Re: [Repeater-Builder] Micor VHF 12W Amplifier??
Yes, they were commonly used to drive the bigger 330W Tube-type amplifiers. I have some in the VHF band. You may consider using a Japanese power module. (commonly found in mobile rigs) These modules are VERY efficient and are well suited for solar power applications. They can be found at rfparts.com. You'll need to look for one with the output power you desire at the input power you need. Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 tahrens301 wrote: Hi Folks, I've been looking into making a solar repeater (from the Micor repeaters that I already have on hand). Obviously the 100W or 60W amplifiers are out of the question, not only in power, but really in size. I noticed that there is some silkscreen on the transmitter interconnect board (in the big hole to the right of the exciter) that says 12WPA. Didn't know whether Mot actually had put a low power amplifier into the space or not. Anybody know? Thanks, Tim Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.430 / Virus Database: 270.14.116/2579 - Release Date: 12/21/09 07:36:00
Re: [Repeater-Builder] Micor VHF 12W Amplifier??
Yes, Motorola made a TLE1683 for 450-470 and a TLE1681 for 406-420 both 12 watt. Sent from my Verizon Wireless BlackBerry -Original Message- From: tahrens301 tahr...@swtexas.net Date: Mon, 21 Dec 2009 20:54:08 To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor VHF 12W Amplifier?? Hi Folks, I've been looking into making a solar repeater (from the Micor repeaters that I already have on hand). Obviously the 100W or 60W amplifiers are out of the question, not only in power, but really in size. I noticed that there is some silkscreen on the transmitter interconnect board (in the big hole to the right of the exciter) that says 12WPA. Didn't know whether Mot actually had put a low power amplifier into the space or not. Anybody know? Thanks, Tim
Re: [Repeater-Builder] Micor VHF 12W Amplifier??
Please disregard last. I missed the VHF in the header. Sorry. Sent from my Verizon Wireless BlackBerry -Original Message- From: tahrens301 tahr...@swtexas.net Date: Mon, 21 Dec 2009 20:54:08 To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor VHF 12W Amplifier?? Hi Folks, I've been looking into making a solar repeater (from the Micor repeaters that I already have on hand). Obviously the 100W or 60W amplifiers are out of the question, not only in power, but really in size. I noticed that there is some silkscreen on the transmitter interconnect board (in the big hole to the right of the exciter) that says 12WPA. Didn't know whether Mot actually had put a low power amplifier into the space or not. Anybody know? Thanks, Tim
Re: [Repeater-Builder] Micor VHF 12W Amplifier??
tahrens301 wrote: .snip. I noticed that there is some silkscreen on the transmitter interconnect board (in the big hole to the right of the exciter) that says 12WPA. Didn't know whether Mot actually had put a low power amplifier into the space or not. Anybody know? Hi Tim, Yes, the 12 watt PA was used in UHF Stations in that location. On VHF, the amplifier was usually mounted externally - usually in the form of a mobile heat sink mounted into the rack above the Unified Chassis. The VHF 12 watt PA was commonly used to driver higher level tube-type PA's. The MICOR series is not known for its efficiency, especially when commercial frequency range gear is tuned into the ham band without being properly converted. That being said, there are several things that you can do to improve the power efficiency. I don't believe the exciter itself is terribly inefficient, as it uses an unheated channel element. The tuning of the exciter into the ham band usually results in factory specification performance without modification, the exciter filter and PA are another story. Modification of the exciter filter is usually not difficult, but the PA conversion can be. So, since you only want a small amount of transmitter power, you might want to look into using a Japanese Power Brick for the PA; as they are usually very power efficient. Repeater Builder makes a little circuit board to aide in the use of such a module for this type of purpose. http://www.repeater-builder.com/products/ The receiver can be made to have better power efficiency by removing the B+ from the audio power amplifier. Since these circuits are Class A/B, they draw current all the time. In solar applications I usually place a SPST switch in the B+ lead to the audio power amp so the current can be cut off when it's not in use. There is a bunch of other circuitry that you might also consider eliminating, like any cards that may no longer serve any useful purpose. Most repeaters can be built to deliver the necessities to a controller and the rest of the support circuitry can be gotten rid of. The NHRC Micro is a really good controller choice where power consumption is concerned. The Micro installed in a MICOR allows solid RF technology to be interfaced with a modern controller. http://www.nhrc.net Good luck with the project, Kevin Custer
Re: [Repeater-Builder] Micor VHF 12W Amplifier??
Hi Scott, Thanks for the info... I've got a board with an older Motorola RF module on it (plus a couple of spares). I think that I might use that board, else I'll checkout the boards here on R-B. Got to thinking that I'd like to make it a 20w repeater, so the 12w strip wouldn't work anyhow. I'll probably start working on the power reduction tomorrow.. I do micro design software for a living, have written many small micro jobs, including some small repeater controllers. Shouldn't take too much code, as the requirements are quite small for what I want to do. Thanks again!! Tim
