered weather and traffic alerts.
It was very useful as I was deeply off the grid (no radio stations at all during the day and AM skywave only at night), and the car alerted me to nearby lightning and thunderstorms that I couldn't see because of the terrain.
Re: Reviving Teletext for Ham Radio
#33I think you had 999 pages but each page could have 9999 sub pages. The pages were send one by one so if you typed 200 you would have to wait for page 200 to cycle by. If it had 100 sub pages you would have to wait 100 times as long. I believe more important pages could be send more often or similarly the cycle would skip less important pages. Decent TV's would just store pages and sub pages until the next cycle. I as…
Considering you're mentioning guilders - was this the thing shown on TV back then https://nos.nl/teletekst ?
yes, on the national channels.
Re: Reviving Teletext for Ham Radio
#34I think you had 999 pages but each page could have 9999 sub pages. The pages were send one by one so if you typed 200 you would have to wait for page 200 to cycle by. If it had 100 sub pages you would have to wait 100 times as long. I believe more important pages could be send more often or similarly the cycle would skip less important pages. Decent TV's would just store pages and sub pages until the next cycle. I as…
Viewing the fee as being for a volume of storage doesn't seem the right perspective. It's $1500 to lease some %age of spectrum for some period. If true Teletext on an analogue signal and broadcast vs cable, then $1500 for 0.05% of the total non-media spectrum doesn't feel like a terrible deal. $1500 today is probably in the region of 10s of GB, sure, but that's almost a commodity volume by comparison in terms of supp…
The way I thought of it at the time was that they had 2 kinds of content, official stuff like news, to make the service actually useful, for which they didn't get a cent and commercial stuff which started at that unfunny amount. They had nothing in between.
For example, I could have made a page with sub-pages with the menu from various restaurants in town. It didn't occur to me that one could monopolize delivery and squeeze restaurants into handing over a large amount of money per meal. (read: cut a large amount of food) I'm not that kind of entrepreneur. I'm sure they do actually pay ƒ1500 now for a dumb listing on a food delivery website. I thought of it as more of a fun thing to have for the local tv station (that hardly anyone watched)
I was just fooling around really but my main plan at the time was classifieds. The normal formula for those at the time was to deliver the text some place and pay in cash. I had considered a paid phone number but those also cost 1500 + 50% of the call cost. A 3 minute call would work out to cost 3 bucks of which I would get ƒ1.50 and I would need 1000 per month just to pay for the phone line. Absurd prices, local (land line) calls at the time cost 10 cents each for unlimited duration and 35 guilders every 2 months.
For a TV station with less than 100 k "viewers" I don't expect many thousands of classifieds. It wouldn't even fit on the page. Say you can fit 10 of them. Say 300 one day ads per month. As a customer, I wouldn't pay ƒ5 per day. The local newspaper started at ƒ6 and the text will stay there for the entire week.
Re: Reviving Teletext for Ham Radio
#35Please consider framing your project in your mind as a hobby. It’s valuable to the degree that you enjoy it. Learning and other external values don’t have to apply here. Just the fun of doing it can be enough.
I'm familiar with the author's past work on ieee.org and have a sense that he likes to write to/for both hobbyist and professional camps: https://spectrum.ieee.org/u/stephen-cass
You have me pegged correctly :)
Re: Reviving Teletext for Ham Radio
#36Imagine a meshtastic network of devices across a city or country, broadcasting a set of rotating teletext pages with no ability to censor it. That would be something.
The same author dabbled in a similar project, so maybe there's a Teletext over ham radio tie-in possible? https://spectrum.ieee.org/run-a-meshtastic-bbs
Author of the OP article here: Yes, you could 100% send teletext frames over meshtastic: if you're using the unlicensed bands you could even send full carousels with many pages, which is something that isn't really kosher under my reading of the FCC regs for amateur radio, which is why I stuck to a single page SSTV replacement in the article!
Re: Reviving Teletext for Ham Radio
#37This is fantastic, the article and the implementation, it looks really good. I have been working on a BBS client lately, and Teletext was also on my maybe wishlist for one day. I also dabble with radio, not HAM though, im not licensed. So i'm still a CB radio supporter.
Maybe I’m getting senile, but the article lacks even the tiniest amount of detail and contains no link to the implementation. I found also nothing on the intarweb about it, other than this article and a few clones of it. I wonder if this is real at all. It’s an IEEE article, so it should be. But I find this lack of detail very depressing.
Original article author here: There's isn't anything on the wider web about this project because it is a bespoke creation for IEEE Spectrum's Hands On column! If you're not familiar with the column, it's always written at a pretty high level. That said, I will be putting all the code up on a public repo, once I get a chance (hopefully very soon!) to verify a cold install on a fresh machine does work.
Re: Reviving Teletext for Ham Radio
#38I think you had 999 pages but each page could have 9999 sub pages. The pages were send one by one so if you typed 200 you would have to wait for page 200 to cycle by. If it had 100 sub pages you would have to wait 100 times as long. I believe more important pages could be send more often or similarly the cycle would skip less important pages. Decent TV's would just store pages and sub pages until the next cycle. I as…
Original article author here: Yes, key pages were multiple times over teletext. It's a bit of a grey area for amateur radio regs, so I didn't mention it in the article, but you could use the software with say, an license-free part 15 short wave FM transmitter, to send an entire carousel of many pages. As such the code does have an option to flag ket pages and specify how many times they should be repeated over a carousel's broadcast.
Re: Reviving Teletext for Ham Radio
#39That brings back fond memories of my first employer in the early 90s. They used to rent a single scan line (VBI) of the TV broadcast to use as a data transmission method encoded the same way Teletext was. IIRC you could fit 45 bytes in a single scan line, with 50 per second that gives you a nationwide data broadcast capability of something like 18 kbit/s. We had a 19,200 bits/second leased line to send the data. That…
I love learning about pre-internet ways of transferring data on the back of other things. Another cool example is that the UK is only shutting down its longwave AM radio service this month (as opposed to decades ago) because the carrier is phase-modulated with data telling older electric meters to switch over. For years this was the only reason such an antiquated radio system stayed alive.
You should check out the Media Archeology Lab, they are very interested in alternate networks of all types! https://www.mediaarchaeologylab.com/
Re: Reviving Teletext for Ham Radio
#40Earlier quoted context omitted.
Maybe I’m getting senile, but the article lacks even the tiniest amount of detail and contains no link to the implementation. I found also nothing on the intarweb about it, other than this article and a few clones of it. I wonder if this is real at all. It’s an IEEE article, so it should be. But I find this lack of detail very depressing.
Original article author here: There's isn't anything on the wider web about this project because it is a bespoke creation for IEEE Spectrum's Hands On column! If you're not familiar with the column, it's always written at a pretty high level. That said, I will be putting all the code up on a public repo, once I get a chance (hopefully very soon!) to verify a cold install on a fresh machine does work.
Thanks! To be clear, it’s totally fine to write articles like this, obviously. I just felt that some who goes above and beyond on such an esoteric subject would be vibrating with energy to share as many details with likeminded enthusiasts:)
If I had more time, I’d like to play with this (and trying to recreate an old style stand alone tnc for packet radio) :)