SS and AR
- To: <firstname.lastname@example.org>
- Subject: SS and AR
- From: Dewayne Hendricks WA8DZP <75210.10@CompuServe.COM>
- Date: 03 Jan 91 13:35:22 EST
Below is an excerpt of a posting I made to the group yesterday:
>>It's hard to explain the last years of tinkering and thinking, but some of
>>the things worth noting include:
>>1) Radio receivers intended to work in LAN environment ( 50-200 ft)
>> don't have to be as sensitive as receivers for MANs or even WANS.
>> Those PROXIMs work to about -40dBm. The units Glenn put together
>> so far work down to about -75dBm. That HT on your belt goes down
>> to -110 dBm ( ignoring or lumping a few Ktb's in).
> Thanks for pointing this out. You are correct that the Proxim units were
>designed for the LAN environment. The units which I am now playing with work
>at -90 dBm.
Upon reviewing this posting, Mike Chepponis K3MC, who is a part of this effort,
made the following comments to me which I thought were important to post:
Only _minor, minor_ thing is -90dBm figure; basically that is the value that
the detector begins to work (I believe). I would think that this figures are
comparing apples & oranges. In particular, if Glenn's radios do -75 dBm, then
the Proxim radios *certainly* do no better than -60 dBm or so (***if that***).
This is because I have a diagram of Glenn's radio, and it is a very carefully
engineered radio & front end, etc. That is, -75 dBm is damn near state-of-the
art for a 250 kbit/sec data rate. So the problem with Proxim's numbers vs
Glenn's numbers is that they must be comparing different things; they way the
numbers are now suggest that Glenn's radios are deaf, when, in fact, we know
that the Proxim boxes could use a system noise figure reduction.
I hope that clarifies the earlier posting a bit for those who are
-- Dewayne WA8DZP