MARC  WB3JOE/R  W3NWA  Southeastern PA

FM Repeaters

MARC Repeaters

MARC operates six repeaters providing wide area coverage of southeastern Pennsylvania, southern New Jersey and northern Delaware.  The 147.06 MHz repeater (+600 kHz offset, PL 131.8 Hz) is located at the site of the commercial radio tower in Newtown Square, PA, shown at the right.  The 145.13 MHz (-600 kHz offset, 131.8 Hz PL) and the 445.675 MHz (-5 MHz offset, PL 131.8 Hz) repeater is at Paoli Hospital in Paoli, PA.  The 147.36 MHz repeater (+600 kHz offset, PL 131.8 Hz), the 224.5 MHz repeater (-1.6 MHz offset, PL 131.8 Hz) and the 444.050 MHz repeater (+5 MHz offset, PL 131.8 Hz) are located at the Mercy Fitzgerald Hospital in Darby, PA.

The MARC 145.13 MHz, 445.675 MHz  and the 147.06 MHz repeaters are linked with a dedicated bi-directional UHF radio path as shown at the right (center and right most picture) and have complementary antenna patterns that extend the reliable coverage area. The MARC 145.13 MHz repeater in Paoli, PA has a cardioid pattern directed from Paoli through King of Prussia and Norristown and covering Phoenixville, Royersford, Ambler, Willow Grove, Conshohocken and Radnor, PA. The MARC 147.06 MHz in Newtown Square, PA repeater covers Philadelphia, Southern New Jersey, Delaware and eastern Penns
ylvania.

The MARC 147.36 MHz, 224.50 MHz and 444.050 MHz in Darby, PA repeaters are linked for cross band activity, can operate on  the emergency generator power system of the Mercy Fitzgerald Hospital and complements the coverage of the MARC repeater system, extending north to the Bucks, Burlington and Mercer County but also Philadelphia and Southern New Jersey and Delaware. The MARC Darby repeaters uses three Super Station Master antennas mounted on a 50 foot tower on an 11 story building, shown at the right (left most picture). Note that the MARC 224.50 MHz repeater is currently QRT for testing.    

The MARC repeater system is 'open' to all Amateur Radio operators and newcomers to the Amateur Radio fraternity are most welcome!

MARC Yaseu Fusion WIRES-X Nodes

MARC has implemented Yaesu Fusion WIRES-X nodes using the 444.050 MHz and 445.675 MHz DR-2X repeaters in Darby and Paoli, PA. The sysop for Darby is Steve K3ZFT who hosts the node connected to various Yaesu Fusion WIRES-X nets and rooms. The sysop for Paoli is Dennis K3DS who hosts the node usually connected to either the Keystone Wide WIRES-X Room #60328 or the East Coast WIRES-X Room #43817. Both the 444.050 MHz and 445.675 MHz repeaters also operate in AMS (Automatic Mode Selection) can utilize both C4FM digital and analog FM.

The MARC Darby 444.050 WIRES-X node is usually connected to the Kansas City Wide WIRES-X Room #28054 but can be relocated to any room except when hosting a net. Since you are allowed to move the MARC Darby 444.050 WIRES-X node to another room you should watch Good Operating Practices for Fusion Repeaters and Nodes (~30 minutes). Afterwards operators should return the MARC WIRES-X node to the original room. There is a one hour timeout that also returns the MARC Darby 444.050 WIRES-X node to the home room.

The WIRES-X nets currently available on the MARC Darby 444.050 Fusion repeater with days and times in local ET are: 

Sunday 1500 New England Fusion Group Technical Net WIRES-X Room #28941 [nefg.us]
Sunday 2000 Keystone Wide Fusion Net WIRES-X Room #60328 [
https://www.w3pie.org/index.php/wires-x-keystone-wide/ and
      
https://www.facebook.com/Keystone-Wide-WIRES-X-Room-60328-a-Digital-Intercom-for-PA-Hams-624368174878421/]
Monday 2030 MNWIS Fusion Technical Group WIRES-X Room #21493 [
wp.hamoperator.com/]
Tuesday 1900 Absolute TechNet WIRES-X Room #46361 [
absolutetech.org] many different technical subjects. Once a month devoted to the Raspberry Pi and once a month devoted to Linux.
Wednesday 2100 Digital Learning Net WIRES-X Room #46361
Saturday 2100 International WIRES-X Net-- {NOT Technical} WIRES-X Room #21080

MARC Repeater Upgrades

The MARC Paoli 145.13 MHz repeater underwent an upgrade in 2012.  The before and after equipment cabinets are shown here.  The Motorola Micor VHF repeater, Motorola UHF link transceiver and S-COM 7K controller (shown below left) was replaced by a Kenwood TKR-750 VHF repeater, a Kenwood TK-8180 UHF link transceiver, Crescend 100 W VHF power amplifier, S-COM 7330 controller and Astron 13.5 V 50 A power supply, shown below center and right.

          

The MARC Paoli
445.675 MHz UHF repeater (shown below left)  was an ICOM RP-4120 25 W repeater located on top of the equipment cabinet and cross-linked to the MARC Paoli 145.13 MHz and 147.06 MHz VHF repeater system. The MARC 445.675 MHz repeater (shown below right) has been replaced by a Yaesu Fusion DR-2X repeater with Automatic Mode Selection for both analog FM and C4FM digital modes and can be linked to the 145.13 MHz and 147.06 MHz repeater system in the analog FM mode.

     

The MARC Newtown Square 147.06 MHz VHF repeater also underwent an upgrade in 2013.  The before and after equipment cabinets are shown here.  The Motorola Micor VHF repeater, Motorola UHF link transceiver and S-COM 7K controller (shown below left) was also replaced by a Kenwood TKR-750 VHF repeater, a Kenwood TK-8180 UHF link transceiver, Crescend 100 W VHF power amplifier, S-COM 7330 controller and Astron 13.5 V 50 A power supply, shown below center and right.

            

The MARC Darby 147.360 + 224.50 <> 444.050 MHz linked repeaters were replaced by two Bridgecom VHF repeaters for 2 m and 1.25 m and a Yaseu Fusion DR-2X 70 cm UHF repeater at the Mercy Fitzgerald Hospital.  The before and after equipment cabinets are shown here. The former 2 m repeater was an E F Johnson Model 100 purchased in 1985 (shown left below). The MARC 147.36 MHz and 224.50 MHz repeaters (shown right below) are cross-linked with an SCOM 7330 controller. The MARC 444.050 MHz repeater has Automatic Mode Selection for both analog FM and C4FM digital modes and can be linked to the 147.36 MHz and 224.50 MHz repeater system in the analog FM mode.

  

Repeater Frequency Spectrum

The analog frequency modulated (FM) index is adjusted for correct operation using a spectrum analyzer. Shown is the unmodulated carrier (yellow) and modulated (purple) frequency spectrum of the 444.050 MHz repeater in analog FM. The frequency deviation at -23 dB down from the peak of the unmodulated carrier is approximately +-4.2 kHz (5 kHz per horizontal division).