[Repeater-Builder] Re: Need microphone Pin Outs For QUANTAR
Tim, According to the diagram on page 5 of 6881085E13-C, the wiring of handset connector P10 on the Station Control Module CLN6873D is as follows: 1 is NC 2 is receive audio output through a 1 kohm resistor 3 is mike PTT 4 is mike audio input 5 is chassis ground 6 is signal ground 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, afa5tp w7...@... wrote: Happy 4th Group! I am in need of microphone jack pin out for the Quantar Rpt. I have plenty of Motorola mikes, but all have the wrong size modular connector! Once I get the correct pin out, I have crimper in hand, and ready to go! Thanks much for any info. TIM W7TRH Vashon Is. Wa.
[Repeater-Builder] Re: Written standard for installs at radio and cell sites?
Robert, Motorola has published the R56 Manual for many years, and it has become the bible for many cellular and repeater installations. It covers almost every aspect of site design, construction, and maintenance. There are a few fine points of electrical grounding that do not comply with the National Electrical Code, so you should always check with your local building inspector before installing any grounding conductors. The 350-page print manual is publication number 6881089E50, and is currently priced around $90. The R56 manual is also available on CD- ROM as publication number 9880384V83, for about $70. There are other manuals that are valuable, and more information is here: www.repeater-builder.com/rbtip/radiositerules.html The National Electrical Code devotes an entire chapter to the proper installation, grounding, and protection of radio and television equipment- including Amateur Radio stations. This guidance is in Article 810 of the 2005 NEC- which is the current edition that has been ratified by most states. 73, Eric Lemmon WB6FLY -- In Repeater-Builder@yahoogroups.com, georgiaskywarn kd4...@... wrote: Hi Folks, Is there such a beast? We are getting ready to move into a new site and will be installing everything from installing antennas, hardlines to the repeaters. One of the fellows in our ham group does this for a living, however that doesn't help me and the other fellow dressing out the repeaters...in the cabinets, in our own hamshacks before. The term Motorola Standard keeps being used. Anyone heard of this? I know there are certain electrical codes that must be followed...but Moto Codes? I have a 6ft cabinet on wheels right now. It was mentioned that the cabinets must be bolted to the floor. Hoping that I do not have to take the wheels off (real heavy!). Also hoping just to use some sort of J hook to make that happen...but not sure if it is code. Also with the other cabinet we're putting in...we were told it is not code to mount the cans on the outside of the cabinet. Is there something written on the web folks could point us to? Thanks, Robert Burton KD4YDC DEC NWS / Peachtree City, GA Skywarn www.georgiaskywarn.com
[Repeater-Builder] Reed vs. Reedless PL Boards
I recently acquired a Kenwood HM-250 Audio Distortion Analyzer, and I have been experimenting with various CTCSS tone encoders to find which produce the purest tones. Since I am putting together a 6m repeater using Mitrek radios, I wanted to compare the older HLN4020B reed board to the newer HLN4181A reedless board. What an eye-opener! My gut feeling was that the reed board would produce a purer tone than the digital reedless board, since the reeds are essentially tuning forks. That turned out to be a false assumption. With two known-good tone boards hooked up on the bench, the 4020B reed board consistently produced a 127.3 Hz tone with distortion ranging from 0.75% to 1.52%, while the 4181A reedless board produced the same tone with only 0.43% distortion. I adjusted the output level pot (R23) on the 4181A board to match the output level of the 4020B board. I tested the 4020B board with six 127.3 Hz reeds. Another interesting fact emerged from my experiment: Although the PL tone reeds can be plugged into their sockets in either of two positions, I found that there was definitely a difference in the amount of distortion produced. The differences ranged from 0.1% up to 0.6%- not much, but surprising, since the reeds are supposedly symmetrical. I got similar results with KLN6209A, KLN6210A, and TLN6824A reeds. For comparison, I measured the distortion at 127.3 Hz from several pieces of test equipment, with the following results: HP 204B Audio Generator: 0.24% Motorola R2600D Service Monitor: 0.26% Wavetek 188 Audio Generator: 0.19% CSI TE-64D Tone Generator: 0.76% My next step is to evaluate the purity of the CTCSS tones after passing through an RF link. Some radios- cheap ones especially- use rather coarse tone synthesis techniques to generate PL tones, and the resulting tones are prone to falsing and talk-off problems. Stay tuned... 73, Eric Lemmon WB6FLY
[Repeater-Builder] Re: MTR2000 Backplane Fuse
I took a close look at a spare Motorola MTR2000 fuse, part number 6583049X16, and can provide some additional data: The fuse is rectangular, with a square cross-section, and measures about 6.0mm by 2.6mm. It has a ceramic body, with silver-plated end caps. The legend IE5A is printed on one face. This fuse seems to be identical to Littelfuse (note the spelling) Series 453 Nano fuses. The data sheet is here: www.littelfuse.com/data/en/Data_Sheets/Littelfuse_Fuse_451_453.pdf 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Ray Brown kb0...@... wrote: - Original Message - From: Chuck Kimball n0...@... To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 28, 2008 5:45 AM Subject: [Repeater-Builder] MTR2000 Backplane Fuse Good Day Everyone: I'm looking for some info on the small fuses on the backplane of the MTR2000 repeaters. I've got a Instruction/Field Service Manual 68P81096E30-C, and can't find anything in there on the part number for the fuse. Apparently Motorola doesn't think those are field replaceable. ;) They are a 5A very small 1/8x1/8x1/4* fuse not much larger than a surface mount resistor - looks to be ceramic with metal ends. I've seen these once before, but don't know the name of that style to do any sort of a search on it. LittleFuse. I forget their exact part designation but several models of hospital beds uses them. I had never seen them before and unfortunately got them from the mfgr. of the beds because I needed some overnight and didn't have time to search. I got about 10 of each (they range from 0.5 to 7 amps @ 32 VDC) plus fuse holders for each one for $200. (sigh) I can't give any of the fuses away, but if anyone wants any surface- mounts for these fuses, I think I have about 30 of them that I could give away. :-) Anyway, Newark stocks them, too. :-) Ray, KBØSTN
[Repeater-Builder] Re: Astron P/S question
I should point out that Astron has made several significant changes to the RS-series regulator boards over the past 20 years, and that may explain why some Astron power supplies always blow the input fuse when shorted, while others never do. Every one of my own Astron linear power supplies is more than twenty years old, and all of them blow the input fuse when shorted by the SCR. Some posters report differing results, and that may be due to recent changes in the regulator board's design. For what it's worth, almost every Astron regulator board I've seen has a few extra resistors or capacitors added to it, as if each one was customized during manufacture. According to Fred, Astron's lead technician, some components are still being changed to make the units more stable- decades after the original design! Here's one tip I learned a long time ago: Use exactly the fuse type and rating that Astron specifies for the specific power supply. Don't substitute a slow-blow fuse for a fast-blow, and don't use a higher-rated fuse or one that is intended for automotive use in place of one rated for 250 volts. If the correct fuse keeps blowing, there is a problem that should be found and fixed. Most Astron power supplies include an MOV (Metal Oxide Varistor) immediately downstream of the fuse. Such devices are usually rated for 130 VAC when applied on devices that operate at 120 VAC. If the line voltage is abnormally high, the MOV will get warm and become more likely to enter avalanche mode on modest spikes. Utilities are supposed to maintain the nominal utilization voltage at 120 VAC +/- 5%, so if the voltage ever exceeds 126 VAC, or falls below 114 VAC, it's time to complain to the electrical provider. 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Adam T. Cately atcat...@... wrote: At 07:38 AM 12/26/08 -0500, you wrote: That pretty much confirms my thinking. If the supply is blowing fuses, something is actually wrong. The crowbar shouldn't cause it to happen. Well... Yes and no... If the SCR fires, you dump all the available current through the supply to ground, and the supply will blow the fuse - THAT is the designed re- sponse so that you don't let it sit there and burn up. When you short the output - IF the current-sense circuitry is working to spec, the supply sees the rise in current and shuts down the voltage to alleviate the SCR from firing - again, THAT is what this circuit was designed for. I always *assumed* the SCR was for over-voltage (shorted output pass transistor) and the fold-back was for over-current, under regular output conditions. If the supply blows the fuse, something IS wrong, but it IS DESIGNED to do that when something is wrong, so... Chuck WB2EDV - Original Message - From: william...@... To: Repeater-Builder@yahoogroups.com Sent: Thursday, December 25, 2008 11:41 PM Subject: Re: [Repeater-Builder] Re: Astron P/S question I have an Astron RM-35M (35Amp) that I just tested by shorting the output and it doesn't blow the fuse. I think I would be looking for something in the primary circuit that might be shorting like the transformer primary or the surge arrestor or maybe the wiring. I have seen transformers that short after they warm up a little. Bill - WA0CBW In a message dated 12/25/2008 10:11:11 P.M. Central Standard Time, lar...@... writes: --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2edv@ wrote: I have an old Bullet power supply built from a kit (anyone remember those?) that uses the 723. You can short the output time and time again and it simply folds back. heheheh I have one of those still in service on a repeater. Re-capped it a year ago and it still works fine. As I recall a shorted output simply folds back, like you say. I also have two Astrons here on the bench. One is a VS12, the other is a RS12. When the output is directly shorted with heavy wire they both simply fold back. Shorted them dozens of times; never a blown fuse. Laryn K8TVZ Yahoo! Groups Links --- --- Don't be the last to know - click here for the latest news that will have people talking. !DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.0 Transitional//EN HTMLHEAD META http-equiv=Content-Type content=text/html; charset=iso-8859- 1 META content=MSHTML 6.00.6000.16788 name=GENERATOR STYLE/STYLE /HEAD BODY id=role_body style=FONT-SIZE: 10pt; COLOR: #00; FONT- FAMILY: Arial bottomMargin=7 bgColor=#ff leftMargin=7 topMargin=7 rightMargin=7 DIVThat pretty much confirms my thinking. If the supply is blowing fuses, something is actually wrong. The crowbar shouldn't
[Repeater-Builder] Re: Astron P/S question
Laryn, If the power supply were a switching design, current foldback would occur. But, in the typical Astron RS-series linear supply, the firing of the SCR puts a bolted short on the output. As soon as the large capacitors on the output start to lose their charge, the regulator tries to maintain the output voltage by turning on the pass transistors to full conduction, quickly exceeding the current ratings of the transformer and rectifier diodes and blowing the fuse. Every time this has happened to an Astron RS supply (that I have personal knowledge of), it has blown the fuse. Every time. Odd that your experience is different. The fuse ratings are specified by Astron to ensure that they will blow under such conditions. Because of their (RS-series) relative instability in high-RF environments, I now install only Duracomm, Samlex, and Astron switching power supplies. Lightweight, very efficient, and very reliable. 'Nuff said. 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Laryn Lohman lar...@... wrote: snip Why is the fuse blowing? Shouldn't the crowbar firing cause simple current foldback? All of my Astrons do, and never blow fuses. My apologies if this has been brought up before... Laryn K8TVZ
[Repeater-Builder] Re: fan timer circuit
I mostly agree. My thinking is that a fan that runs continuously wastes power and draws dust and dirt into the equipment. I also believe that a fan that runs only during PTT is not doing much good except on very long transmissions- when the heat of the PA has made it to the fins. It may take several minutes of key-down time before the fins start getting warm, so running the fan before then is ineffective. My practice is to fix a normally-open thermal switch to one of the heat-sink fins, using heat-sink compound for good heat transfer. I have found that a switch that closes at 122 degrees Fahrenheit (50 degrees Celsius) works best, since it opens about ten degrees lower, and provides near-ideal hysteresis. The thermal switch directly controls a small AC or DC fan that blows on the fins. Not only is this an extremely simple solution, but it ensures that the fan will run only when needed and for as long as needed. I use a Cantherm switch that Digi-Key sells under catalog number 317- 1094-ND for about $7. 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2...@... wrote: Maybe it's just me, but I've never understood the need for a special circuit to run cooling fans. I run my fans from the PTT line using a relay. I have also used a simple chassis thermostat, but prefer using PTT. I suppose you could easily use both methods so that in the event that the equipment remained too warm when PTT halts, the thermostat could keep it running longer. However, I contend that if this is happening, your fans are inadequate and not keeping up with the demand right along. Why the need to continue cooling after the QSO has ended? Just because you can? Chuck WB2EDV - Original Message - From: skipp025 skipp...@... To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 12:24 PM Subject: [Repeater-Builder] Re: fan timer circuit Re: fan timer circuit I've seen a number of fan delay, time on, time off circuits posted on web. The neat'o web page url I just posted here on the group has one and it might be the one you're looking for. http://www.w1ghz.org/small_proj/small_proj.htm and the fan controller information is about half way down the page with a picture and down-loadable zip file. My own personal preference is to run everything warm and even a lot higher temp than most of you would expect. In a repeater station operation only an RF PA and un-modified Astron Power Supply with an undersized heat sink might get a fan. Never a failure of a well planned installation. Some of our local start-up radio clubs throwing repeater packages in place often start out using and stay with an external RF amplifier designed for mobile operation. Sometimes the amp runs so hot you can't keep your hand on the heat sink but I've yet to see one fail. cheers, skipp
[Repeater-Builder] Re: please identify unknown 222Mhz repeater equipment
Chris, That is definitely a VHF Engineering repeater, made from a kit. You can download the manuals for these repeaters from several Web sites. Here's one: http://www.qsl.net/yu4dpr/radiotehnika/ Look for the folders with vhfeng in the title. 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Chris Peterson [EMAIL PROTECTED] wrote: All, Please help me identify this unknown 222 TX and RX. It was donated gear, so if you're just going to tell me to throw it away, please be prepared to donate something to replace it. http://www.sector14.net/~curt/unknown-rx.jpg http://www.sector14.net/~curt/unknown-tx.jpg Thanks, Chris, KG0BP -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.13 - Release Date: 4/16/2005 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/
