Dumbed down consumer electronics: Adding DTV channels

This was in the days of point to point data transfer. Modules specs, manuscripts, et cetera. Some of those connections went over "singing wires" where the last mile could actually be more like 30 miles. You've seen them, where the wires basically keep the poles from falling over. Add in a crackling transatlantic connection with no SNR to write home about.

How did you get a cross-pond analog line at a time when there were 56K modems?

It wasn't a 56k modem. It was a 9600bd modem and later a 14.4k. But even at that the connection would immediately error out unless I forced it to start at 4800bd. It wouldn't have been any different with a 56k modem unless it couldn't ratchet down to 2400 and 1200 (then you wouldn't be able to connect). You can't beat Shannons theorem, when the channel is weak there is nothing you can do except throttling down.

It depended a bit on the country. Germany-US would often hold 4800 through the whole session, but no more. For Germany-Canada it was sometimes better to start even lower so it wouldn't cut out on me. Same to Korea and places like that. But every reduction by a factor of two meant a doubling of the costs of the call. Also, it was really important to have a speaker run at least for the first 1/4 of the transmission. That is because phone costs per minute were high back then and sometimes it was smarter to cut it all loose after 5min and start over. Some connections would gradually deteriorate for some reason and then you had to try until you got one that didn't. After so many transmissions you could almost predict whether a connection would stick or not.

We also split stuff up so partial reads would be useful and someone could piece it back together at the other end. Sometimes when I hear kids bemoan that the 5Mb/sec broadband at their parents' house is sluggish I wish they could experience that old modem stuff just once.

If you had a >100k file and it wasn't super urgent it was cheaper to spool it onto a floppy and airmail it.

Back In The Day...

Some Commodore 64 terminal programs would display the data being downloaded and play music in the background to keep you vaguely entertained, I guess -- I remember doing some 180k transfer (effectively an entire 5.25" floppy disc -- how incredibly puny that seems today!) at 300bps... took rather awhile, especially with the early file transfer protocols such as Xmodem that would transfer a small chunk (say, 256 bytes) and wait for a positive acknowledgment before sending the next block.

I was duly impressed the first time I saw Zmodem by Chuck Forsberg -- it would just stream and stream and stream data continuously, simultaneously waiting to hear back from the downloader if any blocks needed to be re-sent or whatever. On a clean phone line, your 2400bps model would really get you 240 bytes per second.

---Joel

:-)

I took your advice and purchased a spare DSL modem/router/WAP given that my wife works at home and all. $50 is cheap insurance...

Although we don't have a regular phone line, so if the DSL itself dies, she'll be heading for the nearest Starbucks, I suppose. :-)

---Joel

Make sure there is also a dial-up modem and the dial-in numbers written down somewhere near it. I don't use that feature (yet) but my router has a RS232 connector to which you can let it fall back if it can't get a DSL connection. Someone at the manufacturer (SMC) must have really had their thinking cap on.

A Starbucks will be quite a drive from your home :-)

I don't know if you guys are subscribed to one of the 3G phone networks but an engineer from a client said he can also use his access to 3G with a laptop. By plugging in a USB thingie, which in your case might need an antenna hack so a nice yagi can be connected. Of course I don't know how long the backup power on those towers will last.

The real modems were a bit more efficent than 240bps net :-)

But even at 2400bps one had to watch it. When using the German telecom monopoly back then they charged us around a buck per minute on international calls. Luckily that was split into 10-15 cent slivers so you could listen in and try again and again until you got a connection with only modest crackle on it.

Hi Joerg,

Routers with dual WAN connections seem to be getting popular as well... I guess some people sign up with both, e.g., DSL and a cable modem, and even if one goes down it's no big deal... and when they're both up, they obtain additional bandwidth. (E.g.,

For us, a 3G backup is pretty good idea. I've tethered my phone to a laptop in the past, although my wife's phone is old enough that it doesn't support that very readily. The USB dongles certainly work well but they want rather a lot of money for them monthly...

---Joel

Unless you use it only as backup. The cards expire very quickly but if the Sprint network in your area holds up during outages and web access is super important for your wife's work then it may be an option:

I use their cell service, works well. But as usual one has to read all the fine print. I wish they had some non-expiring data plan like with their cell service. If she needs mainly low bandwidth connections to exchange things like Excel files and email then a dial-up would suffice, as long as there are some dial-in numbers farther away that are more likely to be outside the outage area.

Well, unless their standards have dropped considerably in the last few years, EVERY telco CO has a back up generator, and enough diesel to last for several days if not a week or two! The batteries are just there to filter the load, and hold it for a few minutes while the generator kicks in, although they are sized to last for several hours!

Charlie (former CO equipment maintainer!)

Thanks Charlie... do you know if those same standards apply to the cell phone carriers?

Not really. They have hundreds (if not thousands) of towers, and the maintance costs of maintaining that many gensets would be prohibited. IIRC, they basicall just have good UPS's in the towers, so after a day or so, they are down too. I am sure that SOME of their sites will have gensets, esp. those co-located with a regular CO or other manned locations, so there may be islands of service even days after a major power outage.

Charlie

The reasonableness is taking a nosedive. It is more the idiot managers than the engineers. Mindset is less code = fewer bugs.

signal

Part of the problem is that Jeorg needs a mast with about 4 modest antennas on it and has a nutso HOA.

camera,

to 35 Euro,

shorter

Can't resist the entree; try Isaac Asimov's "I, Robot" series.

signal

How do you know? Hint: We have no HOA whatsoever. That would have been a reason for me not to buy a house here. I told our realtor back then: No HOA, no Mello-Roos taxes, and I don't want furniture to rock when I jump on the floors (the "Joerg" test, as she called it).

Besides, the mast won't help. If I had four masts half a mile apart, maybe. Yesterday the usual happened, none of the news channels made into into this area, they all pixelated out shortly before 10:00pm. Meaning lots of people in a middle-class neighborhood haven't seen any of the ads, meaning ...

Kids out here would respond that TV is so last week, get on the Internet and watch news there because it always works.

What's an HOA? I thought initially another variant of SWMBO.

What braodcast frequencies are we talking about in the US? I am guessing upto 1GHz or thereabouts. A phased array can be of very modest size. You probably only need to roughly null out a narrow band of sky.

You might find it worthwhile having a pair of identical basic log yagi aerials combined as an interferometer and an adjustable vertical spacing of around 1m as a starting guess.

Paradoxically if your signal is too strong that may make multipath misbehaviour worse. It might be worth playing around with inline UHF attenuators to see if the signal can be brought back from the brink.

Or alternatively how small an aerial you can get a picture with. Where I live the signal is so strong a nail and a there right length of connecting wire will bring in a picture on the main channels.

Regards, Martin Brown

Home Owners Association. In those, the elected leaders sometimes behave like they have to "protect" their fiefdoms. Not a good thing to have, usually.

However, this is an airpark community meaning there is a runway almost next door. So no tall towers allowed.

Just the UHF band is left, with the upper 100MHz gone, auctioned off by the FCC. VHF has largely been shut down by stations moving to UHF. I don't think it was a good idea for them to give that up as lower frequencies mean better range.

Ok, but I don't want to make a science project out of it :-)

I already put an attenuator in there because the "RF engineering" in television sets has always been the pits, and still is.

Same here, with one station but not the others. So I have a noth filter for that one.

Martin Brown wrote

Joerg write

Fabulous.