EME resources

Websites - PA0ZN, W3EME, N0UK

Look at JT44 as a digital mode for moonbounce

Transceiver Clinic Introduction

IC 706 is 100BDR (not good)

Most of the transmitters have lots of noise on 2M.

Software Defined Radio for Hams

Desktop speed has now become important now that we are at 2.3 Ghz Intel boxes

• DSP-10 (Bob Larkin, W7PUA did an early chip). KK7P at tapr.org has come out with a new update with a new chip

• Gnu Radio open source open hardware project.

• The hardware is the Universal Software Radio Peripheral with USB 2.0 connection !!

Does samples to 65 Mhz. No Anitaliasing, so you need to do that.

www.ettus.com - Matt Ettus, N2MJI

• Look at Nov / Dec 2003 QEX on signal classifications

• DSP56000 Homebrew Low Noise Synth by Oleg Skydan (UR3IQO)

• PSK 4 author Moe (AE4JY) Peter N4IP have a spectrum analyzer product http://www.rfspace.com/sdr14.html

• http://www.sdradio.org Borland C 6.0 console for the SDR-1000 Aberto

• Look at Linrad noise blanker (Articles in QEX Nov/Dec 2002 --> Jan/Feb 2004)

• Frank Brickle (AB2KT) and Bob McGwier (N4HY) speaker have been working on a collection of C routines in C.

Heart of SDR1000 console (Linux and MS VS.NET)

Multi-threaded, large connection of new routines

• Quadrature Sampling Architecture is the key to the SD1000 (Sample and hold)

BW = 1/pi*nR(ant)C(s)

Limit is the speed of the switch FST3253 and AD9854

• New version (design) of SD1000 has new front end inputs to the base

One does 160M-6M the other 2M and up (Down East Microwave)

High accuracy Doppler Shift

Talk about how to figure doppler shifts, program on the CD

For K3FXS about 1KHz per second at 432 Mhz if you look at only the movement of the earth

But the moon is also moving (about 1Km/sec), adding about 35Hz at 432Mhz to the doppler shift.

But the issue is not really on 432 Mhz, but more on the higher bands

The W2DRZ Antenna Controller board

Small offset stress dish for portable 1296 EME

Look at Daul Dipole Feed. Looks like four dipoles around the outside a square.

Polar mount, mount points to the north star, then it only rotates around the polar axis

Small changes in declination are needed.

Dish feed with Septum

Cool talk on this feed that he makes, it does a nice split of the polarization

500 watt 23cm Amplifier

Very nice homebrew amplifier construction

EME Receiving System Optimization

Modified Dual Dipole Feed for 432Mhz

He puts a dual Dipole in the center of his dish. He can then rotate it to get the best reception

Multiple Reflector Dishes

Check out his web site

Parabolic reflector, the feed is at the focus

Most of the time we don't get a good feed, there is illumination loss and spillover.

Newtonian

flat refelector

Gregorian

ellipsoid reflector

Cassegrain

hyperboloid refector

Schmitt-cassegrain

spherical mirror, use curved refector, needs a corrective ellement to start.

Small dishes don't work, objects / curvatures ~ wavelength -- Feed is not a point source

f/D deep .35 -.45 f/D shallow .10 - .2

Dual mode feeds for dishes

W1GHZ use a flat reflector to bounce from the dish out W1GHZ.org

New digital modes for EME

He is working on some new digital modes for EME that should be easy to use and improve the level of contacts. Check his website

Use of IS Radar

Where is Millstone Hill near Boston

Using 2 by 4CX250B -- can I find one of these amps? and 4 17 element 2M yagis Horizontal Polarization

47GHz EME

His homebrew attempts to do EME at 47GHz