600mW ECB-8610S now shipping

I have been testing the new EnGenius 600mW ecb-8610s and the range is the best I have ever tested.

It is giving me %50 better range than the 400mW ecb-3220 units.

There is a short video here showing off the product features.

'Keenan Systems Wireless Store Featuring Engenius'

formatting link

------------------------------------------------------------------------ View this thread:

formatting link

Reply to
keenanj
Loading thread data ...

keenanj hath wroth:

Ok, let's do the math. dB = 10 log (600/400) = 1.76 dB. Hmmm.... not much. That's the difference you should see using Netstumbler or the typical laptop signal strength indication.

As for the range increase, range doubles for every 6dB increase in system gain. So, a 1.76dB increase will yield: range_increase = 10^(1.76/20) = 1.22 time or a 22% increase in range.

To get a 50% increase in range, you would also need to improve the receiver sensitivity. Since most units are running near the best sensitivity that can be achieve with current technology, that's not going to happen this week.

I didn't think You-Tube allowed commercial advertising. Incidentally, I suggest you ease up on the confusing model numbers. Unless the viewer already owns one, I doubt if the long model numbers mean anything to a prospective buyer.

Good luck, and please lay off the miraculous claims.

Reply to
Jeff Liebermann

I wish the manufacturers would concentrate on lower noise receivers versus higher power.

Reply to
miso

I'm not sure they can do much more with non-cryogenically cooled front ends. Most are SiGe or GaAs. The front end noise figures aren't going to get much better without cooling. With integrated chipsets, the minimum sensitivity is typically set by the internal noise pickup, not by the NF.

It would also be nice if they would stop lifting the numbers from the chipset data sheet and actually test for sensitivity. So far, only DLink seems to be supplying real numbers. Everyone else lies:

Personally, I'd like to see the RF section seperate from the digital stuff, so I can install it high on top of a tower. Alvirion has had this for a long time, but it's expensive. Note that this implies a receiver front end that can handle some serious overload and not go into blocking in high RF environments. Incidentally, that's one application where a tower mounted power amp and pre-amp can do some good. However, the rx amps in the boxes that I've seen are actually worse that what's in the access points.

Reply to
Jeff Liebermann

The whole intent of SiGe was heavy integration. I don't think there is enough money in SiGe stand alone amp chips, or perhaps better stated the money is in the system on a chip. Agreed that the RF on a different chip than the logic would be better.

Incidentally, I got a 2400Mhz video receiver. There is not a lot of

2400mhz video, but there is enough that I bet some people wonder why they do their site survey, find a free chanel, then wonder why they have problems.
Reply to
miso

snipped-for-privacy@sushi.com hath wroth:

Probably true for individual transistors, but there's quite a bit of SiGe in use in the form of simple downconverters and RF front ends. For example:

Most are in the 1.5 to 3.0dB NF range, which is nowhere near the 0.4dB NF that can be achieved with a properly optimized discrete GaAs FET design.

Yep. Lots of security cameras are also wireless. The TV video "rabbit" links are suppose to only occupy perhaps 12Mhz (double sideband, not VSB). In theory, they only trash a few channels. Anyway, that's why I use a spectrum analyzer for dealing with possible non-802.11 interference.

Reply to
Jeff Liebermann

I worked for Maxim at the time they got their SiGe working. Those engineers were nearby, so I would visit once in a while to absorb what I could absorb. [I'm a baseband guy, not RF engineer.] Maxim made those building blocks because that was all they could do. That doesn't mean it was a good market. I'm not sure how many of the RF engineers are even there anymore. My last contact with the group quit for a start up.

The RF guys had a hell of a time measuing the noise figure of SiGe. If there was a market, you could make nearly impossible to measure amp in the VHF band up to say 400MHz. The input stage had to be sized differently, though I was told you could parallel the building block amps to do this. The trouble is bipolar amps were pretty good in that frequency range, so there was no market.

Reply to
miso

Was reading about these last week. BFU725F's

formatting link

Reply to
LR

BFU725F's

formatting link
Interesting. The C is for carbon.

Reply to
miso

LR hath wroth:

Yep. Much easier to bias and protect SiGe xsistors than to deal with the tangled mess required for GaAs FET's. 0.4dB NF and 26dB gain at

1.8GHz is very close to what a commodity GaAS FET will do. Thanks for the pointer. That's the first I've heard of SiGeC.
Reply to
Jeff Liebermann

snipped-for-privacy@sushi.com hath wroth:

Same here. I can setup a measurement twice, and get two substantially different numbers. At one company, I had to setup a temporary RF shield room to get fairly consistent numbers. See Fig 3-1 on page 12 at:

for a clue.

For 150 to 400Mhz, I prefer cheap Dual Gate MOSFET amplifiers. They have almost the same noise figure as GaAs in the VHF frequency range. The NF of bipolar is far worse. The big different is in handling intermod and blocking. The Dual Gate MOSFET can handle much more signal than either bipolar or GaAs as shown by its much higher 3rd order intercept specification.

However, at 2.4GHz, things change. The DG MOSFET won't work at much above 500MHz. Si bipolar is rather noisy above 1GHz. That leaves GaAs FET and SiGe by default.

Reply to
Jeff Liebermann

This is from 2003 but worth a read.

formatting link

Reply to
LR

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.