VE3RNR - Fonthill
| Location: | Lookout Village, Fonthill, ON |
| Sponsor: | The Tenants of Lookout Village |
| Custodian: | VA3UL |
| System Hardware: | G.E Master II @ 60 watts Pacific Research R1300 controller Sinclair Duplexer Battery backup Sinclair SD318H |
| Voter: | None planned at this time. |
| Frequency: | Input: 448.175 MHz FM (CTCSS 107.2 Hz) Output: 443.175 MHz FM (CTCSS 107.2 Hz) |
| Notes: | As resources become available, VE3RNR will be interconnected to other NPARC repeaters. |
VE3RNR - News
VE3RNR Duplexer Replaced
The Duplexer on the UHF repeater VE3RNR in Fonthill was replaced this morning by Dave, VA3UL. Tests done earlier indicated abnormal power losses and it was traced to the Duplexer. Dave gives us some insight about the duties of a duplexer in a radio repeater below.
The Duplexer device serves a critical role in a repeater. To make a long story short, the duplexer separates and isolates the incoming signal from the outgoing and vice versa. Even though the repeaters input and output frequencies are different, the duplexer is still needed. Why? Have you ever been in a place where there's lots of RF activity, and noticed the receive performance of your radio degrades to some degree? This is called desensitization, or desense, and it's a bad thing on a repeater. The receiver goes deaf or gets desensitized from the strong RF signals being radiated in its vicinity and confused about which signal it should receive. The result is poor receive quality, or in extreme cases, complete lack of receive capability. Keep in mind that in this example, the radios are picking up radiated power from one another and that's enough to cause trouble. Now imagine how much trouble there will be if you not only have the transmitter and receiver close together, but connect them to the same antenna! Transmitting only a few hundred kHz away in frequency would blow away the input to the receiver if the equipment was simply connected together with a Tee. That's where the duplexer comes in; it prevents the receiver and transmitter from 'hearing' one another by the isolation it provides.
A duplexer is a device that is referred to by several different names like cavities or cans. A duplexer has the shape of tall canisters and is designed to pass a very narrow range of frequencies and to reject others. There is some loss to the system because of the duplexer, however, the advantage of being able to use a single antenna usually outweighs the drawbacks.
Thank-you for your information Dave.
Peter, VA3WET
Wednesday, December 6th, 2006
VE3RNR Repeater Coverage Improved
In an early morning assault on Friday November 24th, Dave, VA3UL, Conrad, VE3LOS and Peter, VA3WET went down to Fonthill and did some antenna work on the 440 repeater, VE3RNR. Conrad, equipped with safety harness and nerves of steel climbed the tower and managed to loosen the clamps with little difficulty. He then rotated the antenna approximately 90 degrees thus bringing St. Catharines into it's radiation footprint. Preliminary tests by Dave, VA3UL indicate that reception is greatly improved into St. Catharines. Users may now find less sensitivity into the Grimsby and Oakville area. Photos to follow.
Peter, VA3WET
November 26th, 2006
