[Repeater-Builder] Mitreks as UHF Repeaters?
After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR
Re: [Repeater-Builder] Re: how far
On Sun, 25 Apr 2010, George wrote: well this amplifier is rated 90 watts you can see it on e-bay just type powerwave in the search. it has error eliminating computer inside and no distortion what so ever. i have it modified and use it at 450 watts and i pushed it with two power supplys that can put more than 120 ampers at 24 volts. the antenna is rated at 500 watts... i wonder why woud they do that...just to put out 5 watts? power over bandwidth. 90W on a 200KHz channel, combined with other channels... Take all that power amplification capability, and put it into a single carrier +/-4.5KHz wide and you've got a nice large peak on the spectrum analyzer. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: how far
On Sun, 25 Apr 2010, Joe wrote: Just be careful. At the ERP antenna output levels that you are playing with and frequencies involved, things can get dangerous for human exposure. Anything above 50W, an OET 65 RF Field Study must be done. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] GE amp
Eric Thanks for the confirmation. I found a Micor UHF amp so will use that and put the GE on the shelf. Larry
[Repeater-Builder] Re: how far
This is entirely right! --- In Repeater-Builder@yahoogroups.com, Kris Kirby k...@... wrote: On Sun, 25 Apr 2010, George wrote: well this amplifier is rated 90 watts you can see it on e-bay just type powerwave in the search. it has error eliminating computer inside and no distortion what so ever. i have it modified and use it at 450 watts and i pushed it with two power supplys that can put more than 120 ampers at 24 volts. the antenna is rated at 500 watts... i wonder why woud they do that...just to put out 5 watts? power over bandwidth. 90W on a 200KHz channel, combined with other channels... Take all that power amplification capability, and put it into a single carrier +/-4.5KHz wide and you've got a nice large peak on the spectrum analyzer. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] AC buzz on VHF
Hello all, I am in the process of putting up a 2M repeater on what I would consider a pretty vacant site. There is only one other machine (70cm Repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actuall signal you can here it. We have heard this on both handhelds and mobiles. This site is unique as it is a duel tower with old (unused)Microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM reciever. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT
RE: [Repeater-Builder] AC buzz on VHF
Start here: http://www.arrl.org/radio-frequency-interference-rfi GL, 73, john WA1ABI
RE: [Repeater-Builder] AC buzz on VHF
Wade, This sounds like a defective insulator or cable clamp sparking on a power pole. Such interference can carry for many miles. Try using a portable radio with a handheld Yagi antenna to pinpoint the source. The power company must repair this defect. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kc0mlt Sent: Monday, April 26, 2010 7:24 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] AC buzz on VHF Hello all, I am in the process of putting up a 2m repeater on what I would consider a pretty vacant site. There is only one other machine (70cm repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actual signal you can hear it. We have heard this on both handhelds and mobiles. This site is unique as it is a dual tower with old (unused) microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM receiver. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT
Re: [Repeater-Builder] AC buzz on VHF
How do they power the site if the nearest HV is over a mile away? I suspect when you say HV, you mean transmission voltages. However, distribution voltages are pretty high - 2.4 KV and up. Chuck WB2EDV - Original Message - From: Eric Lemmon wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:36 AM Subject: RE: [Repeater-Builder] AC buzz on VHF Wade, This sounds like a defective insulator or cable clamp sparking on a power pole. Such interference can carry for many miles. Try using a portable radio with a handheld Yagi antenna to pinpoint the source. The power company must repair this defect. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kc0mlt Sent: Monday, April 26, 2010 7:24 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] AC buzz on VHF Hello all, I am in the process of putting up a 2m repeater on what I would consider a pretty vacant site. There is only one other machine (70cm repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actual signal you can hear it. We have heard this on both handhelds and mobiles. This site is unique as it is a dual tower with old (unused) microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM receiver. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.814 / Virus Database: 271.1.1/2836 - Release Date: 04/26/10 02:31:00
Re: [Repeater-Builder] AC buzz on VHF
Distribution voltages begin at 2,400 and go to 34,500 volts. Transmission voltages begin at ... depends upon the utility. Could be 46,000, 69,000 or 115,000. Anyway... it's not the voltage. It's simply there is a device issue somewhere on a power line. Could be a bad connector. A bad transformer. A bad lightning arrester. A bad switch. A bad insulator. Bottom line, something is breaking down and creating this buzz. Begin by driving around the area and narrowing the area down. Then with a small yagi try to pin point things down to a few poles, or THE pole. Some electric companies have staff that can assist with RFI, and some do not. Don't assume they do. If you have questions, drop me a line. 73, Kim - WG8S
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Good question Paul. Remember the Mitrek RF decks are almost the same used in the MSR2000 repeater, and with their tuned helical front end make great receivers. For the transmitter however, I would not run it on its own. Also reducing the power output below 50-66% of rating might cause spurious issues. The best is to get a manual and bypass the PA, running driver power only. Then use an external amp to get your power up to where you need it. This is how every Micor, MSR, MSF repeater is designed. Motorola typically spec'd transmitters at 70.7% to get the best balance from the parts, and typically used multiple stages to get there (i.e. 200mW-2W-15W-50W). I recently picked up two 50W Mitrek Plus models that I will be using for linking duty, and will be bypassing the PA on those as well. At only 10 miles driver power only should work, but I have yet to complete that phase. Good luck on your project! You'll never know what duty cycle is needed during an event, so better to overprepare than worry. Tony On 04/26/2010 01:47 AM, Paul Plack wrote: After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR
RE: [Repeater-Builder] AC buzz on VHF
Remote hilltop sites are very often fed with a lateral power line that taps off from a major distribution line that could be miles away. If nothing but the hilltop site is on that lateral, and with the site owner's permission, the power utility can pull the cutout fuses to kill the lateral circuit. If the AC buzz goes away, the utility crews must find and correct the problem. As Kim points out, there are many possible causes of noise problems. Question: Does the noise change or go away when it rains? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of whensle...@comcast.net Sent: Monday, April 26, 2010 7:59 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] AC buzz on VHF Distribution voltages begin at 2,400 and go to 34,500 volts. Transmission voltages begin at ... depends upon the utility. Could be 46,000, 69,000 or 115,000. Anyway... it's not the voltage. It's simply there is a device issue somewhere on a power line. Could be a bad connector. A bad transformer. A bad lightning arrester. A bad switch. A bad insulator. Bottom line, something is breaking down and creating this buzz. Begin by driving around the area and narrowing the area down. Then with a small yagi try to pin point things down to a few poles, or THE pole. Some electric companies have staff that can assist with RFI, and some do not. Don't assume they do. If you have questions, drop me a line. 73, Kim - WG8S
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
I've used a lot of Mitreks as repeaters and loved them, but you're right about the PA -- if you don't like fans, it's going to get too hot. Consider getting the exciter output after the helical filters and use a different PA. I have a couple of Mitreks stashed in a corner somewhere just in case -- I've moved on to newer synthesized stuff, but I know in a pinch I can have one up and running as a repeater with a couple hours of work. On Apr 26, 2010, at 1:47 AM, Paul Plack wrote: After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR -- Cort Buffington H: +1-785-838-3034 M: +1-785-865-7206 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] MTR2000 CTCSS
I am brand new to this group. I am setting up a MTR2000 with an ARCOM RC210 controller. All is going well until I get to the CTCSS encode/decode. How do you set this up? There is a pin on the MTR called Rx Un-squelched. Is that where I should get the CTCSS audio out from the MTR? Then what? Thanks Stan
Re: [Repeater-Builder] Re: how far
Kevin - I'd like a copy for our files as well, just in case. Thanks! John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn - Original Message - From: kevin valentino To: Repeater-Builder@yahoogroups.com Sent: Saturday, April 24, 2010 9:40 PM Subject: Re: [Repeater-Builder] Re: how far Sent the program to George, Bon Hal. If anyone else wants a copy you can ask myself or them. Please do not post It in a file section on any groups, (I look in those), It's copyrighted. It's nothing fancy but does a fairly good job with some nice little utilities to boot. Old as dirt but hey I did'nt pay for it either. To the ones that get it, please let me know how you like it. I have another that's great for calculating transformers and other such good junk. Enjoy --- On Sat, 4/24/10, kevin valentino kevinvalent...@sbcglobal.net wrote: From: kevin valentino kevinvalent...@sbcglobal.net Subject: Re: [Repeater-Builder] Re: how far To: Repeater-Builder@yahoogroups.com Date: Saturday, April 24, 2010, 10:31 PM Allright just found the darn program. Was on an older machine. Norton picks up a virus, ARRGH, so i will remove it and send it to ypu. You can share this amongst yourselves but I would appreciate if you DID NOT upload it to any files section of ANY group , it is copyrighted. Back to removing the NYB, wish me luck --- On Sat, 4/24/10, kevin valentino kevinvalentino@ sbcglobal. net wrote: From: kevin valentino kevinvalentino@ sbcglobal. net Subject: Re: [Repeater-Builder] Re: how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 9:00 PM OK there is a cute little program that actually comes fairly close to calculating effective radio range based on height, power, line loss(has a cable database), and frequency. Add the cavity losses in with the line loss. Calculate the portable at 6 feet, unity gain, using worst case terrain type scenario. I will send it to you. --- On Sat, 4/24/10, George gueorg...@yahoo. com wrote: From: George gueorg...@yahoo. com Subject: [Repeater-Builder] Re: how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 8:43 PM ok the antenna is from cell site 14dbm 4-element in a plastic housing, the amplifier is 600 watts capable linear mosfet 8element hybrid splitters and combiners... but the power supply is up to 65 ampers at 24 volts, driven by a C class 130 watt amplifier. the antenna is not on a commercial tower (no luck here). 20 feet above the house. the line is heliax andrew semi-rigid. the repeater is in the attic and the line is 30feet. the duplexer is celwave doesn't like more than 450 watts in. --- In Repeater-Builder@ yahoogroups. com, kevin valentino kevinvalentino@ ... wrote: Any approximation would depend on the repeater antenna height and the terrain of the area. I would hate to see the price tag on an 800MHZ 450W amplifier :-) I do mean literally approximation. Many factors come into play. Especially at high frequencies. The length and type of the antenna feedline, gain of antenna used, etc. --- On Sat, 4/24/10, George gueorg...@. .. wrote: From: George gueorg...@. .. Subject: [Repeater-Builder] how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 7:24 PM Â what is the range of a 800mhz handheld 4watts with msf5000 repeater 450watts on the antena
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
I converted a UHF Mitrek for full duplex packet operation once. Don't recommend it because the Mitrek rx and tx are on a single board which results in transmit chain spurs and harmonics getting into the rx. The task required a spectrum analyzer and several hours experimenting with various shielding and filtering techniques to get the rx desense down to a reasonable level. 73 de Jack - N7OO - Original Message - From: Tony KT9AC To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 8:09 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Good question Paul. Remember the Mitrek RF decks are almost the same used in the MSR2000 repeater, and with their tuned helical front end make great receivers. For the transmitter however, I would not run it on its own. Also reducing the power output below 50-66% of rating might cause spurious issues. The best is to get a manual and bypass the PA, running driver power only. Then use an external amp to get your power up to where you need it. This is how every Micor, MSR, MSF repeater is designed. Motorola typically spec'd transmitters at 70.7% to get the best balance from the parts, and typically used multiple stages to get there (i.e. 200mW-2W-15W-50W). I recently picked up two 50W Mitrek Plus models that I will be using for linking duty, and will be bypassing the PA on those as well. At only 10 miles driver power only should work, but I have yet to complete that phase. Good luck on your project! You'll never know what duty cycle is needed during an event, so better to overprepare than worry. Tony On 04/26/2010 01:47 AM, Paul Plack wrote: After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR --
Re: [Repeater-Builder] AC buzz on VHF
I have found tracking to be pretty easy using my ham mobile tuned to an AM aircraft frequency and open the squelch. Gets you down to the individual pole. Chuck WB2EDV - Original Message - From: Eric Lemmon wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 11:13 AM Subject: RE: [Repeater-Builder] AC buzz on VHF Remote hilltop sites are very often fed with a lateral power line that taps off from a major distribution line that could be miles away. If nothing but the hilltop site is on that lateral, and with the site owner's permission, the power utility can pull the cutout fuses to kill the lateral circuit. If the AC buzz goes away, the utility crews must find and correct the problem. As Kim points out, there are many possible causes of noise problems. Question: Does the noise change or go away when it rains? 73, Eric Lemmon WB6FLY
Re: [Repeater-Builder] AC buzz on VHF
Could also be a ground loop in the audio chain somewhere...start lifting shields one at a time in the repeat audio chain and see if it goes away. On 4/26/2010 10:36 AM, Eric Lemmon wrote: Wade, This sounds like a defective insulator or cable clamp sparking on a power pole. Such interference can carry for many miles. Try using a portable radio with a handheld Yagi antenna to pinpoint the source. The power company must repair this defect. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kc0mlt Sent: Monday, April 26, 2010 7:24 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] AC buzz on VHF Hello all, I am in the process of putting up a 2m repeater on what I would consider a pretty vacant site. There is only one other machine (70cm repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actual signal you can hear it. We have heard this on both handhelds and mobiles. This site is unique as it is a dual tower with old (unused) microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM receiver. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT
RE: [Repeater-Builder] MTR2000 CTCSS
Stan, You can find the answers to many questions on the MTR2000 pages, here: www.repeater-builder.com/motorola/mtr2k/mtr-index.html I'm curious: Since the MTR2000 has a very capable controller built-in, why use an external controller? There are some functions that will require the Auxiliary I/O card, and they're not cheap. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of wa2uet Sent: Monday, April 26, 2010 7:38 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] MTR2000 CTCSS I am brand new to this group. I am setting up a MTR2000 with an ARCOM RC210 controller. All is going well until I get to the CTCSS encode/decode. How do you set this up? There is a pin on the MTR called Rx Un-squelched. Is that where I should get the CTCSS audio out from the MTR? Then what? Thanks Stan
Re: [Repeater-Builder] MTR2000 CTCSS
At 07:37 AM 04/26/10, you wrote: I am brand new to this group. I am setting up a MTR2000 with an ARCOM RC210 controller. All is going well until I get to the CTCSS encode/decode. How do you set this up? There is a pin on the MTR called Rx Un-squelched. Is that where I should get the CTCSS audio out from the MTR? Then what? Thanks Stan Did you see this? http://www.repeater-builder.com/motorola/mtr2k/mtr-index.html Especially this - which specifically addresses your question... http://www.repeater-builder.com/motorola/mtr2k/mtr-interfacing/mtr2000-interfacing.html Mike WA6ILQ
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Isn't the rpt. going to be built using (2) Mitrex, thus shielding should not be a problem. I have, in the past (with the help of a Bridgeport mill), fashioned Larger Heatsinks, that bolt onto the orig. Mitrex heat sinkseems to dissipate heat well. I have an MSR-2000 (100w) rpt. that has been in service 15 yrs w/o a problem..really like the Mitrex design, and easy to replace discrete components, if need be! With two separate radios, controller and duplexersyou are off and running! Best Regards, Tim W7TRH Vashon Is. Wa. - Original Message - From: Jack Taylor j...@n7oo.com To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 8:27:44 AM GMT -08:00 US/Canada Pacific Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? I converted a UHF Mitrek for full duplex packet operation once. Don't recommend it because the Mitrek rx and tx are on a single board which results in transmit chain spurs and harmonics getting into the rx. The task required a spectrum analyzer and several hours experimenting with various shielding and filtering techniques to get the rx desense down to a reasonable level. 73 de Jack - N7OO - Original Message - From: Tony KT9AC To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 8:09 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Good question Paul. Remember the Mitrek RF decks are almost the same used in the MSR2000 repeater, and with their tuned helical front end make great receivers. For the transmitter however, I would not run it on its own. Also reducing the power output below 50-66% of rating might cause spurious issues. The best is to get a manual and bypass the PA, running driver power only. Then use an external amp to get your power up to where you need it. This is how every Micor, MSR, MSF repeater is designed. Motorola typically spec'd transmitters at 70.7% to get the best balance from the parts, and typically used multiple stages to get there (i.e. 200mW-2W-15W-50W). I recently picked up two 50W Mitrek Plus models that I will be using for linking duty, and will be bypassing the PA on those as well. At only 10 miles driver power only should work, but I have yet to complete that phase. Good luck on your project! You'll never know what duty cycle is needed during an event, so better to overprepare than worry. Tony On 04/26/2010 01:47 AM, Paul Plack wrote: After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR
Re: [Repeater-Builder] MTR2000 CTCSS
I want the external controller so that I can control 2 repeaters and a remote base from the same controller. Also I want to use some of the features on the Arcom controller. Stan From: Eric Lemmon Sent: Monday, April 26, 2010 11:50 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] MTR2000 CTCSS Stan, You can find the answers to many questions on the MTR2000 pages, here: www.repeater-builder.com/motorola/mtr2k/mtr-index.html I'm curious: Since the MTR2000 has a very capable controller built-in, why use an external controller? There are some functions that will require the Auxiliary I/O card, and they're not cheap. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of wa2uet Sent: Monday, April 26, 2010 7:38 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] MTR2000 CTCSS I am brand new to this group. I am setting up a MTR2000 with an ARCOM RC210 controller. All is going well until I get to the CTCSS encode/decode. How do you set this up? There is a pin on the MTR called Rx Un-squelched. Is that where I should get the CTCSS audio out from the MTR? Then what? Thanks Stan
Re: [Repeater-Builder] AC buzz on VHF
At 07:23 AM 04/26/10, you wrote: Hello all, I am in the process of putting up a 2M repeater on what I would consider a pretty vacant site. There is only one other machine (70cm Repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actuall signal you can here it. We have heard this on both handhelds and mobiles. This site is unique as it is a duel tower with old (unused)Microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM reciever. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT The way I'm reading this is that you are hearing an AC buzz (60hz) on a FM receiver listening to ANY VHF frequency at a site that has only one UHF repeater, and it's there even when the AC feeder to the site is totally dead, right? Look for a arcing insulator on a power pole. And it might be a rural cross-country high tension tower that is MILES away from any pavement. I had one of those a number of year ago, and it took using an AM receiver on the highest frequency we could monitor (initially the aircraft AM band. We got an initial bearing at the repeater site, and it pointed into a national forest !!! We went to other sites several miles away with the intent of getting cross bearings and couldn't hear it. So we fell back to plan B ... A friend was a pilot bit we could not figure out how to get a directional antenna onto an airplane, and we quickly figured out that the one airplane that had a loop antenna wasn't going to cut it... first, it was a twin and not only was the plane rental out of sight, but out pilot wasn't multi-rated, plus we couldn't afford to feed the twin radial engines. So we fell back to plan C. Look at this photo - it's somethign like what we used... http://www.ultralightnews.ca/sunfun02/images/lilbreeze.jpg We mounted a VHF beam under the fuselage.. The pilot (a ham) started at about 1500 feet over the repeater site and on an idle aircraft channel, then flew a circle to get an initial bearing, then flew towards the noise. By the way, the real initial bearing was about 20 degrees off of what we had from ground level at the repeater site. The noise peaked over a power line over 7 miles from the site the source but could have been any one of two dozen towers. He then switched to a PRO-43 handheld scanner set to AM and pretuned to the top of it's coverage range) and shielded so it was directional. The scanner was in a piece of plastic pipe lined with foil and grounded to the chassis. The tube was duct-taped to the ultralight frame and pointed downwards at about 30 degrees. Crude, but you could point it like a bazooka and get a noise peak. He was able to ID the individual power tower by flying over the power line until the noise peaked, then turning away and coming back at it from right angles to it and flying over each individual tower until he found which tower had that same peak. He bombed the ground near the particular tower with a bag of flour, then flew the access road to where it met the highway and noted where that was (anybody remember Sky King flour bombing from the Songbird? that's where he got the idea). All during this time he was in contact with us, the chase crew. We drove to the maintenance road access gate, drove to the tower, and could HEAR the arcing and zapping above us - no electronics needed ! We copied the tower ID number - and didn't take any chances, we used both pencil and paper and a 35mm camera! (Southern California Edison has a 10-character ID number on each tower) and reported it. SCE had WA6FQG (now SK) as their in-house RFI guy since the 1960s... and for many years he had a tech session at every ARRL Southwestern Division convention... one of us had his business card from one of those sessions. A couple of weeks later we met FQG and his tower crew at the gate and followed them in, and watched while they changed the insulator. Problem solved. As I re-read what I've written above, it sounds like it took one flight - it didn't - it took three Saturdays across eight weeks as we had scheduling problems with the ultralight, the pilot, and we had to figure out the mounting for the 2m beam, and we had to build the bazooka tube for the scanner. And the overall attitude was SAFETY - we were not going to duct-tape a beam to the airplane, and we couldn't (and wouldn't) drill any holes. The keys to finding power line interference: 1) A directional AM
[Repeater-Builder] MT1000 DTMF programming
I have taken up programming MT1000's. I am having trouble getting some radios that have DTMF to accept the fronts. I have several different model fronts and have tried them all to no avail. Is there a specific procedure to get the control module to recognize the DTMF front? I continually get the message this radio front incapable of DTMF. Sometimes the program version R03.01.02 states that a model ntn5697A front must be used. That is an encode/decode front and hard to come by. As I understand it, these radios should still be able to use the other fronts. I have tried the continuous and short burst fronts with the same results. Can anyone help me with this issue? Thanks... Ray
[Repeater-Builder] Re: AC buzz on VHF
Yes, it does go away when it rains. I can't believe I forgot that detail in the original post. I do thibnk the Air band AM reciever trick will be used by us to locate this. One other thing I just remembered. There is another site abuot 30 miles away. (The site that this tower orginally transmitted to.) that has the same problem. Wade --- In Repeater-Builder@yahoogroups.com, Eric Lemmon wb6...@... wrote: Remote hilltop sites are very often fed with a lateral power line that taps off from a major distribution line that could be miles away. If nothing but the hilltop site is on that lateral, and with the site owner's permission, the power utility can pull the cutout fuses to kill the lateral circuit. If the AC buzz goes away, the utility crews must find and correct the problem. As Kim points out, there are many possible causes of noise problems. Question: Does the noise change or go away when it rains? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of whensle...@... Sent: Monday, April 26, 2010 7:59 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] AC buzz on VHF Distribution voltages begin at 2,400 and go to 34,500 volts. Transmission voltages begin at ... depends upon the utility. Could be 46,000, 69,000 or 115,000. Anyway... it's not the voltage. It's simply there is a device issue somewhere on a power line. Could be a bad connector. A bad transformer. A bad lightning arrester. A bad switch. A bad insulator. Bottom line, something is breaking down and creating this buzz. Begin by driving around the area and narrowing the area down. Then with a small yagi try to pin point things down to a few poles, or THE pole. Some electric companies have staff that can assist with RFI, and some do not. Don't assume they do. If you have questions, drop me a line. 73, Kim - WG8S
[Repeater-Builder] Re: how far
i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever --- In Repeater-Builder@yahoogroups.com, Kris Kirby k...@... wrote: On Sun, 25 Apr 2010, Joe wrote: Just be careful. At the ERP antenna output levels that you are playing with and frequencies involved, things can get dangerous for human exposure. Anything above 50W, an OET 65 RF Field Study must be done. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] MT1000 DTMF programming
Make sure that you have DTMF fronts and not selectable MDC1200 fronts, IIRC they looked pretty much alike. The MDC ones had a protrusion at the top while the DTMF ones did not. Milt N3LTQ - Original Message - From: brown7...@bellsouth.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:05 PM Subject: [Repeater-Builder] MT1000 DTMF programming I have taken up programming MT1000's. I am having trouble getting some radios that have DTMF to accept the fronts. I have several different model fronts and have tried them all to no avail. Is there a specific procedure to get the control module to recognize the DTMF front? I continually get the message this radio front incapable of DTMF. Sometimes the program version R03.01.02 states that a model ntn5697A front must be used. That is an encode/decode front and hard to come by. As I understand it, these radios should still be able to use the other fronts. I have tried the continuous and short burst fronts with the same results. Can anyone help me with this issue? Thanks...Ray Yahoo! Groups Links
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Tim, My plan at this point is to convert them to full duplex, so I can use the second Mitrek to prepare a complete, plug-in, standby set of RF decks. The mods look very straightforward, but I was wondering if there were any gremlins people discovered. Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90º twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR - Original Message - From: w7...@comcast.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:16 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Isn't the rpt. going to be built using (2) Mitrex, thus shielding should not be a problem. I have, in the past (with the help of a Bridgeport mill), fashioned Larger Heatsinks, that bolt onto the orig. Mitrex heat sinkseems to dissipate heat well...
Re: [Repeater-Builder] AC buzz on VHF
I had a similar problem at my house and it was tearing up my packet digipeater. It turned out to be microspark interference. See this message: http://www.mail-archive.com/repeater-builder@yahoogroups.com/msg50828.html It turned out to be a tie-wire that is used to hold the wire into the insulator on the high voltage line in front of my house. The tie wire was just long enough to resonate in the 2 meter VHF band, but very little noise was being created on the AM broadcast band. Do the test that I described in the above message and see if it is AC power line interference. If it is, you should ride around the general area of the tower and listen on your car AM radio. When you get very close to it, you should hear the interference on both the VHF and Am radio. If you have a handheld scanner that receives AM it will be easier to find the interference. 73, Joe, K1ike On 4/26/2010 10:23 AM, kc0mlt wrote: Hello all, I am in the process of putting up a 2M repeater on what I would consider a pretty vacant site. There is only one other machine (70cm Repeater) currently out there. My concern is with an AC (60Hz) buzz that comes across on the VHF band. It doesn't have a signal to it that will key uip a radio, but when you receive an actuall signal you can here it. We have heard this on both handhelds and mobiles. This site is unique as it is a duel tower with old (unused)Microwave panels and drums on the bridge at the top of the two towers. The microwave equipment is no longer hooked up. We have had the power company totally unhook the power to the site and the buzz was still present. The nearest high voltage lines are about 1.5 to 2 miles away. You can not hear the buzz on any AM reciever. Does anybody have a clue as to what this could be and what we could to do prevent it? We have some thoughts on the grounding of the guy wire being a cause but we are unsure of that. Any ideas would be greatly appreciated! Thanks Wade KC0MLT Yahoo! Groups Links
[Repeater-Builder] Re: MT1000 DTMF programming
Milt, I have NTN5040A and NTN5596A fronts, which are DTMF. --- In Repeater-Builder@yahoogroups.com, Milt men...@... wrote: Make sure that you have DTMF fronts and not selectable MDC1200 fronts, IIRC they looked pretty much alike. The MDC ones had a protrusion at the top while the DTMF ones did not. Milt N3LTQ - Original Message - From: brown7...@... To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:05 PM Subject: [Repeater-Builder] MT1000 DTMF programming I have taken up programming MT1000's. I am having trouble getting some radios that have DTMF to accept the fronts. I have several different model fronts and have tried them all to no avail. Is there a specific procedure to get the control module to recognize the DTMF front? I continually get the message this radio front incapable of DTMF. Sometimes the program version R03.01.02 states that a model ntn5697A front must be used. That is an encode/decode front and hard to come by. As I understand it, these radios should still be able to use the other fronts. I have tried the continuous and short burst fronts with the same results. Can anyone help me with this issue? Thanks...Ray Yahoo! Groups Links
RE: [Repeater-Builder] Mitreks as UHF Repeaters?
Because of the internal desense issue, I'd build them the same, but operate the two radios separately. That is, use one as a transmitter and the other as the receiver by default. No duplex mods required. If the Tx dies on one, swap the system cables around to make the formerly-transmitter radio the receiver, and vice-versa. You could even automate the changeover via a couple of coaxial relays and some simple homebrew transistor and/or relay logic tied into your controller. --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Paul Plack Sent: Monday, April 26, 2010 1:49 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? ? Tim, My plan at this point is to convert them to full duplex, so I can use the second Mitrek to prepare a complete, plug-in, standby set of RF decks. The mods look very straightforward, but I was wondering if there were any gremlins people discovered. Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90º twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR - Original Message - From: w7...@comcast.net mailto:w7...@comcast.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:16 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Isn't the rpt. going to be built using (2) Mitrex, thus shielding should not be a problem. I have, in the past (with the help of a Bridgeport mill), fashioned Larger Heatsinks, that bolt onto the orig. Mitrex heat sinkseems to dissipate heat well... No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2792 - Release Date: 04/26/10 02:31:00
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
At 10:49 AM 4/26/2010, Paul Plack wrote: Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. Remember folks that heatsink capability is not the only issue when it comes to duty cycle. Components such as caps, resistors, diodes and even pc board traces all factor in as well and, even though you might be able to suck the heat away from the transistors adequately, other parts aren't necessarily up to the task and could very well fail. Ken -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
Re: [Repeater-Builder] Re: how far
On Mon, 26 Apr 2010, George wrote: i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever You'd think that, but have a gander at the FCC Rules, Part 97.13. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
On Mon, 26 Apr 2010, Paul Plack wrote: Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90? twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR Remember, the 100W Mitrek had a heatsink that was rated for 35W and used the duty cycle to keep things cool. If you do a case swap from a 30W radio into a 100W case, you could be fine for 100%, barring excessive temperature climb. My druthers would be to use an Original Syntor. It's got the helicals of a Mitrek, and the programming of a PROM. At $10 per frequency change (the going rate of the PROM chip), it's still cheaper than the Mitrek and uses the Mitrek/Motrac accessories. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Paul, Using one Chassis for full duplex may cause some problems, as mentioned in an earlier post! More than likely, you should be able to find many Mitrek radios for next to nothing. This way, you will be able to run separate rec. and xmitter, thus you won't have to worry too much about shielding or by-passing. (The difference is apparent, when looking at a MSR2000 base and MSR2000 rpt. The rpt. has much by-passing, yet uses the same boards for rec. and exciter.) I ran seperate Mitrek radios for several years for AirForce MARS without any particular problems. That is the machine that I used the large heatsink with. I would recommend using seperate rec. and xmitters. Regards, Tim Hardy W7TRH/AFA0TP Vashon Is. Wa. - Original Message - From: Paul Plack pl...@xmission.com To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:49:00 AM GMT -08:00 US/Canada Pacific Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Tim, My plan at this point is to convert them to full duplex, so I can use the second Mitrek to prepare a complete, plug-in, standby set of RF decks. The mods look very straightforward, but I was wondering if there were any gremlins people discovered. Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90º twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR - Original Message - From: w7...@comcast.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:16 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Isn't the rpt. going to be built using (2) Mitrex, thus shielding should not be a problem. I have, in the past (with the help of a Bridgeport mill), fashioned Larger Heatsinks, that bolt onto the orig. Mitrex heat sinkseems to dissipate heat well...
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Ken, Correct, of course, but I'm assuming that in a 30w PA, smaller components not somehow directly sunk to the main chassis heatsink will reach their max operating temps in a very few seconds of key-down, and therefore have to be spec'd the same for intermittent duty PAs as if they would if they were in continuous duty. I'm willing to roll those dice, especially if a similar design was used by the manufacturer in repeater service. There seem to be plenty of Mitreks used as repeaters in the past, so I think we'll be OK. I'm gathering, however, that as cheap as these radios have become, it mike just make sense to use two radios, and source more spares. 73, Paul, AE4KR - Original Message - From: Ken Arck To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:01 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? At 10:49 AM 4/26/2010, Paul Plack wrote: Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. Remember folks that heatsink capability is not the only issue when it comes to duty cycle. Components such as caps, resistors, diodes and even pc board traces all factor in as well and, even though you might be able to suck the heat away from the transistors adequately, other parts aren't necessarily up to the task and could very well fail. Ken -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
[Repeater-Builder] 3' motorola or GE cabinet wanted.
I've been looking around for a short cabinet, and can't seem to find what I'm looking for. The MSR2000 cab I have is not deep enough for my repeater project. If anyone has anything they want to get rid of in the CT area, contact me off list. Thanks!!
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Kris, looking at the pictures of the Mitreks of various power levels, I'm not confident there would be holes and heatsink pads in the high-power case that line up with the board mounts and needed contact points of the low-power PA board. But yes - I had considered that approach. I am completely unfamiliar with the Syntor, cost, availability, etc., but I'm also early in the process of nosing around locally. I'm willing to look at any plentiful, high-quality radios for the conversion. 73, Paul, AE4KR - Original Message - From: Kris Kirby To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:26 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? On Mon, 26 Apr 2010, Paul Plack wrote: Remember, the 100W Mitrek had a heatsink that was rated for 35W and used the duty cycle to keep things cool. If you do a case swap from a 30W radio into a 100W case, you could be fine for 100%, barring excessive temperature climb. My druthers would be to use an Original Syntor. It's got the helicals of a Mitrek, and the programming of a PROM. At $10 per frequency change (the going rate of the PROM chip), it's still cheaper than the Mitrek and uses the Mitrek/Motrac accessories. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Jeff, I appreciate the thoughts. Anytime I've looked at a scheme which allows simply swapping the TX and RX to get back on the air, I arrive at the same conclusions... (1) If I took a lightning hit at the site, I'd want my spares to have been stored somewhere else. (2) Once I swap the TX and RX, I still can't bring either home for repair without taking the machine off the air. As far as the automated switchover, the 7K has three receiver and two transmitter ports, so I wouldn't even need coax relays to provide remote swap capabilities. I could just crystal each radio for simplex, wire both receivers and both transmitters into the controller, issue a remote DTMF command to swap them, and instantly implement a second repeater on the upside-down split. I think my answer is going to end up being building a stash of spares, and using two radios. 73, Paul, AE4KR - Original Message - From: Jeff DePolo To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:11 PM Subject: RE: [Repeater-Builder] Mitreks as UHF Repeaters? Because of the internal desense issue, I'd build them the same, but operate the two radios separately. That is, use one as a transmitter and the other as the receiver by default. No duplex mods required. If the Tx dies on one, swap the system cables around to make the formerly-transmitter radio the receiver, and vice-versa. You could even automate the changeover via a couple of coaxial relays and some simple homebrew transistor and/or relay logic tied into your controller. --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Paul Plack Sent: Monday, April 26, 2010 1:49 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? ? Tim, My plan at this point is to convert them to full duplex, so I can use the second Mitrek to prepare a complete, plug-in, standby set of RF decks. The mods look very straightforward, but I was wondering if there were any gremlins people discovered. Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90º twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR - Original Message - From: w7...@comcast.net mailto:w7...@comcast.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 10:16 AM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? Isn't the rpt. going to be built using (2) Mitrex, thus shielding should not be a problem. I have, in the past (with the help of a Bridgeport mill), fashioned Larger Heatsinks, that bolt onto the orig. Mitrex heat sinkseems to dissipate heat well... No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2792 - Release Date: 04/26/10 02:31:00
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
At 11:47 AM 4/26/2010, Paul Plack wrote: Ken, Correct, of course, but I'm assuming that in a 30w PA, smaller components not somehow directly sunk to the main chassis heatsink will reach their max operating temps in a very few seconds of key-down, and therefore have to be spec'd the same for intermittent duty PAs as if they would if they were in continuous duty. ---There are several components that are common failures in Mitreks used in duty cycle apps greater than it was designed for. One should read the following: www.ecso.com/srca/modmitrek_files/mitrex_mod.pdf Just sayin' -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
RE: [Repeater-Builder] Mitreks as UHF Repeaters?
I appreciate the thoughts. Anytime I've looked at a scheme which allows simply swapping the TX and RX to get back on the air, I arrive at the same conclusions... (1) If I took a lightning hit at the site, I'd want my spares to have been stored somewhere else. (2) Once I swap the TX and RX, I still can't bring either home for repair without taking the machine off the air. Understood. As far as the automated switchover, the 7K has three receiver and two transmitter ports, so I wouldn't even need coax relays to provide remote swap capabilities. I could just crystal each radio for simplex, wire both receivers and both transmitters into the controller, issue a remote DTMF command to swap them, and instantly implement a second repeater on the upside-down split. Yikes, upside-down? Your co-channel neighbors will just love that! I think my answer is going to end up being building a stash of spares, and using two radios. Yeah, I'd definately go with split radios however you end up doing it. If you're going to assume you're going to make the trip to the site in the event of a failure, then there's probably no need to order two sets of crystals, just move the elements when you swap radios and net them on frequency. These days, the cost of crystals is usually more than the cost of the radio they're going into...which is why I've mostly gone synthesized. --- Jeff WN3A
Re: [Repeater-Builder] 3' motorola or GE cabinet wanted.
Same here Larry - We have a bunch of cabinets that we are trying to get rid of on the cheap as well. Deep ones like yours. Need to make room for a Two Way Radio Museum here and scrapping the units that are not selling. We dont even have the units on eBay or Craigslist, but Kijiji and Craigslist might not be a bad idea. People out there DO need them. John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn - Original Message - From: larryjspamme...@teleport.com To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 12:43 PM Subject: Re: [Repeater-Builder] 3' motorola or GE cabinet wanted. Too bad you're so far away (I'm in Portland, OR). I'm just getting ready to list some on the local craigslist - my garage is overflowing and some cars need the space. I have some of the deep Quantar/MICOR type cabinets - the short ones, medium height, and 5-foot tall ones. And one - 40 tall GE MASTR II Cabinet. All of the Motorola cabinets are the deep ones that would hold repeaters with duplexers, etc. IF they don't sell locally, they're off to the metal scrapper. Larry -Original Message- From: rush8001 Sent: Apr 26, 2010 11:47 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] 3' motorola or GE cabinet wanted. I've been looking around for a short cabinet, and can't seem to find what I'm looking for. The MSR2000 cab I have is not deep enough for my repeater project. If anyone has anything they want to get rid of in the CT area, contact me off list. Thanks!!
Re: [Repeater-Builder] 3' motorola or GE cabinet wanted.
At 12:43 PM 4/26/2010, larryjspamme...@teleport.com wrote: Too bad you're so far away (I'm in Portland, OR). I'm just getting ready to list some on the local craigslist - my garage is overflowing and some cars need the space. I have some of the deep Quantar/MICOR type cabinets - the short ones, medium height, and 5-foot tall ones. And one - 40 tall GE MASTR II Cabinet. All of the Motorola cabinets are the deep ones that would hold repeaters with duplexers, etc. IF they don't sell locally, they're off to the metal scrapper. ---Let me know Larry. I'm looking for some.. Ken -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
Re: [Repeater-Builder] 3' motorola or GE cabinet wanted.
Go visit your local two-way shops, chances are they have some. Milt N3LTQ - Original Message - From: rush8001 unidens...@hotmail.com To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 2:47 PM Subject: [Repeater-Builder] 3' motorola or GE cabinet wanted. I've been looking around for a short cabinet, and can't seem to find what I'm looking for. The MSR2000 cab I have is not deep enough for my repeater project. If anyone has anything they want to get rid of in the CT area, contact me off list. Thanks!! Yahoo! Groups Links
[Repeater-Builder] OT: Programming Help Needed - Saber
I have run into a brick wall at a rather high rate of speed... as fast as DOS can run anyway. I am trying to figure out the band split of a (Presumed) VHF Saber Securenet Capable portable / handheld. I have the standard DOS RSS for Saber version 07.01.00 with a Moto Rib Box etc. I have programmed and read many other models of Sabers, except for this one particular model. Factory ID: H43TUN5170CN Model is H99QX + 104H, which I think is a package number. Google turns up that it may be a Military issue and no information can be found on this. Is this true? Thanks for your input! John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Ken, Thanks, appreciate the link. This document adds a few details to what I had on hand. Good to know the high-split Mitreks weren't prone to the spurs when duplexed. Also encouraging to read that the 30w radios will run 100% at 20w with the smaller heatsink. That's probably all the power I'd need in my application. 73, Paul, AE4KR - Original Message - From: Ken Arck To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 1:09 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? At 11:47 AM 4/26/2010, Paul Plack wrote: Ken, Correct, of course, but I'm assuming that in a 30w PA, smaller components not somehow directly sunk to the main chassis heatsink will reach their max operating temps in a very few seconds of key-down, and therefore have to be spec'd the same for intermittent duty PAs as if they would if they were in continuous duty. ---There are several components that are common failures in Mitreks used in duty cycle apps greater than it was designed for. One should read the following: www.ecso.com/srca/modmitrek _files/mitrex_mod.pdf Just sayin' -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
Re: [Repeater-Builder] Re: how far
On Mon, Apr 26, 2010 at 2:20 PM, Kris Kirby k...@catonic.us wrote: On Mon, 26 Apr 2010, George wrote: i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever You'd think that, but have a gander at the FCC Rules, Part 97.13. -- Kris Kirby, KE4AHR Disinformation Analyst Likewise it is the principal basis on how a microwave oven works, granted the frequency is slightly higher in the oven. There are many microwave ovens in the 800-900 Watt range that still manage to boil water. -- Dan Simmons KC2BEZ President North Country Amateur Radio Club W2LCA http://groups.google.com/group/w2lca
Re: [Repeater-Builder] 3' motorola or GE cabinet wanted.
Larry, are any of your cabinets outdoor types? I'm in Salt Lake City, but have relatives near you who could pick up store, and might be interested. - Paul, AE4KR - Original Message - From: larryjspamme...@teleport.com To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 1:43 PM Subject: Re: [Repeater-Builder] 3' motorola or GE cabinet wanted. Too bad you're so far away (I'm in Portland, OR). I'm just getting ready to list some on the local craigslist - my garage is overflowing and some cars need the space. I have some of the deep Quantar/MICOR type cabinets - the short ones, medium height, and 5-foot tall ones. And one - 40 tall GE MASTR II Cabinet. All of the Motorola cabinets are the deep ones that would hold repeaters with duplexers, etc. IF they don't sell locally, they're off to the metal scrapper. Larry
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
On Mon, 26 Apr 2010, Paul Plack wrote: I am completely unfamiliar with the Syntor, cost, availability, etc., but I'm also early in the process of nosing around locally. I'm willing to look at any plentiful, high-quality radios for the conversion. 73, Paul, AE4KR Syntor -- not Syntor X or Syntor X9000 -- has the helicals of the Mitrek and excellent suppression of other nearby signals. The radio is only about 2MHz wide at widest tuning. Every other Motorola radio beyond them is 22-28MHz wide. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] OT: Programming Help Needed - Saber
On Mon, 26 Apr 2010, La Rue Communications wrote: I have run into a brick wall at a rather high rate of speed... as fast as DOS can run anyway. I am trying to figure out the band split of a (Presumed) VHF Saber Securenet Capable portable / handheld. I have the standard DOS RSS for Saber version 07.01.00 with a Moto Rib Box etc. I have programmed and read many other models of Sabers, except for this one particular model. Factory ID: H43TUN5170CN H43TUN5170xN, 6 watt, VHF Systems Saber I Model is H99QX + 104H, which I think is a package number. Google turns up that it may be a Military issue and no information can be found on this. Is this true? Generate a new codeplug in the RSS and dial the options around until you see a model tag that matches the above Model. That will tell you without reading what you're holding. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] OT: Programming Help Needed - Saber
Thanks Kris! Good stuff! Can you think of any reason why this radio will not be read by the RSS in the first place? All I get are Serial Bus I/O Error was detected. I know it seems like something not connected properly, but it reads all other models of Sabers just fine. This is the only RSS I have for the Sabers. COuld it be an improper version? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn - Original Message - From: Kris Kirby To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 2:07 PM Subject: Re: [Repeater-Builder] OT: Programming Help Needed - Saber On Mon, 26 Apr 2010, La Rue Communications wrote: I have run into a brick wall at a rather high rate of speed... as fast as DOS can run anyway. I am trying to figure out the band split of a (Presumed) VHF Saber Securenet Capable portable / handheld. I have the standard DOS RSS for Saber version 07.01.00 with a Moto Rib Box etc. I have programmed and read many other models of Sabers, except for this one particular model. Factory ID: H43TUN5170CN H43TUN5170xN, 6 watt, VHF Systems Saber I Model is H99QX + 104H, which I think is a package number. Google turns up that it may be a Military issue and no information can be found on this. Is this true? Generate a new codeplug in the RSS and dial the options around until you see a model tag that matches the above Model. That will tell you without reading what you're holding. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] OT: Programming Help Needed - Saber
Yes, I can. A Systems Saber radio requires RVN4051 RSS, while a Saber radio requires RVN4002 RSS, and an Astro Saber radio requires RVN4182 RSS. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of La Rue Communications Sent: Monday, April 26, 2010 2:13 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] OT: Programming Help Needed - Saber Thanks Kris! Good stuff! Can you think of any reason why this radio will not be read by the RSS in the first place? All I get are Serial Bus I/O Error was detected. I know it seems like something not connected properly, but it reads all other models of Sabers just fine. This is the only RSS I have for the Sabers. COuld it be an improper version? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn http://tinyurl.com/2dtngmn - Original Message - From: Kris Kirby mailto:k...@catonic.us To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 2:07 PM Subject: Re: [Repeater-Builder] OT: Programming Help Needed - Saber On Mon, 26 Apr 2010, La Rue Communications wrote: I have run into a brick wall at a rather high rate of speed... as fast as DOS can run anyway. I am trying to figure out the band split of a (Presumed) VHF Saber Securenet Capable portable / handheld. I have the standard DOS RSS for Saber version 07.01.00 with a Moto Rib Box etc. I have programmed and read many other models of Sabers, except for this one particular model. Factory ID: H43TUN5170CN H43TUN5170xN, 6 watt, VHF Systems Saber I Model is H99QX + 104H, which I think is a package number. Google turns up that it may be a Military issue and no information can be found on this. Is this true? Generate a new codeplug in the RSS and dial the options around until you see a model tag that matches the above Model. That will tell you without reading what you're holding. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Re: 3' motorola or GE cabinet wanted.
Paul, I have some aluminum traffic signal boxes that are 5 1/2 feet tall 20 inches wide and 3 1/2 feet deep. Here in Northern California that are just perfect for outdoor repeater cabinets. Gregory AC6VJ --- In Repeater-Builder@yahoogroups.com, Paul Plack pl...@... wrote: Larry, are any of your cabinets outdoor types? I'm in Salt Lake City, but have relatives near you who could pick up store, and might be interested. - Paul, AE4KR - Original Message - From: larryjspamme...@... To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 1:43 PM Subject: Re: [Repeater-Builder] 3' motorola or GE cabinet wanted. Too bad you're so far away (I'm in Portland, OR). I'm just getting ready to list some on the local craigslist - my garage is overflowing and some cars need the space. I have some of the deep Quantar/MICOR type cabinets - the short ones, medium height, and 5-foot tall ones. And one - 40 tall GE MASTR II Cabinet. All of the Motorola cabinets are the deep ones that would hold repeaters with duplexers, etc. IF they don't sell locally, they're off to the metal scrapper. Larry
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
I ran a Duplexed 50W UHF mitrek @30W with a Fan on the heat sink for 5 years without a problem. I Upgraded that site to a full blown UHF Micor Repeater that is 75W. As expected on the TX the range is better, but the Micor is also a slight bit better on the RX as well. I will probably re-use the mitrek radio in a future RX site since I have it and the channel element. That being said, the Mitrek served me well and was a great way to get the repeater going. If I did Mitreks again I would use two radios, not because I had any problems, but because of the redundancy it would offer. TX or RX dies, just swap radios and your back on the air. As a side note to running a single duplexed radio, I never had any measurable de-sense, but I did get spurrs and crap when I tried setting the TX power too low. Its happiest at 50-75% of its rated power. Tom W9SRV --- On Mon, 4/26/10, Paul Plack pl...@xmission.com wrote: From: Paul Plack pl...@xmission.com Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? To: Repeater-Builder@yahoogroups.com Date: Monday, April 26, 2010, 3:07 PM Ken, Thanks, appreciate the link. This document adds a few details to what I had on hand. Good to know the high-split Mitreks weren't prone to the spurs when duplexed. Also encouraging to read that the 30w radios will run 100% at 20w with the smaller heatsink. That's probably all the power I'd need in my application. 73, Paul, AE4KR - Original Message - From: Ken Arck To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 1:09 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? At 11:47 AM 4/26/2010, Paul Plack wrote: Ken, Correct, of course, but I'm assuming that in a 30w PA, smaller components not somehow directly sunk to the main chassis heatsink will reach their max operating temps in a very few seconds of key-down, and therefore have to be spec'd the same for intermittent duty PAs as if they would if they were in continuous duty. ---There are several components that are common failures in Mitreks used in duty cycle apps greater than it was designed for. One should read the following: www.ecso.com/ srca/modmitrek _files/mitrex_ mod.pdf Just sayin' - - - - - - - --- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcon trollers. com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp. net We don't just make 'em. We use 'em!
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Tom, Yes - the spurs mentioned were not the ones created by running the power too low. Apparently, the 406-420 Mitreks had a separate issue which was not dependent on power setting, in which the local oscillator for the receiver would get into the exciter's multiplier chain. I think almost any of these discreet-component PAs wander off the spec chart if you run them too far below rated power. My last UHF repeater was a 35w Mastr II, and it started getting pretty gritty below about 18 watts. 73, Paul, AE4KR - Original Message - From: TGundo 2003 To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 3:26 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? I ran a Duplexed 50W UHF mitrek @30W with a Fan on the heat sink for 5 years without a problem. I Upgraded that site to a full blown UHF Micor Repeater that is 75W. As expected on the TX the range is better, but the Micor is also a slight bit better on the RX as well. I will probably re-use the mitrek radio in a future RX site since I have it and the channel element. That being said, the Mitrek served me well and was a great way to get the repeater going. If I did Mitreks again I would use two radios, not because I had any problems, but because of the redundancy it would offer. TX or RX dies, just swap radios and your back on the air. As a side note to running a single duplexed radio, I never had any measurable de-sense, but I did get spurrs and crap when I tried setting the TX power too low. Its happiest at 50-75% of its rated power. Tom W9SRV --- On Mon, 4/26/10, Paul Plack pl...@xmission.com wrote: From: Paul Plack pl...@xmission.com Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? To: Repeater-Builder@yahoogroups.com Date: Monday, April 26, 2010, 3:07 PM Ken, Thanks, appreciate the link. This document adds a few details to what I had on hand. Good to know the high-split Mitreks weren't prone to the spurs when duplexed. Also encouraging to read that the 30w radios will run 100% at 20w with the smaller heatsink. That's probably all the power I'd need in my application. 73, Paul, AE4KR - Original Message - From: Ken Arck To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 1:09 PM Subject: Re: [Repeater-Builder] Mitreks as UHF Repeaters? At 11:47 AM 4/26/2010, Paul Plack wrote: Ken, Correct, of course, but I'm assuming that in a 30w PA, smaller components not somehow directly sunk to the main chassis heatsink will reach their max operating temps in a very few seconds of key-down, and therefore have to be spec'd the same for intermittent duty PAs as if they would if they were in continuous duty. ---There are several components that are common failures in Mitreks used in duty cycle apps greater than it was designed for. One should read the following: www.ecso.com/ srca/modmitrek _files/mitrex_ mod.pdf Just sayin' - - - - - - - --- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcon trollers. com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp. net We don't just make 'em. We use 'em!
[Repeater-Builder] Re: how far
sir i agree...if you have infra red heater at front of you 2kw and the power is heating your ass after 6 hours of working outside at temperature below 20 degrees F you will be apreciative for the comfort this thing provides and you will not be asking yourself how hapmful this microwave emitter isthis is the reality: stay away from antennas that emmit 1000 watts...mine is less than 500 watts and no body is lurking arround. --- In Repeater-Builder@yahoogroups.com, Dan KC2BEZ simmons@... wrote: On Mon, Apr 26, 2010 at 2:20 PM, Kris Kirby k...@... wrote: On Mon, 26 Apr 2010, George wrote: i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever You'd think that, but have a gander at the FCC Rules, Part 97.13. -- Kris Kirby, KE4AHR Disinformation Analyst Likewise it is the principal basis on how a microwave oven works, granted the frequency is slightly higher in the oven. There are many microwave ovens in the 800-900 Watt range that still manage to boil water. -- Dan Simmons KC2BEZ President North Country Amateur Radio Club W2LCA http://groups.google.com/group/w2lca
[Repeater-Builder] TLE1713A
Greetings to the group Just wondering if anyone has a schematic for the TLE1713A PA. I have been trying to fire it up with 1 watt from a Maxtrac but not a thing out of it. Randy Elliott VE3JPU Technical Director South Pickering Amateur Radio Club Inc. Box 53 Pickering, Ontario, Canada L1V 2R2 905-427-6853 ve3...@rac.ca
[Repeater-Builder] Re: how far
if the microwave oven is a square of 10 meters does it gonna boil watter...??? --- In Repeater-Builder@yahoogroups.com, Dan KC2BEZ simmons@... wrote: On Mon, Apr 26, 2010 at 2:20 PM, Kris Kirby k...@... wrote: On Mon, 26 Apr 2010, George wrote: i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever You'd think that, but have a gander at the FCC Rules, Part 97.13. -- Kris Kirby, KE4AHR Disinformation Analyst Likewise it is the principal basis on how a microwave oven works, granted the frequency is slightly higher in the oven. There are many microwave ovens in the 800-900 Watt range that still manage to boil water. -- Dan Simmons KC2BEZ President North Country Amateur Radio Club W2LCA http://groups.google.com/group/w2lca
Re: [Repeater-Builder] OT: Programming Help Needed - Saber
On Mon, 26 Apr 2010, La Rue Communications wrote: Can you think of any reason why this radio will not be read by the RSS in the first place? All I get are Serial Bus I/O Error was detected. I know it seems like something not connected properly, but it reads all other models of Sabers just fine. This is the only RSS I have for the Sabers. COuld it be an improper version? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn Systems Sabers require Systems Saber RSS. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Interference from local 600 kHz radio station.
There was a 6 meter repeater here in Connecticut that was receiving interference from an AM station several states away that was broadcasting on 1000KHz. It only occurred in the nighttime. (The 6 meter repeater was on a 1MHz split). They narrowed it down to something on the 21+ towers that are on the site, but never found it to my knowledge. It could have been a piece of loose hardware, rusty joint, bad antenna, etc. If I remember correctly, rain made it go away. This can be a real bugger of a problem to find. I would look at guy wires or anything that is long enough to pick up enough signal from your 600KHz station. Does it happen when it rains? 73, Joe, K1ike On 4/25/2010 11:06 PM, lpcoates wrote: Hi We have a local AM radio station on 600 kHz. Their transmitter site is about 10 miles from the center of the city. From what I've found on the web, they run 25,000 watts during the day and 8,000 watts at night. On at least one of our repeaters we're finding that this is mixing with the output of repeater to create a phantom signal exactly on the input. We're not sure whether the mixing is happening inside the repeater or in something in the environment near the repeater. We've confirmed this is the source of the problem on one repeter and supect it on another. Has anyone had experince with a loacl AM station on 600 kHz? We're looking for way to combat the interference. Thanks Bruce - VE5BNC
Re: [Repeater-Builder] Interference from local 600 kHz radio station.
I snowed here yesterday, does that count? ;-) In all seriousness so far we only know that it comes and goes. We've yet to find a clear pattern of day/night, week day/weekend (it's on an office tower) , hot/cold, wet/dry, etc. yet. We hope to do a bit of a fox hunt at the sight later this spring. 73, Bruce - Original Message - From: Joe k1ike_m...@snet.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 8:16 PM Subject: Re: [Repeater-Builder] Interference from local 600 kHz radio station. There was a 6 meter repeater here in Connecticut that was receiving interference from an AM station several states away that was broadcasting on 1000KHz. It only occurred in the nighttime. (The 6 meter repeater was on a 1MHz split). They narrowed it down to something on the 21+ towers that are on the site, but never found it to my knowledge. It could have been a piece of loose hardware, rusty joint, bad antenna, etc. If I remember correctly, rain made it go away. This can be a real bugger of a problem to find. I would look at guy wires or anything that is long enough to pick up enough signal from your 600KHz station. Does it happen when it rains? 73, Joe, K1ike On 4/25/2010 11:06 PM, lpcoates wrote: Hi We have a local AM radio station on 600 kHz. Their transmitter site is about 10 miles from the center of the city. From what I've found on the web, they run 25,000 watts during the day and 8,000 watts at night. On at least one of our repeaters we're finding that this is mixing with the output of repeater to create a phantom signal exactly on the input. We're not sure whether the mixing is happening inside the repeater or in something in the environment near the repeater. We've confirmed this is the source of the problem on one repeter and supect it on another. Has anyone had experince with a loacl AM station on 600 kHz? We're looking for way to combat the interference. Thanks Bruce - VE5BNC Yahoo! Groups Links
RE: [Repeater-Builder] Interference from local 600 kHz radio station.
No words of wisdom, Bruce. but wanted to offer my condolences. The dang pager interference we've got is about to drive me to drink. which is probably the ONLY nice thing I can say about it. Hope you find your demon! 73, Mike WM4B _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Bruce Coates Sent: Monday, April 26, 2010 10:27 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Interference from local 600 kHz radio station. I snowed here yesterday, does that count? ;-) In all seriousness so far we only know that it comes and goes. We've yet to find a clear pattern of day/night, week day/weekend (it's on an office tower) , hot/cold, wet/dry, etc. yet. We hope to do a bit of a fox hunt at the sight later this spring. 73, Bruce - Original Message - From: Joe k1ike_m...@snet. mailto:k1ike_mail%40snet.net net To: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com Sent: Monday, April 26, 2010 8:16 PM Subject: Re: [Repeater-Builder] Interference from local 600 kHz radio station. There was a 6 meter repeater here in Connecticut that was receiving interference from an AM station several states away that was broadcasting on 1000KHz. It only occurred in the nighttime. (The 6 meter repeater was on a 1MHz split). They narrowed it down to something on the 21+ towers that are on the site, but never found it to my knowledge. It could have been a piece of loose hardware, rusty joint, bad antenna, etc. If I remember correctly, rain made it go away. This can be a real bugger of a problem to find. I would look at guy wires or anything that is long enough to pick up enough signal from your 600KHz station. Does it happen when it rains? 73, Joe, K1ike On 4/25/2010 11:06 PM, lpcoates wrote: Hi We have a local AM radio station on 600 kHz. Their transmitter site is about 10 miles from the center of the city. From what I've found on the web, they run 25,000 watts during the day and 8,000 watts at night. On at least one of our repeaters we're finding that this is mixing with the output of repeater to create a phantom signal exactly on the input. We're not sure whether the mixing is happening inside the repeater or in something in the environment near the repeater. We've confirmed this is the source of the problem on one repeter and supect it on another. Has anyone had experince with a loacl AM station on 600 kHz? We're looking for way to combat the interference. Thanks Bruce - VE5BNC Yahoo! Groups Links
[Repeater-Builder] COR signal from ICOM 37a
I want to link two repeaters together and have a couple of Icom 37a 220 rigs on the shelf. I have been searching for info on the best place to grab a signal to drive a COR. Does anyone have any info on this? Thanks!! 73 K5ILS Robert
Re: [Repeater-Builder] COR signal from ICOM 37a
Didnt those have a green LED on the front panel for COR? On Mon, Apr 26, 2010 at 9:07 PM, Robert McNeill rob...@ncbfi.org wrote: I want to link two repeaters together and have a couple of Icom 37a 220 rigs on the shelf. I have been searching for info on the best place to grab a signal to drive a COR. Does anyone have any info on this? Thanks!! 73 K5ILS Robert
[Repeater-Builder] Direct Strike Lightning Detector
Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
Jesse, A radio engineer in Atlanta years ago told me a neat trick he said allows confirming a strike, and estimating the current it produced. It involves rexcording an audio tone on a piece of magnetic tape several feet long, sealing it in a weatherproof, non-conductive tube, and positioning it perpendicular to a tower leg. If lightning strikes, the magnetic flux produced around the conductor will vary proportionate to the current, and playing back the tape will reveal an erased portion which can be measured for its physical length. I have no idea how well that would actually work, or how to calculate the current based on how many inches of tape are erased. These days the only magnetic tape machines left in common use are old cassette decks, but it might be worth a piece of PVC pipe and some glue to try it. If you just want to know if it's hit, set up a vertical conductor some distance from the tower, but well within its cone of protection, connected through a fuse to an independent ground. If the tower gets smacked, you can bet some serious current will be induced in a 10-foot vertical wire. Years ago, an engineer for WBEN radio in Buffalo told me that on summer days when thunderstorms would hit the Toronto area across Lake Erie to the north, a hit on a radio tower up there would produce a spark across the ball gaps on the towers in Buffalo. That's 90 miles! 73, Paul, AE4KR - Original Message - From: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 11:32 PM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
