k1jt – wa3bzt – k2txb wb2rvx – w3cmp – w3hms packrats 21 october, 2010 moonbounce...

K1JT – WA3BZT – K2TXB

WB2RVX – W3CMP – W3HMS

PackRats 21 October, 2010

Moonbounce “HowTo”

Overview

K1JT – EME fundamentalsWA3BZT – antenna, preamp, feedline, …K2TXB – “back end” setup; making QSOsWB2RVX – EME and contestingW3CMP – portable EMEW3HMS – 1296 EME with a 3m dish

EME Basics

• It’s hard… so it’s fun!• Path loss: -240 to -290 dB• Best possible Rx NF• High power, big antennas ???• Which band(s)… and why?

Sky Map: Galactic Noise, 144 MHz

Spectrumf -2.6

Tsys – the Fundamental Limit

Pnoise = kTB

50

144

432 1.3 3.4

10

Which Band ?

• 50: galactic noise → high Tsys

• 144: most activity, easiest• 432: smaller antennas; low Tsys

• 1296: 10-12ft dish “enough”• 2.3, 3.4: SSPAs; activity gaining• 5.7, 10: TWT amplifiers

Desirable Equipment

• Preamp at antenna• Sequencer to protect preamp• Low-loss feedline• 144, 432: polarization diversity• Antenna positioning in Az, El• Computer-rig interface

Typical Requirements, CW EME(BW = 50 Hz S/N = 3 dB)

Frequency Ant G HPBW TxPwr (MHz) Type (dBi) (deg) (W)

50 4×12 m 19.7 18.8 1200 144 4×6 m 21.0 15.4 500 432 4×6 m 25.0 10.5 250 1296 3 m 29.5 5.5 160 2304 3 m 34.5 3.1 60 3456 2 m 34.8 3.0 120 5760 2 m 39.2 1.8 60 10368 2 m 44.3 1.0 25

But: JT65 needs 10 – 15 dB less

KL7UW – 4×6m yagis, 144 MHz

VA7MM – 3m dish, 1296 MHz

10 GHz Xvrtr TWT PA

N4MW – 2.6m dish

TF/DL3OCHIceland 3A/DL3OCH

Monte CarloMoon

Portable/QRP EME, DXpeditions

DL3OCH: 1296 MHz EME station

Does EME Really Work?K1JT on 144 MHz• WAS = 50• DXCC = 97• WAZ = 34• VUCC = 543• 2m grids, VHF SS = 76• EME “initials” = 638• EME QSOs ~ 3000

Putting it all together

• Finding and tracking the Moon• Good times of the month• Measuring Sun noise

• Hearing/detecting your own echo• Computer-to-rig interface• The “loggers”• Making QSOs