Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
On Oct 6, 2009, at 10:12 AM, Douglas wrote: Let me tell you a little story about this kind of problem. I had a similar situation on a VHF mastr II repeater where a signal sounded great one time and noisy the next. The problem turned out to be a hairline crack in a solder pad that was used to bridge two circuit boards and the output connectors to a circuit board, within the PA assembly. It would run great power and then low power from one transmission to the next. The output power would drop noticably as seen on a relative signal meter on my rig. That was how I localized it. When we would put a meter on the output, it had just enough sstress on the cable to make a good connection and all was well, hookk it back to the duplexer, and the intermittant problem returned. I suspect that same kind of thing could happen on a receiver connection. The only real way to fix is to touch all the solder terminals that are used for primary signal in the input or output route. Good luck. I liked to have lost my brain over that one (what brain is left from the 60s). Doug KC0SDQ MASTR II PA's can also make funny noises (really ugly stuff on a spectrum analyzer) if they're experiencing this type of crack at the PA output going into the harmonic filter board... you literally can HEAR it happening on the repeater's output. Often the arcing happening over that joint modulates the FM signal in the form of a low-level squeal in the background of the repeater's signal, and/or a frying sound. It's not pleasant, but also not always so bad you can hear it. http://www.repeater-builder.com/ge/pix/mvc-474f.jpg From: http://www.repeater-builder.com/ge/mastrIIparepair.html Look carefully. Sometimes it's hard to spot. There's a little strip of metal under that solder blob, that bridges that gap, which is almost under that capacitor. Re-heating this area, you'll often find the problem, but be careful not to cook the cap. We've done the bump fix, and we've also done the just clean up the pads and re-use the factory metal strip fix. Can't say that either way is better when the screws surrounding the joint are torqued to factory specifications. If either side is loose, or too tight the boards will flex during heating and cooling and break the connection again. Had one that was so burnt the board itself and the charcoal became conductive and it would visibly arc over every time it was keyed. That one had to have both the final board and the harmonic filter board replaced, and was stinky. Usually they're sneakier than that, though. I was fighting with VHF PA's a couple of years ago, and when I finally enlisted the help of someone FAR more patient than I to completely rebuild one, including pulling ALL of the boards off the PA heatsink, scraping all of the old/dead heatsink compound off of everything and re-applying new, re-torquing all the screws to FACTORY specs (it's in the LBI, and many late model repeater PA's, not the mobiles usually, have stickers with the EXACT torque specs of all screw types on the PA board), resoldering every joint with good quality solder... etc. A real re-work job. This was done slowly and carefully by Scott W0KU... then following the rule we've given ourselves that ALL MASTR II PAs get an isolator... His rebuilt PA has gone through antenna hell (long story, but let's just say it wasn't radiating, feeding into the isolator at 85W continuous for hours and hours) plus has also worked great on-the-air for three years now. I now really believe that these 30 year old PA's just need a little bench TLC before they go up to a site, and I'm MORE than willing to go work them over thoroughly, and buy beers for Scott to enjoy in his backyard shed after the soldering and tricky stuff is done with. I rebuilt two, they died. Scott rebuilt one, after I explained what I thought I'd rushed through, or done badly, and how frustrating it was to see two of them die... we made a plan to meet up and work slowly and carefully and do a complete tear-down and rebuild on one utilizing whatever boards/parts we had on-hand. That rebuilt PA has kept working now for a long time. I definitely credit the removal and replacement of the completely dried out, dead heatsink compound as a component of much of this success. After seeing the flaky, useless stuff that came off the heatsink (the date stamp read 1981 on this particular PA), I highly recommend the full tear-down and rebuild of MASTR II PA's before giving them a week long stress test at 110W into a dummy load in the basement for a week... before they ever go anywhere near a repeater site. Also I mention this, but don't think from your symptoms it's what's happening, but it's good info for anyone taking over a MASTR II... since what you're fighting is on and off receiver sensitivity loss, you MIGHT be suffering from the
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Nate, I have read most all of the documents on RB and learned quite a bit about repeaters and the GEs. 73 John --- In Repeater-Builder@yahoogroups.com, Nate Duehr n...@... wrote: On Oct 6, 2009, at 10:12 AM, Douglas wrote: Let me tell you a little story about this kind of problem. I had a similar situation on a VHF mastr II repeater where a signal sounded great one time and noisy the next. The problem turned out to be a hairline crack in a solder pad that was used to bridge two circuit boards and the output connectors to a circuit board, within the PA assembly. It would run great power and then low power from one transmission to the next. The output power would drop noticably as seen on a relative signal meter on my rig. That was how I localized it. When we would put a meter on the output, it had just enough sstress on the cable to make a good connection and all was well, hookk it back to the duplexer, and the intermittant problem returned. I suspect that same kind of thing could happen on a receiver connection. The only real way to fix is to touch all the solder terminals that are used for primary signal in the input or output route. Good luck. I liked to have lost my brain over that one (what brain is left from the 60s). Doug KC0SDQ MASTR II PA's can also make funny noises (really ugly stuff on a spectrum analyzer) if they're experiencing this type of crack at the PA output going into the harmonic filter board... you literally can HEAR it happening on the repeater's output. Often the arcing happening over that joint modulates the FM signal in the form of a low-level squeal in the background of the repeater's signal, and/or a frying sound. It's not pleasant, but also not always so bad you can hear it. http://www.repeater-builder.com/ge/pix/mvc-474f.jpg From: http://www.repeater-builder.com/ge/mastrIIparepair.html Look carefully. Sometimes it's hard to spot. There's a little strip of metal under that solder blob, that bridges that gap, which is almost under that capacitor. Re-heating this area, you'll often find the problem, but be careful not to cook the cap. We've done the bump fix, and we've also done the just clean up the pads and re-use the factory metal strip fix. Can't say that either way is better when the screws surrounding the joint are torqued to factory specifications. If either side is loose, or too tight the boards will flex during heating and cooling and break the connection again. Had one that was so burnt the board itself and the charcoal became conductive and it would visibly arc over every time it was keyed. That one had to have both the final board and the harmonic filter board replaced, and was stinky. Usually they're sneakier than that, though. I was fighting with VHF PA's a couple of years ago, and when I finally enlisted the help of someone FAR more patient than I to completely rebuild one, including pulling ALL of the boards off the PA heatsink, scraping all of the old/dead heatsink compound off of everything and re-applying new, re-torquing all the screws to FACTORY specs (it's in the LBI, and many late model repeater PA's, not the mobiles usually, have stickers with the EXACT torque specs of all screw types on the PA board), resoldering every joint with good quality solder... etc. A real re-work job. This was done slowly and carefully by Scott W0KU... then following the rule we've given ourselves that ALL MASTR II PAs get an isolator... His rebuilt PA has gone through antenna hell (long story, but let's just say it wasn't radiating, feeding into the isolator at 85W continuous for hours and hours) plus has also worked great on-the-air for three years now. I now really believe that these 30 year old PA's just need a little bench TLC before they go up to a site, and I'm MORE than willing to go work them over thoroughly, and buy beers for Scott to enjoy in his backyard shed after the soldering and tricky stuff is done with. I rebuilt two, they died. Scott rebuilt one, after I explained what I thought I'd rushed through, or done badly, and how frustrating it was to see two of them die... we made a plan to meet up and work slowly and carefully and do a complete tear-down and rebuild on one utilizing whatever boards/parts we had on-hand. That rebuilt PA has kept working now for a long time. I definitely credit the removal and replacement of the completely dried out, dead heatsink compound as a component of much of this success. After seeing the flaky, useless stuff that came off the heatsink (the date stamp read 1981 on this particular PA), I highly recommend the full tear-down and rebuild of MASTR II PA's before giving them a week long stress test at 110W into a dummy load in the basement for a week...
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Let me tell you a little story about this kind of problem. I had a similar situation on a VHF mastr II repeater where a signal sounded great one time and noisy the next. The problem turned out to be a hairline crack in a solder pad that was used to bridge two circuit boards and the output connectors to a circuit board, within the PA assembly. It would run great power and then low power from one transmission to the next. The output power would drop noticably as seen on a relative signal meter on my rig. That was how I localized it. When we would put a meter on the output, it had just enough sstress on the cable to make a good connection and all was well, hookk it back to the duplexer, and the intermittant problem returned. I suspect that same kind of thing could happen on a receiver connection. The only real way to fix is to touch all the solder terminals that are used for primary signal in the input or output route. Good luck. I liked to have lost my brain over that one (what brain is left from the 60s). Doug KC0SDQ --- In Repeater-Builder@yahoogroups.com, W3ML w...@... wrote: Thanks Mark, I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML --- In Repeater-Builder@yahoogroups.com, Mark n9wys@ wrote: John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
John - A word of caution may be in order since you are dealing with a club. These days, the typical ham doesn't begin to comprehend the complexity of a repeater system. To many, one simply needs to go out a purchase new equipment, plug it all together, and it runs. Wrong! Don't let your club go down that path. The end result will be lots of money being spent and unhappy results. I've watched it happen. If you are running a repeater, you WILL have problems with it, no matter what brand of equipment you use, no matter if it's new or used. You appear to be taking the steps to learn about it. It's the only way you'll be able to cope unless the club pays a commercial two-way shop to maintain the system. In the meantime, keep plugging away. It can get very frustrating at times. Chuck WB2EDV - Original Message - I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Doug, Thanks for the story. This next weekend I will go over the inside with a fine tooth comb and see if I can find any cracks or bad solder joints. My brain is going to but not just from this project. 73 John --- In Repeater-Builder@yahoogroups.com, Douglas dougd...@... wrote: Let me tell you a little story about this kind of problem. I had a similar situation on a VHF mastr II repeater where a signal sounded great one time and noisy the next. The problem turned out to be a hairline crack in a solder pad that was used to bridge two circuit boards and the output connectors to a circuit board, within the PA assembly. It would run great power and then low power from one transmission to the next. The output power would drop noticably as seen on a relative signal meter on my rig. That was how I localized it. When we would put a meter on the output, it had just enough sstress on the cable to make a good connection and all was well, hookk it back to the duplexer, and the intermittant problem returned. I suspect that same kind of thing could happen on a receiver connection. The only real way to fix is to touch all the solder terminals that are used for primary signal in the input or output route. Good luck. I liked to have lost my brain over that one (what brain is left from the 60s). Doug KC0SDQ --- In Repeater-Builder@yahoogroups.com, W3ML w3ml@ wrote: Thanks Mark, I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML --- In Repeater-Builder@yahoogroups.com, Mark n9wys@ wrote: John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Well Chuck, there will be no new radio unless I buy it out of my pocket and that won't happen as I need a new rotor. This club has no money. I was able to get a grant for emergency communications and that is how I ended up with the stuff we have now. My big problem seems to be that I took this radio in for free instead of buying one from that ham in Florida that sells GEs for repeaters. As I have said before being a ham for 30 years now has taught me nothing about the maintenance of a repeater. I have built rigs before and trouble shot many a good HF radio, and now I am actually somewhat having fun playing with this thing. I have done more reading on repeaters than I have at my regular job and that is the Teaching of English Literature. Of course if we were to buy a new one, hi hi, then there would be nothing to learn and we all need to keep learning to keep our brains working. I really appreciate everyone on here helping out not only myself, but the others that come on here who need help and are just starting out in this area of ham radio like me. 73 John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2...@... wrote: John - A word of caution may be in order since you are dealing with a club. These days, the typical ham doesn't begin to comprehend the complexity of a repeater system. To many, one simply needs to go out a purchase new equipment, plug it all together, and it runs. Wrong! Don't let your club go down that path. The end result will be lots of money being spent and unhappy results. I've watched it happen. If you are running a repeater, you WILL have problems with it, no matter what brand of equipment you use, no matter if it's new or used. You appear to be taking the steps to learn about it. It's the only way you'll be able to cope unless the club pays a commercial two-way shop to maintain the system. In the meantime, keep plugging away. It can get very frustrating at times. Chuck WB2EDV - Original Message - I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Your antenna needs to come down and be gone over before you buy anything new. Those G7s will get bad connections in them that act like diodes and rectify all kinds of crud to desense your otherwise good system. I understand that there is a document on the RB site about refurbing that antenna. You may have heard this before. Good Luck, Eric (W1EL) Eric Lowell Eastern Maine Electronics Inc. 48 Loon Road Wesley ME 04686 eme@starband.net www.satnetmaine.com --- On Tue, 10/6/09, W3ML w...@arrl.net wrote: From: W3ML w...@arrl.net Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments To: Repeater-Builder@yahoogroups.com Date: Tuesday, October 6, 2009, 5:36 PM Well Chuck, there will be no new radio unless I buy it out of my pocket and that won't happen as I need a new rotor. This club has no money. I was able to get a grant for emergency communications and that is how I ended up with the stuff we have now. My big problem seems to be that I took this radio in for free instead of buying one from that ham in Florida that sells GEs for repeaters. As I have said before being a ham for 30 years now has taught me nothing about the maintenance of a repeater. I have built rigs before and trouble shot many a good HF radio, and now I am actually somewhat having fun playing with this thing. I have done more reading on repeaters than I have at my regular job and that is the Teaching of English Literature. Of course if we were to buy a new one, hi hi, then there would be nothing to learn and we all need to keep learning to keep our brains working. I really appreciate everyone on here helping out not only myself, but the others that come on here who need help and are just starting out in this area of ham radio like me. 73 John --- In Repeater-Builder@ yahoogroups. com, Chuck Kelsey wb2...@... wrote: John - A word of caution may be in order since you are dealing with a club. These days, the typical ham doesn't begin to comprehend the complexity of a repeater system. To many, one simply needs to go out a purchase new equipment, plug it all together, and it runs. Wrong! Don't let your club go down that path. The end result will be lots of money being spent and unhappy results. I've watched it happen. If you are running a repeater, you WILL have problems with it, no matter what brand of equipment you use, no matter if it's new or used. You appear to be taking the steps to learn about it. It's the only way you'll be able to cope unless the club pays a commercial two-way shop to maintain the system. In the meantime, keep plugging away. It can get very frustrating at times. Chuck WB2EDV - Original Message - I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Eric I read that document that you speak of. We cleaned it , re-fiber-glassed some of it and then sprayed it with polyurethane finish and screwed the sections so they would not move even though they had clamps on them. But, like you I think with it being used there may be a problem inside that we can not see. 73 John --- In Repeater-Builder@yahoogroups.com, Eric Lowell elowell9...@... wrote: Your antenna needs to come down and be gone over before you buy anything new. Those G7s will get bad connections in them that act like diodes and rectify all kinds of crud to desense your otherwise good system. I understand that there is a document on the RB site about refurbing that antenna. You may have heard this before. Good Luck, Eric (W1EL) Eric Lowell Eastern Maine Electronics Inc. 48 Loon Road Wesley ME 04686 eme@... www.satnetmaine.com --- On Tue, 10/6/09, W3ML w...@... wrote: From: W3ML w...@... Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments To: Repeater-Builder@yahoogroups.com Date: Tuesday, October 6, 2009, 5:36 PM Well Chuck, there will be no new radio unless I buy it out of my pocket and that won't happen as I need a new rotor. This club has no money. I was able to get a grant for emergency communications and that is how I ended up with the stuff we have now. My big problem seems to be that I took this radio in for free instead of buying one from that ham in Florida that sells GEs for repeaters. As I have said before being a ham for 30 years now has taught me nothing about the maintenance of a repeater. I have built rigs before and trouble shot many a good HF radio, and now I am actually somewhat having fun playing with this thing. I have done more reading on repeaters than I have at my regular job and that is the Teaching of English Literature. Of course if we were to buy a new one, hi hi, then there would be nothing to learn and we all need to keep learning to keep our brains working. I really appreciate everyone on here helping out not only myself, but the others that come on here who need help and are just starting out in this area of ham radio like me. 73 John --- In Repeater-Builder@ yahoogroups. com, Chuck Kelsey wb2edv@ wrote: John - A word of caution may be in order since you are dealing with a club. These days, the typical ham doesn't begin to comprehend the complexity of a repeater system. To many, one simply needs to go out a purchase new equipment, plug it all together, and it runs. Wrong! Don't let your club go down that path. The end result will be lots of money being spent and unhappy results. I've watched it happen. If you are running a repeater, you WILL have problems with it, no matter what brand of equipment you use, no matter if it's new or used. You appear to be taking the steps to learn about it. It's the only way you'll be able to cope unless the club pays a commercial two-way shop to maintain the system. In the meantime, keep plugging away. It can get very frustrating at times. Chuck WB2EDV - Original Message - I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
--- On Tue, 10/6/09, W3ML w...@arrl.net wrote: From: W3ML w...@arrl.net Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments To: Repeater-Builder@yahoogroups.com Date: Tuesday, October 6, 2009, 5:36 PM Well Chuck, there will be no new As I have said before being a ham for 30 years now has taught me nothing about the maintenance of a repeater. I have built rigs before and trouble shot many a good HF radio, and now I am actually somewhat having fun playing with this thing. I have done more reading on repeaters than I have at my regular job and that is the Teaching of English Literature. When getting into the ham radio repeater business, have a good hammer ready. Either hit the repeater, the users or just hit yourself in the head. I have been messing with the repeaters for over 30 years and have felt like doing all three.
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w...@... wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over the place. Any reason you cannot run it at least 1/2-2/3 power? Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 4:46 PM, W3ML w3ml@ wrote: So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. Yahoo! Groups Links
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w...@arrl.net To: Repeater-Builder@yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w...@... wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over the place. Any reason you cannot run it at least 1/2-2/3 power? Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 4:46 PM, W3ML w3ml@ wrote: So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. Yahoo! Groups Links Yahoo! Groups Links
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Hello W3ML, I've been following this thread over the weekend and I think the issue has been addressed. I would check the antenna and related connectors. In fact, for my 2 cents, I'd replace the G7 with a commercial grade antenna, such as a DB product or equal. Now, to your scenario today, I would ask what the wind was like? If memory serves me correctly, that G7 has a couple of joints and is somewhat flimsy in terms of material strength and antenna height. There ya go, thp W3ML wrote: Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w...@... wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over the place. Any reason you cannot run it at least 1/2-2/3 power? Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 4:46 PM, W3ML w3ml@ wrote: So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. Yahoo! Groups Links
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
I've been following it too. You can lead a horse to water, but you can't make him drink. K4LJP On Mon, Oct 5, 2009 at 8:49 PM, Tom Parker t...@ntin.net wrote: Hello W3ML, I've been following this thread over the weekend and I think the issue has been addressed. I would check the antenna and related connectors. In fact, for my 2 cents, I'd replace the G7 with a commercial grade antenna, such as a DB product or equal. Now, to your scenario today, I would ask what the wind was like? If memory serves me correctly, that G7 has a couple of joints and is somewhat flimsy in terms of material strength and antenna height. There ya go, thp W3ML wrote: Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w...@... w...@... wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over the place. Any reason you cannot run it at least 1/2-2/3 power? Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 4:46 PM, W3ML w3ml@ wrote: So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. Yahoo! Groups Links -- Always drink upstream from the herd.
RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Sounds like he has a noise source near by causing him his problems. Probably not in the repeater at all. Had similar experience with a 50 mhz repeater located on a mountain top. Grounding wasn't the best and any noise generated by the wind moving the towers made the repeater at times almost unusable. Times signals were full quieting and then they were noisy. David -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Monday, October 05, 2009 7:47 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w...@arrl.net mailto:w3ml%40arrl.net To: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w...@... wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Tom, The wind was calm today and knowing that the sections tend to work loose, we screwed them together with sheet metal screws. I would like to get a DB antenna but 700 bucks is not in our budget. 73 John --- In Repeater-Builder@yahoogroups.com, Tom Parker t...@... wrote: Hello W3ML, I've been following this thread over the weekend and I think the issue has been addressed. I would check the antenna and related connectors. In fact, for my 2 cents, I'd replace the G7 with a commercial grade antenna, such as a DB product or equal. Now, to your scenario today, I would ask what the wind was like? If memory serves me correctly, that G7 has a couple of joints and is somewhat flimsy in terms of material strength and antenna height. There ya go, thp W3ML wrote: Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w3ml@ wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over the place. Any reason you cannot run it at least 1/2-2/3 power? Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 4:46 PM, W3ML w3ml@ wrote: So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. Yahoo! Groups Links
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2...@... wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w...@... To: Repeater-Builder@yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com, W9SRV tgundo2003@ wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my iPhone On Oct 4, 2009, at 5:46 PM, W3ML w3ml@ wrote: No, except when it was at the 2o watts the swr was almost 1 and someone said that was the problem causing the de-sense. So we were afraid to run it higher. Like you said guess it was only a problem from running too little of power. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com, W9SRV tgundo2003@ wrote: You answered your own question : So it appears that this radio, which is a GE Mastr II mobile, doesn't like to run at the lower wattage of 10 to 20 watts out. 110w radio will not be stable at 10-20w. If you look at your output on a spectrum you probably have spurs all over
RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2...@... wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Mastr II is a good radio. Likely not much wrong with it. They're a great deal better than most of what you buy today; however, we're pretty impressed with the Kenwood TKR's in our shop for mid tier units. Our 22 trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of MSR 2000's and one site of R1225's with Henry amps. Most are five channel and up. The TKR's are in stand alone situations or conventional users who own their on. You ought to stick with what you have and work out the problems or get some help. thp W3ML wrote: I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Chuck Kelsey wb2...@... wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w...@... To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check the power coming out of the cans. You should see something like 60-70w, depending on the spec of the duplexer. If your seeing much less than you may have a duplexer tuning issue. Figure out the real problem, let the radio run at a real spec power output, than absorb the title of far lord as every one thanks you for giving the repeater twice as many s-units. (then be prepared for the next round of complaints that become your problem) Tom W9SRV Sent from my
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Mark, I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML --- In Repeater-Builder@yahoogroups.com, Mark n9...@... wrote: John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Tom, Getting help around here is the hard part. I am the most experience and that is mostly from book reading and now a little playing around with the radio. No one else knows anything about repeaters either. We are just now getting into the repeater stage for our club. 73 John --- In Repeater-Builder@yahoogroups.com, Tom Parker t...@... wrote: Mastr II is a good radio. Likely not much wrong with it. They're a great deal better than most of what you buy today; however, we're pretty impressed with the Kenwood TKR's in our shop for mid tier units. Our 22 trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of MSR 2000's and one site of R1225's with Henry amps. Most are five channel and up. The TKR's are in stand alone situations or conventional users who own their on. You ought to stick with what you have and work out the problems or get some help. thp W3ML wrote: I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w3ml@ To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, W9SRV tgundo2003@ wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Well then, that's what everyone on this group is here for. All you have to do is ask, and you've done that. All the advice tonight is valid, so now you need to make some measurements. You definitely need an iso-tee, and good watt meter, i.e., Bird or Telewave, and a service monitor with at least a spectrum analyser would be a good start. Read the RB page and follow the suggestions. We actually had a couple of Mastr II mobiles rigged as repeaters, but we didn't de-rate the PA's. They saw heavy use with zero problems for over ten years before we replaced them with stations. Of course the tower building was a constant 74oF in the Texas sun and the A/C ran most of the winter. It's a shame there's not another antenna on the tower you could borrow for a few minutes. thp W3ML wrote: Thanks Tom, Getting help around here is the hard part. I am the most experience and that is mostly from book reading and now a little playing around with the radio. No one else knows anything about repeaters either. We are just now getting into the repeater stage for our club. 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Tom Parker t...@... wrote: Mastr II is a good radio. Likely not much wrong with it. They're a great deal better than most of what you buy today; however, we're pretty impressed with the Kenwood TKR's in our shop for mid tier units. Our 22 trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of MSR 2000's and one site of R1225's with Henry amps. Most are five channel and up. The TKR's are in stand alone situations or conventional users who own their on. You ought to stick with what you have and work out the problems or get some help. thp W3ML wrote: I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w3ml@ To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided
RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
John, One thing to keep in mind about a particular PA's tendency to go spurious is that it will probably be well-behaved when tested on the bench while feeding a dummy load. A good dummy load is purely resistive, while a duplexer input is highly reactive- just what a flaky PA needs as a trigger to become unstable. Any additional triggers, such as loose connections, aging coax, or an antenna with loose elements, can quickly become a nightmare. It may be helpful to monitor your repeater's emissions on a spectrum analyzer when the noise occurs. Use a short whip on the analyzer to pick up the signal- don't connect into the feedline at all, since doing so will upset the conditions you want to monitor. It's possible that the radio itself may have a problem, and I don't think that has been ruled out yet. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML Sent: Monday, October 05, 2009 7:25 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Thanks Mark, I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Mark n9...@... wrote: John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Thanks Tom, Yes, the advice is all good and I have tried several of the suggestions and most, if not all, did help some. Tomorrow, I will turn it up to 70 watts out, which should give me 60 out of the duplexer, if it works like it does not at 55 and 45 out. Then we will see what happens. In fact I did hook it up to another antenna on an adjacent tower. It worked worse than the G7. Funny thing is when I hook the G7 to a regular 2 meter radio and transmit on simplex, it works really well, hearing stations far a way and putting out a solid signal. 73 John --- In Repeater-Builder@yahoogroups.com, Tom Parker t...@... wrote: Well then, that's what everyone on this group is here for. All you have to do is ask, and you've done that. All the advice tonight is valid, so now you need to make some measurements. You definitely need an iso-tee, and good watt meter, i.e., Bird or Telewave, and a service monitor with at least a spectrum analyser would be a good start. Read the RB page and follow the suggestions. We actually had a couple of Mastr II mobiles rigged as repeaters, but we didn't de-rate the PA's. They saw heavy use with zero problems for over ten years before we replaced them with stations. Of course the tower building was a constant 74oF in the Texas sun and the A/C ran most of the winter. It's a shame there's not another antenna on the tower you could borrow for a few minutes. thp W3ML wrote: Thanks Tom, Getting help around here is the hard part. I am the most experience and that is mostly from book reading and now a little playing around with the radio. No one else knows anything about repeaters either. We are just now getting into the repeater stage for our club. 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Tom Parker thp@ wrote: Mastr II is a good radio. Likely not much wrong with it. They're a great deal better than most of what you buy today; however, we're pretty impressed with the Kenwood TKR's in our shop for mid tier units. Our 22 trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of MSR 2000's and one site of R1225's with Henry amps. Most are five channel and up. The TKR's are in stand alone situations or conventional users who own their on. You ought to stick with what you have and work out the problems or get some help. thp W3ML wrote: I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w3ml@ To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, October 05, 2009 8:33 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would
[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
I agree Eric, it might be the radio or it could be the old coax and old antenna. Finding an spectrum analyzer is the trick. The one ham that I know who has one had a heart attack and won't be able to visit for some time. So, I keep trying the little suggestions without one to see how much I can improve it. Thanks and 73 John --- In Repeater-Builder@yahoogroups.com, Eric Lemmon wb6...@... wrote: John, One thing to keep in mind about a particular PA's tendency to go spurious is that it will probably be well-behaved when tested on the bench while feeding a dummy load. A good dummy load is purely resistive, while a duplexer input is highly reactive- just what a flaky PA needs as a trigger to become unstable. Any additional triggers, such as loose connections, aging coax, or an antenna with loose elements, can quickly become a nightmare. It may be helpful to monitor your repeater's emissions on a spectrum analyzer when the noise occurs. Use a short whip on the analyzer to pick up the signal- don't connect into the feedline at all, since doing so will upset the conditions you want to monitor. It's possible that the radio itself may have a problem, and I don't think that has been ruled out yet. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML Sent: Monday, October 05, 2009 7:25 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Thanks Mark, I will go read that article. Thought I read them all, since January, trying to learn all I can. That is when I decided to get into this repeater business. It has been a great learning experience for sure. 73 John, W3ML --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Mark n9wys@ wrote: John, I'll chime in here and agree with Chuck's suggestion to try a little more fire in the wire... It sounds as if your PA is less spurious now than before, but you need to dial it up more to eliminate all the spurious products. Solid state PAs, especially mobiles, are noted for this when run at considerably less than rated output. If I remember the beginning of the thread, this was a Mastr-II mobile... Seems as if I remember a rule of thumb that a solid state PA won't be stable beginning around 60-70% of its rated output. If you're at 55W now, another 10-15W won't make much difference in the received signal strength, but will help a LOT to stabilize the PA. This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html http://www.repeater-builder.com/ge/mastrIIgeneral.html says not to run Mastr-II PAs at less than 40%. In your case, you're at about 50% now and still a little spurious, so... crank her up a tad more (to maybe 70W) and see if that clears it all up. ;-) The article also has other suggestions on how to deal with desense. 73, Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com On Behalf Of W3ML I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
That's typical. Duplex is a different animal. If there's a slight problem with a connection in the antenna, it will show up in duplex service. Chuck WB2EDV - Original Message - From: W3ML w...@arrl.net To: Repeater-Builder@yahoogroups.com Sent: Monday, October 05, 2009 10:54 PM Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Funny thing is when I hook the G7 to a regular 2 meter radio and transmit on simplex, it works really well, hearing stations far a way and putting out a solid signal. 73 John
RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Tom, You mentioned in an earlier posting that you had a six-cavity duplexer. Most six-cavity duplexers will have an insertion loss of about 2.25 dB, which means that with 70 watts in, you should see about 42 watts out. If you actually were measuring 45 watts out with 55 watts in, your duplexer has an insertion loss of only 0.9 dB. If your measurements are accurate, the duplexer tuning seems to be way off. What make and model duplexer is it? What instrument are you using to measure RF power? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML Sent: Monday, October 05, 2009 7:54 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments Thanks Tom, Yes, the advice is all good and I have tried several of the suggestions and most, if not all, did help some. Tomorrow, I will turn it up to 70 watts out, which should give me 60 out of the duplexer, if it works like it does not at 55 and 45 out. Then we will see what happens. In fact I did hook it up to another antenna on an adjacent tower. It worked worse than the G7. Funny thing is when I hook the G7 to a regular 2 meter radio and transmit on simplex, it works really well, hearing stations far a way and putting out a solid signal. 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Tom Parker t...@... wrote: Well then, that's what everyone on this group is here for. All you have to do is ask, and you've done that. All the advice tonight is valid, so now you need to make some measurements. You definitely need an iso-tee, and good watt meter, i.e., Bird or Telewave, and a service monitor with at least a spectrum analyser would be a good start. Read the RB page and follow the suggestions. We actually had a couple of Mastr II mobiles rigged as repeaters, but we didn't de-rate the PA's. They saw heavy use with zero problems for over ten years before we replaced them with stations. Of course the tower building was a constant 74oF in the Texas sun and the A/C ran most of the winter. It's a shame there's not another antenna on the tower you could borrow for a few minutes. thp W3ML wrote: Thanks Tom, Getting help around here is the hard part. I am the most experience and that is mostly from book reading and now a little playing around with the radio. No one else knows anything about repeaters either. We are just now getting into the repeater stage for our club. 73 John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Tom Parker thp@ wrote: Mastr II is a good radio. Likely not much wrong with it. They're a great deal better than most of what you buy today; however, we're pretty impressed with the Kenwood TKR's in our shop for mid tier units. Our 22 trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of MSR 2000's and one site of R1225's with Henry amps. Most are five channel and up. The TKR's are in stand alone situations or conventional users who own their on. You ought to stick with what you have and work out the problems or get some help. thp W3ML wrote: I probably will turn it up more to see what happens. When I had it at 5 watts out we had no problems at all. Over the 10 watts is when the noise was really bad. Now at 55 it works and then it doesn't and then it works again. So, yes I still have something wrong and maybe one of these days I will get another grant and convince the club to buy another GE Mastr II and and a new antenna and coax. Maybe that will fix it. People we got radio from are not answering. John --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I'd suggest turning the power up more. You have it set at about 50% and the transmitter may be intermittently spurious at that level. Watch the wattmeter when things act up and see if anything changes when you notice the desense happening. You can also pull the TX ICOM when the problem is happening and see if the receive clears up on the local speaker. There are so many things that could be at fault - loose connector, bad antenna, problem with transmitter, problem with receiver, intermod issue, etc. Ask the people you got the radio from if they had the same problem with it. Chuck WB2EDV - Original Message - From: W3ML w3ml@ To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Well, you don't really need my input, you certainly have gotten plenty of quality responses tonight... Don't let the flurry of ideas overwhelm you. Take it one step at a time. You still might be too low on the power output. I had a transmitter that didnt like to be turned down less than 2/3 rated power, at 1/2 power it would create problems on the reciever, its spurs would mix with some local 2-way stuff and come thru on the receiver from time to time, had me convinced it was local interference and I needed filtering. Turning up the power solved the problem. KISS method is always a worth a try. There are way more qualified guys on the list here to help you, but here is what I would do (without having a spectrum analyzer to look at your output): 1. Terminate the TX into a dummy load. Turn the power up to 80W. Key the transmitter for a good long time and get it warmed up. Keep your wattmeter in line and watch it, make sure it stays stable at 80W. If you notice it acting up then you have a problem in the radio. If not- go to step two. 2. Once the transmitter is nice and warmed up have someone with a weaker signal start giving you a signal on the input. Leave the transmitter hooked up to the dummy load for this test and the reciever hooked up to the antenna system. First, disable the transmitter and have them continue transmissions while you monitor the input. It may take several tests like this if it is outside interference, since it's likely not consistent. Try and notate any particular times of day the noise happens to get a better clue into this. If you do hear the noise, then you know its interference or something in the antenna system. If not, then move on to step three. 3. With your friend still sending a signal on the input enable the transmitter into the dummy load. If the noise appears then something in the radio is amiss, like the PA is going spurious or there's a bad jumper or connector somewhere . If not- move onto step four. 4. Reconnect everything back to normal. Leave the power level at 80W. If the noise re-appears then you still need to look into the antenna system. The G7 could have a problem, or something in the feedline. If all is well then it was likely the power level of the PA was still too low. Problem solved! Hopefully one of these steps without the proper test gear will get you pointed in the right direction. Let us know your findings! Tom W9SRV --- On Mon, 10/5/09, W3ML w...@arrl.net wrote: From: W3ML w...@arrl.net Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments To: Repeater-Builder@yahoogroups.com Date: Monday, October 5, 2009, 7:33 PM Hi Tom, I did crank up the power to 55 watts out of radio and that gives me 45 out of the duplexer. Decided on this wattage until I can figure the problem better. It is working better than before, but still having trouble. So from what you said about power coming out duplexer, the duplexer must still be okay. However, during the day today there were 3 hams talking and they said (later) that all of them were loud and clear. But, when I got home and tried to call one of them, he was covered in noise. Later one of the others called in and he would be clear, then the repeater would cut out and his signal would be gone, then it would come back with noise on his signal and then clear again. Then the other one came in with a lot of noise, then he would come in with a little noise and then no noise at all and then back again through this cycle. This cycle of noise and then no noise is driving me crazy. The set up is this: GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a service monitor prior to bringing it here. There is a bandpass filter on the receive side after the duplexer and before the radio. We have used 1/2 inch hardline going up to the used G7-144. Then only thing I can think of is the radio is bad, the antenna is no good and the coax is shot. Now, the radio was given to us by a group that had used it, but decided to replace it with a Kenwood. I am thinking that they had the same problem and that is why they gave it away. Any advice would be greatly appreciated. 73 John, W3ML - In Repeater-Builder@yahoogroups.com, W9SRV tgundo2...@... wrote: Ok- 1. Where are you checking the swr at in the chain? Make sure you bypass the duplexers to check the antenna, the cans can throw off the reading on some meters like you describe using. If you are less than 1.5:1 I would not worry too much more about it, any reflected power will get eaten up back in the cans. If you are really concerned about protecting the TX put a circulator in-line with it. 2. Make sure all the interconnecting cables are good shielded and not foil/ braid type. RG-213 and RG-400 are good choices, though there are a few more. 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run thru the duplexer and check
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
Just throwing a side-comment in here... How do you know if a PA is spurious or if you're bothering your spectrum neighbors? You MUST MEASURE IT. Beg, borrow, or steal the proper test gear for working on repeaters and this whole process of elimination by e-mail disappears... Spectrum analyzer, and/or a good RF Service Monitor, a known good- quality dummy load, bias T or directional coupler, high-quality double-shielded test cables, Bird or other good quality Wattmeter... all these things really SHOULD make their way into any Repeater- Builder's box of tricks, sooner or later. We've ALL seen repeaters that worked the 1st time out without measuring anything. We've all also seen repeater owners fight and claw and struggle for months trying to figure out a problem, without the proper test gear, and wondering if they'll ever figure it out. It's s much less time-consuming and easier to just measure the repeater and find the problem than to go back and forth with symptoms and possible solutions. When I started reading this thread, my first thought was desense isn't caused by changes in RF power. Of course, I also thought, The MASTR II PA is known for going spurious at low power settings, wonder which PA he has... the little one with only a driver, or a 110W one that could likely freak out at that low a power. Then the new symptom that measured SWR was changing with power level... Oh man, that thing's probably throwing spurs, I thought to myself... but... I kinda refuse to get into guessing games. It just leads to making more problems you have to fix later if we all guess wrong. The way to find out if the PA is spurring, is to look at the output of the repeater on a Spectrum Analyzer. (And if you don't know, how do you know you're within your coordinated repeater spectrum limits? Is there an adjacent pair repeater above/ below you? Do you owe it to them to KNOW and not be guessing?) Trying to troubleshoot repeaters without begging, borrowing, or stealing the proper test gear, is kinda like shooting fish in a barrel, but in a dark cave with no lights on... You might hit the fish, or you might blow your foot off. Don't wait until the adjacent repeater pair repeater owner sends you and the coordinator a nasty-gram. Ya know? If you're throwing spurs, you need to fix your station... and if you don't know if you're throwing spurs, you need to find out... and the only way to do that is... Measure it. -- Nate Duehr, WY0X n...@natetech.com
Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments
P.S. Before I get flame-broiled by the group for being mean... Realize that I'm not an ogre, and the answers you're getting from other folks might sound more friendly, and so far, they're all leading the right direction too, it'll just be a long journey to get there without the proper test gear. None of the below is meant in anger or in any way negative. In fact, you MUST imagine me asking the questions below with a twinkle in my eye and a friendly inquisitive but forceful demeanor to get how I would ask the questions in person, if they were posed on the phone, or face-to-face. A repeater guru who taught me once asked, with that same twinkle in his eye, right after I said that I thought XYZ was wrong with my repeater... Are you a thinkin' man, or are you a KNOWIN' man? :-) --- NOTE BIG SMILE... and a real one on my face, typing this. Here's something I've always wanted to do, but never had time... write up the learning process I personally went through, including ALL of the annoying things I've chased and troubleshot on repeaters that led me to buy (or beg, or steal... okay, not steal... but you know what I mean) the right test gear over the last number of years. All those learning experiences put together in story format, might convince someone that: a) Repeater operation just isn't for them. b) Repeater operation is just bloody expensive to do right. c) Repeater operators are crazy and often spend as much time/money/ effort on really well done repeaters as the most crazed HF contester does on his station. (Yep! That's it!) Nate WY0X On Oct 5, 2009, at 11:37 PM, Nate Duehr wrote: Just throwing a side-comment in here... How do you know if a PA is spurious or if you're bothering your spectrum neighbors? You MUST MEASURE IT. Beg, borrow, or steal the proper test gear for working on repeaters and this whole process of elimination by e-mail disappears... Spectrum analyzer, and/or a good RF Service Monitor, a known good- quality dummy load, bias T or directional coupler, high-quality double-shielded test cables, Bird or other good quality Wattmeter... all these things really SHOULD make their way into any Repeater- Builder's box of tricks, sooner or later. We've ALL seen repeaters that worked the 1st time out without measuring anything. We've all also seen repeater owners fight and claw and struggle for months trying to figure out a problem, without the proper test gear, and wondering if they'll ever figure it out. It's s much less time-consuming and easier to just measure the repeater and find the problem than to go back and forth with symptoms and possible solutions. When I started reading this thread, my first thought was desense isn't caused by changes in RF power. Of course, I also thought, The MASTR II PA is known for going spurious at low power settings, wonder which PA he has... the little one with only a driver, or a 110W one that could likely freak out at that low a power. Then the new symptom that measured SWR was changing with power level... Oh man, that thing's probably throwing spurs, I thought to myself... but... I kinda refuse to get into guessing games. It just leads to making more problems you have to fix later if we all guess wrong. The way to find out if the PA is spurring, is to look at the output of the repeater on a Spectrum Analyzer. (And if you don't know, how do you know you're within your coordinated repeater spectrum limits? Is there an adjacent pair repeater above/ below you? Do you owe it to them to KNOW and not be guessing?) Trying to troubleshoot repeaters without begging, borrowing, or stealing the proper test gear, is kinda like shooting fish in a barrel, but in a dark cave with no lights on... You might hit the fish, or you might blow your foot off. Don't wait until the adjacent repeater pair repeater owner sends you and the coordinator a nasty-gram. Ya know? If you're throwing spurs, you need to fix your station... and if you don't know if you're throwing spurs, you need to find out... and the only way to do that is... Measure it. -- Nate Duehr, WY0X n...@natetech.com
