Steve, I wonder if you're "fixing" the wrong part of your repeater. Repeater coverage is limited *primarily* by the ability of the repeater to receive the distant (usually portable) stations, not by the transmitter power. The Vertex/Yaesu VXR-5000 repeater does not have a very good receiver- I have one in service, and I know that it is its weak point.
Before you spend any money trying to increase the power output, try adding a good preamplifier such as an Angle Linear PHEMT with a couple of bandpass cavities between it and the duplexer. When I did exactly this mod on my VXR-5000, the range improvement was phenomenal. Don't expect a cheap Ramsey or Hamtronics preamp to equal the Angle Linear unit. The bandpass cavity filter is a critical part of the solution. I use two 8-inch cavities in series, with the insertion loss set for 0.5 dB on each cavity. I generally use a 6 dB attenuator on the output of the preamp, but that value can vary. 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of stephenucedu Sent: Monday, December 25, 2006 9:10 AM To: [email protected] Subject: [Repeater-Builder] local club needs repeater amp I am new to the group, and just wanted to know if anyone had a 200-250 watt amp for sale for our 2-meter repeater. The core of the system is the Vertex 5000, but its output is 25 watts, and after the duplexer, there just isn't enough coverage to match the receivers that we use. We had a 100 watt Motorola for years and kept saying that we needed to increase the output and improve the transmit antenna/location. Well, that amp went down, but we have everything else in place now. There is no size limitation, so a big amp is fine. The Motorola 1/4 k amp that was recently posted would have been perfect, but looks like it's gone. Thanks, Steve WA4BVO
