1. 10 & 24 GHz Propagation Observations with VE4 Beacons
Barry Malowanchuk VE4MA
2010 Microwave Update
October , 2010

2. 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

3. 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

4. The Red River Valley
Winnipeg
Beacon
Grand Forks
Fargo

5. 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

6. 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.

7. Letellier Site EN19id

8. 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

9. 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

10. 24 GHz Beacon Cont’d Beacon is Pointed at Winnipeg
Antenna is looking though Tower/ Site Clutter

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

12. 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 dB below 10 G signal in Winter)
FREQUENT Enhancements Seen on both Bands !
Most Often both bands are Enhanced Similarly

13. 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?

14. 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

15. 10 GHz Signal Normal Propagation

16. 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

17. Light Snow Scatter

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

19. Dec 25 Heavy Snow

20. 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

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

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

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

24. Feb 16 Super Refraction Event

25. 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 !

26. April 9 Super Refraction Event

27. 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 !

28. Effect of Summer Weather
Previously during the dry Winter months we had seen the 24 GHz signals about 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.

29. 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

30. 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

31. 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?