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Owner / Club
Minuteman Repeater Association
Air date: on the air
Yes. Full-time IRLP node 4977 to the Near-900
link-up to five other 900 MHz repeaters. Rapidly growing.
Part-time Tuesday evenings only: MMRA net
47th floor penthouse, One Financial Center, Boston. This is a very high quality, well managed commercial rooftop with two
Coverage: wide area in all directions but will also address a
significant coverage area hole on the north shore and to the northwest.
As with many 900 MHz repeaters located in a populated area, the receive
frequency is effected by unlicensed 900 MHz consumer and commercial
appliances. Although challenged by other RF sources, talk-in
coverage is still quite good.
Motorola MSF5000 130W
dual antennas: Dual. RX antenna in a protected RX-only
zone. Tower-top-mounted, inverted. TX antenna on roof.
RX: dedicated 9DB gain DB809 donated by K1WUK
TX: dedicated 12 dB gain PD-10017-6
Neither with downtilt.
RX: 200ft 1 5/8" Heliax donated by N1OTY, TX:
60ft 7/8" Heliax donated by
tip: 685ft AMSL
power: Yes. House Diesel + 2200W APC UPS
RX 927.775 DPL-244
TX 902.775 DPL-244
Clear = OFF
Many people from a wide geographic area have been
purchase repeater and controller. Start MSF-5000 recapping with initial tune-up
(repeater works fine)
Repeater, TX antenna, duplexer and controller later donated to MMRA
donate 200ft of 1 5/8" Heliax & connectors (RX) and delivered to Broadcast Towers in
Broadcast Towers: donate 60ft 7/8" Heliax with connectors (TX)
Broadcast Towers: Heliax elevated to roof-level via window washer
donate RX antenna, Heliax jumpers, Polyphasers
tune-up duplexer, later to be turned onto TX and RX filters
took over repeater prep and was lead on recapping, physical
reconfigurations and final tweak.
Anything to do with the local IRLP interface and setup
Integrate S-COM 7K controller
- K1IW: Program S-COM 7K controller
N3HFK, K1IW, W1BRI, K1RJZ, N1ZZN, KC1HO, N1JFU: Sunday
repeater "tune-up party" at N3HFK.
N3HFK, K1IW, W1BRI, K1RJZ: Lug MSF-5000 to roof penthouse via three flights of fire
escape (350 lbs)
- Now on
the air with the permanent RX & TX antennas (TX on roof, RX on
|This is not your typical Spartan radio
Even by commercial standards, this is a very high-end facility which was
designed to be more of a mission-critical datacenter.
The red box is the dry-pre-action
fire suppression controller, FM200 fire suppression is in another
section. Diesel generator
emergency power is also provided.
Polyphasers donated by K1WUK
A huge thank you for donated ham antenna tower rigging
goes to Broadcast Towers of Bridgewater, MA. Work was provided while
working on another customer project.
|Broadcast Towers is the exclusive tower
rigger for One Financial Center. No rusted bolts, no
unlabelled coax, no abandoned gear left on the roof. Their pride and quality of work
Helicopter shot provided by... someone.
Please consider these fine
companies of you need tower rigging or you are looking to
rent a very well-managed commercial tower site:
Broadcast Towers, Chris Loycano, Bridgewater
Peter Kovaleski 860-684-1511
Good food and great company!
Also participating was Bob DiMattia,
K1IW who was remotely programming the S-COM controller while he was
|Particular attention was
paid to audio quality and by the end of the day, everyone
was quite pleased. Audio frequency response and
amplitude had to match between end user audio, voice ID's
and IRLP linking. The sharing of knowledge
among these peer experts made the trip worth it for
This one is headed far outside of the
Boston hardware relocation day.
These are some of the key players
that made it all come together. The large red bottles in the
for FM-200 inert gas fire suppression. This is a truly
Permanent TX antenna location
Trying to optimize 900 MHz
The roof-top site itself is very
clean but the off-site and unlicensed urban 900 MHz environment
might be called "The Wild West".
Spectrum analyzer plot showing Part-15 unlicensed
users on repeater input frequencies.
Without the RX filter included above, RFI extended well beyond 912
Receive antenna performance improved
but the Part-15 RFI also increased
#1 Relocate RX antenna
|Now relocated. Possibly less exposure from urban
Part-15 RFI while improving coverage to the west and
north. The shadowed area now orients to the south which
already has very good linked 900 MHz repeater coverage
from Hingham and Marshfield. New location showed
some improvements but not dramatic improvements to the
west and north.