Re: [Repeater-Builder] Micor Recrystalled Element Problem
If you wonder if its the 11 Meter Mantality if they thought a Killowatt would operate a repeater they probably would install it ! between the golden screwdriver and crank up the output to full max and the theory of heat, light & smoke ! I seen a coffee machine smoke a relay board here a few months ago. also if they jump when a cap goes off like a fire cracker then they might think twice ! mark h. [EMAIL PROTECTED] wrote: I see lots of the same kind of mentality around here. Many of the local hams that figure "if a little gain is good, then a whole lot more must be a lot better." 40-watt PA decks driving 100-watt PA decks, receiver preamplifiers running wide open at high-RF sites, single-shield coax for jumpers, RG-8 type coax for feedlines, no isolators/circulators anywhere, etc. etc. Trying to explain or reason with them just falls on deaf ears, and I'm the "Bad Guy". Then, after getting into a good repeater site, they continue to bring in (sneak in) more and more equipment (much more thn they had originally made arrangements for) without asking anyone who is actually involved with the site. Then they get kicked out of the site completely, ruining it for any hams who want to put up something in the same place (and do it properly!) in the future. Pretty sad LJ -Original Message- From: Eric Lemmon <[EMAIL PROTECTED]> Sent: Feb 6, 2006 10:15 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Micor Recrystalled Element Problem Randy, I think the subject has been covered well enough already. Perhaps the best analogy would be a Hewlett-Packard power meter, where the sensor is matched to, and calibrated with, the meter itself. If the sensor should somehow be destroyed by accident, one could not simply purchase a new sensor and expect it to work with the existing meter. One must ship the meter and the sensor back to the factory for alignment and calibration. Like the crystal and the channel element, they are a "matched pair." While I understand and respect the opinions of those who maintain that Amateur Radio transmitters can embrace a much more relaxed level of precision than commercial transmitters, I cannot help but wonder why this feeling is so pervasive. My personal feeling is that the public impression of Amateur Radio (notice the capitals!) is greatly enhanced when such installations meet or exceed the workmanship levels found in a typical commercial installation. Many others more vocal than I have lamented that some installations by Amateur Radio licensees have been so amateurish that they demean the name. I submit that an Amateur Radio repeater should always incorporate the State of the Art, with the appropriate bandpass cavities, isolators, filters, and components that will ensure a reliable, trouble-free installation. Moreover, I cringe when I hear that a substandard installation is okay, simply because it's "only" an Amateur Radio project! I congratulate you on taking the high road to correct the problem with your channel element. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com] On Behalf Of Randy Nelson Sent: Monday, February 06, 2006 6:26 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Recrystalled Element Problem I tried another channel element and the error was worse. Both the xtal and element are on their way back to ICM. It will be interesting to see if ICM admits an error or blames it on the element. Randy 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/ -- MZ YAHOO! GROUPS LINKS Visit your group "Repeater-Builder" on the web. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. begin:vcard fn:Mark A. Holman n:Holman;Mark A. email;internet:[EMAIL PROTECTED] title:Webmaster, IT Student note;quoted-printable:IT, Student Member IEEE, Life Member ARRL, Assoc. Member SBE, CRO, ARRL= VE=0D=0A= Welcome to the Snowy stuff of Michigan=0D=0A= x-mozilla-html:TRUE url:http://www.ab8ru.org version:2.1 end:vcard
RE: [Repeater-Builder] Micor Recrystalled Element Problem
I see lots of the same kind of mentality around here. Many of the local hams that figure "if a little gain is good, then a whole lot more must be a lot better." 40-watt PA decks driving 100-watt PA decks, receiver preamplifiers running wide open at high-RF sites, single-shield coax for jumpers, RG-8 type coax for feedlines, no isolators/circulators anywhere, etc. etc. Trying to explain or reason with them just falls on deaf ears, and I'm the "Bad Guy". Then, after getting into a good repeater site, they continue to bring in (sneak in) more and more equipment (much more thn they had originally made arrangements for) without asking anyone who is actually involved with the site. Then they get kicked out of the site completely, ruining it for any hams who want to put up something in the same place (and do it properly!) in the future. Pretty sad LJ -Original Message- >From: Eric Lemmon <[EMAIL PROTECTED]> >Sent: Feb 6, 2006 10:15 PM >To: Repeater-Builder@yahoogroups.com >Subject: RE: [Repeater-Builder] Micor Recrystalled Element Problem > >Randy, > >I think the subject has been covered well enough already. Perhaps the best >analogy would be a Hewlett-Packard power meter, where the sensor is matched >to, and calibrated with, the meter itself. If the sensor should somehow be >destroyed by accident, one could not simply purchase a new sensor and expect >it to work with the existing meter. One must ship the meter and the sensor >back to the factory for alignment and calibration. Like the crystal and the >channel element, they are a "matched pair." > >While I understand and respect the opinions of those who maintain that >Amateur Radio transmitters can embrace a much more relaxed level of >precision than commercial transmitters, I cannot help but wonder why this >feeling is so pervasive. My personal feeling is that the public impression >of Amateur Radio (notice the capitals!) is greatly enhanced when such >installations meet or exceed the workmanship levels found in a typical >commercial installation. Many others more vocal than I have lamented that >some installations by Amateur Radio licensees have been so amateurish that >they demean the name. I submit that an Amateur Radio repeater should always >incorporate the State of the Art, with the appropriate bandpass cavities, >isolators, filters, and components that will ensure a reliable, trouble-free >installation. Moreover, I cringe when I hear that a substandard >installation is okay, simply because it's "only" an Amateur Radio project! > >I congratulate you on taking the high road to correct the problem with your >channel element. > >73, Eric Lemmon WB6FLY > > >-Original Message- >From: Repeater-Builder@yahoogroups.com >[mailto:[EMAIL PROTECTED] On Behalf Of Randy Nelson >Sent: Monday, February 06, 2006 6:26 PM >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] Micor Recrystalled Element Problem > >I tried another channel element and the error was worse. Both the xtal >and element are on their way back to ICM. It will be interesting to see >if ICM admits an error or blames it on the element. > >Randy > > > > > >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] Micor Recrystalled Element Problem
Eric, My entire reason for posting my original question was because for years I have ordered just xtals for elements on commercial repeaters and changed them myself. Everytime the xtal netted just fine. Even in tower shacks with minimal temperature control it was very rare for the need to retune. I've never moved an element from 463 to 444 MHz and thought with my past success on the commercial freqs, there must be something I missed. It's in the capable hands of ICM so I'll just be patient for the next couple of weeks!! :-) Randy Eric Lemmon wrote: >Randy, > >I think the subject has been covered well enough already. Perhaps the best >analogy would be a Hewlett-Packard power meter, where the sensor is matched >to, and calibrated with, the meter itself. If the sensor should somehow be >destroyed by accident, one could not simply purchase a new sensor and expect >it to work with the existing meter. One must ship the meter and the sensor >back to the factory for alignment and calibration. Like the crystal and the >channel element, they are a "matched pair." > > 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] Micor Recrystalled Element Problem
Randy, I think the subject has been covered well enough already. Perhaps the best analogy would be a Hewlett-Packard power meter, where the sensor is matched to, and calibrated with, the meter itself. If the sensor should somehow be destroyed by accident, one could not simply purchase a new sensor and expect it to work with the existing meter. One must ship the meter and the sensor back to the factory for alignment and calibration. Like the crystal and the channel element, they are a "matched pair." While I understand and respect the opinions of those who maintain that Amateur Radio transmitters can embrace a much more relaxed level of precision than commercial transmitters, I cannot help but wonder why this feeling is so pervasive. My personal feeling is that the public impression of Amateur Radio (notice the capitals!) is greatly enhanced when such installations meet or exceed the workmanship levels found in a typical commercial installation. Many others more vocal than I have lamented that some installations by Amateur Radio licensees have been so amateurish that they demean the name. I submit that an Amateur Radio repeater should always incorporate the State of the Art, with the appropriate bandpass cavities, isolators, filters, and components that will ensure a reliable, trouble-free installation. Moreover, I cringe when I hear that a substandard installation is okay, simply because it's "only" an Amateur Radio project! I congratulate you on taking the high road to correct the problem with your channel element. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Randy Nelson Sent: Monday, February 06, 2006 6:26 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Recrystalled Element Problem I tried another channel element and the error was worse. Both the xtal and element are on their way back to ICM. It will be interesting to see if ICM admits an error or blames it on the element. Randy 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] Micor Recrystalled Element Problem
I tried another channel element and the error was worse. Both the xtal and element are on their way back to ICM. It will be interesting to see if ICM admits an error or blames it on the element. Randy 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] Micor Recrystalled Element Problem
> I am moving a 463/468 MHz Micor repeater to 444/449 MHz. I > ordered new > xtals from ICM and the receive xtal is OK. However I can't > get the xmit > xtal to pull onto freq. It will pull within 3 KHz above 444.350 MHz. I'm assuming this is a real Micor repeater, not a converted mobile, so you should have a KXN1052 transmit channel element. Open it up again, and ;ook behind the trimmer cap. You should see a ceramic disc cap that is not quite parallel with the back of the trimmer cap - that's your target. Further behind the ceramic disc is a plastic-case transistor (just to verify we're on the same page). Look at the value of the ceramic disc; it should be somewhere in the tens of pF range. Increase its value by approximately 20% and you should be in the ballpark for moving from 463 to 444 (i.e. if it was 22 pF originally, use 27 pF instead). Lacking any other means of real compensation, use an NP0 cap. As others have pointed out, this doesn't give you any form of accurate temperature compensation. This only lets you center range of the trimmer cap so you can put the transmitter on frequency. If the repeater will be in a temperature-stable environment (say, +/- 10 or 15 degrees ambient as a ballpark), you might be OK. Next time, spend the money and send the element to ICM and let them do it right. --- Jeff Jeff DePolo WN3A - [EMAIL PROTECTED] Broadcast and Communications Consultant 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] Micor Recrystalled Element Problem
Randy Nelson wrote: I am moving a 463/468 MHz Micor repeater to 444/449 MHz. I ordered new xtals from ICM and the receive xtal is OK. However I can't get the xmit xtal to pull onto freq. It will pull within 3 KHz above 444.350 MHz. This isn't the first Micor I have changed rocks in myself. I've done several in the 450-470 MHz range without any problems and no realignment callbacks to the tower site. This isn't my "first time." I have a Micor test meter and used it to align the exciter and everything tuned as designed. I called ICM and they doubted it was their error and it must be my channel element since the frequency move was quite far. But for $30.00 they would "fix" the problem. Does anyone have any technical docs on the Micor channel elements and the require capacitor changes? The channel element is KXN1052A. I would rather replace the required cap with the correct value and get this repeater on the air instead of waiting another 3 weeks for ICM. I have read the Repeater-Builder webpage regarding Micor elements and it doesn't address the need to replace any components inside the element when moving from 463 to 444 MHz. The first thing I'd check is to make sure the variable capacitor (the netting capacitor) isn't broken. It is easy to break the ceramic rotator on the netting cap; which results in the element not being able to go low enough. At any rate, here is some information on Motorola Micor Channel Elements: http://www.repeater-builder.com/micor/micor-element-info.html The KXN-1019B and KXN-1052A are the same element with only a few exceptions, so the schematic and layout available (for the 1019B) from this page will help you with your 1052A. Changing the capacitor in parallel with the netting trimmer will change where the crystal resonates. Realize the capacitance in parallel with the trimmer and the type of capacitors used there affect the loading and temperature stability of the element. Please realize that the frequency stability of the element is only as good as the crystal installed in it, and the thermal compensation that was done at the time the crystal was installed in the element. If you are serious about your repeater, especially if it is going to be located in a hilltop building that has no environmental controls, do yourself a favor and when you purchase the crystals for your repeater send the elements back to the crystal manufacturer and pay to have them compensate the element to the new crystal. The elements will hold 2ppm or 5ppm only if the individual element is matched to the crystal - i.e. if the crystal tends to swing upwards in frequency as the temperature rises, the element has to swing lower, and the same amount. Likewise, if it swings down in frequency, then naturally the element has to swing upwards. Another way to think of this behavior is "frequency tracking with temperature". Note that the compensation components in the element are dependent on the characteristics of the individual crystal, and those characteristics have to be measured after the crystal is made, and the components selected by hand to match, and then installed in the element. Hence, this has to be redone whenever the element is recrystaled. Many of the cheaper suppliers simply install the new crystal into the element and ship it back. This can result in real problems if the new crystal swings the opposite of the old one, and as the temperature causes the crystal to drift off frequency the compensation components push it even further off frequency. Also note that there is a difference between a receive crystal and a transmit crystal. A crystal with the *wrong* cut may not exhibit enough *rubberiness* for full deviation to occur. This situation happens when crystal vendors cut a crystal for absolute stability and don't know that it will be used in an FM transmit element, like the KXN-1052A. ICM and Bomar are the only companies that I know of that actually test the modulation capability and insure modulation symmetry in elements. They are also the only companies that I know of that actually change the temperature compensation components (capacitors and resistors) to *properly* TC the element. When you are ready to recrystal an element and are calling around to get prices, you need to ASK what each company consider "compensating". Considering what you are going to spend on the entire repeater paying a little extra for a professional top quality rock house to manufacture the crystals and do the compensation is definitely worth it. Now you know why ICM wants $30 for this effort. Realize that it is NOT only to get the crystal/element on frequency, but to make sure it stays there in varying temperatures as well! All new crystals drift during the first few months of operation (most noticeable on 900MHz, and quite visible even on 2m). This is called "crystal aging", and IS QUITE NORMAL. Even if your brand new UHF channel element drifts as much
RE: [Repeater-Builder] Micor Recrystalled Element Problem
Randy, The problem you now have is one that frequently occurs when an uncompensated crystal is installed in a previously-compensated channel element. For that reason, it is not a good idea to replace the crystal yourself. There are two functions of the components in the channel element that must be matched to the *specific* crystal: 1) Adjusting the capacitance so that the crystal oscillates more or less in the center of its intended frequency range, and 2) Selecting the temperature coefficients of those capacitors so that the temperature response of the *specific* crystal is compensated. When done properly, with the appropriate instrumentation, the crystal is matched to the channel element over a wide range of temperature. When you ordered your bare crystal from ICM, it was manufactured to fit a *nominal* channel element. However, your channel element was not nominal at all, since it had been previously modified with components to compensate a different crystal. It is just blind luck that the range of the trimmer can set the bare crystal on frequency, but it is highly unlikely that the temperature-compensating components are correct for the bare crystal. It is possible that the existing TC components are working in the wrong direction with the new crystal, causing the drift to be worse than if none were used. Motorola used several crystal suppliers over the years, and ICM has no way of knowing who originally compensated the channel element. I suggest that you ship the bare crystal and the channel element to ICM, and pay for proper temperature compensation. If there is a problem in your channel element, ICM will let you know. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Randy Nelson Sent: Friday, February 03, 2006 9:05 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Recrystalled Element Problem I am moving a 463/468 MHz Micor repeater to 444/449 MHz. I ordered new xtals from ICM and the receive xtal is OK. However I can't get the xmit xtal to pull onto freq. It will pull within 3 KHz above 444.350 MHz. This isn't the first Micor I have changed rocks in myself. I've done several in the 450-470 MHz range without any problems and no realignment callbacks to the tower site. This isn't my "first time." I have a Micor test meter and used it to align the exciter and everything tuned as designed. I called ICM and they doubted it was their error and it must be my channel element since the frequency move was quite far. But for $30.00 they would "fix" the problem. Does anyone have any technical docs on the Micor channel elements and the require capacitor changes? The channel element is KXN1052A. I would rather replace the required cap with the correct value and get this repeater on the air instead of waiting another 3 weeks for ICM. I have read the Repeater-Builder webpage regarding Micor elements and it doesn't address the need to replace any components inside the element when moving from 463 to 444 MHz. 73's, Randy WB0VHB 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/
