7 Sep
2017
7 Sep
'17
1:21 p.m.
The modems in Vancouver were GRAPES modems, but may have come from a
different supplier, and they were fully built rather than kits. Dennis
designed a new transverter and power amplifier to connect to the modem.
The repeater on Mount Seymour (at the CBC television transmitter site)
was linked to the Internet using 900 MHz radios across Burrard Inlet to
Simon Fraser University on Burnaby Mountain (where I worked at the
time). I had a station up the Fraser Valley in Maple Ridge, and although
I did not have line of sight, it worked just fine bouncing off a nearby
mountain. Dennis had a station in Chilliwack, and there was another
repeater at the Industry Canada (Canadian version of the FCC) monitoring
station near there. As to mobile - Dennis put a station in his car, and
had good connectivity and speed driving in from Chilliwack to Vancouver
(about 30 miles).
I'd say that the GRAPES modems did well in both mobile and multipath
situations.
Dennis' radio and duplexer designs were so clean that Industry Canada
let us put the antenna for the repeater at the top of their tower - they
said that they had never measured *commercial* equipment that clean. 70
cm was like DC to Dennis - his commercial work went up into the tens of
GHz. :-)
- Richard, VE7CVS
On 9/2/2017 10:17 AM, Ken Koster wrote:
The problem with the GRAPES modem was cost, the kit
was reasonable but add
in all the other pieces and it was more than many of us could afford.
We had a few GRAPES modems here in the Pacific Northwest but very few ever
made it on the air.
We did have a dedicated 56k link over an 80 mile path between Camano Island
north of Seattle and a 56k repeater on Mount Seymour in British Columbia. The
repeater and the link radio used a 56k modem designed by Dennis, AC7FT (then
VE7BPE). It was compatible with GRAPES but was a completely separate design.
That link provided additional connectivity for the 1200/9600 IP network in
central Puget Sound for several years and was reasonably reliable.
Those were fun times