[d-star] Antennas - 1.2

Fri May 4 15:49:40 UTC 2007

We have a few rooftop repeater sites lined up and want to get some antennas
for stock.  We are constrained by height and visibility.  I just ordered an
MFJ-1532-N from Radio City, and am working on a Comet GP-93 from them.  I am
not a big Comet fan as our in service failure rate has been high.

Is there a new Icom base antenna for 1.2?

-----Original Message-----
From: Mark Thompson [mailto:wb9qzb at yahoo.com] 
Sent: Thursday, May 03, 2007 11:30 AM
To: List for people interested in the D Star repeaters
Cc: ewestgard at att.net
Subject: Re: [d-star] Site

Erik that is great news regarding the 1.2 GHz repeaters. 

Skywarn is another reason to also have D-STAR repeaters on 2m or 440. Mobile
units with GPS can be transmitting both voice reports & location data that
can be plotted using D-PRS and APRS. The new generation of D-PRS software
just announced can run on the gateway PC and collect location information
from all repeaters at the site so there no longer has to be separate user
radios monitoring the repeater's digital voice low-speed data for GPS
information.  

73, Mark, WB9QZB
Chicago, IL

In a message dated 5/3/2007 11:22:05 A.M. Central Daylight Time,
ewestgard at att.net writes:
Mark
Dan who runs Radio City in Mounds View did this twice for us- he bought 10
ID1s for stock 
and got two repeaters.  
One repeater is already in the hands of Metro Skywarn - Doug Reed 
Erik
-----Original Message-----
From: Mark Thompson [mailto:wb9qzb at yahoo.com] 
Sent: Thursday, May 03, 2007 11:11 AM
To: List for people interested in the D Star repeaters
Cc: ewestgard at att.net
Subject: Re: [d-star] Site
I don't know if the offer is still available, but back in January five of us
here in the Chicago area each bought ID-1 radios and as a result got from
Icom a free set of the first generation RP-1 1.2 GHz voice & data repeaters.
In that generation of repeaters the controller was built into the data
repeater instead of being a separate module. It can also control an
additional voice repeater so one of our group bought the 440 voice module.
I've attached a copy of the offer from Icom. I think it was limited by
number of RP-1s available. 
We've affiliated with a club that has two sites at which it operates analog
FM repeaters. We're putting the 1.2 GHz voice & data repeaters and the 440
voice repeater on top of a 600 ft. building about 5 miles north of downtown
Chicago where a 440 FM repeater already exists. We're donating all the
equipment to the club in exchange for them running it permanently. 
The interesting thing about D-STAR is that this the first time ham radio
digital means voice not just data. Most hams who experience D-STAR will do
so through voice not data. In addition, on the 2m, 440 & 1.2 radios the
low-speed data that is concurrent with voice transmissions has GPS &
messaging capabilities that offers some very interesting opportunities. 
Most D-STAR repeaters voice & data in the country are linked to the internet
via the PC gateway. It brings capabilities impossible in the traditional FM
repeater environment. 
The high-speed data on 1.2 GHz brings some very interesting capabilities for
mobile data, however for backbone links there are less expensive approaches
that offer higher speeds. 
To get internet on the 600 ft. building we could either install commerical
DSL with a monthly cost of at least $50 per month or put in a radio link.
We've opted for a radio link made by AvaLAN Wireless. I discovered AvaLAN by
talking with some Pennsylvania hams who use their off-the-shelf equipment to
link EOCs with back-bone links. They have equipment on 900 MHz & 5.8 GHz
that operates at about 1 megabit. Because of likely interference in the
unlicensed 900 MHz band in an urban area we using 5.8 GHz to the club's
other repeater site which has free internet and is 10 miles line of sight.
The defunct & disbanded local packet radio club has agreed to use their
remaining treasury towards buying the data two radios which is about $1,300
with antennas. 
I've given over 30 D-STAR overview presentations at clubs & hamfests. I see
tremendous interest in digital voice. I really think D-STAR is an
opportunity for the repeater clubs & the traditional packet data groups to
for the first time work together to provide both voice & data. More
importantly repeater clubs tend to have access to high location sites and
sometimes the resources to make these projects happen. I think it's
important that D-STAR be implemented as one would a wide-area repeater so
that it offers coverage comparable to the traditional FM repeater. In
addition, by offering digital voice on 2m or 440  much larger numbers of
hams will gain exposure to D-STAR and some of them will also buy ID-1 1.2
GHz radios either for personal use or for club use to provide mobile data
for public service & emergency activties. 
The other D-STAR repeater site up is 45-miles west of downtown Chicago in
the far western suburbs. A geneous ham who has tower access bought the
entire set of repeaters. He's put 2m & 440 antennas 370 ft. up on a tower
facing east towards the Chicago suburbs and they're gatewayed to the
internet. Due to feedline losses he's putting the 1.2 GHz voice & data
repeaters at 150 ft. at his home which 15 miles east and closer to more
population where he already operates a 1.2 GHz analog repeater. He has
affiliated all of these repeaters with a local & very active club in the
western suburbs that already operates 2m & 440 FM repeaters and an ILRP
node. 
In both situations the clubs' callsign is used for the D-STAR repeater so
you don't want to use an individual's callsign anyway for technical reasons.

When I bought my ID-1 I inadvertently discovered a wide-area 1.2 GHz FM
repeater that is located on a tall building in downtown Chicago. It is no
longer officially coordinated and used to be owned by a local repeater club
that disbanded a few years ago and had repeaters on all the VHF & UHF bands.
It's a 10-watt Icom FM repeater. I've been experimenting with using it and
making contacts on it. I am amazed how well 1.2GHz works in an urban area.
On 2m & 440 there can be a lot of picket fencing on the signal, but on 1.2
GHz there is no apparent picket fencing. The system has a range of about 30
miles. So I'll be interested to see how the D-STAR digital voice repeater on
1.2 GHz works in comparison. 
There are two other inviduals / clubs in the greater Chicago area interested
in D-STAR. One individual is 50 miles NW of Chicaog and another club is 60
miles south of Chicago. Both operate wide area FM repeaters and are
interested in implementing D-STAR. 

Sorry for the long email, but I thought I would let everyone know what we're
up to here in the Chicago area. Let me know if you have any questions. 
73, Mark, WB9QZB
Chicago, IL

----- Original Message ----
From: Erik Westgard <ewestgard at att.net>
To: List for people interested in the D Star repeaters
<d-star at lists.twinslan.org>
Sent: Thursday, May 3, 2007 6:58:52 AM
Subject: [d-star] Site

Possible New D-Star Site
I spent some time on a rooftop 100 feet plus S of downtown MPLS the other
day.  We would have room- maybe- for a small antenna (GP93?- 6'-8' max) and
a small cabinet.  No Internet unless we get it off-air.  It has an
unobstructed view in a wide arc North and East - not so good West.  
The idea would be to put in a controller and 1.2 data module.  Feedline
length - 20 feet :-)
Access requires bothering the building manager.  
The other users of the site would be on 2M/440 so having a co-resident
packet system would be tricky.
So the idea is this would be a non-Internet standalone 1.2 data repeater.
Would this work?  Could we uplink data and then downlink data with no back
end at all?  
We would use this for the Marathon etc to reach a Trivnet server and or a
Citadel server someplace else.  
Anybody know what the shortest 1.2 repeater antenna is?  

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