Oakland County Amateur Radio Public Service Corp (ARPSC)

W8OAK Repeaters – 146.900 MHz/100pl & 444.325 MHz/107.2pl

Weekly 2 meter net 8 pm every Thursday

Hospital Radio Net – 7:30 pm last Thursday of Month

Packet 144.950 MHz/1200 baud, connects made with Oakxxx or

Callsign-# to OAKBBS (W8OAK-3) with nodes at

OAKNOD (N8NM-1 Pontiac – most coverage),

OAKEOC (W8OAK-7 at EOC) or K8DTX-7 (White Lake)

APRS – 144.390 MHz

Web Site: http://www.arpsc.com


Meeting Minutes for 4 January, 2012

            On 4 January 2012 at 7 pm, Jim Richards - AB8JR, Emergency Coordinator (EC) for the Oakland County ARPSC, called the meeting to order in the County Emergency Operations Center (EOC).  The order of business included:

(I). Report from Steve Iannucci, Homeland Security Division – Oakland County:

            Steve hopes this year will be safe and memorable for everyone’s families.   Oakland County was fairly quiet in December except for a few power outages.

(II). Report from the Emergency Coordinator (EC), Jim Richards - AB8JR:

            The new repeater voter and controller are now in the hands of Steve Murphy – N8NM, County Radios who will install them.

            The Annual ARPSC Dinner Meeting will be 7 March 2012 at the Oakland County Executive Building.   Reservations (RSVPs) for this meeting will begin later and can be called to Bethany Kenney at Oakland County Homeland Security Department at 248-858-5300.

            Funeral for Mike Smith – N8GUZ, our AEC for Training, took place 2 December 2011.   Jim thanks everyone who came to his funeral.  Memorial donations were made at the meeting in Mike’s name.    Mike, we will miss you.

            New additions to our administrative personnel are (1) Greg Siemasz – W8VIJ as Assistant for Hospital Radios and (2) Ron Miotke- WD8MNX for Membership.   Volunteer coordinators are needed for sirens and training, and additional net control operators for our weekly radio nets and sirens.   The next Siren Net is only two months away.   Please consider volunteering for one of these and contact Jim.  

(III). Presentation – DMR versus D-Star Radio by Randy Love – WF5X:  (Any errors in this abstract are the fault of this secretary and not the speaker)

            Analog modulation is still the most common amateur radio format, which offers low cost equipment at the expense of using wider band widths. 

Advantages of digital radio include:

(1). Narrower band widths, such as 6.25 kilohertz instead of 12.5.    

(2). Better quality of voice/data receive as distance increases.  This occurs as long as there are no multi-path signals and as long as the signal is above a minimum threshold (“radio cliff”).

(3). Able to handle voice and data concurrently.

Disadvantages of digital radio include:

(1). Not easily serviced; i.e. measurement of power output difficult because digital transmits only part of time causing lower readings.

(2). “Radio cliff,” already mentioned

(3). Depends on special protocols and proprietary systems

(4). Narrow band widths create less quality in voice reproduction.

There are several protocols in ham radio that maximize the greatest possible use for a given bandwidth:

(1). Time Division Multiple Access (TDMA) places two way communications into timed slots and shares them between users.

(2). Frequency Division Multiple Access (FDMA) has different signals assigned by frequency.   One form permits a 12.5 kilohertz signal to be divided into ½ or two channel band widths.      

In ham radio, the three most common digital formats, beginning with the most used are (1) D-Star, (2) P-25, and (3) DMR (Digital Mobile Radio).

(1). D-Star is used on 2 meter, 440, and 1.2 GHz bands.   One report states it now has about 835 internet gateway enabled repeaters and 20,000 registered in gateways used around the world.    It uses GMSK (Gaussian minimum-shift keying) modulation – a form of FDMA, 6.25 kilohertz bandwidth, and only one manufacturer is developing it.    It is not compatible with DMR.   D-Star requires a band width guard for each station and this doesn’t easily permit double side-by-side channeling by two 6.25 kilohertz frequencies. That is why we can not put two 6.25 D-Stars slots next to each other.     Users with D-Stars register with each repeater. 

(2). P-25 has been around longer than the others and has use in ham radio.   It is used by public safety radios and has so many protocols and different radio spectrums that incompatibility issues are problem.   

(3). Digital Mobile Radio (DMR), a 2 slot (channel) TDMA access, is an open standard two-way format found in Europe and complies with U.S. Federal Communications Commission (FCC) mandates in the U.S.  It uses 12.5 and 6.25 KHz narrowband, provides voice and data, and can be used as simplex.    Manufacturers involved in DMR include Yaesu (Vertex Standard), TRC (Tait Radio Communications), HYT (Hytera), Motorola, and Vertex Standard. 

Having multiple manufacturers helps to keep prices more competitive.   Advantages include slightly better audio quality.   One old analog radio station with 12.5 kilohertz bandwidth can be transformed into two channels of 6.25.   DMR’s work with other DMR’s and can link repeaters.  Every DMR repeater has two frequency slots, but currently there is nothing available “out-of-box” for hams.  The number of ham DMR-MARC worldwide repeaters is increasing, with one being DK8EYF in Southfield, Michigan.  When an operator’s machine is verified once, he/she can transmit into world wide networks.    Short text messaging is possible.  From a pricing perspective, each D-Star band module costs $3000 and the controller $3500.  A DMR repeater with two slots costs about $2800 and some DMR repeaters can switch between digital and analog.  

Randy observed during one MS bike ride, that repeater needs for DMR (versus analog) required less power in wattage requirements and antennas didn’t need to be as high.   The same goes for a DMA handheld.

Jim Richards – AB8JR, EC stated that the intent of this presentation is to educate our members about digital modes.  He believes digital ham communications will increase.   At this point in time, scanners cannot access DMR or D-Star, thereby increasing the privacy of emergency communications.    Further information can be found at http://www.dvara.org and http://dmr-marc.net.

 (IV). AEC-Management Team Reports:

             (1). Report from Pete Gladysz – K8PGJ, Operations

             Pete presented a movie about the 2004 SCCA (Sports Car Club of America) Pro Rally held at the Sno-Drift Rally in Atlanta, Michigan.    Viewers were showed what it was like to race cars through snow and ice.  In it, Pete was interviewed several times and was a second member of one sports car in the race. 

 The next Sno-Drift Rally takes place for two days on 27-28 January 2012 near Atlanta, Montmorency County in northeastern lower Michigan.   Pete Gladysz – K8PGJ is Chief of Communications, with Randy Love - WF5X and Ted – N8ZSA being net controls.   Barbara Steencken – KC8SWF is Chief of Controls and needs volunteers to assist in various functions, but the sign-up window is quickly vanishing.   If interested, go to www.sno-drift.org and apply under heading of “volunteers.”

(2). Report from Fred Czubak – KD8CMD, Administration

            Monthly reports about our activities are sent to the ARRL, and these are based on time spent on nets, meetings, special events, Skywarn, etc.  For the year of 2011, we had 113 events and generated 5486 volunteer man-hours.   If calculated at $18.50/hour, this amounts to $100,381 of donated labor.    

            (3). Report from Mike Vander Veer – KD8ATK, Net Operations:

            Our W8OAK nets are held weekly on Thursday evening at 8 pm.  Additional net control operators are needed.  If interested, please contact Mike or Jim –AB8JR, EC.      

 (V). Specialty Officer/Coordinator Reports:

             (1). Report from Ron Miotke – WD8MNX, Membership:

            Two or three new applications came in last month.  Ron will work to streamline the application process and rearrange membership listings.   He says “there will be more to come.”

            (3). Report from Mark Schurig – KC8WPS, Hospital Communication Teams:

            Mark thanks everyone who participated in the 29 December 2011 Hospital Net.  

            (4). Report from Maurice Davidson – K8SJD, National Weather Service Liaison:

            The year of 2011 had the highest rainfall in recorded history. 

(VI). New and Other Items of Interest:

1.  Sunday, 15 January 2012 is the Hazel Park ARC Swap.  Details can be found at www.hparc.org.

2.  Beginning Monday, 9 January 2012 from 7-9 pm, there will be a General Class License Course, sponsored by the Hazel Park Amateur Radio Club.  Duration is twelve Monday sessions and location is at the Southfield Emergency Management Office in the basement of the Parks and Recreation Building.   Cost is free except $23 charge for book at discount.  Contact Wallace Murray at ke8hr@arrl.net.

3.  Beginning Friday, 27 January 2012 from 7-9 pm, there will be an Amateur Extra Class License Course.   Duration is up to sixteen Friday Sessions at the same Southfield location.  Cost is free except $23 for book at discount.   Contact Ron Miotke at wd8mnx@arrl.net.


Respectfully submitted,

James R. Murphy, N8SML

Secretary, Oakland County, ARPSC

5 January 2012

Minutes corrected and approved by Jim Richards – AB8JR, EC