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Introduction to Microwave Amateur Radio. Steve Kavanagh, VE3SMA April 2008. What are Microwaves ?. Just radio waves with short wavelengths Definition is imprecise, but usually means frequencies above 1 GHz (1000 MHz) Hams sometimes include 902 MHz band Microwaves are fun !. 902-928 MHz
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Introduction to Microwave Amateur Radio Steve Kavanagh, VE3SMA April 2008
What are Microwaves ? • Just radio waves with short wavelengths • Definition is imprecise, but usually means frequencies above 1 GHz (1000 MHz) • Hams sometimes include 902 MHz band • Microwaves are fun !
902-928 MHz 1240-1300 MHz 2300-2450 MHz 3300-3500 MHz 5650-5925 MHz 10.0-10.5 GHz 24.0-24.25 GHz 47.0-47.2 GHz 76.0-81.5 GHz * 122.25-123.0 GHz * 134-141 GHz * 241-250 GHz * = change in Table of Frequency Allocations – not yet in RIC-2 Microwave Ham Bands
Types of Activity • DXing and Contests • Mostly CW/SSB, some FM on 10/24 GHz, some digital modes • Portable activity is popular • Moonbounce • FM Repeaters • Somewhat rare • 902 MHz & 1.2 GHz • Amateur Television • Lots of bandwidth available • Activity on 902 MHz, 1.2, 2.3 & 10 GHz • Satellites • 1.2, 2.4 & 24 GHz, so far • High Speed Data
Propagation Modes • Line of sight • For gains that do not vary with frequency signal is much lower at shorter wavelengths - repeater/mobile operation works poorly above 2 GHz • But for fixed antenna size signal is proportional to f2 - long distance point-to-point links with directional antennas work at virtually any frequency • Need to avoid blockage by buildings, trees • Reflection paths • Tropospheric scattering, ducting • Rain (and snow) scatter • Moonbounce • No ionospheric propagation, aurora, meteor scatter (so far !)
Equipment • Commercially built transceivers • Kenwood TS-2000X & Icom IC-910H (with optional module) cover 1.2 GHz (multi-mode) • 1.2 GHz FM-only transceivers (and multi-band FM handhelds covering 1.2 GHz) have been made but I am unaware of any current models • ATV gear : PC Electronics makes TV transmitters & receivers for 902 MHz, 1.2 & 2.3 GHz • Advanced Receiver Research TR-10GA & TR-24GA 10 & 24 GHz wideband FM radios (discontinued)
Equipment • Commercially available transverters • Convert a lower frequency rig (usually 28 or 144 MHz) to operate at a higher frequency • 902 MHz to 47 GHz transverters available fully built or as kits from • Down East Microwave Inc. (Florida) • Kuhne Electronic (Germany)
Equipment • Homebrew & Surplus • Plenty of scope for the homebrewer who wants a challenge • But often much easier than you might think ! • Some fairly easily converted commercial gear • Possibility of using 902 MHz, 2.4 GHz and 5.8 GHz wireless equipment – a good example is the “Wavecom Jr” 2.4 GHz TV transceiver.
Antennas • Mobile and other omnidirectional verticals • Available from Comet (902 MHz), Diamond (multiband incl. 1.2 GHz) • Yagi • OK for 902 MHz, 1.2 GHz, performance hard to maintain at higher bands
Antennas • Helix • Circularly polarized • Used for satellite work at 1.2 GHz
Antennas • Loop Yagi • Good for 902 MHz to 3.5 GHz • Available from Directive Systems in Maine
Antennas • Horn • Useful from 3.3 GHz up • 10 & 24 GHz horns available from Advanced Receiver Research (CT) • Easy to make
Antennas • Dish • Useful from 1.2 GHz up • Gain often > 30 dB
What Kind of DX is Possible ? • Here are my results with modest gear (CW or SSB):
902 MHz (33 cm) • 902-928 MHz shared with ISM and unlicensed consumer equipment (mostly cordless phones) – QRM is a reality ! • SSB/CW stations in this area: • VE3BFM (nr. Alliston), VE3CRU (Whitby), VE3OIL (Freelton), VE3NPB (Toronto), VE3TFU (Waterford), VE3SMA (Cambridge) • Propagation similar to 70 cm (430 MHz)
1.2 GHz (23 cm) • 1240-1300 MHz shared with radar • I occasionally get radar QRM • 1296 MHz SSB/CW stations in this area: • NP4B/VE3 (Hamilton), VE3BFM (nr. Alliston), VE3TFU (Waterford), VE3OIL (Freelton), VE3NPB (Toronto), VE3SMA (Cambridge)
2.3 GHz (13 cm) • 2.3-2.45 GHz shared with various services. QRM from WLAN and cordless phones to satellite downlinks at 2401 MHz is common. • Can use WLAN (e.g. IEEE 802.11) equipment in amateur service with higher power/bigger antennas than permitted without a licence. • 2304 MHz SSB/CW stations in this area: • VE3CRU (Whitby), VE3OIL (Freelton), VE3NPB (Toronto), VE3TFU (Waterford), VE3SMA (Cambridge) • At least 70 identified stations recently active across Canada (all modes)
3.4 GHz (9 cm) & 5.7 GHz (6 cm) • 3.4 GHz • Currently only VE3OIL (Freelton), VE3SMA (Cambridge) and VE3TFU (Waterford) active in this area (CW & SSB at 3456 MHz). • 5.7 GHz • Currently only VE3SMA (Cambridge) active in this area (CW & SSB at 5760 MHz). VE3TFU will be on soon. • VE3OIK has worked over 500 km (West Virginia) on this band
10 GHz (3 cm) • One of the most popular microwave bands • A few dozen southern Ontario hams have been active over the past 20 years on both wideband FM and SSB/CW • Currently active on 10.368 GHz SSB/CW in this area: • VE3CRU (Whitby), VE3NPB (Toronto), VE3FHM (Georgetown), VE3TFU (Waterford), VE3SMA (Cambridge) • Several others on WBFM
24 GHz • Shared with various services but no QRM problems observed • 24.192 GHz SSB/CW stations in this area: • VE3SMA (Cambridge) • VE3TFU (Waterford) • VE3FHM (Georgetown) is under construction • 24 GHz WBFM activity: • VE3SMA, VE3FHM, VE3VXO (Waterloo), VE3CRU (Whitby), VE3EZP (London) • Water vapour absorption makes 24 GHz more difficult.
47 GHz • Highest frequency for which commercial equipment is available • Only activity in Ontario has been by visiting Rochester NY area hams • VE4MA was the first ham anywhere to hear a signal on this band reflected from the moon (from RW3BP), and has now made a 2-way contact with him
76 GHz & Up • Homebrew equipment only ! • No activity yet in Canada, but VE4MA is collecting parts • New allocations shared with radio astronomy – do not expect any QRM !
LASER (470,000 GHz !) • Optical communication is not strictly amateur radio…but it is interesting to play with • Because all frequencies above 300 GHz are allocated to amateurs in the USA it is considered a ham band in the USA and counts in ARRL VHF/UHF/Microwave contests • Gear can be very simple • Transceiver kits available from Ramsey • Must be very careful with safety (potential for eye damage, distracting drivers and pilots)
Simple Wideband FM Gear • Block Diagram
Lake Erie Propagation Magic • Long Point (6 ft)-Morpeth (15 ft)...113 km • VE3OIK-VE3NPB/SMA ( 10 GHz SSB) • VE3OIK-VE3CRU (10 GHz WBFM) • Long Point (6 ft)-Wheatley (12 ft)…172 km • Barely able to make contact on 2m CW (25 W each, 5-7 el beams at 10-18 ft) • VE3OIK-VE3NPB/SMA (10 GHz SSB, S-meters pinned !) • Clarke Rd (60 ft)-Morpeth(15 ft)…91 km • Much weaker signals
Lake Erie Propagation Magic • Some paths worked around Lake Erie
Awards and Contests • ARRL VHF/UHF Century Club (VUCC) • Available for each VHF/UHF/Microwave band for working specified number of grid squares (2 longitude x 1 latitude) • Contests involving microwaves: • ARRL VHF Sweepstakes (January) • SBMS 2 GHz & Up Contest (May) • 902 MHz & Up Sprints (May/October) • ARRL VHF QSO Parties (June/September) • ARRL UHF Contest (August) • ARRL 10 GHz & Up Contest (August/September)
Worldwide Community • Internet discussion groups: • WA1MBA Microwave Reflector • See www.wa1mba.org • Ontario VHF Association • www.ovhfa.com , http://home.cogeco.ca/~ovhfa/ • Email reflector: http://groups.yahoo.com/group/OntVHFAssoc_reflector/ • Meetings • OVHFA Annual “Do” • Microwave Update Conference in USA
Worldwide Community • Microwave operators are a fairly small group, and always keen to have more people to work on the microwave bands • I’ve found microwavers are usually helpful and generous with their time, expertise and even equipment • Remember: help is always available to get you going !