Re: [Repeater-Builder] Portable repeater
Allen, Just for fun our club set-up a 250watt repeater w/o cans. We installed the transmit antenna on the roof top of the building. One floor down (its a tiered roof) we installed the receive antenna. We positioned the two antenna so that they were physically separated by the structure. The transmit antenna had full benefit of the highest point on the roof and the receive antenna had open views of about 270 degrees. We achieved about 100db attenuation. It was a compromise on receive but using the building structure allowed the two antennas to be about 70ft apart horizontally and 20ft vertically. It was a net experiment. We eventually installed six cans and used the receive antenna for another project. So, maybe you could use two antennas. Pick a street corner and use the building on the corner as your attenuation device ;-) Good Luck, dave wa3gin www.w4ava.org
Re: [Repeater-Builder] Portable repeater
Hi Allen, I am also in the process of building a portable repeater, however in the UHF band. I think several must have features would have to be: 1: Easy to setup. 2: 1 antenna 3. DTMF control (as you are already thinking) 4: 100% duty cycle I know you said you didnt want a duplexor, but there a mobile style units for the VHF band that will enable you to run a single antenna. The units do require quite a big frequency split (in the range of 40Mhz) but are still small enough to carry portable. They have about 1.5db of insertion loss and 72 db of isolation. Look at http://www.rfi.com.au/downloads/wireless/multicoupling/duplexer132_174.pdf Please post some pics when you are done and maybe some along the way. Thanks Greg VK2VGM --- On Mon, 8/3/09, vhsproducts captal...@aol.com wrote: From: vhsproducts captal...@aol.com Subject: [Repeater-Builder] Portable repeater To: Repeater-Builder@yahoogroups.com Date: Monday, August 3, 2009, 10:09 PM I am in the design stages for a portable VHF (2 meter ham) repeater, and thought I would solicit the views of the group for desired features. In broad strokes, we plan on a computer programmable unit, capable of one or two field selectable operation modes. CTCSS only, no COS or DTS. This is primarily to support our SAR users (I manufacture the Micro-Trak line of APRS tracking systems sold by Byonics-www. byonics.com) We will have DTMF remote control. The goal is a bare-bones repeater, with no provision for a duplexer, so wide channel separation and physically separate antennas will be a must. Battery power will be the norm, and I am thinking of a system with no more than 8 Watts output. What features are a must-have in this kind of a machine? What DTMF remote functions do we need as a minimum, and are there any features that we should have that other controllers don't offer? ( We will be writing our own code for the controller, an Atmega microprocessor) Has anyone ever attempted a servo controlled duplexer? Did it work? 73, Allen VHS AF60F
Re: [Repeater-Builder] Portable repeater
Packaging, ease of use and battery life are way up there on the list. Without addressing these issues, It's just another portable repeater Have a look at this. This is what we made for Emergency services http://www.signals.net.nz/special_offers/ Either VHF or UHF. Regards Gareth Bennett
Re: [Repeater-Builder] Portable repeater
Use a solar panel to keep a charge on the battery. if the repeater is only 5 watts then a small solar panel will do the trick easily. you can get a 120 watt panel or an array of smaller panels for portability which will charge the battery plus run the repeater all day and allow the system to operate through the night on battery power. Thanks, Rev. Robert P. Chrysafis I Recycle Computers Saving UnWanted PC's From The Landfill One Computer At A Time :) Note: I do Pickups the 1st week of the month. Owner: FreeStuffWarrenNJ Moderator: Hunterdonfree
Re: [Repeater-Builder] Portable repeater
if you go with 2 ant you will have a lot of coax to lug around !! if you could go to UHF the duplexer are smaller even 220 mhz ! unless you have a non Ham freq than you could run a mobile duplexer on VHF and have 2 of them and swap jumper cables in the box Good luck ! Rick On Tue, Aug 4, 2009 at 7:58 AM, Rev. Robert P. Chrysafiskc8...@hotmail.com wrote: Use a solar panel to keep a charge on the battery. if the repeater is only 5 watts then a small solar panel will do the trick easily. you can get a 120 watt panel or an array of smaller panels for portability which will charge the battery plus run the repeater all day and allow the system to operate through the night on battery power. Thanks, Rev. Robert P. Chrysafis I Recycle Computers Saving UnWanted PC's From The Landfill One Computer At A Time :) Note: I do Pickups the 1st week of the month. Owner: FreeStuffWarrenNJ Moderator: Hunterdonfree
RE: [Repeater-Builder] Portable repeater
We use a couple of M-10 radios turned down to 10W and a simple controller along with the duplexer with a solar panel and deep cycle battery for our portable repeater and it seems to work very well. Just make sure that you have a controller to charge the battery properly and that the solar cell can keep it charged on a full duty cycle for the repeater. GM300 or GR300 can be used as long as your not driving them at full power or you will burn up the finals. Peter Summerhawk -Original Message- From: Rev. Robert P. Chrysafis kc8...@hotmail.com Sent: Tuesday, August 04, 2009 5:58 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Portable repeater Use a solar panel to keep a charge on the battery. if the repeater is only 5 watts then a small solar panel will do the trick easily. you can get a 120 watt panel or an array of smaller panels for portability which will charge the battery plus run the repeater all day and allow the system to operate through the night on battery power. Thanks, Rev. Robert P. Chrysafis I Recycle Computers Saving UnWanted PC's From The Landfill One Computer At A Time :) Note: I do Pickups the 1st week of the month. Owner: FreeStuffWarrenNJ Moderator: Hunterdonfree [The entire original message is not included]
Re: [Repeater-Builder] Portable repeater
Allen, I'll echo the comments of those who've said 2m is not the best choice for a portable repeater, due to the required close frequency spacing. A 440 MHz repeater solves a number of problems regarding duplex operation. I built a solar-powered repeater a few years ago, and had to operate it on a very limited power budget. After looking at options, I used a Repco 2-watt UHF transmitter sourced from an RFID application, and a companion receiver. The transmitter drew only 650 mA at 1.8 watts output, and the receiver only another 22 mA in squelched standby. The controller was the most inefficient part of the package, drawing 100 mA continuous. Still, I had four days' reserve battery power even if the solar panel failed, assuming 100% duty cycle, using a group-27-sized deep-cycle marine battery, which was rated at 105 amp hours. If I had your needs, I'd do something similar, but using a much more power-efficient controller. This would allow using a much smaller battery. SAR outings often don't last more than a few days, so solar charging might not even be necessary, especially if you could occasionally visit the repeater site with a vehicle to recharge the battery. Also look into the options for small-scale wind turbines. There are mast-mount generators available in the recreational vehicle market that would easily hold up a small repeater in heavy use. They look a little pricey, and not terribly durable, but for this application they'd be great. When looking for a transmitter, do your homework to find one which is efficient at the power level you want. Most transmitters become very inefficient when run below their rated max output. Choose one that's running full-bore at the power level you need - it will use less current and dump less heat than a larger transmitter dialed back. Some small crystal-controlled receivers have very low current drain compared to their synthesized equivalents. Regarding control, there may be locations at which CTCSS access will save more battery current than the decoder draws. Especially if you're in the midst of a bunch of public service agencies running enough power to overload your receiver's front end, you're transmitter may stay up way more than it should. If you really must use 2m, my first choice would be to modify a pair of dual-band, full-duplex-capable handhelds to make a split-site repeater using a UHF link frequency. The receive site wouldn't take much in the way of mods...find a way to add a simple controller, and run low power with CTCSS or DCS on the UHF transmit. The other end would need some sort of external heatsink, and might need building a new enclosure for the radio, but you could have 2-5 watts continuous if you needed it. Separate the sites by a half-mile or more, and you're there. But UHF would be much cleaner, and faster and easier to set up. 73, Paul, AE4KR - Original Message - From: vhsproducts To: Repeater-Builder@yahoogroups.com Sent: Monday, August 03, 2009 11:09 PM Subject: [Repeater-Builder] Portable repeater I am in the design stages for a portable VHF (2 meter ham) repeater, and thought I would solicit the views of the group for desired features. In broad strokes, we plan on a computer programmable unit, capable of one or two field selectable operation modes. CTCSS only, no COS or DTS. This is primarily to support our SAR users (I manufacture the Micro-Trak line of APRS tracking systems sold by Byonics-www.byonics.com) We will have DTMF remote control. The goal is a bare-bones repeater, with no provision for a duplexer, so wide channel separation and physically separate antennas will be a must. Battery power will be the norm, and I am thinking of a system with no more than 8 Watts output. What features are a must-have in this kind of a machine? What DTMF remote functions do we need as a minimum, and are there any features that we should have that other controllers don't offer? ( We will be writing our own code for the controller, an Atmega microprocessor) Has anyone ever attempted a servo controlled duplexer? Did it work? 73, Allen VHS AF60F
RE: [Repeater-Builder] Portable repeater
Allen, Most portable repeaters for 2m are more like footlockers, often weighing more than 60 pounds- even without batteries. Such repeaters usually contain a full-size duplexer, in order to operate at a 600 kHz split. It is not practical to use two antennas at a 600 kHz split, because you'd need about 150 feet of vertical spacing or nearly 1.5 miles of horizontal spacing to achieve reasonable isolation- even with 8 watts of transmit power. Some coordinating bodies have already anticipated the need for low-power, portable 2m repeaters for temporary use, and have set aside a wide-spaced pair for that specific purpose. In California, TASMA has allocated a 2m pair that has a 2.655 MHz spacing: 147.585 MHz input and 144.930 MHz output. I have built a portable repeater to use that pair, with a Motorola R1225 full-duplex radio and a Celwave 5085-1 compact duplexer. Although the duplexer is specified for 3 MHz separation, it works flawlessly at the 10 watts output of the (low-power) R1225. I chose the R1225 because it has a built-in controller with IDer, and it draws very little power in idle. Best of all, the entire repeater, including duplexer, fits into a Pelican-style case that measures around one cubic foot. The duplexer info is here: www.rfsworld.com/dataxpress/DataSheets/?q=5085-1 I will write up a article about this project, once I have the time. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of vhsproducts Sent: Monday, August 03, 2009 10:09 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Portable repeater I am in the design stages for a portable VHF (2 meter ham) repeater, and thought I would solicit the views of the group for desired features. In broad strokes, we plan on a computer programmable unit, capable of one or two field selectable operation modes. CTCSS only, no COS or DTS. This is primarily to support our SAR users (I manufacture the Micro-Trak line of APRS tracking systems sold by Byonics-www.byonics.com) We will have DTMF remote control. The goal is a bare-bones repeater, with no provision for a duplexer, so wide channel separation and physically separate antennas will be a must. Battery power will be the norm, and I am thinking of a system with no more than 8 Watts output. What features are a must-have in this kind of a machine? What DTMF remote functions do we need as a minimum, and are there any features that we should have that other controllers don't offer? ( We will be writing our own code for the controller, an Atmega microprocessor) Has anyone ever attempted a servo controlled duplexer? Did it work? 73, Allen VHS AF60F
Re: [Repeater-Builder] Portable repeater
Towards reducing power consumption: Use the sleep mode on the processor. Set RF output power as a function of RSSI. Include multi-chemistry battery management. Include solar panel management. Include charge termination output; would drive a relay which would shut down a small generator which had been left running. 73 de KN6TD (s) Derek At 05:09 8/4/2009 +, you wrote: I am in the design stages for a portable VHF (2 meter ham) repeater, and thought I would solicit the views of the group for desired features. In broad strokes, we plan on a computer programmable unit, capable of one or two field selectable operation modes. CTCSS only, no COS or DTS. This is primarily to support our SAR users (I manufacture the Micro-Trak line of APRS tracking systems sold by Byonics-www.byonics.com) We will have DTMF remote control. The goal is a bare-bones repeater, with no provision for a duplexer, so wide channel separation and physically separate antennas will be a must. Battery power will be the norm, and I am thinking of a system with no more than 8 Watts output. What features are a must-have in this kind of a machine? What DTMF remote functions do we need as a minimum, and are there any features that we should have that other controllers don't offer? ( We will be writing our own code for the controller, an Atmega microprocessor) Has anyone ever attempted a servo controlled duplexer? Did it work? 73, Allen VHS AF60F
Re: [Repeater-Builder] Portable Repeater - A Case History
At 1/2/2005 09:03 PM, you wrote: Kevin, Yes, it is asymmetrical. Each of the three high-pass resonators has two black plastic plugs near the connector end, while the low-pass resonators each have one plastic plug. A Celwave engineer told me that the 5085-1 is manufactured to order, and that the coupling loops are factory-adjusted through these ports for optimum return loss at a particular split, and for a certain band segment. As a result, the 5085-1 is not really tunable over the entire high VHF band. I don't see that as a negative, since it was ordered specifically for this portable repeater application and is not likely to require retuning. 73, Eric Lemmon WB6FLY I'll have to take a closer look at mine (this is the one that I bought Kevin swept at Dayton '03). Turns out it's asymmetrical as well (84 dB notch on high freq., 69 dB on low). Loss is higher on the low side as well (1.8 vs. 1.1 dB), so tighter coupling on the low pass/high notch side makes sense. No need to make any changes for my application, though, since TX happens to be the low freq. And no that had nothing to do with which freq. was picked to be TX for the portapeater pair in the SoCal 2M bandplan! Bob NO6B Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Portable Repeater - A Case History
Kevin, Yes, it is asymmetrical. Each of the three high-pass resonators has two black plastic plugs near the connector end, while the low-pass resonators each have one plastic plug. A Celwave engineer told me that the 5085-1 is manufactured to order, and that the coupling loops are factory-adjusted through these ports for optimum return loss at a particular split, and for a certain band segment. As a result, the 5085-1 is not really tunable over the entire high VHF band. I don't see that as a negative, since it was ordered specifically for this portable repeater application and is not likely to require retuning. 73, Eric Lemmon WB6FLY Kevin Custer wrote: Eric Lemmon wrote: It comprises six helical resonators in a notch-only configuration. Its insertion loss at RX is 1.1 dB, and at TX is 1.4 dB. The notch depth at RX is 92.5 dB and at TX is 79.4 dB. These are very good numbers, better than what is needed for zero desense in this application, and are roughly equivalent to four 8 inch standard cavities at a 600 kHz split. Is it asymmetrical in design or what is the reason for the differing numbers between the two sides? At least the notch of the transmitter side-band noise is the big number. Kevin Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Portable Repeater - A Case History
Eric Lemmon wrote: It comprises six helical resonators in a notch-only configuration. Its insertion loss at RX is 1.1 dB, and at TX is 1.4 dB. The notch depth at RX is 92.5 dB and at TX is 79.4 dB. These are very good numbers, better than what is needed for zero desense in this application, and are roughly equivalent to four 8 inch standard cavities at a 600 kHz split. Is it asymmetrical in design or what is the reason for the differing numbers between the two sides? At least the notch of the transmitter side-band noise is the big number. Kevin Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
