Anything faster I can run on Thinnet?

My mistake then, I went to the Belden site and typed "thinnet" into their search tool.

What, no attenuators for the OP's 10 feet of cable? Hunh, I'd at least have kept an open mind, but maybe that's just me.

Bail us out here, and tell us how long the existing cable is! 8*)

[I kinda like the idea of using the cable _shield_ as an antenna!]

Wich would be some 30 dB per 100 feet at 3 GHz, I guess ? A stretch of 10Base-2 is limited to 600 feet so...

Some browsing revealed that over 50 dB per 100 feet at 3GHz is not an uncommon figure for commercial grade RG 58 C/U thinnet cable. (Which actually surprises me. I didn't expect any testing to be done on this cable in the GHz region. As I wouldn't even expect it to be '50 ohms' at this type of frequencies.)

Great! But the original poster doesn't have either 'purpose-made microwave cable' or 'purpose-made high-frequency video cable''. He has a cable rated as 'thinnet cable' preinstalled.

Sure. I don't claim that you cannot run 2.4 GHz over any coax cable. (Although it is not always easy). I just stated that it is very unlikely that OP can effectively run a 2.4 GHz link over coax that is thinnet rated.

Ah, in that case the wireless thing probably wouldn't work for you. What kind of cable do you have installed?

An interesting statement.

How many dB of loss are there in closely coupled transmitting & receiving antennae ? 100 dB in antenna efficiency? Add to that the inverse-square losses of ~400ft of air (52db?)

-- Robert

In article , Robert Redelmeier wrote: :Gerard Bok wrote: :> What I am saying is, that for Wifi frequencies a Pringle :> can probably outperforms any thinnet cable :-)

:An interesting statement.

:How many dB of loss are there in closely coupled transmitting :& receiving antennae ? 100 dB in antenna efficiency? Add to :that the inverse-square losses of ~400ft of air (52db?)

and choose a consumer access point specification such as +15 dBm transmission and -80 dBm sensitivity. The result is 0.1 miles which is greater than the 0.08 miles which is 400'.

Thus, with a plain inexpensive AP of no great quality, using only the standard omnidirectional diversity antenna, one can go the necessary distance.

That's with omnidirectional. If one using a Pringles can antenna, then the EIRP is much more focused and one can go considerably further.

How much further? Well, under contest conditions in Utah, up to 0.8 miles using jury-rigged antennae.

I don't doubt that. What I wonder is if direct coupling antennae feeds with coax has lower attenuation. All sort of different numbers are floating around for coax attenuation at 2.4 GHz.

It would be relatively interesting that a fairly decent direct-coupled copper line has higher losses than indirect EMF over the air.

-- Robert

Then again, using a cable probably has fewer calories. ;-)

I don't recall any mention of 10' of cable. He did mention 10 Mb.

Exactly my point. Without knowledge of the cable length and characteristics, the whole discussion was degenerating into "We don't know nothing, but it can't possibly work over 165 meters of the lowest quality Thinnet cable, we think...."

Provided you have clear line of sight :-)

I think the first question would be: what happens if you attempt to feed 2.4 GHz into commercial thinnet coax. Are you actually feeding signal into a transmission line or are you chooking your source by connecting some weird object, mainly a huge lumb capacitor to it ?

There is no direct EMF over the air. Either you couple your output directly into a proper antenna or you feed it into a 50 ohms transmission line :-)

Note: output data for your wifi device is only valid if it is terminated as in one of the above situations :-)

I have been been able to find some mention of that technology, but no part numbers or product line names. Would anyone happen to remember what they were called and/or a part number?

Thanks.

Sorry about leaving the length out on my original post; I thought I had included it. There is no usable specification information that I can find on the cable.

sPh

There was an early proposal for a version of FDDI that ran over coax; it was referred to as LDDI. DEC also made a proprietary product (pre-FDDI) that ran on thick Ethernet coaxial cable; it was used for the back-end connection in the original VAXCluster product.

-- Rich Seifert Networks and Communications Consulting 21885 Bear Creek Way (408) 395-5700 Los Gatos, CA 95033 (408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

Wait a moment while I whip out my DEC Network Buyer's Guide 1992-1993 (several hundred pages) Here it is, Chapter 3.

You have the DECbridge 500/600/700 (FDDI ring to 10mb 802.3 ethernet) and the DECconcentrator 500 (FDDI ring to FDDI devices)

You'd need two cables because FDDI requires a ring, or better yet 4 for a dual ring.

I don't know which is worse: that you have that in your possession, or that I envy you for having it when I don't! Must .... hide ...... sickness ... from .... spouse. Must .... hide .......

sPh

Since the impedance of 'thinnet coax' is identical to that of thick Ethernet coax, clearly any system that will run on one will run on the other; the only question is the reduction in length for acceptable levels of operation.

(Remember, other than the connector used to attach to the medium, a 'thinnet' transceiver is *IDENTICAL* to a thick Ethernet transceiver.)

-- Rich Seifert Networks and Communications Consulting 21885 Bear Creek Way (408) 395-5700 Los Gatos, CA 95033 (408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

Do you have any phone lines between the buildings?

Long range ethernet operates at up to 15Mbps full duplex (well 15 is more than 10). Speed though depends on the

*cabling* and *distance*.

Have a quick look at

look up the costs.

Why do you need more than 10Mbps?

If you for example have an old network using repeaters you might be able to get by with installing a switch or router to control the traffic, eliminate unwanted broadcasts, whatever. Maybe you can use data compression?

You can get laser links that will do the job however they are prone to interruption by birds, rain, have a read, just google on [laser ethernet] for example.

In the UK non-omni antenna are illegal for 802.xyz (I think anyway) however there may well be commecial solutions available in the US.

google [802.11 directional antenna]

you go! I would thing a couple of these would sort you out.

amplifiers too - I would go for antennas first.

I am sure that one of the previous contributors to this thread can quickly work out which one of these beasts would do the job for you. I might be able to attempt it but it would take me hours or days and I don't know yet how much confidence I might have in the result:)

Wireless can be affected by weather (maybe other posters can contribute?) so I wouldn't go for the mimimum possible solution.

You can always keep the coax link on 10M as a backup.

The FDDI-ethernet version had 10mb ethernet interfaces so you'd get no speed increase on any single system.

The FDDI ring to fddi computer version requires a FDDI card for one of yoru systems (at both ends). It's possible that the standards are good enough that you could get any PCI fddi card and hook it up.

And, as I said before, FDDI requires a ring so you'd need two TW cables to form one.