[Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
I need a little advise here. I want to test my repeater's sensitivity through the duplexer's while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter is about 4KHz wide, and clean at 100 watts. Any suggestions. Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8 Andrews hardline. But it seems the handhelds are the one's having the problems, and their signal is not really that bad. Help please. Mathew Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Receiver Sensitivity Testing Through Duplexer
--- In Repeater-Builder@yahoogroups.com, w9mwq [EMAIL PROTECTED] wrote: ...I want to test my repeater's sensitivity through the duplexer's while the transmitter is keyed up... __ ___ Start by reading this: http://www.repeater-builder.com/rbtip/effectivesens.html What you want to do is first test the repeater for desense with the transmitter operating into a 50 ohm load. The receiver should have the same sensitivity through the iso-T with the transmitter off or on. If not, you have an issue with your duplexer. Once you have the station operating properly into a load, then begin the test at the site. You are looking for two issues. 1. Is the receiver being desensed by site noise? 2. Does the repeater operate without desense [or without any more desense than observed in step 1] when the repeater transmitter is active and the system is using its antenna. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Ok, looks like I need to get the Iso-tee made then. Mathew - Original Message - From: Chuck Kelsey [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 7:25 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer No. - Original Message - From: Mathew Quaife [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 10:17 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer Could I get by using a seperate antenna to test for desense? Say leaving the antenna for the receiver through the duplexer and hooking the transmitter up to another antenna, would that work the same to test for desense. I tried to make an iso-tee, did not heave real good luck with it, but then as far as a machinest, I have to luck at that, hihi Mathew - Original Message - From: Eric Lemmon [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 6:09 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer Mathew, There may be more than one problem to consider. It is wise to check for desense, but also be aware that some amateur-grade handhelds are notorious for excessive PL deviation. Alincos are the worst, in my opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) receives an input from a user with excessive PL deviation, the user's voice may over-deviate the carrier, causing the PL to be clipped. When this happens on a PL-required repeater, the repeater shuts down on voice peaks. Of course, this symptom is made much worse when the voice deviation is too high, as well. One way to check this is to use a commercial-grade handheld radio to check for the same symptoms. To check for desense, you can use an iso-tee to inject a low-level signal into the antenna feedline at the receiver frequency, while monitoring the receiver audio at 12 dB SINAD with the repeater disabled. Then enable the repeater so that the transmitter turns on. The SINAD reading should drop no more than 1 dB. Some service monitors will change modes when RF is detected, so you may want to use a separate antenna, instead of the iso-tee, to get the test signal into the receiver. If your repeater is at a site with other transmitters, you may need to add some bandpass-only (NOT pass/notch) cavities between the duplexer and the receiver input. As has been noted many times on this list, a pass/notch or BpBr duplexer has almost no bandpass selectivity, and a nearby transmitter many MHz away can easily cause desense in your receiver if not filtered out with a dedicated bandpass cavity. 73, Eric Lemmon WB6FLY w9mwq wrote: I need a little advice here. I want to test my repeater's sensitivity through the duplexer, while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 dB Sinad. Audio out of the transmitter is about 4 kHz wide, and clean at 100 watts. Any suggestions? Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8 Andrews hardline. But it seems the handhelds are the ones having the problems, and their signal is not really that bad. Help please. Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Mathew, No, you should not disturb any of the hookups between your duplexer and antenna, transmitter, or receiver. What I meant by a separate antenna is one connected to the output of your service monitor, and which radiates a signal that is picked up by your repeater antenna. This method will prove or disprove whether desense is caused by your own transmitter. It will also enable you to determine if desense is being caused by a nearby transmitter on a different frequency, if the SINAD reading suddenly drops while your repeater transmitter is disabled. If this happens, you can use a spectrum analyzer to sweep the band several MHz each side of your receiver frequency and note what carriers are present at the same time your SINAD drops. As I noted in a previous posting, a bandpass filter may be needed to eliminate desense caused by a nearby transmitter. 73, Eric Lemmon WB6FLY Mathew Quaife wrote: Could I get by using a separate antenna to test for desense? Say leaving the antenna for the receiver through the duplexer and hooking the transmitter up to another antenna, would that work the same to test for desense. I tried to make an iso-tee, did not have real good luck with it, but then as far as a machinist, I have no luck at that, hihi Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Actually the repeater is here at my home qth, only other transmitter is a 460 commercial repeater about 2 miles away, do don't think I am getting any problems from that one. Mathew - Original Message - From: Mike WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 7:33 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer Forgot to mention one thing - you don't even need to visit the site if the repeater has an autopatch (or even a remote base that is on a different band) you can listen to the RX via the patch or remote and let the main channel TX time out. If the quieting level in the RX goes up exactly when the TX drops off that indicates a problem. Mike WA6ILQ At 07:14 PM 7/26/04, you wrote: I like the idea but I'd use a parked mobile instead. HT's are hand held and can be moved which will change the signal level, plus they pull 3/4 to 1amp from the batteries and can suck them down, which also changes the signal level. The use of a parked mobile - set to the lowest power level it can do - eliminates both factors from the equation. Mike WA6ILQ At 06:57 PM 7/26/04, you wrote: Here's one simple test. Have someone with an HT get into a noisy location, then disable your repeater transmitter while listening on the local speaker. If all of a sudden the HT becomes full quieting, you've got a desense problem. Chuck WB2EDV - Original Message - From: w9mwq [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 8:01 PM Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer I need a little advise here. I want to test my repeater's sensitivity through the duplexer's while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter is about 4KHz wide, and clean at 100 watts. Any suggestions. Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8 Andrews hardline. But it seems the handhelds are the one's having the problems, and their signal is not really that bad. Help please. Mathew Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
That I can do, I have another antenna that is up that I can hook to the SM. From what I can tell I am not getting any desence, as I did have one operator about 25 miles away, listening through the receiver ouput, I could here him just fine and that was with the repeat mode turned off. He would talk, and I would key up the transmitter, nothing would change. I'm leading it back to the PL area, as was mentioned, I think it is killing the PL as they talk. I just want to make sure the duplexer is tuned up properly and all is working there. If its the PL, and is coming from the handie talkie, not much I can do there. Mathew, No, you should not disturb any of the hookups between your duplexer and antenna, transmitter, or receiver. What I meant by a separate antenna is one connected to the output of your service monitor, and which radiates a signal that is picked up by your repeater antenna. This method will prove or disprove whether desense is caused by your own transmitter. It will also enable you to determine if desense is being caused by a nearby transmitter on a different frequency, if the SINAD reading suddenly drops while your repeater transmitter is disabled. If this happens, you can use a spectrum analyzer to sweep the band several MHz each side of your receiver frequency and note what carriers are present at the same time your SINAD drops. As I noted in a previous posting, a bandpass filter may be needed to eliminate desense caused by a nearby transmitter. 73, Eric Lemmon WB6FLY Mathew Quaife wrote: Could I get by using a separate antenna to test for desense? Say leaving the antenna for the receiver through the duplexer and hooking the transmitter up to another antenna, would that work the same to test for desense. I tried to make an iso-tee, did not have real good luck with it, but then as far as a machinist, I have no luck at that, hihi Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
You want the user to be a bit noisy when you do that test. If you then turn your repeater TX on and nothing changes, you don't have desense. Chuck WB2EDV - Original Message - From: Mathew Quaife [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 10:48 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer That I can do, I have another antenna that is up that I can hook to the SM. From what I can tell I am not getting any desence, as I did have one operator about 25 miles away, listening through the receiver ouput, I could here him just fine and that was with the repeat mode turned off. He would talk, and I would key up the transmitter, nothing would change. I'm leading it back to the PL area, as was mentioned, I think it is killing the PL as they talk. I just want to make sure the duplexer is tuned up properly and all is working there. If its the PL, and is coming from the handie talkie, not much I can do there. Mathew, Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
No. - Original Message - From: Mathew Quaife [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 10:17 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer Could I get by using a seperate antenna to test for desense? Say leaving the antenna for the receiver through the duplexer and hooking the transmitter up to another antenna, would that work the same to test for desense. I tried to make an iso-tee, did not heave real good luck with it, but then as far as a machinest, I have to luck at that, hihi Mathew - Original Message - From: Eric Lemmon [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 6:09 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer Mathew, There may be more than one problem to consider. It is wise to check for desense, but also be aware that some amateur-grade handhelds are notorious for excessive PL deviation. Alincos are the worst, in my opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) receives an input from a user with excessive PL deviation, the user's voice may over-deviate the carrier, causing the PL to be clipped. When this happens on a PL-required repeater, the repeater shuts down on voice peaks. Of course, this symptom is made much worse when the voice deviation is too high, as well. One way to check this is to use a commercial-grade handheld radio to check for the same symptoms. To check for desense, you can use an iso-tee to inject a low-level signal into the antenna feedline at the receiver frequency, while monitoring the receiver audio at 12 dB SINAD with the repeater disabled. Then enable the repeater so that the transmitter turns on. The SINAD reading should drop no more than 1 dB. Some service monitors will change modes when RF is detected, so you may want to use a separate antenna, instead of the iso-tee, to get the test signal into the receiver. If your repeater is at a site with other transmitters, you may need to add some bandpass-only (NOT pass/notch) cavities between the duplexer and the receiver input. As has been noted many times on this list, a pass/notch or BpBr duplexer has almost no bandpass selectivity, and a nearby transmitter many MHz away can easily cause desense in your receiver if not filtered out with a dedicated bandpass cavity. 73, Eric Lemmon WB6FLY w9mwq wrote: I need a little advice here. I want to test my repeater's sensitivity through the duplexer, while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 dB Sinad. Audio out of the transmitter is about 4 kHz wide, and clean at 100 watts. Any suggestions? Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8 Andrews hardline. But it seems the handhelds are the ones having the problems, and their signal is not really that bad. Help please. Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Forgot to mention one thing - you don't even need to visit the site if the repeater has an autopatch (or even a remote base that is on a different band) you can listen to the RX via the patch or remote and let the main channel TX time out. If the quieting level in the RX goes up exactly when the TX drops off that indicates a problem. Mike WA6ILQ At 07:14 PM 7/26/04, you wrote: I like the idea but I'd use a parked mobile instead. HT's are hand held and can be moved which will change the signal level, plus they pull 3/4 to 1amp from the batteries and can suck them down, which also changes the signal level. The use of a parked mobile - set to the lowest power level it can do - eliminates both factors from the equation. Mike WA6ILQ At 06:57 PM 7/26/04, you wrote: Here's one simple test. Have someone with an HT get into a noisy location, then disable your repeater transmitter while listening on the local speaker. If all of a sudden the HT becomes full quieting, you've got a desense problem. Chuck WB2EDV - Original Message - From: w9mwq [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 8:01 PM Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer I need a little advise here. I want to test my repeater's sensitivity through the duplexer's while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter is about 4KHz wide, and clean at 100 watts. Any suggestions. Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8 Andrews hardline. But it seems the handhelds are the one's having the problems, and their signal is not really that bad. Help please. Mathew Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Will give that a try tomorrow and see if it is the same and take it from there. I'm almost betting it is the Handhelds with the elevated pl tone output. Going to have to give another stab at making an iso tee to work with. Thanks for the input. Will let you know how it comes out. Mathew You want the user to be a bit noisy when you do that test. If you then turn your repeater TX on and nothing changes, you don't have desense. Chuck WB2EDV - Original Message - From: Mathew Quaife [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 10:48 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer That I can do, I have another antenna that is up that I can hook to the SM. From what I can tell I am not getting any desence, as I did have one operator about 25 miles away, listening through the receiver ouput, I could here him just fine and that was with the repeat mode turned off. He would talk, and I would key up the transmitter, nothing would change. I'm leading it back to the PL area, as was mentioned, I think it is killing the PL as they talk. I just want to make sure the duplexer is tuned up properly and all is working there. If its the PL, and is coming from the handie talkie, not much I can do there. Mathew, Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Bag Cell Phone interface?
On Jul 26, 2004, at 3:26 PM, Steve Smith wrote: Doesn't Verizon have the On Star contract with GM and accordingly has to maintain analog? Don't you mean BlondeStar? ;-) http://www.smartelic.com/ - click on the BlondeStar logos. Very funny stuff. -- Nate Duehr, [EMAIL PROTECTED] - WY0X Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Bag Cell Phone rant?
So THAT'S why my signal sounds like crap, I'm not running it through a muldem.;) 73, Kenneth Buley Bullitt County ARES/RACES Coordinator KE4AWY Bullitt County EMA CD-2 Bullitt County Red Cross Disaster Communications BC-6 -Original Message- From: Steve Grantham [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 1:12 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Bag Cell Phone rant? Don't forget that this digital radio stuff is only digital in the muldem. snip 73, Steve, AA5SG Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Bag Cell Phone interface?
I have a Motorola S1801A Cellular Data-Passage unit that was made for interfacing a computer to a bag phone, I'm not sure if it passes dial tone and voice, it's for sale if you can use it. $10 including shipping. 73, Joe, k1ike All outgoing email scanned with Norton AntiVirus2004. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] 1.2 ghz repeater
Try 902 MHz, lots of commercial gear available at much less cost. Check out the Yahoo group AR902MHZ. 73, Dick, W1KSZ 902.1375/927.1375 131.8 PL -Original Message- From: Russ [EMAIL PROTECTED] Sent: Jul 26, 2004 12:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] 1.2 ghz repeater who makes 1.2 ghz equipment for repeater usage , im drawing a blank and web searches arnt proving helpful either ... Russ N3TIH Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters
I want to know how to make the harness for two of these.Also would like to find out how to make one for four of the db-212 cut for six meters.What are the formulas thanks Mike KC8FWD --- In Repeater-Builder@yahoogroups.com, John J. Riddell [EMAIL PROTECTED] wrote: The following was received after a request to Cook Towers about retuning a DB-212 antenna that i have which is presently on 42 Mhz. John VE3AMZ Waterloo Ontario. - Original Message - From: [EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 9:42 AM Subject: How to modify DB 212 for 6 meters Six meter mod for the DB-212 Real gain for six meters (DBd) For the DB-212, you would just measure the current length of the dipole and then multiply this length by (current_freq/new-freq). So if the current length is 180 and the current freq is 50 and you want to go to 53.5 MHz. The new length is 180*(50/53.5) in inches. To change the length you will need to remove the pop-rivet and a little dimple that the tuner uses to hold the trombone in place until production can install the rivet. Sometimes the vswr depends on the tower face. If you want to super tune the antenna, do the following. Set the antenna up on a tower leg a few feet off the ground. Then free the trombone, put it at the length you want. Next check the refected. Then get some long stick and start moving the trombone while watching the refelcted. When you get the best possible vswr, redo the rivets. This has been tested here in our shop and it works well! Cook Towers, INC. Toll Free (877)992-2665 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters
You mite want to ask the same folks who came up with the mod listed below. - Original Message - From: Michael J.Talkington [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, July 27, 2004 10:04 AM Subject: [Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters I want to know how to make the harness for two of these.Also would like to find out how to make one for four of the db-212 cut for six meters.What are the formulas thanks Mike KC8FWD --- In Repeater-Builder@yahoogroups.com, John J. Riddell [EMAIL PROTECTED] wrote: The following was received after a request to Cook Towers about retuning a DB-212 antenna that i have which is presently on 42 Mhz. John VE3AMZ Waterloo Ontario. - Original Message - From: [EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 9:42 AM Subject: How to modify DB 212 for 6 meters Six meter mod for the DB-212 Real gain for six meters (DBd) For the DB-212, you would just measure the current length of the dipole and then multiply this length by (current_freq/new-freq). So if the current length is 180 and the current freq is 50 and you want to go to 53.5 MHz. The new length is 180*(50/53.5) in inches. To change the length you will need to remove the pop-rivet and a little dimple that the tuner uses to hold the trombone in place until production can install the rivet. Sometimes the vswr depends on the tower face. If you want to super tune the antenna, do the following. Set the antenna up on a tower leg a few feet off the ground. Then free the trombone, put it at the length you want. Next check the refected. Then get some long stick and start moving the trombone while watching the refelcted. When you get the best possible vswr, redo the rivets. This has been tested here in our shop and it works well! Cook Towers, INC. Toll Free (877)992-2665 Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Duplexer...on eBay
Its a Fiplex duplexer. We sell them as well and have had some very good luck with them on the ham bands. -Original Message- From: Ron Stordahl N5IN [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 11:23 To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Duplexer...on eBay I noticed a 2 meter duplexer on eBay which looks promising on the surface. I sent an e-mail to the seller, using the eBay mail system which does not reveal his actual address, but so far (24 hours) no response. My interest is in a more complex device to support 144.39 simplex plus 146.850TX 146.250RX voice repeater to the same antenna, and that was the subject of my e-mail. Here are some links...but if previous experience is any guide these links do not always get thru unbroken in posts like these. So if they don't, try searching for 2 meters ready (yes that is meters) that should do it. The seller has a store SUNPCS if that is any clue. Links http://stores.ebay.com/SUNPCS_W0QQsspagenameZl2QQtZkm http://cgi.ebay.com/ws/eBayISAPI.dll? ViewItemcategory=1502item=5711311161tc=photo So my question...anyone have any idea who the manufacturer of the duplexer? One thing I notice as that the interconnects between the cans is done with uninsulated solid outer conductor (probably aluminum) coax. Ron Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Deviation Limiting/Linearity
Actually, I have two problems so it might take two threads. (Long-winded too...no less) Repeater: MSR2000 Controller: CAT250 interfaced via Squelch Gate card. I have been chasing my tail on two issues. One is deviation limiting and the other is deviation linearity. It seems that if the deviation is not linear when setting up IDC/Repeater Leveland the deviation limiting in the receiver, if has an adverse effect on the DTMF decoding in the VA3TO interface that I use on Echolink. IRLP and WIRES decoders work nearly flawlessly with the same audio. I found that the 147 side of the keyboard would not perform well for a lot of DTMF sources if the deviation didn't track pretty closely from 0 to 3 K or so. We check it by putting in a 1K tone @ 1K deviation, 2K deviation and 3K deviation, etc. There seems to be a couple of schools of thought. One, adjust IDC/Repeater level so it tracks 1:1, e.g., 1=1, 2=2, 3=3, 4=4, etc. The other is to check the deviation with no input and adjust the deviation to compensate for noise in the exciter, e.g., 1=1.2, 2=2.2, 3=3.2, etc. We have done it both ways. It's seems pretty tough to get the linearity AND the deviation limiter in the receiver aligned so that the deviaton is linear and limited to about 5K and see a niceundistorted audio waveform. After we had done an alignment and was fairly satisfied with the results, a month or so later, we began to have what appeared to be an intermod or spur problem which would break squelch and key the repeater. We thought SURE it was a noisy rig somewhere or the TV Channel 11 spur we found a few months ago. We chased it around several days. We re-soldered suspected back planepins on the R1 Audio and though we fixed it. Then it comes back again. Changed out the R1 Audio card and it worked for a day or two, and it's back again! Thought it was the Squelch Gate card and checked every solder joint a few times. Used a scope to lookat everything. This morning at about 4 AM, I put my adjusting tool on the L201 deviation limiting adjustment in the receiver and cracked it a little CW (higherdeviationallowed)and the problem went away. I could see the audio noise waveformchange on the scope at the output of the receiver. I can easily find the ragged edge so I know it's this adjustment. I even put the suspected R1 Audio card back in and it works good. However, 147 won't work on K7IOUs Kenwood (again) nowbecause the deviation is no longer linear. By the way, the repeater still sounds great even if the deviaton is not linear...so long as the limiter is working. Canany of you "gurus" with lots of experience give me a hint on the alignment?Or should I throw away the VA3TO interface? Skipp, I have read your alignment procedure a hundred times, and it makes sense on paper, but I'm not confident that I'm doing it right. I would think that the deviation limiting would not have an effect on the linearity, but it seems that it does. de WD7F John in Tucson Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Dubus VHF PHEMPT GaAs Fet Preamp Article now available on sonic
Hello GaAs Gas Fet Preamplifier People... Now set up to rock and roll (download) from my sonic web page, an excellent Dubus Magazine Article about building a VHF PHEMPT Preamplifier (preamp). The PHEMPT is a newer generation Fet, which has excellent 3rd order intercept preformance. Also my plug for Dubus Magazine is included on the Description page. http://www.radiowrench.com/sonic About half way down the columb (list). If you want the low down on PHEMPT Preamps, this article will get you well on your way. Also added is my poor mans PL (sub-tone) encoder. Enjoy skipp [EMAIL PROTECTED] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Duplexer...on eBay
At 08:23 AM 7/27/04, Ron Stordahl N5IN [EMAIL PROTECTED] wrote: Here are some links...but if previous experience is any guide these links do not always get thru unbroken in posts like these. There is a trick you can do to prevent broken URLS - just bracket them with and characters. It's part of the URL specification - RFC 1738 . Here's the link unbroken: http//cgi.ebay.com/ws/eBayISAPI.dll?ViewItemcategory=1502item=5711311161tc=photo Mike WA6ILQ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Deviation Limiting/Linearity
Well hell, I accidently sent the previous before I was finished: As I was saying, when I said: I could see the audio noise waveform change on the scope at the output of the receiver. I can easily find the ragged edge so I know it's this adjustment. And you said: No, it's not... I have to ask: Then what is causing the squelch to break and why did it quit acting up when I tweaked it just a bit? It's obvisouly not aligned properly. I can turn it a tad CCW until the noise increases (possibly going into oscillation?) and breaks the squelch and then turn it back a hair CW until it stops. I can see the audio noise change when I hit the spot where it goes haywire. I have listened to this repeater for a few months with my trusty HTX-202 so I earballed it and left it until we can get to it. We will do the alignment again according to the manual soon. And you said: As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. I say: Yep, you're perzactly right. However, on our second attemp to set the deviation back in March, we did have it looking pretty good up to 5K looking at the audio at the input of the controller. And it tracked pretty good up to about 3.5K. It held still for a couple months and then we had the Channel 11 spur that drove us crazy. It was so strong, I thought the repeater was broken. One day, there was noise getting through with the antenna disconnected.. During that episode we tweaked it again and probably messed it up. Final comment: Walt, WA4LDS and an engineer at Channel 4 here in Tucson noticed that when the picture changed on our local Fox channel, the repeater noise changed. He was instrumental in getting the Channel 11 engineer to tweak his transmiter and it is all better now. Thanks for the response. de WD7F John in Tucson - Original Message - From: skipp025 [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, July 27, 2004 10:35 AM Subject: [Repeater-Builder] Re: Deviation Limiting/Linearity Hi John, I'm here... WD7F - John in Tucson [EMAIL PROTECTED] wrote: Actually, I have two problems so it might take two threads. (Long-winded too...no less) It seems that if the deviation is not linear when setting up IDC/Repeater Level and the deviation limiting in the receiver. For the non Motorhead (Motorola) people, IDC is the channel element contained deviation control. The repeater in-out deviation will never be (track) linear on any repeater ever. There are at least three wild cards in your problem list. The first is the receiver bandwidth and any included (if used) de-emphasis circuit. The other wild cards are the transmitter (both the users radio and the repeater transmitter) pre-emphasis circuits. When these values get really wacked out, we run into an unbalanced tone level (dtmf is made from two tones) called twist. A big abuser is excessive or user radio over deviation. Most people don't realize how little audio is actually required for proper dtmf and sub-tone (PL) decoding. There are standards, but most out of the box user radios are set excessively hot. Specific to your MSR-2000 and Cat Controller. Know the receiver IF filters are tight. You will not get a good detected waveform with any voice audio deviated signal above 4KHz (without sub tone). So don't try... The statement just above is much of your problem. You also didn't say how you set the receiver on frequency. John, Again set the repeater up as described in my MSR2000 to external controller text, easily found at http://www.radiowrench.com/sonic Then follow what I write below (after a few more comments). it has an adverse effect on the DTMF decoding in the VA3TO interface that I use on Echolink. IRLP and WIRES decoders work nearly flawlessly with the same audio. This might tell you about a level and twist problem with at the dtmf decoders. A scope at the controller dtmf decoder chip input will give you the real answer. I found that the 147 side of the keyboard would not perform well for a lot of DTMF sources if the deviation didn't track pretty closely from 0 to 3 K or so. It's probably more than a deviation tracking problem. We check it by putting in a 1K tone @ 1K deviation, 2K deviation and 3K deviation, etc. There seems to be a couple of schools of thought. Yep... One, adjust IDC/Repeater level so it tracks 1:1, e.g., 1=1, 2=2, 3=3, 4=4, etc. Close, but no cigar. You have to know the preformance of your receiver filter. As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. Everyone setting up a receiver should know how that receiver preforms at X value input deviation. Your target value 1:1 deviation ratio for the the MSR is about 3KHz (set at one
Re: [Repeater-Builder] 1.2 ghz repeater
There are many 1.2 repeaters in Northern California that are comprised of a pair of TM-541's. Several of the systems are linked and get alot of activity with no failures. The Mitsubishi power brick in the 541's is rated at ~18 watts. From the factory the high power setting is 10 watts, so it is some what de-rated to start with. I've just added two small fans to the heat sink and my repeater has been going strong with the original radios since 1995. Here are a few pics of a TM-241 showing the COS connection point, it's the same in all the x41 and x31 radios. http://www.fitzharris.com/~fitz/x41/ For duplexers check out Angle Linear and Telewave. I'm using Wacom, but we all know they are gone. -Sean On Tue, 27 Jul 2004, Russ wrote: I see that icom makes the D-star didi/ana repeater but i have not heard results , and as far as mobles being used , well the local 2 meter repeater here in canton is a pair of 1971 icom -28A radios modded out hooked to Scomm7K controller , 31 yrs and still strong at 30 watts , not to mention 4 different antennii and 2 changes of Feedline , Lightning is not kind in my area esp when the 200' tower is on one of the highest hills around . I was thinking of going the kenwood tm541 direction my self but the only problem is where to tap the COR/COS point , and after that what kind of duplexer or notch filter would u use at that freq , i know comet makes a nice 14.1 dbi base/repeater for around $150 , and we have enuf hardline to send it upa 100' tower , just not sure of the actual radios and controller yet and all the interfacing of it Russ N3TIH - Original Message - From: Jack White [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2004 7:46 PM Subject: RE: [Repeater-Builder] 1.2 ghz repeater Russ, I have been looking for the same information myself. Haven't found much yet other than the Icom D-Star someone mentioned. They are supposed to work digital and analog! I have heard of a few installations where guys are running 2 Kenwood 541s back to back with some minor mods. I don't usually recommend using ham mobiles for repeater duty but they will work in a pinch. The main problem using mobiles is that the power amps are designed for intermittent duty, not 100% duty as needed for repeater operation. Switching to low power and using a fan can help. Sometimes ham mobile transmitters have spurious emissions that hinder repeater operation. A repeater transmitter needs to be clean. Check the Kenwood specs. Maybe they're ok. If you find any More information that helps, I'd love to hear about it. Good Luck, J. White WA2RZG -Original Message- From: Russ [mailto:[EMAIL PROTECTED] Sent: Monday, July 26, 2004 12:03 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] 1.2 ghz repeater who makes 1.2 ghz equipment for repeater usage , im drawing a blank and web searches arnt proving helpful either ... Russ N3TIH Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] ARRL insurance
Curious, Are there any folks in the group who have this for their repeater? Our club is thinking about getting this. Does anyone know if not only does this cover Repeaters but also if a club gets ARRL Affilation and then gets it...that it would cover a Club Repeater? I would like to take your responses to the club since we have a very wide area of repeater owners here. Suggestions and Ideas are welcome, Thanks! Robert Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] FS LINK COMMUNICATIONS CONTROLLER PARTS
I have for sale a Link Communications Deluxe board and rack mount case for the RLC Club controller. You can find all the info on this product at www.link-comm.com . This is the add-on deluxe board with rack mount case only. You will need the main Club Controller board. The deluxe upgrade gives you another radio port, 8 output lines, DVR support and remote base capabilities. I upgrade to the new Deluxe II board and do not need this anymore. This would be great for someone that has the Club board and wants to upgrade. Or if you're thinking about buying the club controller and want to save money on the Deluxe board and case. Please e-mail me off the list! [EMAIL PROTECTED] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
