Marconi Amateur Wireless
Society MEETINGS
AT OUR MOST RECENT MEETING
... JUNE 1, 1999...
We welcomed Patrick, VE1MPB, to the get-together and had some discussion
on repeater operation, mobile vhf equipment, hf linear amplifiers,
CW logging/contesting programs, etc.
Allan, VE1APE, as usual led the charge
with some instruction on diplexers and multicouplers and the potential
trouble spots in actual operation. Multicouplers were explained as tuned
filter cavities which allow multiple receivers and transmitters operating
on different frequencies to utilize the same antenna at the same time.
The popular 4-cavity system has 3 bandpass cavities between the antenna
line and the equipment connection(rx or tx) which are tuned to the equipment
frequency to pass it TO the antenna (for a transmitter) or FROM the antenna
(for a receiver). In the antenna line, just below the connection to the bandbass
cavities, a reject cavity tuned to the equipment frequency is placed. This
rejects or prevents RF at the equipment frequency from travelling downstream
to OTHER equipment.
For a receiver, RF comes DOWN from the antenna and
sees the reject filter, which it cannot pass through. It is thereby
directed into the bandpass filters and into the receiver. Similarly,
a transmitter sends RF out through the bandpass filters to the antenna
line. Any RF that tries to go DOWN, toward other equipment, will be stopped
by the reject filter and has no choice but to travel UP to the antenna.
By placing each receiver or transmitter on a duplexer "equipment" connection,
several transmitters/receivers can use the same antenna at the same time
without undue interference. Unfortunately, losses add up, especially for the last
"downstream" receiver or transmitter.
*Limited info may be found at: www.sinctech.com
Jack, VE1XT, once again demonstrated RUFZ 3.0 , the CW logging/contesting program.
(a la November meeting)
He also pointed out that "portable" operation means a fixed station other
than at the location specified on a station licence. Walking around with
a handheld radio would be called "mobile" operation!
Jack also gave us some info. on proposed changes to licensing and renewal
transactions. One interesting proposal is the elimination of the yearly station licence
renewal fee. (GASP!) Callsigns would be assigned to the actual operator
and not to the station, as is now the case...(more to follow - di-dah-di-di-dit)
APRIL Meeting
Allan, VE1APE, fresh from some "fun in the sun" was in demonstration form once again.
He and Edwin had their Garmin 45's up and running with Allan's unit sporting
its external antenna. While using the external antenna, Allan reported that
his "45" never lost satellite contact once, even under some very difficult
conditions.
Once again Shawn Hudson dropped by with more info on "QRT '99". Most importantly,
the time for the event has been changed to 10:00 a.m. - 12:00 p.m. ADT. The date, JULY 30,
1999, is the same ! It is planned that VCO will transmit on 500 khz and receive on 160 m, while VAS will, of
course, receive on 500 khz and transmit on 160 m.
JACK COLUMBUS, VE1XT, made a great suggestion:
that SARC could continue the operation at VAS and make a special event out of
the occasion...
At our request, Shawn gave us more info about GMDSS (see March meeting) and handed out a
booklet entitled Global Maritime Distress and Safety System: The Future of
Marine Distress and Safety Communications in Canada. There was more discussion
on the frequencies used for VHF and MF distress alerting and communication,
how a vessel in distress is handled, things that can go wrong, EPIRBS, ELT's,
SARSAT, COSPAS, LUT, RCC, (whew!) etc.
The group really appreciated Shawn's expertise and his kindness in sharing
his valuable time with us.
MARCH Meeting
Allan, VE1APE, gave a valuable demonstration of several types of power connectors and how a person
could destroy his equipment by inadvertently reversing polarity. This is relatively easy to do
if one uses the commonly available "trailer connectors" found in auto parts stores. When using
these plugs you must be very careful with the polarity of the connections. Otherwise, your rig
may be " flashed - out "..."**##&&%% !!!"
Special guest speaker was Shawn Hudson, a former V01/VE1 and presently Canadian Coast Guard Radio VCO
MCTS officer (Sydney).
Shawn gave the group a preview of the VCO - VAS cw event planned for July 30, 1999
(2:00 - 4:00 pm ADT).
This occasion marks the end of the use of Morse Code at Coast Guard Station VCO and will involve
present and former C.C.G. radio operators in traffic handling between VCO
(located at Canadian Coast Guard College, Westmount, N.S.),
and the Marconi Exhibit Centre at Table Head, Glace Bay, N.S. (formerly Marconi Station VAS).
With an event of this magnitude, it is expected that a lot of public interest will be generated.
Let's generate some amateur interest and resolve to help out in any way we can !
Shawn also detailed us on the new GMDSS (Global Maritime Distress and Safety System) which is being
implemented worldwide as a replacement for previous marine distress and safety protocol which
included, among other things, the use of cw. The new system uses satellites, digital selective
calling and 406 Mhz EPIRBS.
The group enjoyed Shawn's presentation and we hope to have him
back again soon for an update on " QRT - '99 " and for more information on GMDSS and general
marine safety as it pertains to radio communication.
Why not visit Canadian Coast Guard Radio VCO
and
the Canadian Coast Guard College Page.
FEBRUARY Meeting
There was much discussion on R.F. speech processing and its great advantage in
amateur ssb communication. Allan (ve1ape) played a tape of compressor testing
with ve1rmg's rig as transmitter and Allan's own rig as receiver. He noticed a
great difference in loudness and signal strength (2 s-units) with RF compression.
Since the tape recorder had a built-in AGC, the loudness
increase was not as noticeable on the tape. Robert (ve1rmg) had noticed an increase of
4 amperes in the RMS peak input current to the rig with the RF processor in use. This
would translate into an increase of 4A x 14V = 56 Watts in input power with
processing - quite a difference! It was suggested that the group get together
on HF some evening for more testing. How 'bout it RON...
The group was happy to see Jack back from his trip to Israel. All were anxious to
hear how it went and how Big Brother Mike was doing.
JANUARY Meeting
Allan (L'il AL) VE1APE, Allan gave an overhead demonstration of a CD-ROM
stored topo map. Using this program, Al was able to display topographical
features at several scales
(1 : 50,000 ; 1 : 100,000 ; 1 : 200,000 etc.)
and to produce a horizontal profile of any desired route. As the proposed
route crossed contour lines, the program displayed the "ups and downs" of the
path - giving a more understandable indication of the steepness of the terrain.
This software could also be integrated with GPS.
There was also some
discussion of the status of amateur radio and DX'ing...
DECEMBER Meeting
Allan (L'il AL) VE1APE, distributed handouts listing cable tv channels and
frequencies and provided a lot of good info on TVI, etc.
Allan also gave an
overhead demonstration of WAYPOINT PLUS for Garmin GPS. Using this program, Al was able to
display both recorded tracks and stored waypoints uploaded from his Garmin GPS-45XL. Most of the
tracks were recorded while driving along familiar Cape Breton roadways - the group could see virtually
every bend in the road and could easily relate the many waypoints displayed to familiar landmarks.
In this way, Al created his own personal electronic roadmap complete with waypoints representing
points of interest and places to eat, gas up, or take in some interesting scenery. An enlightening
and comprehensive explanation of the limitations of different tracking settings was also given.
There was some discussion of the differences in features among the Garmin 45XL; 12XL and 12. Phil,
VE1BVD, related his brief tryout of the Garmin GPS 12. His extensive knowledge of navigation helped
greatly in the comparison.
As usual, we navigated to the usual location for wings.
November Meeting
Jack, VE1XT, gave a demonstration of a
neat program for c.w. logging practice known as RUFZ 3.0 or "Rufzeichen - H_ren"
, by DL4MM.
There was also a discussion of planetary
motion and the reason we only see
only one side of the moon from Earth.
As usual, the subject of GPS/APRS was
popular and some demonstration of the
Garmin GPS - 12 was given.
Al, VE1APE, provided some good info on cable/vhf/uhf tv channel allocations.
He also reported briefly on his investigation of a new APRS program.
October Meeting
There was lots of discussion on GPS
(Garmin vs. Eagle / Magellan), DX, Mapping, APRS, and
various software available for same. Thanks to Phil for
illuminating outline of navigation techniques
and the vital role of accurate timekeeping in longitude determination.
Visit the
WWV site for time info.
Another important topic was
emergency preparedness and the role of
amateur radio in post-disaster
communications. We all look forward
to the quantification of amateur radio resources
in the Cape Breton area.
Imagine the potential of GPS portables
+ VHF portables (along with APRS)
in, let's say, a search and rescue operation
!
For more info on time / navigation
and other interesting stuff visit the
U.S. Navy Observatory.
Also, the softcover book
LONGITUDE
by Dava Sobel ( Penguin Books ) may interest you.
Based on this book, a NOVA
presentation aired on PBS Oct. 6. Entitled " Lost at
Sea - The
Search for Longitude ", the program
told the story of John Harrison, the carpenter / clockmaker
who finally solved the longitude problem
with accurate timekeeping.
VISIT
THE NOVA Site
MEETINGS HELD FIRST
TUESDAY EACH MONTH ( Sept. - June )
TUESDAY, OCTOBEER 5, 1999.
ROOM 3149 CABOT BUILDING
COAST GUARD COLLEGE
The purpose of the Marconi
Amateur Wireless Society is to encourage experimentation
in all aspects of amateur
radio in a spirit of friendship and goodwill.
73!
Visit VE1RMG page
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