10 & 24 GHz Propagation Observations with VE4 Beacons Barry Malowanchuk VE4MA 2010 Microwave Update October , 2010

Propagation Observations with the 10 & 24 GHz VE4 Beacons Propagation in the Red River Valley of the North 10 & 24 GHz Beacon Details & Installation Review of Propagation Results to date Future Expansion of Beacons

Propagation in the Red River Valley The Red River Valley is the bottom of an ancient lake bed 300mi (530 km) long, 50 miles (80 km)wide, from south of Fargo, ND to Lake Winnipeg “Shallow” and Very Flat but sharp 400m step on west edge, East edge less distinct

The Red River Valley Winnipeg Beacon Grand Forks Fargo

Propagation in the Red River Valley Long known to produce Inversions within the valley Observations by VE4MA, W0PHD, K0AWU & NT0V on 432 & 1296 MHz Does this extend to 10 GHz & Beyond? 24 GHz wants low humidity Region noted for Low temperatures and relatively dry climate Unique opportunity to observe on a daily basis

VE4MA Beacon Site Access to a electric power station at Letellier, MB about 12 km North of USA and right at MN/ ND border line (EN19id). The site is 80 km / 50 miles from VE4MA, 113 km/ 70 mi from W0PHD, and 160 km/ 99.5 mi to NT0V. Good location for summer RS and tropo observations I had seen a 24 GHz summer morning enhancement from there in July 2008.

Letellier Site EN19id

10 GHz Beacon Details Frequency 10368.286 +/- 5 kHz Transmitter is 9 W with CW/ A1 Modulated ID Ant 2 x 16 slot omni horizontal at 15 ft Fed by 25 ft of EW-90 Elliptical Waveguide

24 GHz Beacon Frequency 24192.000 +/- 35 kHz Transmitter 1/2 Watt CW (A1) modulated ID Antenna is 17 dB gain 90 degree sector horn (90 deg wide but only a few degrees high) Equipment mounted outside in a weather proof, ventilated but unheated box at 10 ft above ground

24 GHz Beacon Cont’d Beacon is Pointed at Winnipeg Antenna is looking though Tower/ Site Clutter

VE4MA 10/ 24 GHz Antenna 30 inch offset dish at 50 ft e/w elliptical WG All radio equipment in shack

10 & 24 GHz Beacon Observations Beacons Installed Sept 10 and Nov 31, 2009 10 GHz Beacon is normally 15 dB/ noise at VE4MA, detectable at S0 at NT0V, but not easily found at W0PHD ( trees near QTH) 24 G Beacon is Not normally heard (It’s about 10- 15 dB below 10 G signal in Winter) FREQUENT Enhancements Seen on both Bands ! Most Often both bands are Enhanced Similarly

10 vs 24 GHz Propagation 24 GHz is severely impacted by a Water Vapour absorption peak at 23 GHz. Mike KM0T has had a lot of experience with 24 GHz, including rain and snow scatter on a spot basis, but perhaps we can learn more from more continuous monitoring?

10 vs 24 GHz Propagation This path to VE4MA has about 43dB of Scatter Loss above the Line of Sight losses. Enhanced Conditions seen on: Dec 1, 5, 9, 12, 20, 24, 25, 26 (Vacation Jan 1-9) Jan 21, 22, 23, 25,26 Feb 1, 2, 6, 9, 10, 16, 17 VE4MA Vacation Feb 20 –April 3 April 5, 6, 9, 10, 17, 18, 19, 22, 23, 26 May 1, 9 Note Red is ~43 dB enhance, Bold Red is Super Ref

10 GHz Signal Normal Propagation

Light Snow Scatter 10 G up to 15-20 dB/ N and 24 about 8 dB/N Both showing spreading with light snow general over area Temp -22C winds of 11 km

Light Snow Scatter

Dec 25 Heavy Snow Snow Storm Moving North Strong Winds Signals Dropped as storm moved Strong Signals & Much Spreading

Dec 25 Heavy Snow

Feb 1 Ice Fog?? -28 C and calm winds ( 6km) …ice fog??? Sigs 55 dB/ N on 10 G, 30 on 24 Up about 40 dB up on 10 and almost same on 24 GHz Later 10 GHz was 60 dB/N

Feb 1 Ice Fog?? 10 G improved to 60 dB but 24 dropping slightly or just QSB?...looks like QSB

Feb 1 Ice Fog?? 24 GHz is 30 dB/ N…incredible !

Feb 16 Super Refraction Event Note InfraRed Picture of Red River Valley Showing Fog/ Cloud Over Valley

Feb 16 Super Refraction Event

April 9 Super Refraction Event Temp is 9.6 C and RH is 29 % wind 9 km ..Low Dew pt 24 G is usually 20 dB below 10 G but its only 10 dB down tonite !

April 9 Super Refraction Event

April 9 Super Refraction Event Nothing showed on local CAN/ US radar (clutter reduction) Next morning Ducting is gone, but look at the radars for Grand Forks ND and Dryden ON Similar to Feb 1 Ice Fog !

Effect of Summer Weather Previously during the dry Winter months we had seen the 24 GHz signals about 10-15 dB lower than 10 GHz. About April 23 we saw the humidity levels increase dramatically and the almost daily night time inversions disappeared. Signals on 24 GHz Dropped by about 20 dB ! Unfortunately monitoring of 24 GHz has not been possible since this event, but will soon resume.

Summary of Propagation with 10 & 24 GHz VE4 Beacons Unexpected Frequency of Enhanced Conditions Subsidence Type Inversions Frequent with: “Dry” Winter Air with Low Dew Pt Temperatures Calm Winds in Late Evening, “Warm” Day/ Cool Nite Rain & Snow Scatter Works Well on 24 GHz When there is not too much moisture to be travelled through Often 24 is enhanced a Little More than 10 G

Summary of Propagation with 10 & 24 GHz VE4MA Beacons Lower Power and More Directional 24 Antenna makes Direct Comparison difficult Expansion to include 47 GHz would be very interesting ! Possible…..but difficult Have 40 mW Beacon, 125 mW is possible Need 47 GHz on tower at home More difficult Site Access Antenna Pointing at Beacon Site

Propagation Observations with the 10 & 24 GHz VE4MA Beacons Propagation in the Red River Valley of the North 10 & 24 GHz Beacon Details & Installation Review of Propagation Results to date Future Expansion of Beacons Questions?