Re: [Repeater-Builder] AM NOISE...
If the iso-coupler is bad, it may show up as a change in the antenna current, or phase if it is a directional. Check with the chief engineer to see if something has changed. Mike - AA8K robd53154 wrote: Hi we have a Ham reptr on a tower of AM radio station and its going through an iso coupler, how ever the receiver is getting a lot of AM noise in it the receive is in the 448 range, is there a filter we need to put on the recvr side or is the iso coupler possibly bad, when you shut the AM off the repeater works just fine! RD
Re: [Repeater-Builder] Re: Looking for 220 Repeater Antenna
I wonder if we might be going at this the wrong way. We're spending $500 or $1,000 for a difficult-to-find commercially made antenna that might be a compromise for the frequency we're on. What if we just make our own antenna? Is it that hard to do? There's a lot of 1/2 inch copper water pipe available. If you don't want to bend it, you could use 90 degree elbow fittings to form the loops. Has anyone done this? For my garage repeater, I would love to have a single folded dipole that I could bolt to the side of Rohn 25. One dipole for 220 MHz and one for 450 MHz. If I buy a commercial 4 bay, I have to mount the mast next to the Rohn anyway. The mast just adds weight and wind load. With my health deteriorating, I think that I can lower and raise the tower one more time, so the antennae that I install must be robust and last the rest of my life without maintenance. I was going to use a Tram 1481 to replace the Comet GP-9 on the 147 MHz repeater. (The top two sections of the GP-9 are leaning over 10-15 degrees. I know I tightened them before raising the tower.) But, after hearing the discussions about lightning damage, I want a DC ground design with no capacitors or coils. The 147 MHz antenna should be shorter than the GP-9, because it whips around in the wind on top of the tower. I'm willing to sacrifice gain for reliability. For 147 MHz, I looked at the Tessco DB201 G, but it's a lot of bucks and may not be resonant on my frequency. I thought about making a J-Pole out of copper pipe, but the transition from a balanced antenna to an un-balanced feedline is an issue. Any ideas for something for 147 MHz that's short, grounded, less-expensive, and rugged? Mike - AA8K
Re: [Repeater-Builder] One way transmitting question
The two nearest NOAA weather transmitters to here are 50 miles away, in adjacent counties. The NOAA site shows coverage to about half of our county to be, 0dBuV to 18dBuV: picking up a signal is possible but unreliable A NOAA antenna at about 45 feet and a Radio Shack receiver allows us to automatically turn on the repeater transmitter with NOAA audio when there is a tornado or severe thunderstorm warning. The locals appreciate it (they like to tell us about hearing the Wednesday tests) and we have not had a complaint yet. Kris Kirby wrote: Why not just have a two-tone pager set to the same frequency and activation tone as the weather alerts? If all available tone slots a set matched to the incoming tone, you'll be able to hear the weather alerts, or unmute the reciever. Then you don't have to mess with FCC compliance, or modification of the repeater. Then you can enjoy the 1+kW EIRP of NOAA's transmitters.
Re: [Repeater-Builder] OT - recommendation needed - battery charger
For my Corvette, I took the cable off the battery and put an ammeter in series. I read the current after the Corvette went to sleep. Used a big 36 volt transformer off an ink jet printer with a diode, resistor, and LED in series, with clip leads to the battery. I chose the resistor for about 25 mA higher than the measured drain. The LED shows my charging current. Works. It can sit for over a month and starts as if you drove it yesterday. One morning I woke up to 5 inches of snow. Didn't have time to shovel the driveway, late for work. Thought I could make it to the street; the snow plow had cleared the road. I didn't even get half way down the driveway. The Corvette wedged the snow underneath until the wheels just spun freely. It took a while to dig the snow out from underneath and get it back into the garage. I took my wife's car to work. She could hardly stop laughing. Only 4 inches of clearance under my Corvette. Mike - AA8K Ken Arck wrote: Hi Mike In Corvette circles, battery tenders tend to be fairly common as many Vette owners don't drive 'em at all during winter. As such there are many good (and well tested) battery tenders out there. Here is one that is recommended pretty frequently (and pretty cheap at $40)
Re: [Repeater-Builder] (anderson power poles revisited)
One more. Let me play Devil's advocate. My mistake was buying terminals from a fellow ham who bought in quantity. I also made a mistake when I soldered some and used a crimp tool on others. My crimp tool did not expand the barrel, and the terminal still pushed freely into the housing. My experience in industrial wiring with lugs, down to avionics connectors apparently doesn't matter. The advantages of the connectors are: You must buy the connectors and a specific crimp tool from only one manufacturer You only need to buy one type of terminal, but two different types of housing, red and black. There is no plug/socket, but a genderless configuration that allows you to plug any wire into any wire. You can even plug + into -, unless you rely on a visual inspection to align the connectors and match colors, or have a special panel mounted connector that physically blocks it. You can even connect two radios to each other, or two batteries to each other, unless the cables are correctly marked and attention is paid when connecting. Adequate lighting, excellent color vision, and patient, clear thinking are always present in an emergency situation. You must glue a pair of connector housings together, or use a roll pin that may vibrate out and, appropriately, roll around, to seek its Murphy fulfillment. To prevent a tug from parting mated connectors, you must use a cable tie or purchase clips or clamps. The standard has 15, 30, and 45 Amp rated contacts. It's still a whole lot better than those blasted cigarette lighter plugs! :)
Re: [Repeater-Builder] Re: A Home Brew 224 MHz Repeater Project. - Part 2
I read about the Anderson Power Pole connectors in QST and thought, What a great idea. I started using them in our county's com van for the portable 800 MHz repeater and ham gear, and was I disappointed. Even the coiled cord for the cigarette lighter plug pulled them apart. Now I'm supposed to buy a plastic clip to hold them together? Bah! I think that my toaster has a better plug on its cord. rahwayflynn wrote: --- In Repeater-Builder@ yahoogroups. com mailto:Repeater-Builder%40yahoogroups.com, skipp025 skipp...@.. . wrote: I stopped using small Anderson Power Pole connectors because of all the grief they caused me on the commercial radio side of my life. A lot of people like and use them but I don't trust or use them anymore after a few 10 hour days sourced back to intermittent small power-pole connectors. Re your problem with the Power Pole Connectors: Was the contact itself intermittent or the wire / contact crimp? I have yet to have a prblem with them in DC service, however for signal and data, I generally use Amp CPC series. Martin
Re: [Repeater-Builder] Re: A Home Brew 224 MHz Repeater Project. - Part 2
Ah, thank you John John J. Riddell wrote: Mike, don't use the little red / black plugsthey don't work so well. I have standardised on the 50 amp plugs...even in my car...they won't pull apart. I also use them on all my Son's farm machinery and he is very pleased with them. 73 John VE3AMZ
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
With new systems, there are usually horror stories. Our county is essentially an ancient lake bottom and is very flat. We will be adding a 5th and possibly a 6th tower to support areas of poor coverage. I consider this a flaw in the original system design for this area. There have also been dead-spots with the traditional FM systems. One of our county's township's firefighter told me that they always switch to analog when arriving at an incident. Their lack of confidence relates in part to a structure fire when they heard a firefighter inside screaming for help to dispatch. Dispatch didn't respond until later when dispatch saw that the emergency button was triggered. Obviously, his transmission was going through the system and it was probably a surge issue at dispatch. Our county has a population of approximately 164,000 with three dispatchers for police, fire, and EMS. The emergency button flashes on all of their screens and also appears at the state-wide site. Our county APCO P25 trainer mentions that local acoustical noise makes the transmission difficult to understand and to be sure to hold the microphone 2 to 5 cm away from the mouth. He discourages the practice of using the microphone at arm's length. He also discourages the practice of clicking the PTT for an acknowledgment, as there is no squelch tail. I particularly enjoy the inter-operability and the instant display of the transmitting station's identification. I occasionally hear garbled voices during a transmission from a person in an area of poor coverage. We have not seen a large enough event to consume all of our talk-paths yet. Each of our towers has at least two different microwave paths. Our county is about 70 Kilometers in the longest direction. The Michigan State Police project is quite an ambitious system in area covered. About 250,000 square km and 10,000,000 population. Gareth Bennett (Ihug) wrote: Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings. ..Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
Re: [Repeater-Builder] Re: Quieting duplex noise from a tower
And, if it will tune the 108 MHz to 118 MHz band, you could receive a nearby VOR. mwbese...@cox.net wrote: Paul, Actually, if you're near enough to the airport, you should be able to hear the ATIS (Automatic Termininal Information System) broadcast. It repeats airfield/weather information continously. That'd be a constant (although perhaps not weak) signal in the aircraft band. Mike WM4B
Re: [Repeater-Builder] Repeater Kerchunk
When I make a transmission on a repeater that hasn't been used for a while, I state my intent and call sign, and the repeater ids after I let go of the PTT. I have made a legal transmission, I gain the information that the repeater has been dormant, AND I know that my transmission held the COR/CTCSS for the entire duration of my transmission. That tells me more that just hearing the hang time of a maybe partial reception of my signal. New hams learn by the example of existing hams. If you are making unidentified transmissions, they will make unidentified transmissions. whensle...@comcast.net wrote: My thoughts would be... let it be. Do NOT let anybody know it may bother you. If they know it bothers you, they will keep doing it. As a long time ham I do kerchunk repeaters, especially my local one. Why? To check the status and cycle of the I.D. If the repeater has been inactive for a while, when it first transmits it sends its I.D. Since I don't want to be 'washed out' by the I.D., I kerchunk the repeater. Once the I.D. has finished, or the I.D. has not been sent, I will then put out my call to see if anybody's on the air. On the road, traveling... I will kerchunk a repeater to see if I can reach it. There's also the other side of the coin to this. You think kerchunking is bothersome? How bothersome is it to be mobile, you bring up a repeater, and you try to use it. You try several times putting your call out there. Several miles later, several attempts later, you discover your audio wasn't getting through. The repeater's ears weren't as good as its mouth. Give me kerchunking any day over that. 73, Kim - WG8S
Re: [Repeater-Builder] Split site link via IP
Thank you Kevin. I understand and appreciate the problem you describe. However, I am not trying to download at 2 Meg; indeed the VOIP app is very happy on a 44 K dial-up with the other Internet provider. There seems to be adequate bandwidth, as I can load my cable connection with additional downloads and it has no effect on the level of packet loss and delay. The garble is at a constant level, whether it is at 8 PM or 5 AM. It seems to me that my VOIP is being tampered with to force me to abandon it in favor of the company VOIP. Others may wish to consider using a link method other than VOIP, depending on their Internet providers. Kevin Custer wrote: Paul Plack wrote: As an engineer of a CATV Internet provider, maybe I can shed some light. Our basic speed is 2M down, and we have optional packages for 4M and 6M. When we do a speed test, it shows the actual speed transferred by our equipment and the servers on the other end. Unfortunately, many of the servers providing services like Yahoo, eBay, MSN, etc. can be loaded down and even with our somewhat humble basic 2M speed we see the effects of what's happening on the other end. These effects get worse to the user as their delivered speed is increased. Folks get 'used to' seeing some sites fly, then believe there is a 'problem' when all of the places they visit don't respond with the same snappiness.
Re: [Repeater-Builder] Split site link via IP
Ethercrash wrote: My repeater group is considering building split-site 6m machine. As an inter-site link, I was thinking of using some sort of VOIP arrangement via the internet. IMHO Doug, KD8B, mentioned a critical point about your VOIP not being interfered with. Remember when network neutrality was voted down? This means that your Internet provider can delay or tamper with your packets. Here is my personal experience. I started having trouble with packet loss on my VOIP traffic on my broadband connection, both on my IRLP node and other VOIP. I did extensive troubleshooting with my PC (Windows XP Home Edition). I substituted another clean PC with Windows XP Pro. I built another PC with just Ubuntu Linux on it. I tested with only one PC directly plugged into the cable modem. In each case I was experiencing about a 10% packet loss with garbled voice and delayed syllables. On a whim, I tried using the original PC, but I disconnected my Comcast High Speed Digital LAN connection and had my PC dial up a modem on my other Internet provider. The connection was at 45.2 Kbps. My packet loss dropped to ZERO! The voices were clear, without garbles and delays. Each time that I have repeated the test, whenever I use the Comcast High Speed Digital, I get 5% to 15% packet loss and when I disconnect the Comcast and use a dial-up modem on my other Internet provider, I get 0% packet loss. Now, I do not use the Comcast Digital Voice VOIP service that Comcast sells, because I cannot use it for the IRLP or my other app. I'm guessing that the customers that do use Comcast Digital Voice do not have the same problem, or they would not still be customers. Of course, if you were using a Comcast Digital Voice competitor like Vonage and had this VOIP type of problem, you would probably discontinue Vonage. I appear to not be the only one experiencing problems: http://arstechnica.com/news.ars/post/20080129-p2p-users-blast-comcast-in-fcc-proceeding.html I am on waiting lists for DSL and fiber optic service, but they are not available to me yet, even though I am a short distance from the telephone office. I used to use two-way satellite for my IP and now regret ending that service. I had only very brief storm outages compared to my downtimes with Comcast. Also, during power failures, Comcast has been going down here not long after the power does, so your Internet connection may not be available when you need it the most.
Re: [Repeater-Builder] Split site link via IP
Hi Mark, I was using Earthlink/Direc two-way satellite. There is the inherent latency. If you are a gamer, it might bother you. I didn't mind it. My fade margin was on the low edge. At my latitude, the angle is fairly low and there was a tree at a distance that was partially obscuring. I would lose signal during an unusually heavy rain storm, and twice a year briefly during the sun crossing. Since I was at work at Noon, that didn't bother me. The downside was that the control software had to run on Windows on a PC. When I upgraded the PC from 98 to XP, Internet Connection Sharing no longer supported Netbeui and my Windows 98 PCs couldn't use the Internet. Comcast hooked me with their low-price initial come-on. I dropped Earthlink/Direc and gave away the dish and transceiver. It was a few months after that that we had the big power failure in the NorthEast. I waited a while and then started my generator. I brought up my PCs and started to watch the TV and pick up my e-mail. Not long after, Comcast cable TV and High-Speed Internet disappeared and didn't come back until days later when the power was restored. If I still had the satellite, I would have had Internet. Glad that I didn't have their reliable home phone service Comcast Digital Voice. Our POTS kept working. I got to see the local C.O. battery room once. A lot of chemical energy in there. They even started up their TURBINE backup generator for us. That was a cool sound. We've since had another long power failure and a brownout and the Comcast services stopped a short while after power did. It was early 2008 that the dropouts started on my VOIP app. I spent a lot of time chasing my Windows problem down before I tried my dial-up Internet provider. It was frustrating. I could start a couple of downloads going at the same time and there was no effect on the VOIP garble. Now it makes sense to me. Note: Comcast is not the only Internet provider that may tamper with your packets; read the fine print in your terms and conditions. Mark wrote: Mike, I'm curious regarding latency issues, especially if using VoIP for connections like IRLP or remote voice links. Did you experience them when on satellite, or was it a non-issue in your experience? And I assume your connections losses while on the bird were due to rain fade or similar??? Mark - N9WYS
Re: [Repeater-Builder] Today's funny two-way radio story (March 09). The Siren - PA Speaker War
A siren test every morning? What a great idea. I think I'll test my car horn and shotgun every morning when I get up. Nate Duehr wrote: On Mar 7, 2009, at 12:23 PM, Daniel Fargo wrote: Yes that is a good one I liked it also. You just never know what neighbors will do. You mean that idiot that used to test his siren next door, every morning? :-) Just kidding... Nate WY0X
Re: [Repeater-Builder] Today's funny two-way radio story (March 09). The Siren - PA Speaker War
Didn't Motorola have a rubber plug for that? I recall it was quite a bit larger than the NMO hole plug. Butch Kanvick wrote: We had one law enforcement officer that checked his shotgun while it was mounted in the shotgun lock, which was attached to the dash. I think his ears are still ringing from the explosion of the shotgun going off and the resulting hole in the roof. Try to explain that to the Captain when you have to see the review board. The officer then had to train the rest of the officers about the safe way to check your shotgun. Double OO buck shot I am not sure how they patched the hole in the roof. Butch, KE7FEL/r
Re: [Repeater-Builder] Somewhat OT - an interesting antenna design
Try: Conical Antenna or Bi-Conical Antenna Gmail - Kevin, Natalia, Stacey Rochelle wrote: Wow, What an interesting artical. A lot of information on the early days of TV in the US. I was however interested in the Cone Dipole antenna they had display in a couple of the photos. I did a quick search for cone dipole on google but came back with no results. Would be interested in sourcing information on this antenna and maybe it's construction.
Re: [Repeater-Builder] Six Meter Repeater Noise Issues
When I lived by the ocean in Southern California, I would watch the corona glow on the power line insulators evenings when it was damp. Mike Dietrich wrote: Hi To All Hope everybody had a good Christmas, While the subject was brought up, I have been having a similar experience here at my location. It is not on a repeater, but a simplex radio (vertex VX3000l mobile) for a base on the natl Red Cross freq of 47 mhz. In the daytime the receiver is quiet and hears fine. It seems as about the time the sun starts going down, the receiver's squelch opens and has a constant static noise for many hours but still receives fine. It may do it all night, I don't know, I haven't stayed up to see, just leave the radio on and go to bed. Was wondering if could be power line noise (but why wouldn't do in daytime also)? Is there any interference to the HF bands like this at night? Thanks, Mike KB5FLX
Re: [Repeater-Builder] Re: fan timer circuit
I put two 120 volt fans in series in one cabinet. Nice and quiet with a gentle air flow. John J. Riddell wrote: Kevin, another method of slowing down an AC fan is to put a capacitor in series with the AC leads as a voltage dropping element. * A local Ham played with this idea many years ago and as I recall he started * * with a 1 Mfd paper capacitor. * * In his case he dropped the voltage to around 90 volts to the fan. * * * * 73 John VE3AMZ * * * * * * * n...@no6b.com mailto:n...@no6b.com wrote: One reason why I've dismissed using any switching on my 110 V cooling fans let them spin 24/7. I have used 220 V muffin fans on 110 V and they last for years. I put one in service in 1997, and it's still turning. Kevin
Re: [Repeater-Builder] Re: fan timer circuit
One Summer's day in Los Angeles I had a service call on a microwave repeater (vacuum tube). It was located in a warehouse, near the roof. In the heat I lugged my stuff up the stairs. As I set down the service monitor I leaned my other arm against the cabinet. I jerked it away because it was burning my forearm. I was impressed that the equipment would operate at those temperatures; but I'm sure that the MTBF was reduced. Mike - AA8K n...@no6b.com wrote: 70 °C, the upper operating temperature limit of many RF devices, is too hot to touch. However, MTBF will definitely be reduced. In addition, without better cooling the devices board will experience greater temperature extremes, which would result in more failures caused by thermal cycling.
Re: [Repeater-Builder] MFJ Analyzers (was Need SWR meter recomendation)
Hmmm. There's always the free FoxIt reader instead of Adobe: http://www.foxitsoftware.com/pdf/reader_2/down_reader.htm It reads it fine and is lighter than Adobe. wd8chl wrote: Eric Lemmon wrote: The file in question likely requires a later version of Adobe Reader than what is being used by those having problems. Simply download the latest version of Reader, and it will work just fine. I have Adobe Acrobat 7.0, and it opened the file with no errors. 73, Eric Lemmon WB6FLY Don't bet on it. The last version of Acrobat Reader that works with Win98 is V6!!!
[Repeater-Builder] VHF and UHF repeaters on one antenna
I've been running an MSR-2000 on a Tram 1481 antenna on 146.72 with a Sinclair Q2330E duplexer and it works fine. I just got a retired Motorola UHF repeater (C64RCB-3105AT) with a Sinclair Q-306D duplexer and was wondering if I could use both repeaters on the same antenna. Would I be able to get away with a ham-type VHF/UHF duplexer like a Comet CF-4160K? Has anyone done this? How bad is the desense? Can the Comet and Tram take the power? What other problems happen? Mike
