February 17, 2014

1960 Snow Lake to Thompson Manitoba Tropo Link

This is what a 28' D S Kennedy Parabolic antenna looks like.
http://www.nitehawk.com/rasmit/ras_pics.html
Back in 1960, a troposcatter communication link was set up between the town of Snow Lake and the City of Thompson.  The two locations are separated by 105-120 miles, and other than their names on the below map from the 1966 edition of the IEEE Spectrum publication; I have no idea where the tropo antennas located at either place were.  From the information below, they would have been a pair of D S Kennedy 28 Foot parabolic antennas at either end, have been built by RCA ~1960, and supported 30 voice channels.  The tropo link was listed as "Common carrier", suggesting it wasn't a military communications link (however, the Hay River / Lady Franklin Point link is also listed as Common Carrier, and it is well known to have been dual use).  On the map below this tropo link is shown as #39.


Because both areas have heavy industry, there are a lot of power lines, roads, rail, and other scars to the landscape that make my usual tricks (like following gaps in the tree line) ineffective at finding the site.  Even after 50 years of growth, a trail in the forrest is still usually visible if a road has gone into disuse - but there are too many dead ends around these areas.

Chisel Lake, Osborne Lake, and Herb Lake are other towns near Snow Lake - but I've found the closest reference point is always used to name these sites, so I'm betting the tropo antennas are closer to Snow Lake than the rest of the surrounding towns.  Unfortunately, I still don't know exactly where.

Different vantage point of a 28' D S Kennedy Parabolic
http://www.k5so.com/Objectives.html
I've checked Google Maps, Bing Maps, Toporama, and leafed through other maps available via GeoGratis.  No luck.  So, I'll just leave this here as an unsolved mystery and come back to it later.






1 comment:

  1. I hope I can cast some light on the MTS Scatter communications system. I graduated from Queen"s University in electrical engineering in 1954 and immediately went to work for RCA in Montreal where I soon became involved with radio relay development. Around the 1959 time frame, my boss gave me project engineering responsibility for this system when the original project engineer and critical development staff abruptly left RCA. It was a baptism by fire for me with a good design background but no project management experience.I am currently writing my story of this program largely for the record but also to inform and possibly entertain members of the RCA and successor companies retiree group "Spartans". Briefly,this was a two hop system connecting to an existing radio relay system from Brandon to Flin Flon with a "break out" at Cranberry Portage. The first hop from Cranberry to Snow Lake, was an unusually long "grazing incidence" path and the Snow Lake to Thompson was a relatively short hop for a scatter system. Both terminals of the scatter system used two 28 foot parabolas on 100 foot guyed towers and were from one to two kilometers from the respective towns. It was a single space diversity system meaning there was one 1Kw transmitter at each site and two receivers at the terminal.To the best of my knowledge, the system was purely commercial to support the new mine at Thompson replacing a voice wire line system running along the railroad spur servicing the new town of Thompson. Lorne Keyes, l.keyes@bell.net

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