RE: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
It looks like the FCC rules give you extra power when opting for dual polarization. No, they don't give you extra power. For commercial stations, horizontal polarization is the standard. You can supplement it with vertical, either as cross-polarized linear, or as elliptial/circular, but that Vpol component's ERP can't exceed the Hpol ERP. For non-commercial stations in the reserved band (i.e. below 92 MHz) within the affected area of a channel 6 station, there are many cases where they are authorized for more Vpol than Hpol to protect channel 6 (which is presumed to always be horizontally polarized). The only extra power you get is additional transmitter power output (TPO) due to the reduced antenna gain (assuming the number of bays remains the same, and the same bay spacing) when you go from horizontal polarizaton to mixed polarity. That's a confusing point, I know. Every circularly-polarized FM station I've seen (and that's a lot of them) use an antenna design that handles the phasing and time-delay to create the circularly-polarized signal. That's pretty much correct, but there are many stations that have a vertical component added that isn't necessarily part of a circularly-polarized array. The vertical may be added as a separate radiator, but not phased with the Hpol radiators to yield circular, so you just have two non-coherent linear polarizations. Or a single linear radiator may be tilted to give slant polarization, which the FCC will accept as having both an Hpol and Vpol component, with the ratio being a function of the tilt angle. The license reference to H and V powers (regarding c-pol station) is intended to say how much ERP should some out when the signal is V and how much when it is H. It is possible to make the two components different, resulting in elliptical polarization rather than circular. They can be different, and yet not be elliptical. If they aren't phased together to yield a coherent rotation at all azimuthal angles, it's just random cross-polarization, not elliptical. 99% of the current topic was covered a year or so ago on this list - might want to revisit the archives. For those thinking about building Cpol bays, I'd suggest starting out with something simple like a ring-stub. Easy to make with a tubing bender (or Armstrong method), feed with a gamma, DC-ground at the mounting bracket at the rear of the bay, decent pattern circularity (but not great axial ratio symmetry), cheap and easy way to start. For those not familiar, a ring stub bay looks like this (I don't recommend OMB, it's just a decent picture of a very basic ring stub bay): http://www.omb.com/en/index.php?option=contenttask=viewid=78Itemid=38 Ring stubs are sometimes also called cycloids (albeit sometimes erroneously), often built with a balanced feed. You can try Googling cycloid, ring stub FM antenna, etc. for more pics and design ideas or email direct. --- Jeff WN3A
Re: [Repeater-Builder] Interference on VHF repeater
Brett, How did you determine it's an IM product? What repeater/controller combination are you using? I'd try powering down the controller and manually keying the transmitter. If that solves it, it could be the controller's reference oscillator or divider outputs leaking onto the PTT line or elsewhere. Any compact fluorescent lights nearby? 73, Paul, AE4KR - Original Message - From: brett To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 5:26 AM Subject: [Repeater-Builder] Interference on VHF repeater I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged.
Re: [Repeater-Builder] Interference on VHF repeater
Bret, you might have your PA going in to oscillation creating the spurs due to a highly reactive duplexer. We had a similar problem here many years ago and fixed it with a simple tuner on the TX similar ot the GE Z matcher . The one that we used was Home Brew. When the tuner was adjusted for minimum VSWR, the spurs went away. 73 John VE3AMZ - Original Message - From: brett brett_daw...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 7:26 AM Subject: [Repeater-Builder] Interference on VHF repeater Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD. Yahoo! Groups Links
Re: [Repeater-Builder] UHF Circulator
At 9/3/2010 18:56, you wrote: I'm looking for a UHF circulator to buy (or borrow). I have a mix that involves our transmitter but I'm not sure it's in our transmitter. We have a Micor repeater with the built in circulator but some feel an outboard two port is required for our nasty hill. It would be good if I could test one and not spend money on something that won't help. Aside from the the borrow request what do others think about this. Is more circulator than the stock Micor necessary? How far away are the other mix products? If more than a couple of MHz or so you could try a pass cavity after the Micor circulator instead of a 2nd circulator. -- Tim :wq A vi command? That old text editor will never go away! Bob NO6B
[Repeater-Builder] Pyramid SVR200 programming cable
Hello, Was wondering if anyone happened to know how the programming cable is wired for the above pyramid in vehicle repeater ? Cable has a part No. of FY-1 I don't know if the Genuine version has some electronics inside the DB9 plug cover as with the T800 SII that changes levels, etc. The unit has a 2.5mm jack to accept the data from the computer and a db9 plug at the other end to connect to the serial port at the computer. I have a standard RS232 interface box i use for Tait stuff that provides Tx, RX, Gnd outputs but i was wondering if it would be as simple as l + R + ground on the 2.5 stereo plug. I have seen the file that uses the Motorola programming box at the Batlabs site but if i could avoid having to purchase one of those solely for this use i would prefer it. Any info or suggestions gratefully received.
RE: [Repeater-Builder] Interference on VHF repeater
Brett, Some additional information will be helpful. What makes/models of equipment are in your repeater? Are all jumper cables and the antenna feedline double-shielded? Are any of the connectors nickel-plated? Are there any barrels or adapters in your jumpers? Is there an isolator/circulator following the transmitter? What antenna are you using, and how far above the repeater equipment is it located? Try putting your attenuator right at the RX input connector, and repeat your IM test. Putting it at the antenna output is not a good idea, since the TX output power can cause it to overheat. Your description of the IM product suggests that it might be a spur generated within your PA, which could drift due to temperature changes. Have you verified that your TX carrier frequency is stable, and not drifting? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of brett Sent: Saturday, September 04, 2010 4:27 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Interference on VHF repeater Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD.
Re: [Repeater-Builder] UHF Circulator
Tim Sawyer wrote: :wq try: :x Bob N06B wrote: A vi command? That old text editor will never go away! Absolutely! Isn't a recurring theme of this list to keep the old tools that work very well in service and don't replace that which isn't broken? Will Gwin www.N5KH.org
[Repeater-Builder] Micor Pin Gunk
Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV
Re: [Repeater-Builder] Micor Pin Gunk
The station ID adds some real class to the video. Chuck WB2EDV - Original Message - From: w9srv tgundo2...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 1:27 PM Subject: [Repeater-Builder] Micor Pin Gunk Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV
[Repeater-Builder] Re: Interference on VHF repeater
I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. The above says that it's a 2nd order mix, F1+F2, F1-F2, 2F1 or 2F2. Since it looks to be a 2nd order product, proven by your 6 dB attenuator causing a 12 dB drop, whereas a 3rd order IM product would drop the product by 18 dB. Th 2nd order mix indicates that it could be combination of an internally generated signal from your equipment F1, Probably in the receiver input stage itself and an outside signal source F2 from an external transmitter, yours or another adjacent one. A pure 3rd order IM product is typically an indication of an internally generated source in the receiver input stages itself without any externally generated sources, but not always. Also do you have an isolator on the TX output along with a Low Pass filter after the isolator ? Is this a synthesized exciter or crystal controlled ? If you can identify all the signals present on Spectrum Analyzer then with the above 2nd order formulas you could probably zero down the 2 signals causing the problem. Mike --- In Repeater-Builder@yahoogroups.com, brett brett_daw...@... wrote: Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD.
Re: [Repeater-Builder] UHF Circulator
Indeed, long live vi. I do have a pass cavity between the Micor circulator and the duplexer. I'm not sure where the other IM products are just yet. I'm sometimes hearing a pager. Once I heard what I suspect is Orange County Red Cross on 462.9875... still confirming this. I hear the drip from 147.435 every now and then. -- Tim :wq On Sep 4, 2010, at 8:03 AM, n...@no6b.com wrote: At 9/3/2010 18:56, you wrote: I'm looking for a UHF circulator to buy (or borrow). I have a mix that involves our transmitter but I'm not sure it's in our transmitter. We have a Micor repeater with the built in circulator but some feel an outboard two port is required for our nasty hill. It would be good if I could test one and not spend money on something that won't help. Aside from the the borrow request what do others think about this. Is more circulator than the stock Micor necessary? How far away are the other mix products? If more than a couple of MHz or so you could try a pass cavity after the Micor circulator instead of a 2nd circulator. -- Tim :wq A vi command? That old text editor will never go away! Bob NO6B
Re: [Repeater-Builder] UHF Circulator
Same thing but my fingers learned :wq too many years ago to retrain I even type it in my GUI editors... duh! -- Tim :wq On Sep 4, 2010, at 10:10 AM, Will Gwin wrote: try: :x
RE: [Repeater-Builder] Micor Pin Gunk
Tom, Motorola does not now, and never has, recommended DeOxit or any other contact enhancer gunk besides Stabilant 22. Up until just a few years ago, Motorola specified Stabilant 22A, under part number 1180369E78, which is a mixture of pure Stabilant 22 and isopropyl alcohol. Today, Motorola sells a kit under part number 1180384V93 which comprises a 5 ml bottle of pure Stabilant 22, an empty 15 ml bottle, and some tiny swabs. The user then puts 2.5 ml of the Stabilant 22 into the 15 ml bottle and adds 10 ml of 99% isopropanol to make a working solution of Stabilant 22A, or adds 10 ml of pure ethanol to make a working solution of Stabilant 22E. Either solution is extremely effective if applied wet to clean connectors immediately before mating. It is also effective in curing intermittent contacts in card-edge connectors in PCs and electronic instruments. The alcohol solvent is essential for the product to work; undiluted Stabilant 22 is ineffective. Drug-store isopropyl alcohol, aka rubbing alcohol, should not be used since it is diluted with water and will interfere with Stabilant's action. The 1180384V93 kit is sold by Motorola Parts for about $47, but is sufficient to last for years. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of w9srv Sent: Saturday, September 04, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Pin Gunk Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV
Re: [Repeater-Builder] Micor Pin Gunk
Eric, you're singing my tune ! I've used that stuff for many years now and it is really great. It was developed here in Richmond Hill, Ontario, Canada by DW Electrochemicals. As you know only a very small amount is needed on the surface to be effective. The last bottle that I purchased here in Waterloo cost around $35.00. I'd bet that Electro-Sonic would carry it and they are now in the Buffalo areamight be quite a bit cheaper than the Motorola price... John VE3AMZ - Original Message - From: Eric Lemmon wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 2:13 PM Subject: RE: [Repeater-Builder] Micor Pin Gunk Tom, Motorola does not now, and never has, recommended DeOxit or any other contact enhancer gunk besides Stabilant 22. Up until just a few years ago, Motorola specified Stabilant 22A, under part number 1180369E78, which is a mixture of pure Stabilant 22 and isopropyl alcohol. Today, Motorola sells a kit under part number 1180384V93 which comprises a 5 ml bottle of pure Stabilant 22, an empty 15 ml bottle, and some tiny swabs. The user then puts 2.5 ml of the Stabilant 22 into the 15 ml bottle and adds 10 ml of 99% isopropanol to make a working solution of Stabilant 22A, or adds 10 ml of pure ethanol to make a working solution of Stabilant 22E. Either solution is extremely effective if applied wet to clean connectors immediately before mating. It is also effective in curing intermittent contacts in card-edge connectors in PCs and electronic instruments. The alcohol solvent is essential for the product to work; undiluted Stabilant 22 is ineffective. Drug-store isopropyl alcohol, aka rubbing alcohol, should not be used since it is diluted with water and will interfere with Stabilant's action. The 1180384V93 kit is sold by Motorola Parts for about $47, but is sufficient to last for years. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of w9srv Sent: Saturday, September 04, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Pin Gunk Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV Yahoo! Groups Links
Re: [Repeater-Builder] Re: Msf5000 Low Power alarms
You enter that code to get rid of the alarms. I was just wondering how you set them again should you want/need to do that. Joe M. Richard wrote: I'm not quite sure I understand your question. The procedure puts it into normal condition. Nothing further to do. For a conventional MSF5000 (NON-trunking) that is, a radio always without the RF sensor installed, the values 00 and FF are what is loaded at factory; e.g. normal. The problem usually happens when someone replaces a CLB SCB(analog) board with CXB SSCB that came from a 800 trunking radio. It will contain the setpoint values from its previous home. They need to be reset to FACTORY default for CONVENTIONAL stations. Non-trunking=no RF sensor = Factory setpoint value of 00,FF. --- In Repeater-Builder@yahoogroups.com, MCH m...@... wrote: How do you set it back to normal? Joe M. Richard Arnold wrote: There is an RSS software solution (bitbang) to get rid of the alarms. Connect the RIB to the operating MSF. From the main menu hit ALT-F5. A command line bar will appear telling you to enter an IPCB command. Enter the following: (WITHOUT the quotes) /1e1607160800FF it is CASE sensitive. This sets the FWD/REV settings to zero and FF (infinity) I've done it many times, and it works just fine! --- On *Sun, 8/29/10, jimmylpowell /jpow...@.../* wrote: From: jimmylpowell jpow...@... Subject: [Repeater-Builder] Msf5000 Low Power alarms To: Repeater-Builder@yahoogroups.com Date: Sunday, August 29, 2010, 12:36 PM I originally posted this on the MSF5000 board but got no response. I thought I would broaden my search. Does anyone know a way to get a non trunking MSF with out an internal power sensor to stop giving the 7 beeps? I have tried going back to a default codeplug and starting from scratch. This did not work. It seems that once the bit is set it won't go away. I'm sure that it happened when someone went into the screen to adjust the alarms. I know this is a common problem and they tell you not to do it. I have the alarms disabled over the air, but it annoys me on the local audio. I would like to enable the over the air alarms, but I can't until I can clear this one. My MSF has version 4.07 SSCB and 5.04 TTRC. Maybe there's some bit banging that can be done. Jimmy, K5JCT Internal Virus Database is out of date. Checked by AVG - www.avg.com Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: 03/14/10 03:33:00 Yahoo! Groups Links
RE: [Repeater-Builder] Micor Pin Gunk
John, I did not find Stabilant listed in the Electro-Sonic online catalog, but I did find the identical kit at Micro-Tools for only $38, here: www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx I also found that Amazon sells the same kit as Micro-Tools, and for the same price of $38. I should point out that the kit does NOT make 30 ml of solution, as the listing implies; if the instructions are followed exactly- adding 10 ml of alcohol to 2.5 ml of pure Stabilant- the kit will make a total of 25 ml of solution. That's because the 15 ml bottle is filled only to the 12.5 ml point, where the bottle begins to narrow. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of John J. Riddell Sent: Saturday, September 04, 2010 11:47 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Pin Gunk Eric, you're singing my tune ! I've used that stuff for many years now and it is really great. It was developed here in Richmond Hill, Ontario, Canada by DW Electrochemicals. As you know only a very small amount is needed on the surface to be effective. The last bottle that I purchased here in Waterloo cost around $35.00. I'd bet that Electro-Sonic would carry it and they are now in the Buffalo areamight be quite a bit cheaper than the Motorola price... John VE3AMZ - Original Message - From: Eric Lemmon wb6...@verizon.net mailto:wb6fly%40verizon.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Saturday, September 04, 2010 2:13 PM Subject: RE: [Repeater-Builder] Micor Pin Gunk Tom, Motorola does not now, and never has, recommended DeOxit or any other contact enhancer gunk besides Stabilant 22. Up until just a few years ago, Motorola specified Stabilant 22A, under part number 1180369E78, which is a mixture of pure Stabilant 22 and isopropyl alcohol. Today, Motorola sells a kit under part number 1180384V93 which comprises a 5 ml bottle of pure Stabilant 22, an empty 15 ml bottle, and some tiny swabs. The user then puts 2.5 ml of the Stabilant 22 into the 15 ml bottle and adds 10 ml of 99% isopropanol to make a working solution of Stabilant 22A, or adds 10 ml of pure ethanol to make a working solution of Stabilant 22E. Either solution is extremely effective if applied wet to clean connectors immediately before mating. It is also effective in curing intermittent contacts in card-edge connectors in PCs and electronic instruments. The alcohol solvent is essential for the product to work; undiluted Stabilant 22 is ineffective. Drug-store isopropyl alcohol, aka rubbing alcohol, should not be used since it is diluted with water and will interfere with Stabilant's action. The 1180384V93 kit is sold by Motorola Parts for about $47, but is sufficient to last for years. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of w9srv Sent: Saturday, September 04, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Micor Pin Gunk Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV Yahoo! Groups Links
Re: [Repeater-Builder] Re: Interference on VHF repeater
Look around for a switch mode power supply that uses 600kHz as the switch frequency. SMPS Battery Chargers are popular for causing this. Also florescent twist lights are really good for making desense on VHF.
Re: [Repeater-Builder] Micor Pin Gunk
Eric, I checked the web site for DW Electrochemicals and they mention that Electro-Sonic no longer carries their productwe'll have to ask Marty VE3MR what the problem is (he's the owner) Primespec here in Waterloo is where I get mine but shipping might be quite expensive to the USA. None the less it's a great product. 73 John VE3AMZ - Original Message - From: Eric Lemmon wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 3:26 PM Subject: RE: [Repeater-Builder] Micor Pin Gunk John, I did not find Stabilant listed in the Electro-Sonic online catalog, but I did find the identical kit at Micro-Tools for only $38, here: www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx I also found that Amazon sells the same kit as Micro-Tools, and for the same price of $38. I should point out that the kit does NOT make 30 ml of solution, as the listing implies; if the instructions are followed exactly- adding 10 ml of alcohol to 2.5 ml of pure Stabilant- the kit will make a total of 25 ml of solution. That's because the 15 ml bottle is filled only to the 12.5 ml point, where the bottle begins to narrow. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of John J. Riddell Sent: Saturday, September 04, 2010 11:47 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Pin Gunk Eric, you're singing my tune ! I've used that stuff for many years now and it is really great. It was developed here in Richmond Hill, Ontario, Canada by DW Electrochemicals. As you know only a very small amount is needed on the surface to be effective. The last bottle that I purchased here in Waterloo cost around $35.00. I'd bet that Electro-Sonic would carry it and they are now in the Buffalo areamight be quite a bit cheaper than the Motorola price... John VE3AMZ - Original Message - From: Eric Lemmon wb6...@verizon.net mailto:wb6fly%40verizon.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Saturday, September 04, 2010 2:13 PM Subject: RE: [Repeater-Builder] Micor Pin Gunk Tom, Motorola does not now, and never has, recommended DeOxit or any other contact enhancer gunk besides Stabilant 22. Up until just a few years ago, Motorola specified Stabilant 22A, under part number 1180369E78, which is a mixture of pure Stabilant 22 and isopropyl alcohol. Today, Motorola sells a kit under part number 1180384V93 which comprises a 5 ml bottle of pure Stabilant 22, an empty 15 ml bottle, and some tiny swabs. The user then puts 2.5 ml of the Stabilant 22 into the 15 ml bottle and adds 10 ml of 99% isopropanol to make a working solution of Stabilant 22A, or adds 10 ml of pure ethanol to make a working solution of Stabilant 22E. Either solution is extremely effective if applied wet to clean connectors immediately before mating. It is also effective in curing intermittent contacts in card-edge connectors in PCs and electronic instruments. The alcohol solvent is essential for the product to work; undiluted Stabilant 22 is ineffective. Drug-store isopropyl alcohol, aka rubbing alcohol, should not be used since it is diluted with water and will interfere with Stabilant's action. The 1180384V93 kit is sold by Motorola Parts for about $47, but is sufficient to last for years. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of w9srv Sent: Saturday, September 04, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Micor Pin Gunk Hi Guys! I am in the middle of rebuilding a receive site for one of the area repeaters and have come across some interesting Pin Gunk. I've been told that Motorola techs years ago used to apply some kind of goo to help with the connection on all the backplane pins, etc, but I don't know if this is what that is. This receive site has been developing some intermittant issues on several fronts, and maybe this explains them. The problem with this gunk is that is is non-conductive and a real bugger to clean off. DeOxit seems to work the best. I made this quick video last night showing this on the pins of the power control board. Here is the link to the video: http://www.youtube.com/watch?v=tmWumkQetdY Has anyone else ever come across this? Are there any other steps other than cleaning it off to ensure it will not be another problem in the future? Thanks! Tom W9SRV Yahoo! Groups Links Yahoo! Groups
[Repeater-Builder] Re: Pyramid SVR200 programming cable
This what you are looking for? http://www.batlabs.com/svr200.html niteviser --- In Repeater-Builder@yahoogroups.com, tait700 cscan...@... wrote: Hello, Was wondering if anyone happened to know how the programming cable is wired for the above pyramid in vehicle repeater ? Cable has a part No. of FY-1 I don't know if the Genuine version has some electronics inside the DB9 plug cover as with the T800 SII that changes levels, etc. The unit has a 2.5mm jack to accept the data from the computer and a db9 plug at the other end to connect to the serial port at the computer. I have a standard RS232 interface box i use for Tait stuff that provides Tx, RX, Gnd outputs but i was wondering if it would be as simple as l + R + ground on the 2.5 stereo plug. I have seen the file that uses the Motorola programming box at the Batlabs site but if i could avoid having to purchase one of those solely for this use i would prefer it. Any info or suggestions gratefully received.
RE: [Repeater-Builder] Micor Pin Gunk
At 9/4/2010 11:13, you wrote: Tom, Motorola does not now, and never has, recommended DeOxit or any other contact enhancer gunk besides Stabilant 22. Up until just a few years ago, Motorola specified Stabilant 22A, under part number 1180369E78, which is a mixture of pure Stabilant 22 and isopropyl alcohol. Today, Motorola sells a kit under part number 1180384V93 which comprises a 5 ml bottle of pure Stabilant 22, an empty 15 ml bottle, and some tiny swabs. The 1180384V93 kit is sold by Motorola Parts for about $47, but is sufficient to last for years. This looks like the same stuff: http://www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx The description of how Stabilant 22 works reads very similar to the Caig Labs DeOxIt products. A performance comparison between the 2 products would be interesting. Bob NO6B
[Repeater-Builder] Re: Interference on VHF repeater
Hi Mike, thanks for your post - I'll think about this a bit more. There is no isolator on the TX - will add one (and BP filter) when I next go to site this week. The radio is synthesised. Regards, Brett --- In Repeater-Builder@yahoogroups.com, wb8vlc mas...@... wrote: I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. The above says that it's a 2nd order mix, F1+F2, F1-F2, 2F1 or 2F2. Since it looks to be a 2nd order product, proven by your 6 dB attenuator causing a 12 dB drop, whereas a 3rd order IM product would drop the product by 18 dB. Th 2nd order mix indicates that it could be combination of an internally generated signal from your equipment F1, Probably in the receiver input stage itself and an outside signal source F2 from an external transmitter, yours or another adjacent one. A pure 3rd order IM product is typically an indication of an internally generated source in the receiver input stages itself without any externally generated sources, but not always. Also do you have an isolator on the TX output along with a Low Pass filter after the isolator ? Is this a synthesized exciter or crystal controlled ? If you can identify all the signals present on Spectrum Analyzer then with the above 2nd order formulas you could probably zero down the 2 signals causing the problem. Mike --- In Repeater-Builder@yahoogroups.com, brett brett_dawson@ wrote: Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD.
[Repeater-Builder] Re: Interference on VHF repeater
Hi John, I thought we may have a dubious TX issue - either spurs or as you say something unstable or oscillating. I replaced the TX. It had no impact on the problem. The issue appears to be external to the TX. Also I have terminated the duplexer into a 50ohm load and looked at the RX port of the duplexer and found it to be clear of anything. Regards, Brett --- In Repeater-Builder@yahoogroups.com, John J. Riddell ve3...@... wrote: Bret, you might have your PA going in to oscillation creating the spurs due to a highly reactive duplexer. We had a similar problem here many years ago and fixed it with a simple tuner on the TX similar ot the GE Z matcher . The one that we used was Home Brew. When the tuner was adjusted for minimum VSWR, the spurs went away. 73 John VE3AMZ - Original Message - From: brett brett_daw...@... To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 7:26 AM Subject: [Repeater-Builder] Interference on VHF repeater Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD. Yahoo! Groups Links
[Repeater-Builder] Re: Interference on VHF repeater
Paul, no fluro lights on site. Actually no lighting at all - the site is solar powered so little capacity for lighting. No repeater ocntroller - the RX is directly connected to TX via a very simple (passive) audio and PTT circuit. I believe it is an IM product because the RX requires a CTCSS tone to open and the only TX on site that has the correct tone is my TX. Also the interference is only present when my TX is active, and the hollow pipe sound on the audio does sound like audio feed back you'd expect if your own TX was part of the mix. With a spectrum analyser in the RX signal path I can see the intermod products appear when the TX is active. They are at approx 30kHz intervals across the RX half of the duplexer band pass. Cheers, Brett --- In Repeater-Builder@yahoogroups.com, Paul Plack pl...@... wrote: Brett, How did you determine it's an IM product? What repeater/controller combination are you using? I'd try powering down the controller and manually keying the transmitter. If that solves it, it could be the controller's reference oscillator or divider outputs leaking onto the PTT line or elsewhere. Any compact fluorescent lights nearby? 73, Paul, AE4KR - Original Message - From: brett To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2010 5:26 AM Subject: [Repeater-Builder] Interference on VHF repeater I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged.
[Repeater-Builder] Re: Interference on VHF repeater
Eric, all cables are double shielded. No adaptors are used. There is no isolator on the TX side. Connectors are silver plated, with gold pins. Antenna is a single folded dipole mounted about 15m above the equipment shelter. TX power into the antenna is approximately 15W. There are solar panels within 2m (below) of the anntenna. Putting the attenuator at the RX port of the duplexer reduces the IM products 1 for 1, ie 6dB of attenuation at the RX port reduces the IM by 6dB. BTW I used a 50W rated attenuator and Txed for short periods only so think overheating of the attenuator is not that likely. Yes TX freq is stable and not drifting. Also I have tried a second TX with smae results. Regards, Brett --- In Repeater-Builder@yahoogroups.com, Eric Lemmon wb6...@... wrote: Brett, Some additional information will be helpful. What makes/models of equipment are in your repeater? Are all jumper cables and the antenna feedline double-shielded? Are any of the connectors nickel-plated? Are there any barrels or adapters in your jumpers? Is there an isolator/circulator following the transmitter? What antenna are you using, and how far above the repeater equipment is it located? Try putting your attenuator right at the RX input connector, and repeat your IM test. Putting it at the antenna output is not a good idea, since the TX output power can cause it to overheat. Your description of the IM product suggests that it might be a spur generated within your PA, which could drift due to temperature changes. Have you verified that your TX carrier frequency is stable, and not drifting? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of brett Sent: Saturday, September 04, 2010 4:27 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Interference on VHF repeater Hi all, I have come across an interesting problem which you may be able to shed some light on. I have an intermod issue where my TX sometimes opens up my RX. I have the distinctive hollow pipe sound. Both TX and RX have the same CTCSS tone. The intermod product is however not always present, and after looking at the RX output from the duplexer with a SA I see a comb of products that move slowly in time. When one of the products in the comb falls within the RX bandwidth the RX opens, until it moves on. This is not a busy site, and I have been able to power down everything on site except my repeater. Problem remains unchanged. I have also disconnected feeders from all other RF equipment on site - still no change. The fact that the IM product frequency changes with time (drift rate is roughly a few kHz's an hour) makes me think that there is either another unknown source of RF on site which has poor freq stability (pretty unlikley), or somehow my TX freq is involved in producing this freq. I have inserted a 6dB pad in the antenna port of the duplexer and found that the IM products drop 12dB, and also curiously, the frequency of the products change. Removing the pad reverses this effect. I have repeated this many times and the result was always the same. It appears that the frequency of the IM product is dependent on the strength of the radiated field from my antenna. This is my question: I have read that it is possible for a strong EM field to excite metal (eg tower member) such that re-radiation will occur at a frequency which is different from that which excited it. Can anyone confirm they have seen this, or can anyone point me to a reference that talks about this? I should also mention there are multiple solar panels and associated regulators on site. The regulators have been discounted as possible sources, but the panels (given they may have bypass/blocking diodes) may be a mixing location, however the source of the drifting tone is still unclear. Thanks, Brett VK2CBD.
[Repeater-Builder] Re: Interference on VHF repeater
Thanks - no battery chargers on site as all solar powered. There are solar charge controllers, though I think I have discounted these. No fluros either. All equipment was switched off for a test, so any SMPS should have been off. Cheers, Brett --- In Repeater-Builder@yahoogroups.com, DCFluX dcf...@... wrote: Look around for a switch mode power supply that uses 600kHz as the switch frequency. SMPS Battery Chargers are popular for causing this. Also florescent twist lights are really good for making desense on VHF.
[Repeater-Builder] master 3 narowband?
can the uhf master 3 radios be programmed narrowband in compliance with the new fcc rules or should I take it to a ham swapmeet? wb5oxq
Re: [Repeater-Builder] master 3 narowband?
At 05:47 PM 09/04/10, you wrote: can the uhf master 3 radios be programmed narrowband in compliance with the new fcc rules or should I take it to a ham swapmeet? wb5oxq Depends on the vintage of the receiver and exciter modules. Are there any numbers on them? Mike
[Repeater-Builder] Re: Pyramid SVR200 programming cable
Thanks Niteviser, Will examine further, looking at the board it appears that there is only one data line plus ground so that rules out the normal type level converter circuit. Thanks again for the link. Regards, Chris S. --- In Repeater-Builder@yahoogroups.com, niteviser nitevi...@... wrote: This what you are looking for? http://www.batlabs.com/svr200.html niteviser --- In Repeater-Builder@yahoogroups.com, tait700 cscannel@ wrote: Hello, Was wondering if anyone happened to know how the programming cable is wired for the above pyramid in vehicle repeater ? Cable has a part No. of FY-1 I don't know if the Genuine version has some electronics inside the DB9 plug cover as with the T800 SII that changes levels, etc. The unit has a 2.5mm jack to accept the data from the computer and a db9 plug at the other end to connect to the serial port at the computer. I have a standard RS232 interface box i use for Tait stuff that provides Tx, RX, Gnd outputs but i was wondering if it would be as simple as l + R + ground on the 2.5 stereo plug. I have seen the file that uses the Motorola programming box at the Batlabs site but if i could avoid having to purchase one of those solely for this use i would prefer it. Any info or suggestions gratefully received.
[Repeater-Builder] Re: S-Com 7330 Controller
Be sure to join the 7330 Beta Yahoo Group, and search earlier messages in that group. Also look in the FILES section in the Yahoo Group site. About a year ago, I took the entire 7K vocabulary (same as the ACC and Link Comm) vocabulary, sampled it, and converted it all into a custom vocabulary file for the 7330. With this file loaded into your SCOM 7330, your 7330 (like mine) can be made to sound just like an ACC or Link Comm controller. The original 7330 SCOM vocabulary remains with the 0xxx and 1xxx word numbers, but you gain the TI sounding words at slots 3xxx and 4xxx. Eric K2CB (ex K2WD, KE2D) --- In Repeater-Builder@yahoogroups.com, scom...@... wrote: Hi Terry, The two controllers store and play back audio files in very different ways. Here's how it's done in the 7330. As shipped, the 7330 has about 1,600 standard words stored as individual sound files. The owner can add up to 13 minutes of recorded audio in the form of 1 to 2,000 additional sound files (the recordings are created with a PC and sound card, then the finished sound library is loaded into the controller through one of its serial ports). The recordings are internally stored in flash memory as 8-bit, uLaw-compressed samples. When a message is played, the samples are converted back to linear format and sent to a 16-bit D/A converter and 5th-order lowpass filter. Each D/A can access the combined stored recordings at any time, which means the controller can identify all three transmitters with different voice messages at the same time. 73, Bob Bob Schmid, WA9FBO, Member S-COM, LLC PO Box 1546 LaPorte, CO 80535-1546 970-416-6505 phone 970-419-3222 fax www.scomcontrollers.com -Original Message- From: terry dalpoas km...@... To: Repeater-Builder@yahoogroups.com Sent: Fri, Sep 3, 2010 2:34 pm Subject: Re: [Repeater-Builder] S-Com 7330 Controller Thanks. I let him know and he can decide which way he wants to go. -Original Message- Date: Friday, September 03, 2010 2:37:11 pm To: Repeater-Builder@yahoogroups.com From: wd8chl wd8...@... Subject: Re: [Repeater-Builder] S-Com 7330 Controller On 9/3/2010 3:07 PM, terry dalpoas wrote: Does anyone know if the voice on this controller use a TI voice synthesizer or if it has the real speech like on the Arcom RC210? Someone in the club liked how my RLC 1 Plus sounds and he wants one that sounds like it, but less expensive. Yes, it's real speech, much like the 210. It also has the means to upload sound files (well, they need to be converted), so it can say about anything you want it to.
[Repeater-Builder] Re: Micor Pin Gunk
Bob, NO6B, wrote:- This looks like the same stuff: http://www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx The description of how Stabilant 22 works reads very similar to the Caig Labs DeOxIt products. A performance comparison between the 2 products would be interesting. Bob NO6B Take a look at:- http://store.caig.com/s.nl/ctype.KB/it.I/id.1977/KB.215/.f The do the comparison. -Lou- WA6EPD
Re: [Repeater-Builder] Re: Micor Pin Gunk
Thanks Lou, Bob, Eric, John and the rest! I have a bunch of techs around here that all swear by Deox-it as long as its used sparangily, and Caig seems to hit all concern points in their website vs.22. Has anyone had any specific issues directly related to using Deox-it? I want to do the right thing and will order the 22 if necessary, but not only because it is what Circle M recommends...maybe Deox-it was not around when they made the recommendation? From reading the Caig website I think it may be a better choiceI worry a little about the 22 drying into a rigid form. What happens over time as the pins heat up and expand/contract, especially in a non-climate controlled environment? Tom W9SRV --- On Sat, 9/4/10, wa6epd lme...@cox.net wrote: From: wa6epd lme...@cox.net Subject: [Repeater-Builder] Re: Micor Pin Gunk To: Repeater-Builder@yahoogroups.com Date: Saturday, September 4, 2010, 10:57 PM Bob, NO6B, wrote:- This looks like the same stuff: http://www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx The description of how Stabilant 22 works reads very similar to the Caig Labs DeOxIt products. A performance comparison between the 2 products would be interesting. Bob NO6B Take a look at:- http://store.caig.com/s.nl/ctype.KB/it.I/id.1977/KB.215/.f The do the comparison. -Lou- WA6EPD Yahoo! Groups Links
[Repeater-Builder] Mitrek lowband PTT questions
Hi all, Thanks for the previous advice on the Mitrek lockout key; I ordered one off Ebay and it worked fine. Opened the radio up and everything looks visually OK, all the channel elements are there, no burned components, etc. I read through the Repeater-Builder's Mitrek webpages and figured out the pins for hookup. I was wondering if anyone could look over some sections of the Mitrek schematic http://groups.yahoo.com/group/Repeater-Builder/files/Mitrek%20Lowband/ I posted in the Files section under the folder Mitrek Lowband, regarding the PTT circuit. I circled the areas in question in red and blue. (I also hyperlinked to the various schematic sections in this message). I just want some verification before I start wiring up the radio. I found another website where the author said to jumper pin #1 to pin #25 on the interconnect board connection http://f1.grp.yahoofs.com/v1/wBWDTM_dzohoZJ1M25svBvhmyUk3YStFZKcbHdVjzc\ HCTQSgFE9U0-wFOU3PHUQL3NIWEGUG1ndFPkhYrLdul9o1/Mitrek%20Lowband/intercon\ nect_board.jpg , and then just ground pin #13 of the cable connector (or pin #13 on the front of the radio in my case) for PTT operation. (Pin #24 of the interconnect board connector is the same as pin #13 of the cable connector) My questions are: 1. What does the jumper do and is it beneficial for beacon operation? Here is the schematic section http://f1.grp.yahoofs.com/v1/wBWDTDg1U9VoZJ1MJmrSx6917ZszwfFtwKxh8c5tPr\ Kp1IiKeb_dd_z6o52LjBRH6eMjcKXGvRCwASnBIgIJ8PUE/Mitrek%20Lowband/mitrek_P\ TT.jpg of the PTT circuit. 2. I will be using the Mitrek solely as a transmitter beacon, so RX is not necessary. I'll have to disable the antenna relay http://f1.grp.yahoofs.com/v1/wBWDTJ0GE-FoZJ1MoIPDEYBXLqbbFZph6Eymc3u9dF\ QYPG2vhGbVYg92QCtUhDuNVVr89_tTKgsBysS0H3B3Q5eW/Mitrek%20Lowband/Antenna_\ Relay.jpg because it won't last long during constant beacon operation, plus it isn't even needed. Can I just disable the relay by cutting power to it and wire the PA output directly to the antenna jack (two points circled in blue)? Or, just keep voltage on the relay so the RX section is always switched out and the TX switched in? Probably easier that way. 3. The radio has the PL board installed; can I just remove it so it doesn't introduce anything into the carrier, or just leave it alone? I can't tell from reading through the various websites and the schematic if the PL-encode is enabled automatically or if it needs switching on, in which case I will leave it off. Thanks for any advice. Jeff KP3FT
Re: [Repeater-Builder] Mitrek lowband PTT questions
what would it take short of some cash to have one sent to me here in New Zealand as a one off key, not that i need one, i am told i am a Hoarder Marcus On Sun, Sep 5, 2010 at 4:38 PM, KP3FT kp...@yahoo.com wrote: Hi all, Thanks for the previous advice on the Mitrek lockout key; I ordered one off Ebay and it worked fine. Opened the radio up and everything looks visually OK, all the channel elements are there, no burned components, etc. I read through the Repeater-Builder's Mitrek webpages and figured out the pins for hookup. I was wondering if anyone could look over some sections of the Mitrek schematichttp://groups.yahoo.com/group/Repeater-Builder/files/Mitrek%20Lowband/ I posted in the Files section under the folder Mitrek Lowband, regarding the PTT circuit. I circled the areas in question in red and blue. (I also hyperlinked to the various schematic sections in this message). I just want some verification before I start wiring up the radio. I found another website where the author said to jumper pin #1 to pin #25 on the interconnect board connectionhttp://f1.grp.yahoofs.com/v1/wBWDTM_dzohoZJ1M25svBvhmyUk3YStFZKcbHdVjzcHCTQSgFE9U0-wFOU3PHUQL3NIWEGUG1ndFPkhYrLdul9o1/Mitrek%20Lowband/interconnect_board.jpg , and then just ground pin #13 of the cable connector (or pin #13 on the front of the radio in my case) for PTT operation. (Pin #24 of the interconnect board connector is the same as pin #13 of the cable connector) My questions are: 1. What does the jumper do and is it beneficial for beacon operation? Here is the schematic section http://f1.grp.yahoofs.com/v1/wBWDTDg1U9VoZJ1MJmrSx6917ZszwfFtwKxh8c5tPrKp1IiKeb_dd_z6o52LjBRH6eMjcKXGvRCwASnBIgIJ8PUE/Mitrek%20Lowband/mitrek_PTT.jpg of the PTT circuit. 2. I will be using the Mitrek solely as a transmitter beacon, so RX is not necessary. I'll have to disable the antenna relayhttp://f1.grp.yahoofs.com/v1/wBWDTJ0GE-FoZJ1MoIPDEYBXLqbbFZph6Eymc3u9dFQYPG2vhGbVYg92QCtUhDuNVVr89_tTKgsBysS0H3B3Q5eW/Mitrek%20Lowband/Antenna_Relay.jpg because it won't last long during constant beacon operation, plus it isn't even needed. Can I just disable the relay by cutting power to it and wire the PA output directly to the antenna jack (two points circled in blue)? Or, just keep voltage on the relay so the RX section is always switched out and the TX switched in? Probably easier that way. 3. The radio has the PL board installed; can I just remove it so it doesn't introduce anything into the carrier, or just leave it alone? I can't tell from reading through the various websites and the schematic if the PL-encode is enabled automatically or if it needs switching on, in which case I will leave it off. Thanks for any advice. Jeff KP3FT
