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PA2AGA > HDDIG 07.06.00 01:12l 227 Lines 7242 Bytes #-9452 (0) @ EU
BID : HD_2000_157C
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Subj: HamDigitalDigest 2000/157C
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Sent: 000606/1848Z @:PI8HGL.#ZH1.NLD.EU #:48391 [Den Haag] FBB $:HD_2000_157C
From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Tue, 06 Jun 00 19:18:36 MET
Message-Id: <hd_2000_157C>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
signal in the bandpass.
DSP really helps. I am told if it is in the IF stage it is just the
ticket, do not haver that capability. Audio DSP helps but it doesn't
cure the rigs AGC problem.
I'd like to see digital filters added to the software....
73
Den Spiess W2DEN -.-
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
Date: Mon, 05 Jun 2000 13:59:41 -0500
From: Michael Grigoni <msg@computerpro.com>
Subject: HELP PLSE: 2.4GHZ WLAN Antenna matching
Hello All!
We need advice and opinions on building a matching network to convert
wireless lan transceivers from internal patch antennas to external
~50ohm N-connector antenna feeds. The radios are "IBM Wireless LAN"
OEM'ed from Motorola 84D09747T01 Issue 0 P14 (1994) and newer issues
through 1995. The circuitry is all SMT (no stripline visible) and
short of destroying a radio to map traces, obtaining the prints
from Motorola (dream on?) or finding an SMT rework station (not
likely in our area) one can only attempt to deduce some of the wiring.
Here's what I think the output side is:
L PATCH ANT
|---$$$---GND |------------------|
--------- c | c | |
| mrfic |---5--||-o--o-------||--o---|-----o |
| 1801 | | | |
| (u600) |---8----||---------o-- | | |
--------- c c | \ | | |
|--||---o \----|--------o |
o--$$$--| | | |
| L | |------------------|
| c | 48mm/side
GND-----o---||-------o
|---$$$------|
L
The two feedpoints for the patch antenna are 13mm from the edge; the
heights of the patch antenna off the groundplane is ~4mm and the
dielectric is a hard foam. Plugging in the measurements into a
patch antenna calc program and guessing the dielectric constant of
the foam around 1.2 yields the expected 2.4GHZ freq. with ~200MHz
bandwidth. The curious thing is the multiple feedpoints spaced
17mm apart point-to-point and the connection to the 1801 TR switch
through the above network in a fashion reverse to the standard
use of an spst switch driving an antenna. The backend of the switch
appears to be connected to a TOKO 2.450GHz filter and there is another
1801 TR switch somewhat behind that, but not connected to the antenna
networks. The calculated input impedance of a single feedpoint is
around 50ohms.
One might suppose that the two feeds represent Tx and Rx; are the
feedpoints perhaps at quadrature?
The patch antenna has been unsoldered from the board leaving two pads
corresponding to the connection points in the above diagram. What
would any of you do to connect them and match them to an N-connector
on an external case? I suppose it is necessary to determine if the
feedpoints represent exclusive Tx and Rx functions (not easily done);
would one then consider removing the SMT components from the existing
networks and using 1/4wave sections to connect them to a divider which
then could be matched with a stripline network to the N-connector?
All ideas MUCH appreciated.
Michael Grigoni
Cybertheque Museum
------------------------------
Date: Mon, 05 Jun 2000 23:30:21 -0400
From: Joe Leikhim <jleikhim@nettally.com>
Subject: HELP PLSE: 2.4GHZ WLAN Antenna matching
I am having trouble visualizing all this. But I would make a strong bet
that the filter and the antenna switch are 50 ohm impedence. I would guess
the multiple feedpoints represent a diversity receive antenna
configuartion. A common technique is to duplex the transmitter and
receiver on one antenna and provide a second receive antenna for
diversity. The radio logic selects the antenna which produce the best bit
error rate. In this case the second TR switch may be in lieu of a
duplexer which is not always provided in a digital radio. Hope this helps.
Michael Grigoni wrote:
> Hello All!
>
> We need advice and opinions on building a matching network to convert
> wireless lan transceivers from internal patch antennas to external
> ~50ohm N-connector antenna feeds. (snip)
--
Joe Leikhim K4SAT
Jleikhim@nettally.com
"tv dinner by the pool,
i'm so glad i finished school" -F.Zappa 1967
"The Revolution will NOT be televised" -Gil Scott Heron
Dopeler effect: The tendency of stupid ideas to seem smarter when they
come
at you rapidly.
------------------------------
Date: Mon, 5 Jun 2000 07:04:39 -0700
From: "jim madden" <jmadden@pop.nwnexus.com>
Subject: list of packet sites in Seattle
Can anyone point me to an up-to-date resource that lists the 2m adn 70cm
packet frequencies currently operating in the Seattle area?
Thanks.
Jim
KD7GND
------------------------------
Date: Mon, 05 Jun 2000 08:25:02 -0700
From: ac6v <ac6v@ix.netcom.com>
Subject: list of packet sites in Seattle
jim madden wrote:
> Can anyone point me to an up-to-date resource that lists the 2m adn 70cm
> packet frequencies currently operating in the Seattle area?
>
> Thanks.
> Jim
> KD7GND
=-
Hi Jim -- try the North American Digital Systems Directory at URL:
http://www.tapr.org/directory/
For DX Packet Clusters see URL:
http://www.cestro.com/pcluster/dxnodes.html
Good Packeteering
--
73 from Rod in Oceanside, Ca
========================================================
AC6V INDEX TO DX AND HAM RADIO
FEATURING 100+ PAGES, 700 INDEXED TOPICS, AND 3000 LINKS
Over 700,000 Visits On The Counter
http://www.ac6v.com - General Ham Pages
http://www.ac6v.com/pagedx.html - DX Reference Pages
------------------------------
Date: Mon, 05 Jun 2000 15:40:18 GMT
From: "Hank Oredson" <horedson@att.net>
Subject: list of packet sites in Seattle
Tune to145.01, 145.03, 145.05, 145.07, 145.09 and pick any node you hear.
Connect to one of the many resources available, you will find
a network description for your local area.
The list at TAPR tends to be rather spotty, better to just tune around
until you find something actually on air, then ask for the list.
--
... Hank
http://horedson.home.att.net
"jim madden" <jmadden@pop.nwnexus.com> wrote in message
news:8hgc5m$m0a$1@brokaw.wa.com...
> Can anyone point me to an up-to-date resource that lists the 2m adn 70cm
> packet frequencies currently operating in the Seattle area?
>
> Thanks.
> Jim
> KD7GND
>
>
------------------------------
Date: Mon, 05 Jun 2000 21:32:51 -0700
From: "Gary P. Fiber" <gfiber@news.cmc.net>
Subject: list of packet sites in Seattle
On Mon, 5 Jun 2000 07:04:39 -0700, "jim madden"
<jmadden@pop.nwnexus.com> wrote:
>Can anyone point me to an up-to-date resource that lists the 2m adn 70cm
>packet frequencies currently operating in the Seattle area?
>
>Thanks.
>Jim
>KD7GND
>
look at http://wetnet.wa.com
Gary KF7XV
------------------------------
Date: Tue, 06 Jun 2000 10:15:04 GMT
To be continued in digest: hd_2000_157D
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