N6GN's Microwave Link Page

This page contains information about the Multi-Megabit/sec Microwave Data Link article which was first published in the December 1989 Ham Radio Magazine and later in the ARRL Handbook. It is now also published in the ARRL book, Packet: Speed, More Speed and Applications.

As I have not worked on this project for over 10 years, and some of the components are getting pretty dated, you may find a more recent article interesting. It is An Experimental Microwave Data Link for 10-Megabit Ethernet by John Miles KE5FX.

Here is a picture of the Antenna, Feed and RF assembly.

The information here is not intended as a replacement for those publications but only as a source of a few additional details.

Possible source of 10 and 24 GHz transceivers is SHF Microcircuits
Artwork done at the ARRL lab from an initial cut by WD0FHG for the N6GN 10Ghz link design published in the ARRL Handbook, and elsewhere.

10GHz Link Main/Receiver Board
10GHz Link Preamp/RF Board
10GHz Receiver Board Parts Diagram
Here's a scan of both boards with parts loaded:

Here are 2:1 scans of the unloaded preamp board:

The pcb directory has the unzipped contents of Zip file (98954 bytes) which is in postscript(.ps), HPGL(.plt) and hiwire(.pcb) ( hiwire? A pc board layout tool of some kind, used at the ARRL.)
Errata

PCB Fixes relates to problems/corrections on the above artwork.
schematics published by the ARRL may show pin 1 of the LM386 audio amplifier tied (with a dot)to Vcc as well as to the 10 uF compensation capacitor. This is in error, there should be no dot there, the capacitor goes between pins 1 and 8 with no other connection. The original December 1989 Ham Radio Magazine has this correct.
some schematics published by the ARRL may not include a .1 uF bypass on pin 11 of the 10116, a .01 uF bypass on pin 8 of the MC13055 and may not have the 470 nh inductor at the caractor changed to a 100 K resistor.

Microwave link letter is an informational mailing Kevin, n6rce, and I sent out in March of 1992 to people who had expressed an interest in the article.
FSK sense describes operation of the AFC in the presence of data.
ECL<->TTL Interface Schematic is a schematic of an ECL <-> TTL interface and external clock/reset circuits I've used between the 904 MHz 256 Kbps radios and MIO digital cards however the interface circuit is the same as used for the 10 GHz link and may be useful to anyone wanting to drive the microwave link from TTL levels like those of the Ottawa PI2 card.

ECL<->TTL Interface Schematic in HPGL
ECL<->TTL in Assembly drawing HPGL

Higher speeds describes operation of the link at speeds higher than 2 Mbps, most notably with Ethernet controllers. There is also now an addition indicating success in operating Ethernet cards at 2 Mbps.

The following may also be of interest:

M1CFL uWave DataLink An implementation similar to the original design, using a PC serial port at 115 kbps

Date: Tue, 10 Aug 93 16:30:44 CDT
From: bob@lachman.com (Bob Van Valzah)
Subject: 2 MBPS 10 GHz Link Boards Available

Receiver boards are now (at last!) available for the n6gn desinged,
2 MBPS, 10 GHz microwave link as described in the ARRL Handbook and
other places.  You'll still need to make the 1st IF board yourself,
but trust me, that's easy.  I didn't believe Glenn at first, just
follow the procedure in the article and it works!

The receiver board is 4-3/4 x 5-3/4", double sided, and drilled, *but
not plated through* (hence you'll have to solder top and bottom leads
in some cases).  This shouldn't be a big problem because there are no
signal traces on the component side--it's all ground plane.

Folks who helped make these boards available (though they may not all
want to admit it :-) are Glenn Elmore n6gn (of course), John Conner
wd0fhg, Ron Atkinson n8fow, Fred Reimers kf9gx, Bdale Garbee n3eua,
and Jon Bloom ke3z.

They're available from:

        Fred A. Reimers kf9gx
        FAR Circuits
        18N640 Field Ct.
        Dundee, IL  60118-9269

for $15.  Fred just shipped 8 to me for $5 postage, but I'm not sure
what the rate would be for smaller quantities.

73, Bob, ke9yq