Re: [Repeater-Builder] Mastr II mods and parts
Nate thanks for the info, when put into those terms it makes it obvious I should run the PA maybe just turn it down a bit. I am not sure what kind of duplexers I am going to run so thats still a part of the equasion I do not know yet. Thanks for the words of wisdom it is very helpfull. Greg K9GJN --- On Wed, 1/6/10, Nate Duehr n...@natetech.com wrote: From: Nate Duehr n...@natetech.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 4:27 AM On Jan 5, 2010, at 8:22 PM, Greg Niles wrote: Thanks for the reply Richard. I have the GE 110 watt PA I only antipate needing around 35 watts not going to build a power house just a locat repeater. I know I can detune the PA was just trying to cut out the PA for simplicity purposes if that is possible. Greg K9GJN Greg, Do you want 35W of RF to the antenna AFTER the duplexer? You'll have to put in more than 35W to get 35W out to the antenna in a duplexed system, of course. Or are you really saying that you want 35W into the duplexer where you'll probably only have 10-15W at the antenna after that? (Okay that's an exaggeration but have you forgotten that a duplexer is relatively a very lossy device in your TX chain?) The 110W VHF MASTR II hooked into a properly designed and built antenna system, with low-loss hardline feeding the antenna (and usually backed off a bit from 110W... no need to run it flat out, but you can... they're rated for it), proper low-loss jumpers to the duplexer/antenna system, etc... usually yields just about the right amount of power to make a system balanced with 50W mobiles accessing it. Unless you're purposely trying to restrict the coverage area to where a modern 50W mobile with a typical modern sensitivity receiver can't hear the repeater very well where it can still access it, I'd leave the 110W PA on it. For a MASTR II, the stock .25uV sensitivity of the receiver (if you tune carefully and get factory spec out of it) will mean you usually need to do some work on the receive side (adding a very low noise pre-amp and appropriate large high-Q bandpass cavity in RF noisy environments. ..) to bring the receiver sensitivity up to where HT's can get into it pretty nicely in most of its coverage area in flat-land at 110W, and you'll get those HT's in fine in virtually ALL of it's coverage area if it's up high (mountain, really tall building, etc.) GE built it as a 110W repeater for a reason... think about the users at the time... relatively deaf trunk-mounted radios (made up of the EXACT same components as the repeater) in Public Safety vehicles with external antennas... also often running 110W non-continuous- duty... Anyway, to get back to your question... the UHF 100W PA is hackable where you can easily remove the driver stages and get a lower wattage PA - useful for links, etc... that you know don't need the power. But the VHF has a feedback circuit between the driver section and the first amplification section that must be dealt with to do a similar modification. Just run 'er flat out or up around 85-95W... also consider putting an isolator on it, especially if yours doesn't have the late-model Z-matcher in the Low-Pass-Filter near the PA's output. The VHF is especially sensitive to not being driven into a 50 ohm load and they tend to burn up when they're not. The factory Z-matcher was supposed to alleviate this, but their tuning instructions for the thing leave something to be desired. Easier/more effective to just put an isolator on the PA output with proper filtering... . again, eating some of your RF... so 110W starts to look just about right again... -- Nate Duehr, WY0X n...@natetech. com http://facebook. com/denverpilot http://twitter. com/denverpilot
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: Ralph (and others) So is there a IDA equipped version the controller? If not, what does it mean that I have the IDA equiped version? The IDA version of the MASTR II station was (originally) controlled by a means other than the usual plug-in cards. What you bought is okay, but maybe not the preferred version for building a stand-alone repeater. Does that mean I need, for example, a different duplexer? No, it has nothing to do with the duplexer - or anything RF for that matter. When we build repeaters from surplus equipment, most of us rip out the original control circuitry and connect an after market repeater controller of some sort. Many have mentioned the Pion Simon units because they plug right in, but not to the model of station you bought from eBay. That being said, either of the NHRC GE controllers will plug-in to one you bought. The conversion you'll do to this station to make a repeater will likely more closely follow one written for a mobile - as you'll be using the Systems Board for controller interface if you choose a plug-in NHRC model. If you choose some other controller - it'll have to be wired in making it a bit more difficult. Kevin Custer
Re: [Repeater-Builder] Mastr II mods and parts
You can make the IDA controller MASTRII work for you, but you aren't going to find a drop-in controller. Look at: http://www.qsl.net/w4xe/rpttech/rpttech21.htm for some good information about how to do it. I have a UHF MASTRII with an IDA controller here that has been an ongoing project for many years. It keeps getting pushed to the back of the pile, mainly because the Maggiore repeater that the MASTRII is suppose to replace never failed. The IDA controller came in several versions, I have the repeater version in mine. You must leave the IDA controller in place because it supplies the 10 Volts DC that is required to run the MASTRII. I would leave the IDA controller functional, except for cutting the PTT lead to the transmitter. That way you can use the speaker in the IDA controller for a monitor. I plan to leave my IDA functional and have it as a back-up controller that I can switch online. 73, Joe, K1ike Michael Cox wrote: Ralph (and others) So is there a IDA equipped version the controller? If not, what does it mean that I have the IDA equiped version?
Re: [Repeater-Builder] Mastr II mods and parts
I leave my IDA controller intact, just put the repeat switch in the inhibit position. All necessary connections can be made to the repeater for an external controller on the two Molex connectors on the upper left side of the rear of the chassis. I use the unused frequency select pins to bring out the rest of the connections needed to the system board. Jumpers from the freq select pins where they extend through the system board connect to the audio and COS pins on the receiver board that extend through the system board. I use the old style sockets from miniature tube sockets to push over the pins extending through the system board. Mic and PTT terminals already exist on the Molex connectors. If the external controller fails, just unplug it from the Molex connectors and move the repeat switch on the IDA controller back into the repeat position for emergency operation. 73 - Jim W5ZIT --- On Tue, 1/5/10, Joe k1ike_m...@snet.net wrote: From: Joe k1ike_m...@snet.net Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Tuesday, January 5, 2010, 8:22 AM You can make the IDA controller MASTRII work for you, but you aren't going to find a drop-in controller. Look at: http://www.qsl. net/w4xe/ rpttech/rpttech2 1.htm for some good information about how to do it. I have a UHF MASTRII with an IDA controller here that has been an ongoing project for many years. It keeps getting pushed to the back of the pile, mainly because the Maggiore repeater that the MASTRII is suppose to replace never failed. The IDA controller came in several versions, I have the repeater version in mine. You must leave the IDA controller in place because it supplies the 10 Volts DC that is required to run the MASTRII. I would leave the IDA controller functional, except for cutting the PTT lead to the transmitter. That way you can use the speaker in the IDA controller for a monitor. I plan to leave my IDA functional and have it as a back-up controller that I can switch online. 73, Joe, K1ike Michael Cox wrote: Ralph (and others) So is there a IDA equipped version the controller? If not, what does it mean that I have the IDA equiped version?
Re: [Repeater-Builder] Mastr II mods and parts
I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN
Re: [Repeater-Builder] Mastr II mods and parts
No. You need the appropriate power amplifier to get the desired output. The exciter makes less than one watt. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@yahoogroups.com Sent: Tuesday, January 05, 2010 9:33 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00
Re: [Repeater-Builder] Mastr II mods and parts
Thanks Chuck, that answers my qustion. Any other pointers would be appreciated. Greg K9GJN --- On Wed, 1/6/10, Chuck Kelsey wb2...@roadrunner.com wrote: From: Chuck Kelsey wb2...@roadrunner.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 2:45 AM No. You need the appropriate power amplifier to get the desired output. The exciter makes less than one watt. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, January 05, 2010 9:33 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00
Re: [Repeater-Builder] Mastr II mods and parts
Hi Greg, There is no Mod to make the exciter do 35 watts. Its nominal value is about 200 to 300 mw, but normally 250 mw. The way to get about 35 watts is to modify the PA itself. You can bypass the final stages of the PA and just use the first stage. There are many types and some may get you close just of the driver stage. But then again like I say, there are many types to look at that have different configurations. The first question is what is the output of the PA you have? We would need to see the type and give you some guidance from that point of what is the best option. Maybe even a picture or the part number of that PA would help. Best Regards Richard. From: Greg Niles k9...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Tue, January 5, 2010 9:33:59 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN
Re: [Repeater-Builder] Mastr II mods and parts
You need to check this site for a wealth of info on repeater building. http://www.repeater-builder.com/rbtip/ Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@yahoogroups.com Sent: Tuesday, January 05, 2010 9:50 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Thanks Chuck, that answers my qustion. Any other pointers would be appreciated. Greg K9GJN --- On Wed, 1/6/10, Chuck Kelsey wb2...@roadrunner.com wrote: From: Chuck Kelsey wb2...@roadrunner.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 2:45 AM No. You need the appropriate power amplifier to get the desired output. The exciter makes less than one watt. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, January 05, 2010 9:33 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00 -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00
Re: [Repeater-Builder] Mastr II mods and parts
Oh, and since you sound like you are new to this list, don't use LMR or 9913 type coax in duplex service. This topic comes up here every couple of weeks. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@yahoogroups.com Sent: Tuesday, January 05, 2010 9:50 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Thanks Chuck, that answers my qustion. Any other pointers would be appreciated. Greg K9GJN --- On Wed, 1/6/10, Chuck Kelsey wb2...@roadrunner.com wrote: From: Chuck Kelsey wb2...@roadrunner.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 2:45 AM No. You need the appropriate power amplifier to get the desired output. The exciter makes less than one watt. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, January 05, 2010 9:33 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00 -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00
RE: [Repeater-Builder] Mastr II mods and parts
Greg, You've come to the right place for information. First off, the exciter is just that- it is a very low-power (1/4 to one watt) signal source that is intended to drive any of several power amplifiers, from as low as 10 watts to more than 200 watts. It is not practical to modify the exciter; you simply add the appropriate PA to achieve the power output you want. If your repeater is completely stock please advise what the Combination Number is on the data plate. This will help the list members understand what you now have. Has this repeater been modified for Amateur 2m use already, or is it now on a commercial pair and you want to modify it for 2m operation? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Greg Niles Sent: Tuesday, January 05, 2010 6:34 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building. I have a GE Mastr II VHF repeater. Does GE make, or is there a mod to make, the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple? Any input would be greatly appreciated. Thanks, Greg K9GJN
Re: [Repeater-Builder] Mastr II mods and parts
I have read those very big topics, thanks Chuck Greg K9GJN --- On Wed, 1/6/10, Chuck Kelsey wb2...@roadrunner.com wrote: From: Chuck Kelsey wb2...@roadrunner.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 3:01 AM Oh, and since you sound like you are new to this list, don't use LMR or 9913 type coax in duplex service. This topic comes up here every couple of weeks. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, January 05, 2010 9:50 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Thanks Chuck, that answers my qustion. Any other pointers would be appreciated. Greg K9GJN --- On Wed, 1/6/10, Chuck Kelsey wb2...@roadrunner. com wrote: From: Chuck Kelsey wb2...@roadrunner. com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@ yahoogroups. com Date: Wednesday, January 6, 2010, 2:45 AM No. You need the appropriate power amplifier to get the desired output. The exciter makes less than one watt. Chuck WB2EDV - Original Message - From: Greg Niles To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, January 05, 2010 9:33 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.126/2602 - Release Date: 01/05/10 14:35:00
Re: [Repeater-Builder] Mastr II mods and parts
Thanks for the reply Richard. I have the GE 110 watt PA I only antipate needing around 35 watts not going to build a power house just a locat repeater. I know I can detune the PA was just trying to cut out the PA for simplicity purposes if that is possible. Greg K9GJN --- On Wed, 1/6/10, Richard Fletcher rickfle...@yahoo.com wrote: From: Richard Fletcher rickfle...@yahoo.com Subject: Re: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 2:53 AM Hi Greg, There is no Mod to make the exciter do 35 watts. Its nominal value is about 200 to 300 mw, but normally 250 mw. The way to get about 35 watts is to modify the PA itself. You can bypass the final stages of the PA and just use the first stage. There are many types and some may get you close just of the driver stage. But then again like I say, there are many types to look at that have different configurations. The first question is what is the output of the PA you have? We would need to see the type and give you some guidance from that point of what is the best option. Maybe even a picture or the part number of that PA would help. Best Regards Richard. From: Greg Niles k9...@yahoo. com To: Repeater-Builder@ yahoogroups. com Sent: Tue, January 5, 2010 9:33:59 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN
RE: [Repeater-Builder] Mastr II mods and parts
Thanks Eric, its a commercial unit not yet modified what mods would you recommend I do not have a data plate but found the following numbers on the recieve of 19D416693G2 REV and x mitt PL1D4172G6I REV if that tells you anything. I am looking at the PSE-508-2 controler. I have the old ICOMS but they will need to be changed obviously. I have the 110 PA and a GE power supply also the 10 V control card. Thanks Greg K9GJN From: Eric Lemmon wb6...@verizon.net Subject: RE: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Wednesday, January 6, 2010, 3:15 AM Greg, You've come to the right place for information. First off, the exciter is just that- it is a very low-power (1/4 to one watt) signal source that is intended to drive any of several power amplifiers, from as low as 10 watts to more than 200 watts. It is not practical to modify the exciter; you simply add the appropriate PA to achieve the power output you want. If your repeater is completely stock please advise what the Combination Number is on the data plate. This will help the list members understand what you now have. Has this repeater been modified for Amateur 2m use already, or is it now on a commercial pair and you want to modify it for 2m operation? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@ yahoogroups. com [mailto:Repeater-Builder@ yahoogroups. com] On Behalf Of Greg Niles Sent: Tuesday, January 05, 2010 6:34 PM To: Repeater-Builder@ yahoogroups. com Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building. I have a GE Mastr II VHF repeater. Does GE make, or is there a mod to make, the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple? Any input would be greatly appreciated. Thanks, Greg K9GJN
Re: [Repeater-Builder] Mastr II mods and parts
On Jan 5, 2010, at 8:22 PM, Greg Niles wrote: Thanks for the reply Richard. I have the GE 110 watt PA I only antipate needing around 35 watts not going to build a power house just a locat repeater. I know I can detune the PA was just trying to cut out the PA for simplicity purposes if that is possible. Greg K9GJN Greg, Do you want 35W of RF to the antenna AFTER the duplexer? You'll have to put in more than 35W to get 35W out to the antenna in a duplexed system, of course. Or are you really saying that you want 35W into the duplexer where you'll probably only have 10-15W at the antenna after that? (Okay that's an exaggeration but have you forgotten that a duplexer is relatively a very lossy device in your TX chain?) The 110W VHF MASTR II hooked into a properly designed and built antenna system, with low-loss hardline feeding the antenna (and usually backed off a bit from 110W... no need to run it flat out, but you can... they're rated for it), proper low-loss jumpers to the duplexer/antenna system, etc... usually yields just about the right amount of power to make a system balanced with 50W mobiles accessing it. Unless you're purposely trying to restrict the coverage area to where a modern 50W mobile with a typical modern sensitivity receiver can't hear the repeater very well where it can still access it, I'd leave the 110W PA on it. For a MASTR II, the stock .25uV sensitivity of the receiver (if you tune carefully and get factory spec out of it) will mean you usually need to do some work on the receive side (adding a very low noise pre-amp and appropriate large high-Q bandpass cavity in RF noisy environments...) to bring the receiver sensitivity up to where HT's can get into it pretty nicely in most of its coverage area in flat-land at 110W, and you'll get those HT's in fine in virtually ALL of it's coverage area if it's up high (mountain, really tall building, etc.) GE built it as a 110W repeater for a reason... think about the users at the time... relatively deaf trunk-mounted radios (made up of the EXACT same components as the repeater) in Public Safety vehicles with external antennas... also often running 110W non-continuous-duty... Anyway, to get back to your question... the UHF 100W PA is hackable where you can easily remove the driver stages and get a lower wattage PA - useful for links, etc... that you know don't need the power. But the VHF has a feedback circuit between the driver section and the first amplification section that must be dealt with to do a similar modification. Just run 'er flat out or up around 85-95W... also consider putting an isolator on it, especially if yours doesn't have the late-model Z-matcher in the Low-Pass-Filter near the PA's output. The VHF is especially sensitive to not being driven into a 50 ohm load and they tend to burn up when they're not. The factory Z-matcher was supposed to alleviate this, but their tuning instructions for the thing leave something to be desired. Easier/more effective to just put an isolator on the PA output with proper filtering again, eating some of your RF... so 110W starts to look just about right again... -- Nate Duehr, WY0X n...@natetech.com http://facebook.com/denverpilot http://twitter.com/denverpilot
Re: [Repeater-Builder] Mastr II mods and parts
Chuck Kelsey wrote: Yes, it said that in the article. However, the article went on to say that some of the ham dealers sold it for duplex service all the time, so the writer concluded (somehow) that it was OK to use. Go figure. Chuck WB2EDV Yeah-an ARRL staff writer wrote that? No wonder! - Original Message - From: AJ To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 2:17 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Didn't the CEO or someone of similar heft at Times Microwave have a letter in QST a while back stating the entire LMR series wasn't designed for PIM performance, referring potential repeater-use customers to their line of low-PIM cables? No luck on a wildcard search on the ARRL site... Go figure. On Sun, Jan 3, 2010 at 12:18 PM, Chuck Kelsey wb2...@roadrunner.com wrote: At least when it starts causing noise, you'll know where to look. It may take a while, or it could happen pretty soon. Like with anything, some people have managed to dodge the bullet for quite some time. I've seen nothing official that says the problem was resolved. Chuck WB2EDV
Re: [Repeater-Builder] Mastr II mods and parts
Correct. And the vendors in question are likely advertisers in QST whom they don't want to offend. Chuck - Original Message - From: wd8chl wd8...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Monday, January 04, 2010 12:55 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Chuck Kelsey wrote: Yes, it said that in the article. However, the article went on to say that some of the ham dealers sold it for duplex service all the time, so the writer concluded (somehow) that it was OK to use. Go figure. Chuck WB2EDV Yeah-an ARRL staff writer wrote that? No wonder! - Original Message - From: AJ To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 2:17 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Didn't the CEO or someone of similar heft at Times Microwave have a letter in QST a while back stating the entire LMR series wasn't designed for PIM performance, referring potential repeater-use customers to their line of low-PIM cables? No luck on a wildcard search on the ARRL site... Go figure. On Sun, Jan 3, 2010 at 12:18 PM, Chuck Kelsey wb2...@roadrunner.com wrote: At least when it starts causing noise, you'll know where to look. It may take a while, or it could happen pretty soon. Like with anything, some people have managed to dodge the bullet for quite some time. I've seen nothing official that says the problem was resolved. Chuck WB2EDV Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.124/2599 - Release Date: 01/04/10 03:24:00
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. For GMRS, I would go with the -3 version to get the extra tones. It gives you 4 users. While they can't talk at the same time (obviously), a user with one tone won't hear the other users unless he takes his mic off-hook, putting the rx in carrier squelch. (and in commercial service, it is required for users to not interfere with other users on a 'shared' frequency (GMRS is ALWAYS shared with others). This is most easily accomplished by putting the rx in carrier squelch when the mic is taken off the clip to talk. The user then knows not to talk if someone else is already talking. Anyway, you can have 4 different groups of people with the -3 version. Not bad.
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef Sure, it would work. It's a six cavity unit capable of providing enough isolation for desense free operation with a receiver of -116 dBm and a 50 watt transmitter at a 5 MHz TX to RX spacing - as long as you aren't in a crowded RF environment. Would I recommend it? - absolutely not. As I and others have mentioned, a BpBr design, (like the WP-678 I referenced in an earlier mailing) would be a much better choice. Why? You'll likely buy a 100 watt PA to go along with your recent repeater purchase, and likely some day you'll want to add a receiver preamp for hearing the real weak ones The duplexer must provide enough RF isolation so the receiver can hear a very weak signal, while, at the same instant, putting out several watts from the transmitter so people can hear it. Look at it this way, let's say you are listening for a pin to drop on a cushioned floor while someone is shouting into your ear. The duplexer allows you to 'tune out' the person shouting - giving you the ability to hear the pin drop. This can only happen because the transmitter and receiver are on two distinctively separate frequencies and the duplexer is optimized for those exact frequencies. There are places to save money where building a repeater is concerned. The duplexer is not one of them. This doesn't mean you can't save money - you can. The $250.00 WP-678 I spoke of in an earlier mailing was about $800 to $1000 new. I'm recommending you buy $800.00 technology not $79.00 technology. Kevin Custer
Re: [Repeater-Builder] Mastr II mods and parts
Ok. Thanks. As I'm sure everyone does, trying to do this as cheap as possible. I was hoping it would be good, but won't so I won't get it. Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: Kevin Custer kug...@kuggie.com Date: Mon, 04 Jan 2010 15:27:02 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef Sure, it would work. It's a six cavity unit capable of providing enough isolation for desense free operation with a receiver of -116 dBm and a 50 watt transmitter at a 5 MHz TX to RX spacing - as long as you aren't in a crowded RF environment. Would I recommend it? - absolutely not. As I and others have mentioned, a BpBr design, (like the WP-678 I referenced in an earlier mailing) would be a much better choice. Why? You'll likely buy a 100 watt PA to go along with your recent repeater purchase, and likely some day you'll want to add a receiver preamp for hearing the real weak ones The duplexer must provide enough RF isolation so the receiver can hear a very weak signal, while, at the same instant, putting out several watts from the transmitter so people can hear it. Look at it this way, let's say you are listening for a pin to drop on a cushioned floor while someone is shouting into your ear. The duplexer allows you to 'tune out' the person shouting - giving you the ability to hear the pin drop. This can only happen because the transmitter and receiver are on two distinctively separate frequencies and the duplexer is optimized for those exact frequencies. There are places to save money where building a repeater is concerned. The duplexer is not one of them. This doesn't mean you can't save money - you can. The $250.00 WP-678 I spoke of in an earlier mailing was about $800 to $1000 new. I'm recommending you buy $800.00 technology not $79.00 technology. Kevin Custer
Re: [Repeater-Builder] Mastr II mods and parts
On Mon, Jan 4, 2010 at 10:29 AM, wd8chl wd8...@gmail.com wrote: Michael Cox wrote: Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. For GMRS, I would go with the -3 version to get the extra tones. It gives you 4 users. While they can't talk at the same time (obviously), a user with one tone won't hear the other users unless he takes his mic off-hook, putting the rx in carrier squelch. (and in commercial service, it is required for users to not interfere with other users on a 'shared' frequency (GMRS is ALWAYS shared with others). This is most easily accomplished by putting the rx in carrier squelch when the mic is taken off the clip to talk. The user then knows not to talk if someone else is already talking. Anyway, you can have 4 different groups of people with the -3 version. Not bad. So, to make sure I understand correctly, I can program the repeater to use the same frequency but with 4 different PL tones with this Duplexer? Michael H. Cox michaelh...@gmail.com
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: On Mon, Jan 4, 2010 at 10:29 AM, wd8chl wd8...@gmail.com wrote: Michael Cox wrote: Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. For GMRS, I would go with the -3 version to get the extra tones. It gives you 4 users. While they can't talk at the same time (obviously), a user with one tone won't hear the other users unless he takes his mic off-hook, putting the rx in carrier squelch. (and in commercial service, it is required for users to not interfere with other users on a 'shared' frequency (GMRS is ALWAYS shared with others). This is most easily accomplished by putting the rx in carrier squelch when the mic is taken off the clip to talk. The user then knows not to talk if someone else is already talking. Anyway, you can have 4 different groups of people with the -3 version. Not bad. So, to make sure I understand correctly, I can program the repeater to use the same frequency but with 4 different PL tones with this Duplexer? Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones.
Re: [Repeater-Builder] Mastr II mods and parts
Sorry, that's what I meant. Is that what this controller will do? Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: wd8chl wd8...@gmail.com Date: Mon, 04 Jan 2010 17:10:59 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: On Mon, Jan 4, 2010 at 10:29 AM, wd8chl wd8...@gmail.com wrote: Michael Cox wrote: Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. For GMRS, I would go with the -3 version to get the extra tones. It gives you 4 users. While they can't talk at the same time (obviously), a user with one tone won't hear the other users unless he takes his mic off-hook, putting the rx in carrier squelch. (and in commercial service, it is required for users to not interfere with other users on a 'shared' frequency (GMRS is ALWAYS shared with others). This is most easily accomplished by putting the rx in carrier squelch when the mic is taken off the clip to talk. The user then knows not to talk if someone else is already talking. Anyway, you can have 4 different groups of people with the -3 version. Not bad. So, to make sure I understand correctly, I can program the repeater to use the same frequency but with 4 different PL tones with this Duplexer? Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones.
RE: [Repeater-Builder] Mastr II mods and parts
In the link to the unit he bought off ebay, in the photo the GE Mastr II was the IDA equipped version. Doesn't have a card rack to plug the PSE into. Of course you could wire it in, but not as convenient as having the original style card rack where you just plug it in. Ralph W4XE --- Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones.
RE: [Repeater-Builder] Mastr II mods and parts
How does one control, from a distance ,a PSE controller? Using the tone set-up ? Jerry --- On Mon, 1/4/10, Ralph Hogan rhog...@comcast.net wrote: From: Ralph Hogan rhog...@comcast.net Subject: RE: [Repeater-Builder] Mastr II mods and parts To: Repeater-Builder@yahoogroups.com Date: Monday, January 4, 2010, 6:59 PM In the link to the unit he bought off ebay, in the photo the GE Mastr II was the IDA equipped version. Doesn't have a card rack to plug the PSE into. Of course you could wire it in, but not as convenient as having the original style card rack where you just plug it in. Ralph W4XE - - - - - - Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones.
Re: [Repeater-Builder] Mastr II mods and parts
Michael H. Cox wrote: Sorry, that's what I meant. Is that what this controller will do? Thanks, Yes...I haven't been around one, but that's how it reads. Seems like a decent choice, no idea how it performs though. You can get a used Com-spec TP3200 for about the same price, and it's a known good performer, but you will have to make up the interface to the repeater yourself, where the PSE looks like it just plugs in. Ya pays yer money, ya makes yer choices...or something like that! -Original Message- From: wd8chl wd8...@gmail.com Date: Mon, 04 Jan 2010 17:10:59 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: On Mon, Jan 4, 2010 at 10:29 AM, wd8chl wd8...@gmail.com wrote: Michael Cox wrote: Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. For GMRS, I would go with the -3 version to get the extra tones. It gives you 4 users. While they can't talk at the same time (obviously), a user with one tone won't hear the other users unless he takes his mic off-hook, putting the rx in carrier squelch. (and in commercial service, it is required for users to not interfere with other users on a 'shared' frequency (GMRS is ALWAYS shared with others). This is most easily accomplished by putting the rx in carrier squelch when the mic is taken off the clip to talk. The user then knows not to talk if someone else is already talking. Anyway, you can have 4 different groups of people with the -3 version. Not bad. So, to make sure I understand correctly, I can program the repeater to use the same frequency but with 4 different PL tones with this Duplexer? Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones.
Re: [Repeater-Builder] Mastr II mods and parts
Ralph Hogan wrote: In the link to the unit he bought off ebay, in the photo the GE Mastr II was the IDA equipped version. Doesn't have a card rack to plug the PSE into. Of course you could wire it in, but not as convenient as having the original style card rack where you just plug it in. Ralph W4XE heh-yeah, that would be a problem...didn't look that close! might as well get a used TP-3200 then, and he can turn on as many tones as he wants, not just 4! --- Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones. Yahoo! Groups Links
Re: [Repeater-Builder] Mastr II mods and parts
gerald bishop wrote: How does one control, from a distance ,a PSE controller? Using the tone set-up ? Jerry DTMF
Re: [Repeater-Builder] Mastr II mods and parts
Ralph (and others) So is the IDA equipped version the controller? If not, what does it mean that I have the IDA equiped version? Does that mean I need, for example, a different duplexer? Thanks for your help everyone. I appreciate it. On Mon, Jan 4, 2010 at 3:59 PM, Ralph Hogan rhog...@comcast.net wrote: In the link to the unit he bought off ebay, in the photo the GE Mastr II was the IDA equipped version. Doesn't have a card rack to plug the PSE into. Of course you could wire it in, but not as convenient as having the original style card rack where you just plug it in. Ralph W4XE -- Duplexer? Nope, didn't say anything about a duplexer. You mentioned using the PSE508-2 controller (which does one tone), and I suggested using the -3 version instead to get the 4 tones. -- --- Michael H. Cox michaelh...@gmail.com
Re: [Repeater-Builder] Mastr II mods and parts
Thank you for your help. I appreciate it! I've put a couple of questions inline below. On Sat, Jan 2, 2010 at 4:18 PM, Kevin Custer kug...@kuggie.com wrote: Michael Cox wrote: I justed purchased a GE MAST II UHF repeater that has a 450-460 split (see it at http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=230415711221ssPageName=STRK:MEWNX:IT ) I need to get a power adapter, a CWID, You mean a Power Amplifier or simply called a PA. You're right. Thx. For a CWID, I recommend a real repeater controller. and, depening on the price, a duplexer. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. I'd like to modify this to use on either a GMRS repeater or a 40cm ham band. This will be my first repeater. I think you meant 70 cm ham band... Modification is easy, as no RF mods need made for either use. You just need to make it duplex. Information on www.mastr2.com will help you there. Yes, I did mean 70 cm. :) I'm assuming that I could get this http://www.repeater-builder.com/products/ampbd.html for the power adapter. You could, but I'd just buy the right PA. They are on eBay all the time. http://cgi.ebay.com/GE-Ericsson-VHF-Mastr-II-Master-Repeater-100watt-amp_W0QQitemZ260529220211QQcmdZViewItemQQptZ2_Way_Radios_FRS?hash=item3ca8c06a73 Are these what I'm looking for? It looks liek there is a UHF and a VHF version of the PA. Is that correct? Are they not compatible with each other? http://cgi.ebay.com/GE-Ericsson-VHF-Mastr-II-Master-Repeater-100watt-amp_W0QQitemZ260529220211QQcmdZViewItemQQptZ2_Way_Radios_FRS?hash=item3ca8c06a73 http://cgi.ebay.com/GE-Ma-COM-100-watt-amplifier-20-watt-input-MASTR-II_W0QQitemZ200422213614QQcmdZViewItemQQptZ2_Way_Radios_FRS?hash=item2eaa1847ee http://cgi.ebay.com/GE-MASTR-II-100-WATT-AMPLIFIER-VHF_W0QQitemZ140370861181QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item20aec15c7d http://cgi.ebay.com/GE-Ericsson-Mastr-II-Repeater-Cabinet-Console-45W-PA_W0QQitemZ300382163124QQcmdZViewItemQQptZ2_Way_Radios_FRS?hash=item45f02c10b4 Do you have any recommendations for the duplexer and CWID? Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Good luck, Kevin Custer -- --- Michael H. Cox michaelh...@gmail.com
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) Correct. If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Also a good choice. Kevin
Re: [Repeater-Builder] Mastr II mods and parts
For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 11:12 AM Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) Correct. If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Also a good choice. Kevin
Re: [Repeater-Builder] Mastr II mods and parts
Kevin mentioned feedline, but didn't mention to stay away from LMR or 9913 type foil/shield combinations in duplex service. Chuck WB2EDV - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 11:12 AM Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case.
Re: [Repeater-Builder] Mastr II mods and parts
I believe the issues with LMR were resolved years ago Chuck. Can you refresh the group on some of the primary issues? Thanks, dave p.s. we've been using it for five years at ten sites with no problems. - Original Message - From: Chuck Kelsey To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 12:48 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Kevin mentioned feedline, but didn't mention to stay away from LMR or 9913 type foil/shield combinations in duplex service. Chuck WB2EDV - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 11:12 AM Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case.
RE: [Repeater-Builder] Mastr II mods and parts
A local group here in Florida just replaced their feed line to their antenna with LMR 400 coax this past weekend. I cringed after I heard that they had done this. But, am I now hearing that the use of LMR 400 is no longer taboo? - thanks.. - Mike From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of WA3GIN Sent: Sunday, January 03, 2010 1:35 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I believe the issues with LMR were resolved years ago Chuck. Can you refresh the group on some of the primary issues? Thanks, dave p.s. we've been using it for five years at ten sites with no problems. - Original Message - From: Chuck Kelsey mailto:wb2...@roadrunner.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 12:48 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Kevin mentioned feedline, but didn't mention to stay away from LMR or 9913 type foil/shield combinations in duplex service. Chuck WB2EDV - Original Message - From: Kevin Custer mailto:kug...@kuggie.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 11:12 AM Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. __ Information from ESET NOD32 Antivirus, version of virus signature database 4740 (20100103) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com
Re: [Repeater-Builder] Mastr II mods and parts
Yes, it was resolved at a lot of commercial sites by not allowing it to be used ;-) Usually after a bit of time, the cable will start to become a source of noise as the two dissimilar metals start to react with each other. There are many documented cases of this problem. Search this group's messages and you'll see this has been discussed over and over. It comes up about every other week. The manufacturers do not list these cables for low PIM. There's info on the Repeater Builder site here: http://www.repeater-builder.com/antenna/pdf/recommended-coax-and-connectors-for-iden.pdf Personally, I've seen it cause problems on several sites. Getting it out of service solved the problem. Chuck WB2EDV - Original Message - From: WA3GIN To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 1:34 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I believe the issues with LMR were resolved years ago Chuck. Can you refresh the group on some of the primary issues? Thanks, dave p.s. we've been using it for five years at ten sites with no problems.
Re: [Repeater-Builder] Mastr II mods and parts
At least when it starts causing noise, you'll know where to look. It may take a while, or it could happen pretty soon. Like with anything, some people have managed to dodge the bullet for quite some time. I've seen nothing official that says the problem was resolved. Chuck WB2EDV - Original Message - From: Michael Ryan To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 1:41 PM Subject: RE: [Repeater-Builder] Mastr II mods and parts A local group here in Florida just replaced their feed line to their antenna with LMR 400 coax this past weekend. I cringed after I heard that they had done this. But, am I now hearing that the use of LMR 400 is no longer taboo? - thanks.. - Mike From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of WA3GIN Sent: Sunday, January 03, 2010 1:35 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I believe the issues with LMR were resolved years ago Chuck. Can you refresh the group on some of the primary issues? Thanks, dave p.s. we've been using it for five years at ten sites with no problems. - Original Message - From: Chuck Kelsey To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 12:48 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Kevin mentioned feedline, but didn't mention to stay away from LMR or 9913 type foil/shield combinations in duplex service. Chuck WB2EDV - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 11:12 AM Subject: Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. __ Information from ESET NOD32 Antivirus, version of virus signature database 4740 (20100103) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.124/2597 - Release Date: 01/02/10 03:22:00
Re: [Repeater-Builder] Mastr II mods and parts
Didn't the CEO or someone of similar heft at Times Microwave have a letter in QST a while back stating the entire LMR series wasn't designed for PIM performance, referring potential repeater-use customers to their line of low-PIM cables? No luck on a wildcard search on the ARRL site... Go figure. On Sun, Jan 3, 2010 at 12:18 PM, Chuck Kelsey wb2...@roadrunner.com wrote: At least when it starts causing noise, you'll know where to look. It may take a while, or it could happen pretty soon. Like with anything, some people have managed to dodge the bullet for quite some time. I've seen nothing official that says the problem was resolved. Chuck WB2EDV - Original Message - *From:* Michael Ryan mryan...@tampabay.rr.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 1:41 PM *Subject:* RE: [Repeater-Builder] Mastr II mods and parts A local group here in Florida just replaced their feed line to their antenna with LMR 400 coax this past weekend. I cringed after I heard that they had done this. But, am I now hearing that the use of LMR 400 is no longer taboo? – thanks…. - Mike *From:* Repeater-Builder@yahoogroups.com [mailto: repeater-buil...@yahoogroups.com] *On Behalf Of *WA3GIN *Sent:* Sunday, January 03, 2010 1:35 PM *To:* Repeater-Builder@yahoogroups.com *Subject:* Re: [Repeater-Builder] Mastr II mods and parts I believe the issues with LMR were resolved years ago Chuck. Can you refresh the group on some of the primary issues? Thanks, dave p.s. we've been using it for five years at ten sites with no problems. - Original Message - *From:* Chuck Kelsey wb2...@roadrunner.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 12:48 PM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Kevin mentioned feedline, but didn't mention to stay away from LMR or 9913 type foil/shield combinations in duplex service. Chuck WB2EDV - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. __ Information from ESET NOD32 Antivirus, version of virus signature database 4740 (20100103) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.124/2597 - Release Date: 01/02/10 03:22:00
Re: [Repeater-Builder] Mastr II mods and parts
Yes, it said that in the article. However, the article went on to say that some of the ham dealers sold it for duplex service all the time, so the writer concluded (somehow) that it was OK to use. Go figure. Chuck WB2EDV - Original Message - From: AJ To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 2:17 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts Didn't the CEO or someone of similar heft at Times Microwave have a letter in QST a while back stating the entire LMR series wasn't designed for PIM performance, referring potential repeater-use customers to their line of low-PIM cables? No luck on a wildcard search on the ARRL site... Go figure. On Sun, Jan 3, 2010 at 12:18 PM, Chuck Kelsey wb2...@roadrunner.com wrote: At least when it starts causing noise, you'll know where to look. It may take a while, or it could happen pretty soon. Like with anything, some people have managed to dodge the bullet for quite some time. I've seen nothing official that says the problem was resolved. Chuck WB2EDV
Re: [Repeater-Builder] Mastr II mods and parts
At 1/3/2010 11:11, you wrote: Yes, it was resolved at a lot of commercial sites by not allowing it to be used ;-) For me, the resolution came from a Times Microwave sales rep. who admitted that LMR-400 is not appropriate for duplex use. Having said that, you can get away with using it in situations such as temporary/portable repeater installations provided the connectors are installed properly the feedline is not used near the antenna, where RF can couple to the outer braided shield. In no circumstances would I ever use it at a shared comm. site. Usually after a bit of time, the cable will start to become a source of noise as the two dissimilar metals start to react with each other. There are many documented cases of this problem. Search this group's messages and you'll see this has been discussed over and over. It comes up about every other week. BTW, they don't need to be dissemilar metals. I once confirmed a 100% copper braided RG-213 jumper as a PIM source. I only use silver-plated braided coax beyond the duplexer from now on. Bob NO6B
Re: [Repeater-Builder] Mastr II mods and parts
Very interesting...all our sites are dense with RF from Public Safety radio systems 800, 700, VHF, etc. No problems in five years. I suspect it has more to do with how the RF connections are made than the LMR cable. Just my subjective opinion of one. 73, dave wa3gin - Original Message - From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 2:45 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts At 1/3/2010 11:11, you wrote: Yes, it was resolved at a lot of commercial sites by not allowing it to be used ;-) For me, the resolution came from a Times Microwave sales rep. who admitted that LMR-400 is not appropriate for duplex use. Having said that, you can get away with using it in situations such as temporary/portable repeater installations provided the connectors are installed properly the feedline is not used near the antenna, where RF can couple to the outer braided shield. In no circumstances would I ever use it at a shared comm. site. Usually after a bit of time, the cable will start to become a source of noise as the two dissimilar metals start to react with each other. There are many documented cases of this problem. Search this group's messages and you'll see this has been discussed over and over. It comes up about every other week. BTW, they don't need to be dissemilar metals. I once confirmed a 100% copper braided RG-213 jumper as a PIM source. I only use silver-plated braided coax beyond the duplexer from now on. Bob NO6B
RE: [Repeater-Builder] Mastr II mods and parts
Very interesting...all our sites are dense with RF from Public Safety radio systems 800, 700, VHF, etc. No problems in five years. I suspect it has more to do with how the RF connections are made than the LMR cable. Just my subjective opinion of one. Actually it is the cable. My discussion with two engineers at TimesMicrowave indicated that it was not so much the dissimilar metals that were the issue, but the foil over braid and two somewhat independent shields. No mention was made of this being a termination or connection issue. As with everything, Your Mileage May Vary. I use the stuff in non duplex telemetry applications by the 1000 roll, not a problem. We have some on site in use for non duplex applications, but many well engineered public safety sites will not allow the product on site regardless of the use. My personal preference is a 100% copper shield obtained with any of the smaller superflexible Andrews and other products. I try to use ¼, 3/8 and ½ superflex for those duplexer to the radio and duplexer to the lighting arrestor runs. IMHO, nothing says 100% shielded like solid copper. 73 Daron N7HQR
Re: [Repeater-Builder] Mastr II mods and parts
Yes, I agree. Various plated connectors can also be a problem. Unfortunately most antenna manufacturers don't use silver plated coax in their pigtails and harnesses. Chuck WB2EDV - Original Message - From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 2:45 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts At 1/3/2010 11:11, you wrote: Yes, it was resolved at a lot of commercial sites by not allowing it to be used ;-) For me, the resolution came from a Times Microwave sales rep. who admitted that LMR-400 is not appropriate for duplex use. Having said that, you can get away with using it in situations such as temporary/portable repeater installations provided the connectors are installed properly the feedline is not used near the antenna, where RF can couple to the outer braided shield. In no circumstances would I ever use it at a shared comm. site. Usually after a bit of time, the cable will start to become a source of noise as the two dissimilar metals start to react with each other. There are many documented cases of this problem. Search this group's messages and you'll see this has been discussed over and over. It comes up about every other week. BTW, they don't need to be dissemilar metals. I once confirmed a 100% copper braided RG-213 jumper as a PIM source. I only use silver-plated braided coax beyond the duplexer from now on. Bob NO6B Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.124/2597 - Release Date: 01/02/10 03:22:00
Re: [Repeater-Builder] Mastr II mods and parts
At 1/3/2010 12:16, you wrote: Yes, I agree. Various plated connectors can also be a problem. Unfortunately most antenna manufacturers don't use silver plated coax in their pigtails and harnesses. This is probably why all Cushcraft 4-pole antennas eventually cause desense to the systems they're connected to. I have one in use for a TX-only link. Someday I'll take it down replace that harness with RG142 or RG214. Bob NO6B
Re: [Repeater-Builder] Mastr II mods and parts
Well Cushcraft what can I say? I never saw one I liked. Gamma matches make pretty poor performers in my opinion. I don't believe any of the Decibel line over the years used anything but standard copper braid on any of their antennas. My thought is that while the copper braid may occasionally cause PIM, it's most likely very rare. The foil/braid combo is another story. Chuck - Original Message - From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 03, 2010 3:50 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts At 1/3/2010 12:16, you wrote: Yes, I agree. Various plated connectors can also be a problem. Unfortunately most antenna manufacturers don't use silver plated coax in their pigtails and harnesses. This is probably why all Cushcraft 4-pole antennas eventually cause desense to the systems they're connected to. I have one in use for a TX-only link. Someday I'll take it down replace that harness with RG142 or RG214. Bob NO6B Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.124/2597 - Release Date: 01/02/10 03:22:00
Re: [Repeater-Builder] Mastr II mods and parts
Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN wa3...@comcast.net wrote: For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) Correct. If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Also a good choice. Kevin -- --- Michael H. Cox michaelh...@gmail.com
Re: [Repeater-Builder] Mastr II mods and parts
I would not recommend that duplexer for a repeater. -- Original Message -- Received: Sun, 03 Jan 2010 08:47:16 PM PST From: Michael Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN wa3...@comcast.net wrote: For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) Correct. If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Also a good choice. Kevin -- --- Michael H. Cox michaelh...@gmail.com
Re: [Repeater-Builder] Mastr II mods and parts
Any reasons? Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: JOHN MACKEY jmac...@usa.net Date: Sun, 03 Jan 2010 21:55:33 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I would not recommend that duplexer for a repeater. -- Original Message -- Received: Sun, 03 Jan 2010 08:47:16 PM PST From: Michael Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN wa3...@comcast.net wrote: For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future funds. :) Correct. If I decide to make it a GMRS repeater, I won't have to worry about that and will go with the PSE508-2, as its a little less expensive. Also a good choice. Kevin -- --- Michael H. Cox michaelh...@gmail.com
RE: [Repeater-Builder] Mastr II mods and parts
Any reasons? First, it could be used as a duplexer, however you don't get all the benefit you would get from a BpBr duplexer. The one in question is a notch only duplexer, the cavities are designed to notch the two frequencies in use. While it can work, you generally cannot get the required isolation for a fairly sensitive repeater with much of a power output. A more typical duplexer would have band pass cavities, or better yet, band pass band reject cavities. There is a wealth of information on the web regarding the theory and design of duplexers. In short, with a BpBr duplexer, you get two cavities that ONLY pass the receive frequency, and they also notch the transmit frequency. On the transmit side, you get the same double action. This yields more isolation and protects the front end of the receiver a bit from adjacent channel signals by only 'passing' the correct signal. With the notch only duplexer, there is no front end receive protection provided, simply a notch where the transmitter is. If there are other nearby signals they could very well interfere with the receiver. Do the right thing and get a Band Pass Band Reject duplexer, you'll be much happier. 73 Daron N7HQR
Re: [Repeater-Builder] Mastr II mods and parts
Excellent. Thanks for the info. This is going to be my first repeater and so I'm still learning. Thx. Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: Daron Wilson daronwil...@yahoo.com Date: Sun, 3 Jan 2010 22:22:05 To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Mastr II mods and parts Any reasons? First, it could be used as a duplexer, however you don't get all the benefit you would get from a BpBr duplexer. The one in question is a notch only duplexer, the cavities are designed to notch the two frequencies in use. While it can work, you generally cannot get the required isolation for a fairly sensitive repeater with much of a power output. A more typical duplexer would have band pass cavities, or better yet, band pass band reject cavities. There is a wealth of information on the web regarding the theory and design of duplexers. In short, with a BpBr duplexer, you get two cavities that ONLY pass the receive frequency, and they also notch the transmit frequency. On the transmit side, you get the same double action. This yields more isolation and protects the front end of the receiver a bit from adjacent channel signals by only 'passing' the correct signal. With the notch only duplexer, there is no front end receive protection provided, simply a notch where the transmitter is. If there are other nearby signals they could very well interfere with the receiver. Do the right thing and get a Band Pass Band Reject duplexer, you'll be much happier. 73 Daron N7HQR
Re: [Repeater-Builder] Mastr II mods and parts
mobile duplexers generally have poor performance, not enough for a decent repeater. The model you suggested is one of the worst. -- Original Message -- Received: Sun, 03 Jan 2010 10:04:33 PM PST From: Michael H. Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Any reasons? Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: JOHN MACKEY jmac...@usa.net Date: Sun, 03 Jan 2010 21:55:33 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I would not recommend that duplexer for a repeater. -- Original Message -- Received: Sun, 03 Jan 2010 08:47:16 PM PST From: Michael Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN wa3...@comcast.net wrote: For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I go with the Ham repeater, I'll most likely do that. That would require, if I understand correctly, another radio connected in, so that will have to be done later with future
Re: [Repeater-Builder] Mastr II mods and parts
Ok. Thx for info. I appreciate it. Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: JOHN MACKEY jmac...@usa.net Date: Sun, 03 Jan 2010 22:43:41 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts mobile duplexers generally have poor performance, not enough for a decent repeater. The model you suggested is one of the worst. -- Original Message -- Received: Sun, 03 Jan 2010 10:04:33 PM PST From: Michael H. Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Any reasons? Thanks, Michael H. Cox michaelh...@gmail.com -Original Message- From: JOHN MACKEY jmac...@usa.net Date: Sun, 03 Jan 2010 21:55:33 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts I would not recommend that duplexer for a repeater. -- Original Message -- Received: Sun, 03 Jan 2010 08:47:16 PM PST From: Michael Cox michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN wa3...@comcast.net wrote: For fun we operated a 400 watt erp repeater with two antennas and no duplexer. We were able to achieve about 100db attenuation by using the roof equipment penthouse. The transmit antenna was mounted on the top of the penthouse and the receive antenna was installed diagonally from the transmit antenna on the roof below the penthouse. Each antenna was physically separated by the penthouse structure. Transmit performance was good and receiver performance was good about 270 degrees minus the abstructed zone. No feedback or other issues. Eventually, we installed TXRX 6 can duplexer and utilized the penthouse antenna. Receive coverage regained 360 degree coverage. So, it is doable if you have the right antenna site. Best, dave wa3gin - Original Message - *From:* Kevin Custer kug...@kuggie.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Sunday, January 03, 2010 11:12 AM *Subject:* Re: [Repeater-Builder] Mastr II mods and parts Michael Cox wrote: Thank you for your help. I appreciate it! I've put a couple of questions inline below. Well - you'll need a duplexer no mater the price... grin I was under the impression that if I had two antennas, I could get by without a duplexer. Thanks for the heads up. While two antennas will work, and you'd initially think there is a cost savings using two antennas, that isn't always the case. The determining factor usually ends up being the length and size of feed-line necessary to get from the repeater to the antenna. On UHF, unless the feed-line length is really short, you'll want to use some type of hard-line cable. The cost of this cable, depending on type and length, can be costly. It may be less costly to use one antenna and a duplexer then to install two antennas and have two runs of feed-line. In addition, you'll usually end up with a better balanced system using one antenna because using two can cause a disparity if both antennas don't have the exact same pattern - which could be difficult to achieve depending on the tower space available. In installations where you have to pay rent on tower space - it's usually by far cheaper to purchase a duplexer. RE: Power Amplifier Are these what I'm looking for? Generically - Yes. It looks like there is a UHF and a VHF version of the PA. Is that correct? Yes. Are they not compatible with each other? No. VHF and UHF are two totally different bands. You cannot use a UHF PA on a VHF repeater and vice-versa. The third one you listed is a Mobile PA - not something you'll want. You want a UHF Station PA like the second one you listed - but it isn't the exact one either. The one you want requires 200 mW of drive - not 20 watts - but, the correct one looks very similar to the one in your number two listing. I don't presently see a good candidate on eBay - but they show up all the time. Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. I couldn't find any on eBay. Any guesses what I'd be paying for something like this? $250 plus shipping. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm
Re: [Repeater-Builder] Mastr II mods and parts
Michael Cox wrote: I justed purchased a GE MAST II UHF repeater that has a 450-460 split (see it at http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=230415711221ssPageName=STRK:MEWNX:IT http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=230415711221ssPageName=STRK:MEWNX:IT) I need to get a power adapter, a CWID, You mean a Power Amplifier or simply called a PA. For a CWID, I recommend a real repeater controller. and, depening on the price, a duplexer. Well - you'll need a duplexer no mater the price... grin I'd like to modify this to use on either a GMRS repeater or a 40cm ham band. This will be my first repeater. I think you meant 70 cm ham band... Modification is easy, as no RF mods need made for either use. You just need to make it duplex. Information on www.mastr2.com will help you there. I'm assuming that I could get this http://www.repeater-builder.com/products/ampbd.html for the power adapter. You could, but I'd just buy the right PA. They are on eBay all the time. Do you have any recommendations for the duplexer and CWID? Duplexer - used WACOM Products WP-678 (or similar), also available from eBay. Controller - I recommend a NHRC model that plugs into the Systems board, or, one of the Pion Simon models that plug into the card cage. http://www.nhrc.net/ge-stuff.php http://www.pionsimon.com/products.htm Good luck, Kevin Custer
