Repeater Descriptions – EPARC

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  - Repeater DescriptionsHow did we get here and where are we going? After several years of weak signal operating on the 222 MHz band, a number of club members proposed that EPARC activate a 222 MHz FM repeater. The purpose of the repeater is to provide communications among the club members, develop the untapped resource of the 222 MHz band, and provide another somewhat esoteric endeavor for club members. The repeater system is being developed in several stages based on available time and resources. Thanks to all who have donated hardware, money, and/or time to this project. Plans are initially to install a single-site system later followed by the addition of satellite receivers and/or additional repeaters on the same band. Technical performance and reliability are primary considerations. Coverage Maps The following maps were generated using the Radio Mobile software package written by VE2DBE. The signal strength legend is at the top of each map. White indicates areas without coverage. All other colors represent covered areas. Blues indicate marginal signal strength. Greens, yellows, and reds indicate “solid” coverage areas. Repeater Transmitter Maps 250 Watts to 9 dBd Antenna (DB264, 4-pole) at 24 Meters on East side of the Martinsburg, WV 97.5 MHz tower…
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  - MiscellaneousFrom Rohde & Schwarz, here’s an excellent treatise on the the decibel (db) and its applications. From the RF Designline web site here’s a 3-part series titled Understanding RF Instrument Specifications. There is lots of good information on various RF measurements and specifications. Part 1 Part 2 Part 3 They’re not hen’s teeth, but omnidirectional VHF/UHF/SHF antennas are more difficult to find than high-gain directional antennas. Both have their place in weak signal work. Some sources include: WIMO maker of the Big Wheel, The Olde Antenna Lab, and KU4AB Antennas. GM3SEK’s Amateur Radio Technical Notebook contains a broad range of good VHF/UHF reference information including information on antenna stacking. RF Measurement Basics for Non-RF Test Engineers is an article from the November 2006 issue of Evaluation Engineering Magazine written by Robert Green of Keithley Instruments. The Care and Feeding of the R.F. Isolator on the EMR web site is an excellent treatise on the theory and application of RF isolators. RF Cafe is a unique portal of RF, microwave, wireless, and other engineering resources. Vast collection of equations, references and conversions for electrical, mechanical, physical, and mathematical fields. Links for vendors, app notes, test notes, ham radio, magazines, books, active…
- QSL RequestsA self-addressed stamped envelope (S.A.S.E.) is required for all QSL’s. K8EP was issued to EPARC in May of 2004, therefore, the following rules apply: If your QSO was in May 2004 or later: QSL requests should be sent to W3STU at the address listed on QRZ.COM If your QSO was in May 2002 or before: QSL requests should be sent to N1UR at the address listed on QRZ.COM . (The former holder of the call K8EP changed his call to N1UR in May of 2002.)
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- AboutSelect a topic from the drop-down About menu above.
- HistoryIn a February 2006 letter from Jim (KW8I) to Stu (W3STU), Jim stated the following about the genesis of EPARC: “In July of 1990, Dave (KF8FL) Hartman approached me about forming a new radio club. I thought it was a good idea, as long as it would be less formal than other clubs, we would get involved in field day, and VEC activities. We each began to check with the other hams, and found that there was a lot of interest. A few of us met informally and planned the first meeting in August of 1990. Our first field day was in June of 1991.” Trivia Tidbit: The call sign originally issued to EPARC was KB3KEU. It was a 3rd district call because the club mailing address was that of the club secretary W3STU in Boonsboro, MD. After receiving that call, we applied immediately for and received the call K8EP. KB3KEU was never used on the air. If you have any historical data about EPARC such as newsletters, photographs, newspaper articles, artifacts, or even stories about club events, members, or former members, please e-mail them to the address above (or “snail mail” them to the K8EP club address on QRZ.COM)…
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How did we get here and where are we going?

After several years of weak signal operating on the 222 MHz band, a number of club members proposed that EPARC activate a 222 MHz FM repeater. The purpose of the repeater is to provide communications among the club members, develop the untapped resource of the 222 MHz band, and provide another somewhat esoteric endeavor for club members.

The repeater system is being developed in several stages based on available time and resources. Thanks to all who have donated hardware, money, and/or time to this project. Plans are initially to install a single-site system later followed by the addition of satellite receivers and/or additional repeaters on the same band. Technical performance and reliability are primary considerations.

Coverage Maps

The following maps were generated using the Radio Mobile software package written by VE2DBE. The signal strength legend is at the top of each map. White indicates areas without coverage. All other colors represent covered areas. Blues indicate marginal signal strength. Greens, yellows, and reds indicate “solid” coverage areas.

Repeater Transmitter Maps

250 Watts to 9 dBd Antenna (DB264, 4-pole) at 24 Meters on East side of the Martinsburg, WV 97.5 MHz tower to mobile using 5/8 wavelength vertical and 1 uV sensitivity

250 Watts to 9 dBd Antenna (4-pole) at 60 Meters on North side of the Martinsburg, WV 97.5 MHz tower to mobile using 5/8 wavelength vertical and 1 uV sensitivity

200 Watts to 6 dBd Antenna (G7-220) at 60 Meters on North side of the Martinsburg, WV 97.5 MHz tower

To mobile using 5/8 wavelength vertical and 1 uV sensitivity

To HT using rubber ducky and 1uV sensitivity

Repeater Receive Maps

Coverage using a 9 dBd Antenna (DB264, 4-pole) at 24 Meters on East side of the Martinsburg, WV 97.5 MHz tower

From Mobile using 25 Watts and 5/8 wavelength vertical

Coverage using 6 dBd Antenna (G7-220) at 7 Meters on mast on the building of the Martinsburg, WV 97.5 MHz. This represents the predicted receive coverage as installed on November 16, 2005

From Mobile using 25 Watts and 5/8 wavelength vertical

Combined coverage using 6 dBd Antenna (G7-220) at 60 Meters on North side of the Martinsburg, WV 97.5 MHz tower and 6 dBd antenna at 10 meters at the Frederick, MD 103.1 MHz site

From Mobile using 25 Watts and 5/8 wavelength vertical

From HT using 1 Watt and rubber ducky

Coordination

The following forms were submitted electronically to TMARC on April 25, 2005 in order to establish coordination for the repeater. Some of the data looks odd (e.g., RG-58 transmission line), this is due to problems in the TMARC electronic registration process.

Application for Frequency Coordination (PDF format)

Technical Data Survey (PDF format)

E-mail and Information Form (PDF format)

Construction Permit and Certification of Operational Status (PDF format)

Coordination documents for the Frederick to Martinsburg UHF link:

Application for coordination (PDF format)

Construction Permit from T-MARC (PDF format)