SARA Repeater Information

The Schenectady Amateur Radio Association operates the K2AE family of repeaters located at the top of Crawford Hill in Schenectady County near NY State Thruway exit 26. There are presently repeaters on the 2-meter, 1.25-meter, and 70-cm bands. The 2-meter repeater has been in operation continuously since 1962, over 38 years of on the air service.

Repeater(s) Quick Reference

Band	User Transmit Frquency	User Receive Frequency
6-Meters	52.570 MHz	53.570 MHz
2-Meters	147.660 MHz	147.060 MHz
1.25-Meters	222.460 MHz	224.060 MHz
70-Centimeters	449.200 MHz	444.200 MHz

Thanks to Howard Lester, W2ODC, for the following information:

Site Characteristics and Features

Height of ground above average sea level: 1320 feet

HAAT: approx 800 feet; but is about 1300 feet to the North and East

Lightning Protection: full Polyphaser protection ensemble; rigs on wooden platform; heavy ground plate with common tiepoint; all per Polyphaser design engineering specifications

Emergency Power: Two automatic engine-generators, one of which kicks in on drop in line voltage, and stays on for about 15 minutes after power is restored. If one generator doesn't start immediately, the second engine-generator is started. About 15 seconds start time is allowed before the generator is switched in to pick up the load. About one-two weeks of propane fuel is in an outdoor tank.

2-METER REPEATER

Input frequency: 147.660 MHz
Output frequency: 147.060 MHz

Equipment:

Transmitter/Receiver: GE MSTR-II; all solid state
Rx Preamp: ARR GasFet
Repeater Controller: Model 7K
Remote control link: landline and UHF radio
Duplexer: 6-cavity Decibel Products plus one cavity each (bandpass) on transmitter and receiver
Transmission Line: 180 feet of 7/8 " hardline
Antenna: 6 dBd broadband, fixed 4-folded dipole array by Sinclair Labs
Height on tower: approx 160 feet

Performance:

Transmitter Power Output: set down to 75 watts
ERP: 200 watts
Radiation Pattern: Flattened elliptical with major axis northeast-southwest; about one dB down North-South.
Rcvr sensitivity: 0.18 uV for 12 dB SINAD
Duplexer isolation between rcvr and xmtr: better than 120 dB
Duplexer/filter loss: approx 1.8 dB
Carrier operated Relay: NO CTCSS USED.

Coverage: East to about milepost 10 on Mass Pike (I-90);West to about Canojoharie, and Ft. Plain to Mohawk; North to about Ft. Ann and Whitehall; to Warrensburg on Northway (I-87) to Speculator north on Rte #30. South to about Claverack on the East side of the Hudson River; to New Baltimore on the West side of the Hudson River.

NOTE: This has been observed from "signals of opportunity" with the new antenna and location on the tower; new coverage maps have not been taken from more formal measurements.

1.25-METER REPEATER

Input frequency: 222.460 MHz
Output frequency: 224.060 MHz

Equipment:

Transmitter: Yaesu 220 Mobile with KLM amplifier with added fans
Receiver: GE Progress Line converted to 220 MHz by WA2GBO
Rx Preamp: ARR GasFet
Audio and control interference: Custom designed and built by WA2AAU
Duplexer: 4-cavity; made from Air Force surplus cavities Isolation between rcvr and xmtr about 75 dB
Feedline: 7/8" hardline, approximately 190 feet long
Antenna: Celwave Station Master, 6 dB gain.
Height on tower: about 175 feet up on the same tower as 2-m rptr.

Performance:

Transmitter Power Output: about 60 watts
ERP: Approx 200 watts
Rcvr sensitivity: effective sensitivity approx 0.35 microvolts for 12 dB SINAD.
Radiation Pattern: omnidirectional; 5.8 dBd gain
Duplexer isolation between rcvr and xmtr: about 75dB

Coverage: Approximately that of the 2-meter repeater; some places better, some worse. Fill-in around the Canajoharie area is better for the higher frequency 220 MHz repeater than the 2-meter repeater. The increased height of about 20 feet for the 220 MHz repeater on same tower is felt to be inconsequential.

70 - CENTIMETER REPEATER

Transmit frequency: 444.200 MHz
Receive frequency: 449.200 MHz

Equipment:

Transmitter/Receiver: GE MSTR-II
Rx Preamp: ??
Remote control link: ??
Duplexer: 4-cavity
Feedline: ??
Antenna: 10 dBd Sinclair, 8-el
Height on tower: 200 ft

Performance:

Transmitter Power Output: about 75 watts (52 watts out of duplexer)
ERP: Approx 300 watts
Rcvr sensitivity: 0.35 uV @ 12 dB SINAD
Radiation Pattern: ??
Duplexer isolation between rcvr and xmtr: ?? dB

Coverage (partially checked): Good communication at Burlington line, poor downtown. Good at Whitehall, Glens Falls, Cobleskill; fair to Worcester down I-88. Covers Capital District except notch in line through Crossgates. Poor at Exit 23 on Thruway. Good Johnstown, Amsterdam, Gloversville. The notch is due to tower shadow with antenna side-mounted, close to tower.