RE: [Repeater-Builder] Polyphaser EOL ?
Usually the SWR goes up,when the Polyphaser reaches it's EOL, as well as reduced receive. 73 Dan KF8DB To: Repeater-Builder@yahoogroups.com From: wa3...@comcast.net Date: Thu, 5 Aug 2010 13:14:28 -0400 Subject: [Repeater-Builder] Polyphaser EOL ? Hi folks, We noticed reduced sensitivity at one of our remote receivers recently. Went out to check things. All looked good. SWR to the receive antenna was good. Check it with and w/o Polyphaser in line. Replaced Polyphaser and tested again… same SWR but sensitivity much improved. Is this typical for a Polyphaser that has reached EOL? 73, Dave Wa3gin
RE: [Repeater-Builder] Re: how far
1 more request for your program. Thanks, Dan KF8DB To: Repeater-Builder@yahoogroups.com From: kevinvalent...@sbcglobal.net Date: Sat, 24 Apr 2010 21:40:17 -0700 Subject: Re: [Repeater-Builder] Re: how far Sent the program to George, Bon Hal. If anyone else wants a copy you can ask myself or them. Please do not post It in a file section on any groups, (I look in those), It's copyrighted. It's nothing fancy but does a fairly good job with some nice little utilities to boot. Old as dirt but hey I did'nt pay for it either. To the ones that get it, please let me know how you like it. I have another that's great for calculating transformers and other such good junk. Enjoy --- On Sat, 4/24/10, kevin valentino kevinvalent...@sbcglobal.net wrote: From: kevin valentino kevinvalent...@sbcglobal.net Subject: Re: [Repeater-Builder] Re: how far To: Repeater-Builder@yahoogroups.com Date: Saturday, April 24, 2010, 10:31 PM Allright just found the darn program. Was on an older machine. Norton picks up a virus, ARRGH, so i will remove it and send it to ypu. You can share this amongst yourselves but I would appreciate if you DID NOT upload it to any files section of ANY group , it is copyrighted. Back to removing the NYB, wish me luck --- On Sat, 4/24/10, kevin valentino kevinvalentino@ sbcglobal. net wrote: From: kevin valentino kevinvalentino@ sbcglobal. net Subject: Re: [Repeater-Builder] Re: how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 9:00 PM OK there is a cute little program that actually comes fairly close to calculating effective radio range based on height, power, line loss(has a cable database), and frequency. Add the cavity losses in with the line loss. Calculate the portable at 6 feet, unity gain, using worst case terrain type scenario. I will send it to you. --- On Sat, 4/24/10, George gueorg...@yahoo. com wrote: From: George gueorg...@yahoo. com Subject: [Repeater-Builder] Re: how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 8:43 PM ok the antenna is from cell site 14dbm 4-element in a plastic housing, the amplifier is 600 watts capable linear mosfet 8element hybrid splitters and combiners... but the power supply is up to 65 ampers at 24 volts, driven by a C class 130 watt amplifier. the antenna is not on a commercial tower (no luck here). 20 feet above the house. the line is heliax andrew semi-rigid. the repeater is in the attic and the line is 30feet. the duplexer is celwave doesn't like more than 450 watts in. --- In Repeater-Builder@ yahoogroups. com, kevin valentino kevinvalentino@ ... wrote: Any approximation would depend on the repeater antenna height and the terrain of the area. I would hate to see the price tag on an 800MHZ 450W amplifier :-) I do mean literally approximation. Many factors come into play. Especially at high frequencies. The length and type of the antenna feedline, gain of antenna used, etc. --- On Sat, 4/24/10, George gueorg...@. .. wrote: From: George gueorg...@. .. Subject: [Repeater-Builder] how far To: Repeater-Builder@ yahoogroups. com Date: Saturday, April 24, 2010, 7:24 PM Â what is the range of a 800mhz handheld 4watts with msf5000 repeater 450watts on the antena
RE: [Repeater-Builder] Re: Can the 4th harmonic of 1250 AM keep UHF repeaters locked up?
How long is your feed line? Do you have any toriods on your feed line, where it comes in your shack? To: Repeater-Builder@yahoogroups.com From: kt...@ameritech.net Date: Tue, 23 Feb 2010 16:01:45 -0600 Subject: Re: [Repeater-Builder] Re: Can the 4th harmonic of 1250 AM keep UHF repeaters locked up? I was able to match up the audio coming through the repeater and the local AM station. My latest theory is that their signal is so strong that its blowing into the receiver's front end and multiplying/mixing there (past the bandpass filters and all). They are heterodyne receivers after all. I'm considering an ICE broadcast high-pass filter that cuts off at 1.8Mhz (model 402). I have an email into them to see how well it might work at 448 Mhz. Tony tracomm wrote: Had a similiar situation at our site, a station on 106.7 MHz, music on hang time on many repeaters, intermod runs gave no clue to reason, did all the usual, grounding, filters no resolve. Turned out to be the STL Marti system on 450.100 MHz, from an close studio site pointed right at our site, hitting our Rx multicoupler, mixing with our transmitters. Resolution was low passs isolater on the STL system. Make certain which station the broadcast audio is coming from and give the station engineer a friendly call, may reveal some info to help your issue. Chris GMRS Inc. --- In Repeater-Builder@ yahoogroups. com mailto:Repeater-Builder%40yahoogroups.com, Tony KT9AC kt...@... wrote: Hi everyone, A while ago I was troubleshooting a bad feedback or growl problem that was impacting a UHF repeater, of which the short term workaround was to not encode TX PL (PL or DPL would keep it locked until the signal dropped enough or timed out). In doing some more research, I found a 1250kHz AM station within a mile or two that changes pattern between day and night. The interference mentioned above would appear around drive times (like 5pm) so that had me chasing other sources. Still, it was puzzling that a 5Mhz signal could be causing the feedback (it didn't appear when doing normal receiver testing with a service monitor). The recent give away was that I could hear talking underneath my test signal (like a sports show). So, if we take the 1250Khz signal or 1.25Mhz x 4 = 5Mhz. I realize that the 4th harmonic of a 5KW broadcast station isn't very powerful, but being in its nearfield might be enough to cause a mix with the UHF transmit output. Does this make sense? This phenomenon can be duplicated with both a 450 and 440 repeater system - both with standard 5Mhz offsets. I don't think any sort of filtering would work since the mix happens in the air. Only by having split PL's can the lockup be prevented, and equipment was both MSF5000 and Micor systems, through correctly tuned duplexers. Thanks, Tony Yahoo! Groups Links
RE: [Repeater-Builder] Re: Antenna SWR = Desense?
Why don't you raise the antenna, and get the repeater out of the RF field? To: Repeater-Builder@yahoogroups.com From: tahr...@swtexas.net Date: Wed, 2 Sep 2009 21:32:35 + Subject: [Repeater-Builder] Re: Antenna SWR = Desense? Hi Scott, The 100' of separation is from the repeater to where the antenna is located. I have a Telewave 6 cavity BpBr duplexer on the system. Single feed to one antenna. Thanks, Tim W5FN --- In Repeater-Builder@yahoogroups.com, Scott Overstreet sc...@... wrote: Tim--- I forgot that you spoke of 100' antenna separation. This suggests no duplexer and two feedlines. The meat of my story is still good---a corroded transmit antenna is capable of making and radiating allot of receive frequency noise ---even with between antenna pattern attenuation, there might well be enough to desense your receiver. Scott - Original Message - From: Scott Overstreet To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 02, 2009 1:24 PM Subject: Re: [Repeater-Builder] Re: Antenna SWR = Desense? Tim Been there and done that! My guess is that you have corrosion in the antenna on top. The corrosion makes a good wide band rectifier of your transmit power and produces sufficient noise at your receive frequency to get back through your duplexer and into your receiver as desense. Actually, come to think about it, the end result of the situation is simular to bad LMR-400. Scott, N6NXI - Original Message - From: tahrens301 To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 02, 2009 9:56 AM Subject: [Repeater-Builder] Re: Antenna SWR = Desense? Hi All, And the winner is. Door # 2. Put the 2 meter vertical up on the stick at the end of the hard line, the desense was worse! Perfect match at the feed line end. Took dummy load put on far end of hard line no desense. Guess it is the proximity to the antenna. Although about 100', guess the RF is getting back into the box. Gonna set the antenna party for Friday morning. The stuff is going up on the tower (unless somebody can see some flaw in my logic can suggest another test)! Thanks again to all! Tim W5FN -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.75/2340 - Release Date: 09/01/09 20:03:00 -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.76/2342 - Release Date: 09/02/09 18:03:00
RE: [Repeater-Builder] Re: Quieting duplex noise from a tower
ATIS , VORs transmit from 112 Mhz to 120 Mhz AM , continuous... Aircraft band goes from 112-138 Mhz AM Some aircraft band HTs will recieve VOR transmission and give you the bearing to/from the VOR.. To: Repeater-Builder@yahoogroups.com CC: paul_n1...@myfairpoint.net From: mwbese...@cox.net Date: Wed, 18 Mar 2009 08:10:29 -0400 Subject: Re: [Repeater-Builder] Re: Quieting duplex noise from a tower 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 Paul N1BUG paul_n1...@myfairpoint.net wrote: Aircraft handhelds are AM in the 120MHz region. Some handheld scanners do aircraft AM just fine. Ah! Somehow that hadn't occurred to me. The president of our club is a pilot and has one. I guess there are no weak, constant signals in the aircraft band (?) but maybe it's not necessary. I will try climbing the tower with it and see if it does anything when I move or vibrate guy wires and other hardware with the repeater transmitter on of course. It's possible the aircraft handheld will just be desensed by 2 meter RF and unable to hear the noise (?) but it will be interesting to see what happens. Paul N1BUG
RE: [Repeater-Builder] OT: Chicken Stick
Stick with fiberglass. Why are you probing the anode of a klystron?? Dan KF8DB To: repeater-buil...@yahoogroups.comfrom: mwbese...@cox.netdate: Tue, 3 Feb 2009 18:19:12 -0500Subject: RE: [Repeater-Builder] OT: Chicken Stick I’d be wary of wood… it can attract enough moisture to become conductive. Mike WM4B From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Ken ArckSent: Tuesday, February 03, 2009 6:03 PMTo: repeater-buil...@yahoogroups.comsubject: Re: [Repeater-Builder] OT: Chicken Stick At 02:22 PM 2/3/2009, dallasreact112 wrote:Does any one know where I can obtain a fiberglass chicken stick?I had one at Collins Radio that was about a foot long, 1/4 inch indiameter and would like to obtain the same. It is sure a lot saferprobing around the anode of a Klystron with a chicken stick than ametal screwdriver.---Then again there's always wood. Never had a problem with a kiln dried dowel beforeKen--President and CTO - Arcom CommunicationsMakers of repeater controllers and accessories.http://www.arcomcontrollers.com/Authorized Dealers for Kenwood and Telewave andwe offer complete repeater packages!AH6LE/R - IRLP Node 3000http://www.irlp.netWe don't just make 'em. We use 'em!
