Re: [Repeater-Builder] TLN 5731A - Tone Private Line Encoder
The two standards for reverse-burst are switchable in some of the newer radios, such as those that use CPS for programming. Prior to about 10 years ago, Motorola was under the mind-set that you either bought all your radios from them or none of your radios from them, so system inter-operability didn't concern them. If you bought a Brand X radio and used it in your Motorola system, they hoped the audible squelch burst would be annoying enough to get you to go with their brand exclusively. Unfortunately this backfired and a lot of customers went totally with Brand X instead of Brand M. Hence, we now have two slightly incompatible standard methods. Then we have some of the Japanese amateur radios that don't recognize any reverse burst, and always give you a squelch burst on a PL system. The old PL reed encode/decode units used until the mid 1980s, tended to be a lot more forgiving about the phase difference. In fact, the very old encoders from the 1960s used a center-tapped transformer on the PL board, and switched from one phase to the other with the undelayed section of a T/R relay, so the phase was probably 180 degrees back then. It's only the newer radios with microprocessor-based tone decoders that can recognize and enforce the 120 degree shift. DCS (DPL in the Motorola world) got rid of this dual standard by using a 134 Hz turn-off code for about 200 mSec. ALL equipment now plays together a lot better. The only incompatability is with normal vs inverted codes, and this is more a function of the exciter and modulator circuitry that is, by nature, different between various manufacturers. So endeth the lesson for today, gentlemen. (spoken by Mrs. Whistler, the little old lady in South Africa in the opening scene of Ian Fleming's James Bond 007 in Diamonds Are Forever) Bob M. == --- Nate Duehr [EMAIL PROTECTED] wrote: On Nov 28, 2007, at 9:37 PM, Glenn Little WB4UIV wrote: The 1A is an EIA designation. See http://www.personainternet.com/~northscan/dcss.html Google is your friend. Searched for CTCSS Frequency EIA. 73 Glenn WB4UIV There's also an EIA/TIA specification for the reverse burst standards. I don't have access to EIA/TIA standards (since you typically have to pay for them) and judging by the various websites that allude to it (marketing material), there's other things in this spec, it would appear. Here's a blurb from a modern Motorola radio's marketing materials I found a while back: The industry standard EIA/TIA-603 lists two formats for CTCSS Reverse Burst: The format used by Motorola is 120 degree phase shift for 180 milliseconds, while the format used by all other manufacturers as well as by aftermarket tone equipment makers is 180 degree phase shift for 150 milliseconds. They go on to explain that in RSS you can switch to non-standard Reverse Burst on this particular radio. Would love to see the full EIA/TIA-603 spec. But these days when standards are purchased instead of public knowledge... oh well. I'm also surprised the Moto marketing people forgot to put the (TM) after the words Reverse Burst. (GRIN) Maybe it was hiding in the fine print of the document and I missed it. I was more interested in having found a reference to a real EIA/TIA specification for the phase shifts and time periods. Then more Googling found LOTS of manufacturer's marketing materials referencing it, but no copies of the spec sneaking around on someone's website. Oh well. -- Nate Duehr, WY0X [EMAIL PROTECTED] Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
Re: Re: [Repeater-Builder] TLN 5731A - Tone Private Line Encoder
Mike and all, I've always wondered why PL tones were designated with the number/letter. Why not just say 146.2 Hz. Wonder where this designation scheme came from. I might assume it is Mot's way of hiding the tone since Mot sales would tell customers PL would keep others from monitoring you. For PL'd rcvrs with different PL it would and this was used for community repeaters and worked reasonably well with some of the later improvements. 73, ron, n9ee/r From: Mike Morris WA6ILQ [EMAIL PROTECTED] Date: 2007/11/29 Thu AM 01:23:32 CST To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] TLN 5731A - Tone Private Line Encoder At 02:58 PM 11/28/07, you wrote: Our Uhf Micor has a '1A' KLN6210A. What frequecy is 1A? I would like to change this to a 114.8. Pull the reed and look at the label on the side, it will say 103.5hz I was hoping to find a list of all the tone reeds with the corresponding range from 67 - 210; in my Uhf Micor manual. Not likely. No sense in putting commonly available info into every single manual ever printed. I thought of looking on the Repeater-Builder web pages. Though out all this looking, I have yet to find a list. It's already there on the Communications Specialists page http://www.repeater-builder.com/com-spec/com-spec-5switches.html http://www.repeater-builder.com/com-spec/com-spec-6switches.html and again at the end of the TRN-4224 article on the Moto page. http://www.repeater-builder.com/mitrek/mitrek-hln4181-info.html There is a list of DPL codes at the end of the TRN6005 page, complete with a list of the inverted codes. http://www.repeater-builder.com/motorola/trn6005/trn6005-dpl-code-plug.html Agreed, the PL chart is not easy to find. I never thought to add it as a blatant menu item. I apologize. I see Bob M has, however. Thanks, for the Micor PL Encoder modifications, which I will add to our Micor. If it's the mod on disabling the reverse burst, you may not want to do that mod. What is your environment? There is no mod article (yet) on switching the encoder on and off under outside control (like for an IRLP environment). 73's, JimKh6jkg. Mike WA6ILQ Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
[Repeater-Builder] Looking for an old VHF Engineering CW ID'er board
I have a project using an old VHF Engineering repeater and the ID'er board has given up. Looks like it has just had the call changed 1 too many times.. Anyway, anyone out there have one of these old boards you aren't using and would like to get rid of cheap? Would like to use the same stock board for this one... Thanks! Ben W4WSM
[Repeater-Builder] Re: TLN 5731A - Tone Private Line Encoder
Another cute trick tried by some mfgrs is to simply remove ctcss x-time before the rf goes away/drops. The decoder stops and the audio gate(s) close before the crash noise. The other famous anti crash noise through repeaters is the audio delay module clean-up, which doesn't care what kind of signaling you use... including carrier squelch. s. Bob M. [EMAIL PROTECTED] wrote: The two standards for reverse-burst are switchable in some of the newer radios, such as those that use CPS for programming. Prior to about 10 years ago, Motorola was under the mind-set that you either bought all your radios from them or none of your radios from them, so system inter-operability didn't concern them. If you bought a Brand X radio and used it in your Motorola system, they hoped the audible squelch burst would be annoying enough to get you to go with their brand exclusively. Unfortunately this backfired and a lot of customers went totally with Brand X instead of Brand M. Hence, we now have two slightly incompatible standard methods. Then we have some of the Japanese amateur radios that don't recognize any reverse burst, and always give you a squelch burst on a PL system. The old PL reed encode/decode units used until the mid 1980s, tended to be a lot more forgiving about the phase difference. In fact, the very old encoders from the 1960s used a center-tapped transformer on the PL board, and switched from one phase to the other with the undelayed section of a T/R relay, so the phase was probably 180 degrees back then. It's only the newer radios with microprocessor-based tone decoders that can recognize and enforce the 120 degree shift. DCS (DPL in the Motorola world) got rid of this dual standard by using a 134 Hz turn-off code for about 200 mSec. ALL equipment now plays together a lot better. The only incompatability is with normal vs inverted codes, and this is more a function of the exciter and modulator circuitry that is, by nature, different between various manufacturers. So endeth the lesson for today, gentlemen. (spoken by Mrs. Whistler, the little old lady in South Africa in the opening scene of Ian Fleming's James Bond 007 in Diamonds Are Forever) Bob M. == --- Nate Duehr [EMAIL PROTECTED] wrote: On Nov 28, 2007, at 9:37 PM, Glenn Little WB4UIV wrote: The 1A is an EIA designation. See http://www.personainternet.com/~northscan/dcss.html Google is your friend. Searched for CTCSS Frequency EIA. 73 Glenn WB4UIV There's also an EIA/TIA specification for the reverse burst standards. I don't have access to EIA/TIA standards (since you typically have to pay for them) and judging by the various websites that allude to it (marketing material), there's other things in this spec, it would appear. Here's a blurb from a modern Motorola radio's marketing materials I found a while back: The industry standard EIA/TIA-603 lists two formats for CTCSS Reverse Burst: The format used by Motorola is 120 degree phase shift for 180 milliseconds, while the format used by all other manufacturers as well as by aftermarket tone equipment makers is 180 degree phase shift for 150 milliseconds. They go on to explain that in RSS you can switch to non-standard Reverse Burst on this particular radio. Would love to see the full EIA/TIA-603 spec. But these days when standards are purchased instead of public knowledge... oh well. I'm also surprised the Moto marketing people forgot to put the (TM) after the words Reverse Burst. (GRIN) Maybe it was hiding in the fine print of the document and I missed it. I was more interested in having found a reference to a real EIA/TIA specification for the phase shifts and time periods. Then more Googling found LOTS of manufacturer's marketing materials referencing it, but no copies of the spec sneaking around on someone's website. Oh well. -- Nate Duehr, WY0X [EMAIL PROTECTED] Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
Re: [Repeater-Builder] Usage of Linked Repeater Systems vs. Stand Alone Repeaters
Steve Stahl wrote: I'm a Trucker and in my travels it seems that the link systems are about the only place anything is going on I can't tell you how many areas I've been where you open the repeater book, find a bunch of local machines and can't hear or raise a peep out of anyone . On the other hand linked systems like the Win System in California seems to have traffic all the time. Steve ke7ihg I'll say it again-a repeater that's busy all day long with drivel is NOT available when someone needs it! Not to mention that electronic components have a finite life, especially RF power transistors, and the more the transmitter is running, the sooner it will be before it fails. I hate repeaters that are busy all day long with junk. They get pulled out of scan REAL quick! Some of the crap I hear on local repeaters is the biggest waste of spectrum I've seen. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Needed: MSF-5000 Green TEE Cable
Charles Mumphrey Kc5ozh wrote: Rod! It has arrived!!! I will take some physical measurements and post to the group. Measure the coax length from the tip of one center pin to the other. :c) -- Jim Barbour WD8CHL
Re: Re: [Repeater-Builder] Usage of Linked Repeater Systems vs. Stand Alone Repe
A repeater that gets used is much better than one that is not used. One not used is a waste. Most all on Ham Radio is not necessary except for our enjoyment...these are toys...there is nothing wrong with having toys. 73, ron, n9ee/r From: Jim [EMAIL PROTECTED] Date: 2007/11/29 Thu PM 02:10:39 CST To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Usage of Linked Repeater Systems vs. Stand Alone Repeaters Steve Stahl wrote: I'm a Trucker and in my travels it seems that the link systems are about the only place anything is going on I can't tell you how many areas I've been where you open the repeater book, find a bunch of local machines and can't hear or raise a peep out of anyone . On the other hand linked systems like the Win System in California seems to have traffic all the time. Steve ke7ihg I'll say it again-a repeater that's busy all day long with drivel is NOT available when someone needs it! Not to mention that electronic components have a finite life, especially RF power transistors, and the more the transmitter is running, the sooner it will be before it fails. I hate repeaters that are busy all day long with junk. They get pulled out of scan REAL quick! Some of the crap I hear on local repeaters is the biggest waste of spectrum I've seen. -- Jim Barbour WD8CHL Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
Re: [Repeater-Builder] Re: TLN 5731A - Tone Private Line Encoder
Removing the tone works with ALL decoders, but it does take more time for some to realize that the tone is gone, so if the system can keep the transmitter on without modulation for 1/4 to 1/2 second, that'll do nicely. But technically, no-burst is not the same as reverse-burst. Bob M. == --- skipp025 [EMAIL PROTECTED] wrote: Another cute trick tried by some mfgrs is to simply remove ctcss x-time before the rf goes away/drops. The decoder stops and the audio gate(s) close before the crash noise. The other famous anti crash noise through repeaters is the audio delay module clean-up, which doesn't care what kind of signaling you use... including carrier squelch. s. Bob M. [EMAIL PROTECTED] wrote: The two standards for reverse-burst are switchable in some of the newer radios, such as those that use CPS for programming. Prior to about 10 years ago, Motorola was under the mind-set that you either bought all your radios from them or none of your radios from them, so system inter-operability didn't concern them. If you bought a Brand X radio and used it in your Motorola system, they hoped the audible squelch burst would be annoying enough to get you to go with their brand exclusively. Unfortunately this backfired and a lot of customers went totally with Brand X instead of Brand M. Hence, we now have two slightly incompatible standard methods. Then we have some of the Japanese amateur radios that don't recognize any reverse burst, and always give you a squelch burst on a PL system. The old PL reed encode/decode units used until the mid 1980s, tended to be a lot more forgiving about the phase difference. In fact, the very old encoders from the 1960s used a center-tapped transformer on the PL board, and switched from one phase to the other with the undelayed section of a T/R relay, so the phase was probably 180 degrees back then. It's only the newer radios with microprocessor-based tone decoders that can recognize and enforce the 120 degree shift. DCS (DPL in the Motorola world) got rid of this dual standard by using a 134 Hz turn-off code for about 200 mSec. ALL equipment now plays together a lot better. The only incompatability is with normal vs inverted codes, and this is more a function of the exciter and modulator circuitry that is, by nature, different between various manufacturers. So endeth the lesson for today, gentlemen. (spoken by Mrs. Whistler, the little old lady in South Africa in the opening scene of Ian Fleming's James Bond 007 in Diamonds Are Forever) Bob M. == --- Nate Duehr [EMAIL PROTECTED] wrote: On Nov 28, 2007, at 9:37 PM, Glenn Little WB4UIV wrote: The 1A is an EIA designation. See http://www.personainternet.com/~northscan/dcss.html Google is your friend. Searched for CTCSS Frequency EIA. 73 Glenn WB4UIV There's also an EIA/TIA specification for the reverse burst standards. I don't have access to EIA/TIA standards (since you typically have to pay for them) and judging by the various websites that allude to it (marketing material), there's other things in this spec, it would appear. Here's a blurb from a modern Motorola radio's marketing materials I found a while back: The industry standard EIA/TIA-603 lists two formats for CTCSS Reverse Burst: The format used by Motorola is 120 degree phase shift for 180 milliseconds, while the format used by all other manufacturers as well as by aftermarket tone equipment makers is 180 degree phase shift for 150 milliseconds. They go on to explain that in RSS you can switch to non-standard Reverse Burst on this particular radio. Would love to see the full EIA/TIA-603 spec. But these days when standards are purchased instead of public knowledge... oh well. I'm also surprised the Moto marketing people forgot to put the (TM) after the words Reverse Burst. (GRIN) Maybe it was hiding in the fine print of the document and I missed it. I was more interested in having found a reference to a real EIA/TIA specification for the phase shifts and time periods. Then more Googling found LOTS of manufacturer's marketing materials referencing it, but no copies of the spec sneaking around on someone's website. Oh well. -- Nate Duehr, WY0X [EMAIL PROTECTED] Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
Re: [Repeater-Builder] Needed: MSF-5000 Green TEE Cable
You'll find photos of exactly that measurement for both the green and yellow cables in the MSF Photo Tour, although they're not visibly accurate to 1/8 inch. Bob M. == --- Jim [EMAIL PROTECTED] wrote: Charles Mumphrey Kc5ozh wrote: Rod! It has arrived!!! I will take some physical measurements and post to the group. Measure the coax length from the tip of one center pin to the other. :c) -- Jim Barbour WD8CHL Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ
Re: [Repeater-Builder] Re: TLN 5731A - Tone Private Line Encoder
Bob M. wrote: Removing the tone works with ALL decoders, but it does take more time for some to realize that the tone is gone, so if the system can keep the transmitter on without modulation for 1/4 to 1/2 second, that'll do nicely. Unless it's some of the newer Yaesu's, at least hand-helds. Some I've seen don't close the squelch until the signal goes away. It won't open unless the right tone is there, but once it's open, it stays open as long as squelch is open. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: TLN 5731A - Tone Private Line Encoder
Maybe when Motorola buys Yaesu, and before they discontinue all their equipment, they'll fix some of the bugs like that. Sounds likt their tone decoder has about the same amount of filtering that their TX audio does, so it can't handle tone properly except to open the squelch. Bob M. == --- Jim [EMAIL PROTECTED] wrote: Bob M. wrote: Removing the tone works with ALL decoders, but it does take more time for some to realize that the tone is gone, so if the system can keep the transmitter on without modulation for 1/4 to 1/2 second, that'll do nicely. Unless it's some of the newer Yaesu's, at least hand-helds. Some I've seen don't close the squelch until the signal goes away. It won't open unless the right tone is there, but once it's open, it stays open as long as squelch is open. -- Jim Barbour WD8CHL Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ
Re: [Repeater-Builder] Re: TLN 5731A - Tone Private Line Encoder
Bob M. wrote: Maybe when Motorola buys Yaesu, and before they discontinue all their equipment, they'll fix some of the bugs like that. Sounds likt their tone decoder has about the same amount of filtering that their TX audio does, so it can't handle tone properly except to open the squelch. snicker Yeah, I actually think the logic for the decoder is setup as a 'one-shot' so to speak. It was probably easier to write the code that way. - Jim Barbour WD8CHL
RE: [Repeater-Builder] R1225 Repeater
As far as having the coaxes switched, we marked the cables before disassembling the duplexer for re-tuning. However, I do wonder if the guy tuned the notch to the same freq on both sides. I don't recall seeing him change the freq on the monitor while he was tuning the duplexers last night. _ From: Repeater-Builder@yahoogroups.com On Behalf Of Albert Well let us know how it turns out. Hopefully you didn't make the easy mistake of having the coaxes off of the RX and the TX connected to the incorrect ports on the duplexer??? OR maybe the fellow whom tuned the duplexer transposed the high and low sides??? easily enough done and a very easy mistake to make! Albert
Re: [Repeater-Builder] R1225 Repeater
Have you taken the duplexer out of the equation, put a dummy load on the TX port, a tuned antenna on the receive port and see if the receiver is receiving properly? If you have a service monitor, check to see if it is within performance specs for 12db sinad and 20 db quieting. If it is, then it's a duplexer problem. If not, then it's a receiver problem and not a duplexer. Got to first isolate where the trouble is. That would be a very deaf receiver that's either tuned off frequency, shorted coax, busted connectors or other problems. If it's a duplexer, it's tuned wrong and / or highly desensed. Let us know how you make out finding out which component is the culprit. Albert n9wys wrote: A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk... Thanks in advance, Mark - N9WYS
Re: [Repeater-Builder] R1225 Repeater
Well let us know how it turns out. Hopefully you didn't make the easy mistake of having the coaxes off of the RX and the TX connected to the incorrect ports on the duplexer??? OR maybe the fellow whom tuned the duplexer transposed the high and low sides??? easily enough done and a very easy mistake to make! Albert n9wys wrote: I just brought the repeater back to my shack this afternoon... the service monitor test will be one of the first performed. Although I did not tune the duplexers personally, I trust the guy who did tune them - and he did two of them for us. So if it is a bad duplexer, it's actually TWO of them. Thanks for the tips - and now I'm of to the shack and a service monitor. ;-) 73 de Mark - N9WYS From: Repeater-Builder@yahoogroups.com On Behalf Of Albert Have you taken the duplexer out of the equation, put a dummy load on the TX port, a tuned antenna on the receive port and see if the receiver is receiving properly? If you have a service monitor, check to see if it is within performance specs for 12db sinad and 20 db quieting. If it is, then it's a duplexer problem. If not, then it's a receiver problem and not a duplexer. Got to first isolate where the trouble is. That would be a very deaf receiver that's either tuned off frequency, shorted coax, busted connectors or other problems. If it's a duplexer, it's tuned wrong and / or highly desensed. Let us know how you make out finding out which component is the culprit. Albert n9wys wrote: A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk... Thanks in advance, Mark - N9WYS
RE: [Repeater-Builder] R1225 Repeater
I just brought the repeater back to my shack this afternoon. the service monitor test will be one of the first performed. Although I did not tune the duplexers personally, I trust the guy who did tune them - and he did two of them for us. So if it is a bad duplexer, it's actually TWO of them. Thanks for the tips - and now I'm of to the shack and a service monitor. ;-) 73 de Mark - N9WYS _ From: Repeater-Builder@yahoogroups.com On Behalf Of Albert Have you taken the duplexer out of the equation, put a dummy load on the TX port, a tuned antenna on the receive port and see if the receiver is receiving properly? If you have a service monitor, check to see if it is within performance specs for 12db sinad and 20 db quieting. If it is, then it's a duplexer problem. If not, then it's a receiver problem and not a duplexer. Got to first isolate where the trouble is. That would be a very deaf receiver that's either tuned off frequency, shorted coax, busted connectors or other problems. If it's a duplexer, it's tuned wrong and / or highly desensed. Let us know how you make out finding out which component is the culprit. Albert n9wys wrote: A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk. Thanks in advance, Mark - N9WYS
RE: [Repeater-Builder] R1225 Repeater
Mark, Are we talking about the R1225 transceiver itself, or is the repeater actually a GR1225, RKR1225, or a GR400 or GR500 X-Pand repeater? If one of the latter, the duplexer is usually a mobile notch duplexer with six helical resonators in a one-inch-thick package. Does your R1225 repeater use such a duplexer, or is it a full-size BpBr unit with large cavity filters? When a service tech works mostly with BpBr cavities, it is a common error to tune the screws for the pass frequency instead of the notch frequency. A local hospital had a GR1225 repeater come back from a radio shop with the TX and RX cables reversed, and it wouldn't work very well. It tested fine on the service monitor, but the tech got confused about the HIGH and LOW labels on the notch duplexer. The ports should have been labeled REJECT HIGH and REJECT LOW, with the former going to the TX output on the R1225 and the latter going to the RX input on the R1225. If the R1225 is a high-power (25-50 watt) model, it is possible that operating the transceiver with a mis-tuned notch duplexer can burn out the protection diodes in the RX front end. There is no tune-up required on the R1225. The RX front end is varactor-tuned by the CPU to optimize the RX sensitivity. The R1225 service manual is 6880905Z53, about $13, and is a must-have document. If your repeater is a GR1225, you also need the 6880904Z90 manual, also about $13. If your repeater is an RKR1225, you also need the 6880907Z10 manual, about $36. Finally, if your repeater is a GR400/GR500 X-Pand model, you also need the 6880905Z54 manual, about $13. Many early GR1225 repeaters were shipped with a duplexer harness made of RG58 single-shielded cable. I was setting up one such GR1225 on a VHF repeater pair with a 5.26 MHz split, and I was measuring almost 12 dB of desense. I cured the problem completely by making up a new harness using RG-400/U double-silver-shielded cable and the proper connectors on the ends- no adapters. That repeater is still in service after three years with no down time, but is being replaced with a new MTR2000 station. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of n9wys Sent: Thursday, November 29, 2007 4:02 PM To: [EMAIL PROTECTED]; Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] R1225 Repeater A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk. Thanks in advance, Mark - N9WYS
RE: [Repeater-Builder] R1225 Repeater
Hi Eric. The machine I have is as you described as the latter - it employs a mobile-type, 6-resonator notch duplexer. It is on 452/457 MHz. As for the exact model designation, it says Radius GR1225 on the front panel... We've tried reversing the cables going to the duplexer, with no change in performance... I labeled the cables myself when we disassembled the unit to have the duplexer retuned, so I know which one was supposed to go where. I'm seriously beginning to think the duplexer is erroneously tuned to notch the RX freq on both sides. So in essence, there is no high and low notch, there is just high. Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of Eric Lemmon Mark, Are we talking about the R1225 transceiver itself, or is the repeater actually a GR1225, RKR1225, or a GR400 or GR500 X-Pand repeater? If one of the latter, the duplexer is usually a mobile notch duplexer with six helical resonators in a one-inch-thick package. Does your R1225 repeater use such a duplexer, or is it a full-size BpBr unit with large cavity filters? When a service tech works mostly with BpBr cavities, it is a common error to tune the screws for the pass frequency instead of the notch frequency. A local hospital had a GR1225 repeater come back from a radio shop with the TX and RX cables reversed, and it wouldn't work very well. It tested fine on the service monitor, but the tech got confused about the HIGH and LOW labels on the notch duplexer. The ports should have been labeled REJECT HIGH and REJECT LOW, with the former going to the TX output on the R1225 and the latter going to the RX input on the R1225. If the R1225 is a high-power (25-50 watt) model, it is possible that operating the transceiver with a mis-tuned notch duplexer can burn out the protection diodes in the RX front end. There is no tune-up required on the R1225. The RX front end is varactor-tuned by the CPU to optimize the RX sensitivity. The R1225 service manual is 6880905Z53, about $13, and is a must-have document. If your repeater is a GR1225, you also need the 6880904Z90 manual, also about $13. If your repeater is an RKR1225, you also need the 6880907Z10 manual, about $36. Finally, if your repeater is a GR400/GR500 X-Pand model, you also need the 6880905Z54 manual, about $13. Many early GR1225 repeaters were shipped with a duplexer harness made of RG58 single-shielded cable. I was setting up one such GR1225 on a VHF repeater pair with a 5.26 MHz split, and I was measuring almost 12 dB of desense. I cured the problem completely by making up a new harness using RG-400/U double-silver-shielded cable and the proper connectors on the ends- no adapters. That repeater is still in service after three years with no down time, but is being replaced with a new MTR2000 station. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of n9wys A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk. Thanks in advance, Mark - N9WYS
Re: [Repeater-Builder] Looking for an old VHF Engineering CW ID'er board
Ben, I have one plus some other boards I pulled from a VHF Engrg. chassis if interested. Contact me direct at de_ [EMAIL PROTECTED] -- Doug N3DAB/WPRX486/WPJL709 w4wsm [EMAIL PROTECTED] wrote: = I have a project using an old VHF Engineering repeater and the ID'er board has given up. Looks like it has just had the call changed 1 too many times.. Anyway, anyone out there have one of these old boards you aren't using and would like to get rid of cheap? Would like to use the same stock board for this one... Thanks! Ben W4WSM
RE: [Repeater-Builder] R1225 Repeater
If this is the case, you may have steered full transmit power into the receiver. The results would not be good. Keith McQueen 801-224-9460 [EMAIL PROTECTED] -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of n9wys Sent: Thursday, November 29, 2007 9:55 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] R1225 Repeater Hi Eric. The machine I have is as you described as the latter - it employs a mobile-type, 6-resonator notch duplexer. It is on 452/457 MHz. As for the exact model designation, it says Radius GR1225 on the front panel... We've tried reversing the cables going to the duplexer, with no change in performance... I labeled the cables myself when we disassembled the unit to have the duplexer retuned, so I know which one was supposed to go where. I'm seriously beginning to think the duplexer is erroneously tuned to notch the RX freq on both sides. So in essence, there is no high and low notch, there is just high. Mark - N9WYS -Original Message- From: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com On Behalf Of Eric Lemmon Mark, Are we talking about the R1225 transceiver itself, or is the repeater actually a GR1225, RKR1225, or a GR400 or GR500 X-Pand repeater? If one of the latter, the duplexer is usually a mobile notch duplexer with six helical resonators in a one-inch-thick package. Does your R1225 repeater use such a duplexer, or is it a full-size BpBr unit with large cavity filters? When a service tech works mostly with BpBr cavities, it is a common error to tune the screws for the pass frequency instead of the notch frequency. A local hospital had a GR1225 repeater come back from a radio shop with the TX and RX cables reversed, and it wouldn't work very well. It tested fine on the service monitor, but the tech got confused about the HIGH and LOW labels on the notch duplexer. The ports should have been labeled REJECT HIGH and REJECT LOW, with the former going to the TX output on the R1225 and the latter going to the RX input on the R1225. If the R1225 is a high-power (25-50 watt) model, it is possible that operating the transceiver with a mis-tuned notch duplexer can burn out the protection diodes in the RX front end. There is no tune-up required on the R1225. The RX front end is varactor-tuned by the CPU to optimize the RX sensitivity. The R1225 service manual is 6880905Z53, about $13, and is a must-have document. If your repeater is a GR1225, you also need the 6880904Z90 manual, also about $13. If your repeater is an RKR1225, you also need the 6880907Z10 manual, about $36. Finally, if your repeater is a GR400/GR500 X-Pand model, you also need the 6880905Z54 manual, about $13. Many early GR1225 repeaters were shipped with a duplexer harness made of RG58 single-shielded cable. I was setting up one such GR1225 on a VHF repeater pair with a 5.26 MHz split, and I was measuring almost 12 dB of desense. I cured the problem completely by making up a new harness using RG-400/U double-silver-shielded cable and the proper connectors on the ends- no adapters. That repeater is still in service after three years with no down time, but is being replaced with a new MTR2000 station. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com On Behalf Of n9wys A friend of mine has a Motorola R1225 repeater that is as deaf as a fence post. We've tried re-tuning the original duplexer and replacing it with another known-good duplexer. We even tried separating the antennas, although we could only get about 30' of vertical separation between the two. Nothing seems to work - and at 150mW on an HT, I can only get about 30' away from the repeater antenna before I cannot access it. 4W will give me a range of about 100 yds. Does anyone have the manual for this machine? If so, I'd be much obliged for a copy of any receiver tune-up procedures. I hate to think this thing is junk. Thanks in advance, Mark - N9WYS
