History of the SHARC-3 Repeater
N3WX / R
51.440 MHz (Input) 51.940 MHz (Output) -500 kHz Split - PL Tone: 131.8 Hz
Updated 5/31/12

This page is dedicated in memory of SHARC co-founder, Ron Lentz, N3WX (1960-2001)

Callsign changed to N3WX: 4/18/2005 - Open Access Commands: # 8 = Voice ID/Message Board, # 9 = CW ID
# 0 = Touch Tone (DTMF) Test

Click on the update icon for the current status of this repeater.

** Operational ** - The SHARC-3 Repeater (51.940 MHz - PL: 131.8 Hz) project was primarily funded by Ron - N3WX. Secondary financial contributions were made by Mark - N8UVQ, Jim - KA3EBX and anonymous contributors.

They spent a considerable amount of time researching which brand of transceiver to use for the new repeater. They heard a lot of good things about the GE Master II. There was also a lot of GE resource information available on the Internet.

Top View

- Top View -
GE Master Exec II Repeater
w/Built-in Control & Status Panel

Ron purchased a 60W (continuous duty) GE Master Executive II from a company called Micro Computer Concepts (MCC) in Florida. MCC offers a line of repeater controllers and fully functional repeaters.

Ron purchased a completely built and tested GE Master Executive II that included a Communications Specialist PL encoder and decoder and RC-1000V repeater controller. The RC-1000V is mounted inside of the GE repeater and provides the following features:

  • Auto-patch w/Speed Dial
  • Reverse Auto-patch
  • Remote Control
  • Remote Base (Repeater Linking)
  • Digital Voice Recorder (DVR)
  • Front View

    - Front View -
    GE Master Exec II Repeater
    w/Built-in RC-1000V Controller

    Jim - KA3EBX purchased a matching GE Master II, 35A continuous duty, rack mounted power supply in early March, to power both the repeater & controller. The power supply is 7" high, 12.75" deep and weighs 60 lbs.

    The repeater arrived at Ron's door on March 31, 2000. Ron and Jim got together on the following day and refinished a rack that Jim had stored in his basement. Ron, Jim and Jim's daughter Sasha, sanded down the old rack and applied new primer and a new coat of glossy light gray paint.

    The rack is 47.25" tall, 17" deep and mounted on caster wheels (total height = 50"). It has louvered vents on both sides and also on the rear door.

    Jim fabricated a 5.25" front panel and mounted a 4" speaker on it. The speaker panel was installed at the highest position in the rack.

    Next, Jim added right angle vertical rails to the inside of the rack so that the repeater and other gear can be mounted inside.

    The next step was to add a mounting bracket to the GE repeater. Jim removed the outer housing from the repeater and bolted (2) horizontal struts, fabricated from 1/8" thick, right angle aluminum, to the outer housing. Using the horizontal struts, the repeater was easily secured to the vertical rails in the rack.

    Jim installed (2) 3" DC fans on a fabricated 3.5" panel with circular cutouts. The fan panel is mounted directly in front of the repeater's heatsink.

    Jim also added a 7" high shelf, just below the speaker panel which can used to store service manuals or other equipment. Jim also added a horizontal strut to support the rear of the power supply.

    Rear View

    - Rear View -
    GE Master Exec II Repeater

    Ron - N3WX purchased the duplexer on April 7, 2000. It is a WACOM duplexer (acquired by TXRX Systems, Inc.), part number WP-609. WACOM is located in Waco Texas. Specifications are as follows:

  • Freq Range: 50-54 MHz.
  • Min. Frequency Separation: 500 KHz.
  • Max. Power Input: 350 Watts.
  • Insertion Loss (TX & RX) 1.5 dB.
  • Attenuation at TX & RX: 85dB
  • Max. VSWR: 1.5:1
  • Temp. Range: -30 to +60 Deg C.
  • No. of Cavities: 4
  • Height of Cavities: 61".
  • Total Height w/Tuning Rods: 70".
  • Diameter of Cavities: 5".
  • Connectors: Type "N"
  • Finish: Black Hammertone Enamel
  • Weight: 60 lbs.
  • Shipping Weight 138 lbs.
  • List Price: $1480.00
  • Club Discount: 25% or $370.00
  • Discounted Price: $1110.00
  • Cost of shipping: $90.00
  • 6m Repeater

    - Front View -
    Completed SHARC-3 Repeater

  •  Otari Broadcast Cart Machine (top)
  •  5.25" Panel w/4.0" Speaker
  •  7.0" Shelf
  •  GE Master Exec II Repeater
  •  3.5" Timer Controlled Fan Panel Assembly
  •  GE 35A Continuous Duty Power Supply
  • On Sunday, April 16th, 2000, Ron - N3WX & Jim - KA3EBX got together to apply power to the 6-meter repeater for the very first time.

    Ron & Jim installed the GE power supply in the bottom position of the rack and connected the power cables and dummy load. After a brief moment of hesitation and with fingers crossed, Jim flipped the big switch. The repeater came up on frequency and identified in CW.

    Over the next hour, Ron & Jim tried out some of the controller's functions. The callsign was changed to KS3R and Jim called Ron's cellphone on the repeater's autopatch. Ron reported back excellent audio quality.

    Jim created a circuit board that contains a timer circuit that turns on the cooling fans whenever the repeater is in use and continues to operate the fans for 5 minutes after the repeater unkeys. The circuit board is mounted on the rear of the fan panel assembly.

    The cables running between the repeater and duplexer consist of Andrew 1/2" superflex (100% shield) with "N" connectors. Using a Greenlee punch, Jim punched (3) 1" holes in the rack to accommodate the duplexer cables and AC line cord. The holes were lined with a serrated grommet strip.

    6m Repeater

    - Front View -
    Completed SHARC-3 Repeater

    Ron purchased a Diamond 6-meter, 6dB gain (22 ft) colinear antenna. Jim donated 60' ft of Andrew 1/2" heliax and (2) new "N" connectors.

    On Thursday, June 8th, Ron & Jim moved the repeater, antenna, hardline and duplexer to the repeater site.

    SHARC's New 6-Meter Repeater

    SHARC's New 6-Meter Repeater

    On Saturday, June 10th, 2000, Jack - K3DMY, Ron - N3WX and Jim - KA3EBX got together at 9AM and got the machine up & running. Jack did all of the tower work and installed the connectors on the hardline.

    The antenna was side-mounted temporarily on the tower about 50' up using new 1/2" Andrew hardline. We will be moving it to the top of the tower soon. The repeater was put on the air around 3:30 PM.

    SHARC-3's 6-Meter Duplexer

    SHARC's 6-Meter Duplexer

    Prior to throwing the big switch, Jack connected the repeater antenna to his new Yaesu FT-847 and both Ron & Jack worked 6m SSB stations in Texas & Oklahoma and other parts of the midwest. Pretty impressive!
    Ron Throws the Big Switch!

    Ron Throws the Big Switch!

    If you'd like a tour of the new repeater, drop by on SHARC Field Day, which is held the last weekend in June.

    Special thanks to Jack - K3DMY, Ron - N3WX, Mark - N8UVQ, Jim - KA3EBX and to everyone that contributed to this project. Great job guys!

    The spirit of SHARC is strong!

    Photos by Ron - N3WX & Jim - KA3EBX.

    Update: 4/18/2005 - The Lentz family has graciously granted the use of Ron's call sign, N3WX to South Hills Amateur Radio Club. SHARC member, Mark Phillips, N8UVQ has been named as the trustee of the call sign, which will be used for various club events and will be used exclusively on the SHARC-3 repeater. South Hills ARC is extremely grateful to the Lentz family for letting SHARC use Ron's call sign. Those close to Ron knew how much Ron enjoyed being a part of South Hills Amateur Radio Club and we know he would be pleased to see his call used in this manner.

    The callsign of the SHARC-3 repeater was changed from KS3R to N3WX on 4/18/05.

    6-Meter Repeater Antenna at 50 Feet

    6-Meter Repeater Antenna at 50 Feet

    Update: 5/22/05 - Mark, N8UVQ, purchased a GaAsFET pre-amp for the repeater. On Sunday, May 22nd, Mark and Jim met at the repeater site at noon and installed an Advanced Receiver Research, Model P50VDG pre-amp. The pre-amp has +24 dB Gain. A 10 dB attenuator was added between the pre-amp's output and repeater's receiver input to prevent receiver front end overload.

    Update 7/10/05 - The pre-amp quit working several days ago. Karl-WE3Y, Mark-N8UVQ and Jim-KA3EBX went to the site and removed the pre-amp. Mark will be sending it back for repair.

    Mark, N8UVQ standing next to the SHARC-3 Repeater

    Mark, N8UVQ standing next to the SHARC-3 Repeater


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