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#1
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![]() "Ed" wrote in message . 93.175... Mike, Without knowing you, I have to only guess at your previous "CB" experience, and in doing so, will guess that it is a far cry from the knowledge and experience a good LMR technician has. Commercial radio is not CB! Only guessing from the description of your system that you gave, that is is poorly maintained, at best, and that the repeater had probably been neglected for quite some time? Several hours of labor would not be prohibitive, under those circumstances. Assuming you can properly solder/crimp, and install RF connectors, I'd guess that you probably can save some money by doing some of the more basic work yourself. However, you will need more than a CB type SWR meter. I'd suggest a Bird Model 43 with the appropriate slug for your frequency and power. That will set you back at least $300.00+. Also, you probably ought to purchase some good quality connectors, antennas, and antenna cable/NMO installation kits as I expect you will find several of the busses needing them. Good luck trying to do it yourself. Ed K7AAT IMHO a Bird meter is overkill in this situation. It's a bit like recommending a Rolls Royce for doing the weekly shopping. It will work, but so will a VW. There are any number of perfectly adequate meters from a wide variety of manufacturers at prices considerably below that of a Bird. 73 Roger ZR3RC http://www.sarl.org.za/callresponse.asp?Callsign=ZR3RC |
#2
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![]() IMHO a Bird meter is overkill in this situation. It's a bit like recommending a Rolls Royce for doing the weekly shopping. It will work, but so will a VW. There are any number of perfectly adequate meters from a wide variety of manufacturers at prices considerably below that of a Bird. I certainly don't consider a Bird watt meter to be a "Rolls Royce" in the communications maintenance industry. If you look at ANY two-way radio maintenance shop, you will most likely find a Bird watt meter being used on a regular basis. Its more like a "Chevy" than a Rolls! The guy is looking to do maintenance on a fleet of unknown number of busses. I recommended an instrument he can trust, and that will hold up to a considerable amount of physical abuse. So, if you think the Bird is too much, what are your suggestions for this guy? Ed |
#3
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"mike" wrote in message
oups.com... Gentlemen, I work for a student transportation company using UHF radio communications. While I have played around with CB radios several years ago I have no experience with UHF. Our system operates on either of 2 channels near 470 MHz. Channel 1 transmits via a repeater located in the hills a few miles away, while channel 2 is direct. Mike, what is your specific title or role within this company? are you a driver? director/manager of operations? "Playing around with CB radios" experience should not be referenced for this situation - while interesting - no directly relevant. You are discussing a land-mobile system that was likely designed and installed by a professional company in your area. For example, FCC documents had to be filed for this repeater, frequencies coordinated and applies for and appropriate licenses applied for. I am assuming that you are NOT using the General Mobile Radio Service (GMRS) solution. The "radio system" you described for your student transportation company is a "dual purpose" design. Channel 1 provides distance communications via an operational repeater, when communications via Channel 2 would not be possible (terrain, distance, etc.). Channel 2 also provides communications channel between your buses (special event, etc.) when they may be out of range of your local repeater. For most of the last school year we have operated on channel 2 -- as channel 1 wasn't working. So, you did not have an operational communications system (Channel 1) for a period of time? And this did not cause problems in your day to day operations? A company recently came out (not following known company authorization procedures), and apparently repaired a faulty repeater. It is UNUSUAL for an operational repeater (with this type of service) not to have a contract or service agreement. Who owns this repeater? Your transportation company? Your company's legal advisor should be consulted about agreements and terms. Our company was charged about $185.00 for parts and over $600.00 for labor. The rate worked out to be $80.00 per hour over 7.5 hours. Not only does this seem a wee bit steep to me, but the communications are still poor on channel 1. We can only assume that this work was for work on a repeater that you own -- and was not covered under a maintenance agreement (known in the trade as "break-fix" coverage). I do not know "where you are" to comment specifically about regional differences in US labor rates, HOWEVER - the labor charges you are quoting are appropriate (almost identical to my Honda dealer - BTW). You are making 2 mistakes here (common with entry level managers) Confusing an "hourly labor charge" with a personnel hourly rate wage -- which is incorrect. The "hourly labor charge" usually includes the overhead for the company, transportation to site, the laborer's benefits, etc. If you are an operational manager - your financial officer or director will know this difference. The other is that you assume that productivity is constant for all employees -- that's not true -- and you can look your bus shop floor and quicky identify workers that perform higher qualtiy in less time than other workers - are you paying them more? You stated that you did not have an operational repeater (channel 1) for almost all last school year. So how are you determining communications are "still poor on channel 1" ?? Assuming that the repeater is fine now, the problem seems to be more related to the individual busses. This is a contradiction - you paid for repairs - is the repeater working satisfactory or not? Or are you now telling us the real problem? Over the course of time our mechanics have swapped-out radios, mics, and probably antennas as well. Given the nature of the problems and my previous (limited) experience with CB, my suspicion is that the antennas on the busses need to be tuned. I signal losses with coax at UHF (470 MHz) are far greater than at 27 MHz (CB). I have no idea who installed your first radios in these buses -- IF your company did it themselves -- without basic equipment to "cut" these UHF antennas -- then this is part of your problem. Mike - you have a "broken" operational process here -- that needs to be addressed - the company that fixed your repeater likely has a group of installers (who install the radios for public service in your area - police, fire, ambulance, etc.) that deal with this every day and can correctly advise you (and help you set up the correct process) for repeatable and reliable results. I used to tune my CB antennas with an SWR meter and get good results. I understand the basics enough to be able to do that and could probably teach our mechanic as well. However, since I have no experience with UHF I don't know if there's more to it with UHF over standard CB and if there is more equipment required than an SWR meter. Now, you are starting to describes "changes in your operational processes" that need correction. First, I assume that you are responsible for this area of the company? You should identify 1 or 2 individuals within your company to "handle" the radios and antenna installations and changes on these buses. You can likely find someone -- instead of mechanics -- who should be working on the buses. These individuals can be trained to correctly handle this work -- and to assure proper operation. Purchasing the proper equipment (SWR meter) -- this really depends upon: The number of bus radio systems you are maintaining; Your "bus replacement cycle" each year (new buses replacing old buses) IF you wish to internalize this function - site down and have a meeting with your local company -- they can properly advise you to the proper equipment you should buy and properly educate your staff to use this equipment. As an alternative, you can ask for a price for such services from this company (on a "per bus" or "guaranteed number") I am just having a real difficult time paying $80.00 an hour for someone to do something I used to do quite easily. Mike, to professionals in the radio communications field - this statement can be - very insulting - "I pay a professional mechanic to do work on my car at $75 to $80 hour - which I probably could do -- BUT NOT at their productivity level (I do not do this work everyday) -- YET you are telling me that you won't pay $75 to $80 hour for a professional radio tech or engineer to work on your repeater -- that you have no training to troubleshoot or repair." IF you truly believe this - KEEP IT TO YOURSELF. Mike, you may ask - what in the h^%^% do I know about transportation, bus systems or telecommunication systems? I worked for Greyhound Lines as the first Information Center Manager (for the then new PCs, LANs and national network) in the early 1980s. In that position I worked with over 63 bus maintenance and repair centers nationwide as well as 2 major rebuilding operations. Today, I serve as global practice leader for network and telecommunications at an international consulting firm. I am not going to send you "an invoice" for the advice above - my business is operational excellence, cost effectiveness and outstanding quality. Work on those 3 principals. gb |
#4
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Gentlemen,
Thank you for your responses. I appreciate the assistance. It appears that I need to provide a bit more information to give you more insight into the circumstances I am faced with. I had hoped to keep both the question and responses as uncomplicated as possible. However, given the direction that a couple of responses have taken I see the need for expanded information. It is true that I have substantial management experience, but it lies in a very different industry. In fact, for 11-years I owned a consumer electronics engineering/manufacturing company with sales in many foreign countries. During that time my company never borrowed any money and never carried any debt. Nevertheless, the time came to close the company and I did so. While it was not the easiest decision to make, it was the right one and the right time to do it. I took a job last August driving school bus for a local barn for a large foreign-owned company, and shortly thereafter an opening for an operations clerk (glorified secretary), became available and I took it. (Yes, it's been humbling, but I have little room for ego.) It turns out that not only am I new in my position (as well as to the transportation industry), but the dispatcher and operations manager for the particular barn I work in are new in their positions as well. That is not to say that they are new to the company or to the industry. The operations manager has 9-years with the company. I believe that part of my job is to help my superiors be successful and to look good to theirs. While I am hoping that other doors of opportunity will open for me, I have a responsibility to be as good an "operations clerk" as possible. In this particular circumstance, I have come in long after the horse has escaped, as have my two immediate superiors. The issue with the communications amongst the 40 busses at this location is one that the three of us are attempting to clean up. In terms of the rate charged, our mechanic gets about $15 per hour, while I get $9. Local auto dealers charge $45-$65 an hour. Therefore, using this as a reference $80 just seemed a bit steep. That said, if that is customary for UHF work then I will accept that as I said. Given the AP that I've seen, it seems clear that there is no service contract in place. While the repairs made to the repeater did get channel 1 working again, it has a high static level with most but not all busses. A couple of busses sound relatively clear, while most others are nearly unintelligeable. Channel 2 (direct) generally sounds much better across the board. However, even then many of the busses have problems. This is what leads me to suspect various antenna tuning issues. Therefore, my question about the feasibility of doing that in-house. I would much prefer to pay $15 an hour than $80 for the same work, but only of it makes sense to do so. I hope that this provides more of the information that you gentlemen need to help me determine the most prudent course of action. I would like to be able to make a reasonably intelligent and informed recommendation to my superior. Thank you again for your assistance. Mike |
#5
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On 13 Jun 2005 10:35:40 -0700, "
wrote: While the repairs made to the repeater did get channel 1 working again, it has a high static level with most but not all busses. A couple of busses sound relatively clear, while most others are nearly unintelligeable. Channel 2 (direct) generally sounds much better across the board. However, even then many of the busses have problems. This is what leads me to suspect various antenna tuning issues. Hi Mike, Your last sentence is what is called looking for your lost keys at night, beneath the only streetlight. It's not that you lost them there, it is simply your only working option. You may appreciate how poor this strategy actually succeeds in the real world. Static is not a normal indication of good operation. That much rings true. However, tuning antennas is improvement by degree, not by leaps and bounds - unless something very obviously wrong is quite visually evident with the antenna. You may even have to accept the possibility that this system never worked very well to begin with. You say a couple of busses work well, and this in its own right tends to remove the repeater from the list of problems - but your description of problems is still slim. You say nothing of terrain, service area (how many square miles, blocks, or whatever), or pattern of coverage. Unintelligible is another fuzzy word to describe communications. Is this because of static? distortion? other noise? weak signal? Is this static: ignition noise? road noise? power line noise? FM communications rarely presents you with noise problems unless your power level (from the repeater) is seriously low or your receiver is seriously mistuned, or its antenna situation is seriously mangled (have you looked?). Receivers don't get mistuned typically, and antennas are quite robust. You already offer that point to point comm on ch 2 is a mixed bag. Start by using what field medics call triage. That is separate the well from the infirmed, and the dead from those who need help. In the end, you can spend far more at $15/hr accomplishing nearly no good results than you would with an hour's time from a good tech. Have you tried talking to him? I bet no more than 5 minutes of conversation would reveal much. 73's Richard Clark, KB7QHC |
#6
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"Richard Clark" wrote in message
... On 13 Jun 2005 10:35:40 -0700, " wrote: Richard has covered many of your concerns. In terms of the rate charged, our mechanic gets about $15 per hour, while I get $9. With the proper tools, replacement materials, correct knowledge and a motivated/productive worker(s) (less than your $15/hour mechanic) - you can improve the operation of this system. Did you know that many stereo installation workers (e.g. Best Buy, Fry's stereo shops) and even some LMR shops make about this same wage range? It is usually an apprentice or entry level position for LMR shops ! So, how can you make it happen? Richard gave an excellent FIRST step "Start by using what field medics call triage." My Dad and Elmer's taught me 35 years ago that you need to quickly separate the "wheat from the chaff". Some of your "problem radios" in buses may actually be "bad radios" AND "bad antennas". IF a radio has a shorted coax, the final RF transistors inside the radio may have been damaged (like running an engine with no "oil warning" light -- damage is or has occurred and you don't know it !) There is no easy way that you will know this without diagnostic equipment. While the repairs made to the repeater did get channel 1 working again, it has a high static level with most but not all busses. A couple of busses sound relatively clear, while most others are nearly unintelligible. While a number of problems can cause high static levels -- I would FIRST suspect a broken shield in the antenna coax -- due to rough "installs and reinstalls" from buses -- so that ignition noise from the bus engine is being picked up by the radio. Now, you still need to have a sit down conversation (for research and business relationship purposes) with your local LMR. The purpose of this meeting (about 30 minutes) is to introduce yourself and come away with the following accomplishments. Something like this: 1. Establish a business relationship with the owner or manager of this business. Who is he/she? How long in business? Did they originally install and design this system for the company? You just handed him a check for services -- and he/she should be happy to do this. 2. Outline -- at a high level -- your problem, which is: + Due to regular replacement of buses, your staff has to remove and install 40 radios very 12 to 24 months. + You have recently joined the company and discovered that the knowledge to do this work properly has been lost (due to employee turnover). + The company needs to regain sufficient knowledge to perform this work at "odd hours" or on "short notice". + You would like a proposal from this LMR company: Cost to perform this changeout service per bus (at their facility OR at your facility - likely 2 prices here) - and any discounts for guaranteed volume of work (per bus) for a given time period. (This service should include assurance of both the radio and antenna) 3. Ask the company if they would be willing to have 2 of your staff members "shadow" his install technicians. I know of many LMR that are restricted from doing this by their business insurers (similar restrictions exist for many insurance policies at automotive and truck garages - you may have such a restriction at your own bus garage Your staff likely knows "buses" better than his LMR techs - and joint knowledge may be required for proper power routing to radio and antenna placement on the bus. No one has mentioned this - but the placement of a UHF antenna on a large bus is a KEY DECISION for proper operation. AFTER, you get his written or verbal proposal, I would suggest that you propose to your management to try this out on the 2 bus radio installs - for you suspect that there are several issues at work in those instances. Select the worst 2 bus radios --- preferably to be removed and installed in 2 brand new buses. This is what I refer to as a "BOOT STRAP" upgrade - taking the worst and making it the best. NEW BUS - GOOD RADIO, POSITIVE Driver comments about these NEW BUSES - immediate quality improvement -- easier to continue program -- you get "buy in". You will likely find the following reported to you by the LMR company -- as they have the "UHF bus radios" on the bench. 1. Bad coax that needs replacing 2. New whip required for antenna or "recutting" 3. You may require "noise suppression" on the power lead from the battery due to engine noise (e.g. spark plug, ignition system) 4. Damage or failure of the radio -- if you have no maintenance agreement -- this is break fix at a bench rate -- the alternatives are NO RADIO, FIX RADIO or REPLACE RADIO Lastly, although you are upgrading and changing buses on a regular schedule (and tires) - where is the yearly budget allocation for the communication system? Did you know that if you handle the accounting properly -- you can include these radios in the overall capital depreciation of the buses? IF you did not know this (kick your accountant in the ass for me) - that is pretty basic. Greg w9gb |
#7
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Thank you again for your replies.
I agree with your assessment that much of our (company's) internal (operational) systems may be considered "broken" by virtue of current circumstance. Unfortunately (or perhaps fortunately depending on ones point of view), I am not in a position to have any real effect in matters I am not paid to have an opinion on. However, regarding the communications amongst the 40 or so busses I can have a positive effect on, there may be some positive contributions I can make. I have recently learned that our mechanic has been the one to install the radios, coax, and antennas all along. The way the (broken) system apparently works: Barn gets new bus in. Manager asks for permission to buy new radio for new bus. Uppon approval, manager orders new radio system (radio, coax, antenna, hardware, etc.), from local company. Mechanic installs new radio into new bus. Everyone hopes for the best. In the course of conversation with our mechanic this morning on the matter, I learned that he has mounted a number of the antennas on a part of the bus that is fiberglass. I tried to explain a bit about ground-plane to him and the need for the antennas to be mounted on a metal part of the bus. I' am having him take one of the "worst" communicating busses and move the antenna to a metal part of the bus. I am also having him go through all the contacts and connections and cleaning them. I'll post what was done and what the results have been. Thanks again for your help! Mike |
#8
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" wrote in message
oups.com... Thank you again for your replies. I agree with your assessment that much of our (company's) internal (operational) systems may be considered "broken" by virtue of current circumstance. Unfortunately (or perhaps fortunately depending on ones point of view), I am not in a position to have any real effect in matters I am not paid to have an opinion on. However, regarding the communications amongst the 40 or so busses I can have a positive effect on, there may be some positive contributions I can make. I have recently learned that our mechanic has been the one to install the radios, coax, and antennas all along. The way the (broken) system apparently works: Barn gets new bus in. Manager asks for permission to buy new radio for new bus. Uppon approval, manager orders new radio system (radio, coax, antenna, hardware, etc.), from local company. Mechanic installs new radio into new bus. Everyone hopes for the best. In the course of conversation with our mechanic this morning on the matter, I learned that he has mounted a number of the antennas on a part of the bus that is fiberglass. I tried to explain a bit about ground-plane to him and the need for the antennas to be mounted on a metal part of the bus. I' am having him take one of the "worst" communicating busses and move the antenna to a metal part of the bus. I am also having him go through all the contacts and connections and cleaning them. I'll post what was done and what the results have been. Thanks again for your help! Mike Mike - VERY USEFUL INFORMATION. Yes, fiberglass is worthless for the required ground plane of a 1/4 wave UHF antenna - and requires additional materials. PCTEL based in the Chicago area is a major antenna mfg. and suppliers (e.g. MAXRAD, Antenna Specialists). They have 2 suitable products specifically made for fiberglass body vehicles and antenna mounting (Page 44 of their catalog) http://www.antenna.com/lm_cat/pdf/lmr_catalog.pdf Ground Plane Kit Model K-67 Ground plane kit for fiberglass-bodied vehicles. Complete with instructions and sufficient adhesive backed foil for one low-band/high-band or six UHF ground planes (3 inches x 44 ft). Includes metal clips for circuit continuity. Ground Plane Disk Model K-332 Provides ground plane for fiberglass-bodied vehicles. THIS NEEDS TO BE ADDED TO THE "BILL of MATERIALS that you are ordering from the "local company" supplying the radio and antenna materials ======================================= Greg, w9gb |
#9
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gb wrote:
Mike - VERY USEFUL INFORMATION. Yes, fiberglass is worthless for the required ground plane of a 1/4 wave UHF antenna - and requires additional materials. PCTEL based in the Chicago area is a major antenna mfg. and suppliers (e.g. MAXRAD, Antenna Specialists). They have 2 suitable products specifically made for fiberglass body vehicles and antenna mounting (Page 44 of their catalog) http://www.antenna.com/lm_cat/pdf/lmr_catalog.pdf Ground Plane Kit Model K-67 Ground plane kit for fiberglass-bodied vehicles. Complete with instructions and sufficient adhesive backed foil for one low-band/high-band or six UHF ground planes (3 inches x 44 ft). Includes metal clips for circuit continuity. Ground Plane Disk Model K-332 Provides ground plane for fiberglass-bodied vehicles. THIS NEEDS TO BE ADDED TO THE "BILL of MATERIALS that you are ordering from the "local company" supplying the radio and antenna materials ======================================= Greg, w9gb Thanks, Greg. I've printed out their catalog and noted the products you suggested. Yesterday afternoon I had an opportunity to examine our busses more closely and found a couple different types of antennas in use. Several look very much like the ASPRD1610 shown in the catalog. The others look like the ASP-7654, but perhaps with a different base. I have always understood that when it comes to antennas, the longer they are the better(in general). The short ones appear to be between 4-6 inches in length. There is some variation in their lengths. Given their varied mounting locations on the busses combined with what I learned yesterday about how things have been done here, I can only assume that very little is actually "right". At this point, I'm not very confident that the local supplier pre-cut the antennas, although they may well have. A phone call will answer that. As an aside, this particular company appears to make little if any investment in their people. The manager here must get prior approval from the regional manager to purchase string for the weed-eater. This may well help explain why there has been no service contract in place, nor has there been any attempt to fix the problem(s) with the radios. This makes me think that other than our remounting the antennas properly and cleaning connections there may be little we can do. Perhaps that will be enough to get our communications to a point of being adequate for our needs. Anyway, thanks for the information. I'll let you know what we find. Mike |
#10
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On 16 Jun 2005 11:44:19 -0700, "
wrote: The short ones appear to be between 4-6 inches in length. There is some variation in their lengths. Hi Mike, You can expect some "minor" variations. Tuning these up will NOT change a poor situation. I'm not very confident that the local supplier pre-cut the antennas, although they may well have. A phone call will answer that. The call to the supplier will draw a blank here. They provide goods, not services. The antennas are "factory tuned." Installation is not a matter of making things fit like a cabinet maker. An installer would make sure of sufficient sheet metal to offer the antenna a counterpoise - this is an implied presumption that a garage mechanic would be wholly unaware of. In this regard, your antennas WOULD be seriously detuned. Trimming them will do absolutely nothing to improve this. As has been pointed out, you need real metal footings. Researching this last point may take some effort to match to your situation of neglect and tight purse strings. As an aside, this particular company appears to make little if any investment in their people. You run in serious chance of upsetting the apple cart in an attempt to shine - not the response you would care for. A friend once pointed out to me in a similar situation: If it was important to them, it wouldn't be a problem. 73's Richard Clark, KB7QHC |
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