Re: [Repeater-Builder] need some upgrade help
Hey Mike, thanks man. i didnt find anything but out dated info when i searched out the internet on this and right now i dont have any equipment up here so i cant even get up on a local 2 meter repeater or anything. i just got done leaving william a voice mail and perhaps i'll send him an email too. we'll see what happens. thanks again all Dave --- On Mon, 9/22/08, Mike Morris WA6ILQ [EMAIL PROTECTED] wrote: From: Mike Morris WA6ILQ [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] need some upgrade help To: Repeater-Builder@yahoogroups.com Date: Monday, September 22, 2008, 8:37 AM At 08:47 PM 09/21/08, you wrote: hey all, i would like to first say that this has nothing to do with building a repeater (sorry Kevin and the Mods here) but its a good large group that might be able to help me. i moved from southern california to southern oregon almost 2 years ago. well i am comming up on having to renew my license and i want to upgrade to a general. the thing is i cant seem to find anything online about VE sessions going on here in Grants Pass Oregon. anyone out there know anything? once again Kevin and the mods here, sorry but yall got a good large group here. i thought i would give it a try 73s Dave KF6WJA From the web page at http://www.arrl. org/arrlvec/ examsearch. phtml that lists almost 3 dozen upcoming license exams in Oregon... 21-Nov-2008 Sponsor: SOARC Time: 6:30 PM (Walk-ins allowed) Contact: WILLIAM A TYNER (541)476-2703 Email: GOODGRENDL @ AOL.COM VEC: ARRL/VEC Location: FRUITDALE GRANGE 1440 PARKDALE DR US 99 GRANTS PASS, OR 97526 And there may be more that are close to you but I don't know the geography well enough to know if, for example, Corvallis, Lincoln City, Lebanon or White City is within reasonable driving distance of Grants Pass. Good luck on your upgrade. Mike WA6ILQ (who lived in the Portland area for 4 months once doing a contract job at Intel...)
Re: [Repeater-Builder] need some upgrade help
at the moment, funds are tight. hell, i dont even have a rig right now. so i really cant afford to spend the money on gas to go to california. thanks for the idea though. dave --- On Mon, 9/22/08, Fred Townsend [EMAIL PROTECTED] wrote: From: Fred Townsend [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] need some upgrade help To: Repeater-Builder@yahoogroups.com Cc: Repeater-Builder@yahoogroups.com Date: Monday, September 22, 2008, 12:30 PM Have you thought about going to Pacificon? Fred Townsend --- [EMAIL PROTECTED] net wrote: From: Mike Morris WA6ILQ [EMAIL PROTECTED] net To: Repeater-Builder@ yahoogroups. com Subject: Re: [Repeater-Builder] need some upgrade help Date: Mon, 22 Sep 2008 08:37:33 -0700 At 08:47 PM 09/21/08, you wrote: hey all, i would like to first say that this has nothing to do with building a repeater (sorry Kevin and the Mods here) but its a good large group that might be able to help me. i moved from southern california to southern oregon almost 2 years ago. well i am comming up on having to renew my license and i want to upgrade to a general. the thing is i cant seem to find anything online about VE sessions going on here in Grants Pass Oregon. anyone out there know anything? once again Kevin and the mods here, sorry but yall got a good large group here. i thought i would give it a try 73s Dave KF6WJA From the web page at http://www.arrl. org/arrlvec/ examsearch. phtml that lists almost 3 dozen upcoming license exams in Oregon... 21-Nov-2008 Sponsor: SOARC Time: 6:30 PM (Walk-ins allowed) Contact: WILLIAM A TYNER (541)476-2703 Email: GOODGRENDL @ AOL.COM VEC: ARRL/VEC Location: FRUITDALE GRANGE 1440 PARKDALE DR US 99 GRANTS PASS, OR 97526 And there may be more that are close to you but I don't know the geography well enough to know if, for example, Corvallis, Lincoln City, Lebanon or White City is within reasonable driving distance of Grants Pass. Good luck on your upgrade. Mike WA6ILQ (who lived in the Portland area for 4 months once doing a contract job at Intel...)
[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
[Repeater-Builder] Modification on old Q202
Hi group, I have an old duplexer Q202 without harness and I want to transform the pass cavite into Q Filter, with a piston capacitor in serial with the loop. Maybe someone in the group know the range in pF of this capacitor for VHF ham band? My freq. are TX 147.165 and RX 147.165 Thank you for your help. Eric
[Repeater-Builder] coax length
Dear RP, I am doing some testing and have the 145.410 repeater connected to a dummy load. To get an accurate output indication in watts is it critical to have 1/2 wavelength cables? I have used an 18 cable from TX to wattmeter and then a 72 cable from wattmeter to load resistor. I have noticed a big difference in wattmeter indication between using the 72 cable and connecting the load right to the wattmeter. Also the same indication with a cable 144 long. I am making some cables 1/2 wavelength long for tuning use. Am I doing right? Thanks, Collin
[Repeater-Builder] Re: VHF and UHF repeaters on one antenna
I am running a Diamond X-200 with a MFJ-916 diplexer on 146.850 and 443.050 with excellent results. The VHF makes about 50 watts the UHF 30. I tested the diplexer with a 5 watt bird slug while transmitting 100 watts into the opposite port, before attempting the configuration. Both repeaters also have good duplexers, tuning checked at the site. --- In Repeater-Builder@yahoogroups.com, Mike Naruta AA8K [EMAIL PROTECTED] wrote: 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
Re: [Repeater-Builder] VHF and UHF repeaters on one antenna
At 9/22/2008 19:10, you wrote: 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? Yes. Just make sure it's the model without pigtails, be careful if either of the repeaters runs more than 50 watts. The combined TX power rating will probably be lower due to capacitor voltage ratings being the limiting factor as opposed to heating. Bob NO6B
Re: [Repeater-Builder] Quick Question -- Sense of COS
At 9/23/2008 06:33, you wrote: After reading and re-reading the manuals, I am still not 100 percent certain what COS high and COS low mean. Please straighten me out. When the signal is strong, greater than -100 dBm, the COS logical output is zero volts. When the signal is less strong, less than -110 dBm, the COS logical output is +10 volts. Is this COS active LOW? Yes. Using the terminology of the ACC RC-96 owners manual, is this RCVR COS LOW TRUE? Yes. Bob NO6B
Re: [Repeater-Builder] VHF and UHF repeaters on one antenna
talk to the people at TX RX - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 23, 2008 10:50 AM Subject: Re: [Repeater-Builder] VHF and UHF repeaters on one antenna At 9/22/2008 19:10, you wrote: 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? Yes. Just make sure it's the model without pigtails, be careful if either of the repeaters runs more than 50 watts. The combined TX power rating will probably be lower due to capacitor voltage ratings being the limiting factor as opposed to heating. Bob NO6B
Re: [Repeater-Builder] coax length
If you can find a manual for a bird wattmeter, they had a chart in the back of how long to make cables to go with the meter for different freqs. With this setup, you could insert it in a system and after tuning remove the meter setup and still have it balanced. Mike - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 23, 2008 4:45 AM Subject: [Repeater-Builder] coax length Dear RP, I am doing some testing and have the 145.410 repeater connected to a dummy load. To get an accurate output indication in watts is it critical to have 1/2 wavelength cables? I have used an 18 cable from TX to wattmeter and then a 72 cable from wattmeter to load resistor. I have noticed a big difference in wattmeter indication between using the 72 cable and connecting the load right to the wattmeter. Also the same indication with a cable 144 long. I am making some cables 1/2 wavelength long for tuning use. Am I doing right? Thanks, Collin
RE: [Repeater-Builder] Update on the MICOR Community Repeater project
Well, Gerald sent me the schematic for the Master Decoder modules I have. I compared connections on the card I have (thanks to his schematic) against what the newer card provides. Here are the comparisons: Pin 1 - Ground = OK Pin 2 - PL Tone to Modulator = OK Pin 3 - To Audio Amplifier on Audio Board - Not called out on newer card - No Connection on newer card Pin 4 - PL Disable (Receiver #1, to Audio Board) = Binary PL Out on newer card Pin 5 - From PL Disable Switch = Not called out on newer card - No Connection on newer card Pin 6 - From Volume Control = Not called out on newer card - No Connection on newer card Pin 7 - PL Tone Out (to 4-User Module) = OK Pin 10 - Quieting Indicator = Binary PL Gate Key on newer card (This signal is on Pin 19 on newer card) Pin 11 - Detector Emitter Bias = OK Pin 12 - A+ = OK Pin 16 - PL Indicator = OK Pin 17 - Switched Ground from 4-User Control = Not called out on newer card - Tone PL Detect on newer card Pin 18 - Detector Base Bias = OK Pin 22 - PL Tone Input from Discriminator = Binary PL Retransmit Input on newer card (This signal is on Pin 23 on newer card) Pin 23 - Receiver Audio Switch on Audio Board = Not called out on newer card - Tone PL Retransmit Input on newer card Pin 24 - Exciter Ground = Not called out on newer card - No Connection on newer card As you can see, there are a LOT of signals that would need to be re-routed for this card to work properly... and others that appear not to be needed at all. I wonder if it is worth the effort. If I can't find the proper card, I think I'll have to resort to an external repeater controller/tone board, like either a Zetron or a Com-Spec get the station to operate properly. That is if I can find the interconnect wiring diagram. So, I ask again - if ANYONE has a TRN6165A Master Decoder card they are not using and would like to put to good use, PLEASE CONTACT ME. Mark - N9WYS
Re: [Repeater-Builder] Quick Question -- Sense of COS
John Transue wrote: After reading and re-reading the manuals, I am still not 100 percent certain what COS high and COS low mean. Please straighten me out. When the signal is strong, greater than -100 dBm, the COS logical output is zero volts. When the signal is less strong, less than -110 dBm, the COS logical output is +10 volts. Is this COS active LOW? Using the terminology of the ACC RC-96 owners' manual, is this RCVR COS LOW TRUE? Thanks for the help? John Transue .ok, the correct term is 'active high' or 'active low'. when a valid signal is present, in your case, you have a low voltage. this means your receiver has an active low COS. this terminology is used in all logic circuitry. active high means there is a voltage above the logic switching threshold, usually around 2 1/2 volts or so, when the desired signal is 'active'. forget about dBm. it's a matter of whether the squelch is open or not.
[Repeater-Builder] Re: Quick Question -- Sense of COS
Hi John, The active high/low label applies when the circuit or device is actually on. On meaning the state of the logic... not just power supplied to the circuit. The output of a typical logic circuit, gate or device is at or very near ground or zero volts when it's on... active low. When the output voltage from an on logic circuit, gate or device is at or near the (positive) + supply voltage it's active high. True is just another old time way to say active or on. The active high voltage can be different values depending on the circuit. In days of old TTL IC Chip circuits... the chips run off +5vdc so the high state measured voltage was often ranged anywhere from about +2.2 volts up toward the +5 volt supply. A newer generation CMOS IC Chip circuit might often run on a higher supply voltage... say +12vdc so the high state measured voltage range might be anything above +6vdc up to the +12vdc value. In the case of a simple transistor circuit... the classic pull-up resistor tied from the collector to a positive + voltage determines the active high voltage. Not super critical in common bi-polar transistor type logic circuits because you need only a small voltage to turn-on the transistor... so in reality almost any + voltage above about .7 volts starts to turn the transistor on. As described... Your receiver cos logic is on with a strong received signal, the output is at or near zero volts which is active low. The ACC controller is setup for active low operation... be aware that some ACC Controllers don't have an internal pull-up resistor so you might need to add one. Else with a voltmeter you might not see the logic at x-location change state with an active receiver. cheers, s. John Transue [EMAIL PROTECTED] wrote: After reading and re-reading the manuals, I am still not 100 percent certain what COS high and COS low mean. Please straighten me out. When the signal is strong, greater than -100 dBm, the COS logical output is zero volts. When the signal is less strong, less than -110 dBm, the COS logical output is +10 volts. Is this COS active LOW? Using the terminology of the ACC RC-96 owners' manual, is this RCVR COS LOW TRUE? Thanks for the help? John Transue
[Repeater-Builder] Heliax/Duplexer needed
I am getting a GE Master Exec II converted to repeater, ready to put on the air on 444.250/449.250. I still need a duplexer and feedline. If anyone has a good duplexer that they would like to sell or a source for 75 feet or so of Heliax that will not break me I would appreciate the info. I am doing the system by my self and money is pretty tight as it is with everyone right now. Please email direct to KK4WH AT YAHOO DOT COM. Thanks for the information and also for the group, this group is a wealth of information! Tim, KK4WH
Re: [Repeater-Builder] VHF and UHF repeaters on one antenna
I build my own diplexers. This way I can insure that the components are suitable for the power level used. The 440 side is built in typical antenna tuner fashion with a series variable cap, a shunt inductor and a series variable cap. Adjust the caps to provide a 1:1 SWR at the operating frequency. The 2 meter side is built using a series inductor, a shunt variable capacitor, and a series inductor. Adjust the capacitor for a 1:1 SWR at the operating frequency. If a 1:1 cannot be obtained, spread or compress one or both of the coils to get 1:1. The theory behind this set-up is that the small capacitor value required to tune the input on the 440 side has negligible effect on the 2 meter frequency, and the input inductor for the 2 meter side looks like an RF choke to the 440 side. Make sure the inductors do not couple to each other and a very successful coupler with added SWR correction, if needed, is possible. A hairpin loop is all that is required on 440 with a couple of 10 pF variable caps and a 20 pF variable cap for the 2 meter tuning with a couple of air wound inductors of 2 or 3 turns will work. I have built these couplers for powers up to 100 watts and the power on one band does NOT add to the power on the other band. Just choose the components and wire sizes for the power level required. 73 - Jim W5ZIT --- On Tue, 9/23/08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] VHF and UHF repeaters on one antenna To: Repeater-Builder@yahoogroups.com Date: Tuesday, September 23, 2008, 9:50 AM At 9/22/2008 19:10, you wrote: 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? Yes. Just make sure it's the model without pigtails, be careful if either of the repeaters runs more than 50 watts. The combined TX power rating will probably be lower due to capacitor voltage ratings being the limiting factor as opposed to heating. Bob NO6B _,___
RE: [Repeater-Builder] Re: Quick Question -- Sense of COS
Skipp, Bob, and WD8CHL, and others whose replies might be in the pipeline, Thank you for very clear explanations. I think I understand it now. John AF4PD -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of skipp025 Sent: Tuesday, September 23, 2008 11:52 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Quick Question -- Sense of COS Hi John, The active high/low label applies when the circuit or device is actually on. On meaning the state of the logic... not just power supplied to the circuit. The output of a typical logic circuit, gate or device is at or very near ground or zero volts when it's on... active low. When the output voltage from an on logic circuit, gate or device is at or near the (positive) + supply voltage it's active high. True is just another old time way to say active or on. The active high voltage can be different values depending on the circuit. In days of old TTL IC Chip circuits... the chips run off +5vdc so the high state measured voltage was often ranged anywhere from about +2.2 volts up toward the +5 volt supply. A newer generation CMOS IC Chip circuit might often run on a higher supply voltage... say +12vdc so the high state measured voltage range might be anything above +6vdc up to the +12vdc value. In the case of a simple transistor circuit... the classic pull-up resistor tied from the collector to a positive + voltage determines the active high voltage. Not super critical in common bi-polar transistor type logic circuits because you need only a small voltage to turn-on the transistor... so in reality almost any + voltage above about .7 volts starts to turn the transistor on. As described... Your receiver cos logic is on with a strong received signal, the output is at or near zero volts which is active low. The ACC controller is setup for active low operation... be aware that some ACC Controllers don't have an internal pull-up resistor so you might need to add one. Else with a voltmeter you might not see the logic at x-location change state with an active receiver. cheers, s. John Transue [EMAIL PROTECTED] wrote: After reading and re-reading the manuals, I am still not 100 percent certain what COS high and COS low mean. Please straighten me out. When the signal is strong, greater than -100 dBm, the COS logical output is zero volts. When the signal is less strong, less than -110 dBm, the COS logical output is +10 volts. Is this COS active LOW? Using the terminology of the ACC RC-96 owners' manual, is this RCVR COS LOW TRUE? Thanks for the help? John Transue __ NOD32 3192 (20080616) Information __ This message was checked by NOD32 antivirus system. http://www.eset.com
Re: [Repeater-Builder] VHF and UHF repeaters on one antenna
Our club ran a Larson diplexer on our 30 watt repeaters for years with no problems. I'd pick one that doesn't have coax tails that may be of questionable quality. Have separate antennas and feedlines now. Gerald Pelnar WD0FYF McPherson, Ks - Original Message - From: Mike Naruta AA8K [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, September 22, 2008 9:10 PM Subject: [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 Yahoo! Groups Links
[Repeater-Builder] WTB: VHF duplexers 4 cavity Micor / MSR2000 need 10
no joke; got an inquiry for 10-12 vhf duplexers 150-174 4 cavity pass/reject similar to those in VHF micor repeaters and MSR2000 repeaters. state qty and price in 1st email or call me at below phone days 0900-1800 cdst. will also consider Phelps-Dodge 6 cav reject types in 19 inch rack mount. possibly other as long as they are rack mountable and can handle power. thanks. we know a long shot when we see one but sometimes ya gotta take a shot. Ted Bleiman K9MDM MDM Radio If its in stock...we've got it! P O Box 31353 Chicago, IL 60631-0353 773.631.5130 fax 773.775.8096 web http://www.mdmradio.com email - [EMAIL PROTECTED] DIRECT ALL EMAIL
Re: [building-repeaters] Re: [Repeater-Builder] Re: Micor to 222 MHz PA Conversion
[EMAIL PROTECTED] wrote: Kevin, I've been meaning to postabout a similar project, and this prompts me to ask - have you done this to rebuild a UHF amp? I have not, but there is no reason one could not. There is 2 watts (approximately) from the MICOR LLA, plenty to split and drive several modules in parallel. I was curious as to how they would hold up under continuously linked repeater duty We run them in repeater service with little trouble on the module itself. Can you provide some more details on the 'Wilkinson power dividers? I have experience with HF torroid combiners/splitters, but UHF is another animal altogether. Google is your friend Basically they are 1/4 wavelength in 75 ohm coax (VF corrected). Do you sell them with the boards? Sorry, no we don't. Is it as simple as mounting the two modules (and the supporting RB circuit boards), the combiner/splitters, and wiring it all up? Yes... Kevin
Re: [Repeater-Builder] coax length
I am not sure what would make a good or not good load resistor. I am using a pair of non inductive 100 ohm 100 watt resistors in parallel, air cooled. I also use a cantenna. Are these not good or fair? Thanks, Collin -Original Message- From: wd8chl [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wed, 24 Sep 2008 8:26 am Subject: Re: [Repeater-Builder] coax length [EMAIL PROTECTED] wrote: Dear RP, I am doing some testing and have the 145.410 repeater connected to a dummy load. To get an accurate output indication in watts is it critical to have 1/2 wavelength cables? I have used an 18 cable from TX to wattmeter and then a 72 cable from wattmeter to load resistor. I have noticed a big difference in wattmeter indication between using the 72 cable and connecting the load right to the wattmeter. Also the same indication with a cable 144 long. I am making some cables 1/2 wavelength long for tuning use. Am I doing right? Thanks, Collin If you have a good dummy load, it WILL NOT matter what length coax you use. In fact, I try to make sure my cables are NOT resonant. If there's a significant difference when you go from a resonant cable to a non-resonant one, or from a 1/4-wave to a 1/2-wave, there is a problem with the load.
Re: [Repeater-Builder] coax length
Colin, Non inductive resistors are quite inductive above 30 Mhz. The Cantenna is also a poor load at VHF / UHF. John VE3AMZ - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 23, 2008 8:25 PM Subject: Re: [Repeater-Builder] coax length I am not sure what would make a good or not good load resistor. I am using a pair of non inductive 100 ohm 100 watt resistors in parallel, air cooled. I also use a cantenna. Are these not good or fair? Thanks, Collin -Original Message- From: wd8chl [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wed, 24 Sep 2008 8:26 am Subject: Re: [Repeater-Builder] coax length [EMAIL PROTECTED] wrote: Dear RP, I am doing some testing and have the 145.410 repeater connected to a dummy load. To get an accurate output indication in watts is it critical to have 1/2 wavelength cables? I have used an 18 cable from TX to wattmeter and then a 72 cable from wattmeter to load resistor. I have noticed a big difference in wattmeter indication between using the 72 cable and connecting the load right to the wattmeter. Also the same indication with a cable 144 long. I am making some cables 1/2 wavelength long for tuning use. Am I doing right? Thanks, Collin If you have a good dummy load, it WILL NOT matter what length coax you use. In fact, I try to make sure my cables are NOT resonant. If there's a significant difference when you go from a resonant cable to a non-resonant one, or from a 1/4-wave to a 1/2-wave, there is a problem with the load. Yahoo! Groups Links
Re: [Repeater-Builder] coax length
John, Very well then, I guess I need to be shopping for a good load. Any suggestions? Any under an arm and a leg? What do the good loads use for a resistor? I was under the impression that a non inductive resistor was the purest resistance you could get. I have been wrong many times in the past. Thanks, Collin -Original Message- From: John J. Riddell [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tue, 23 Sep 2008 9:08 pm Subject: Re: [Repeater-Builder] coax length Colin, Non inductive resistors are quite inductive above 30 Mhz. The Cantenna is also a poor load at VHF / UHF. John VE3AMZ - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 23, 2008 8:25 PM Subject: Re: [Repeater-Builder] coax length I am not sure what would make a good or not good load resistor. I am using a pair of non inductive 100 ohm 100 watt resistors in parallel, air cooled. I also use a cantenna. Are these not good or fair? Thanks, Collin -Original Message- From: wd8chl [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wed, 24 Sep 2008 8:26 am Subject: Re: [Repeater-Builder] coax length [EMAIL PROTECTED] wrote: Dear RP, I am doing some testing and have the 145.410 repeater connected to a dummy load. To get an accurate output indication in watts is it critical to have 1/2 wavelength cables? I have used an 18 cable from TX to wattmeter and then a 72 cable from wattmeter to load resistor. I have noticed a big difference in wattmeter indication between using the 72 cable and connecting the load right to the wattmeter. Also the same indication with a cable 144 long. I am making some cables 1/2 wavelength long for tuning use. Am I doing right? Thanks, Collin If you have a good dummy load, it WILL NOT matter what length coax you use. In fact, I try to make sure my cables are NOT resonant. If there's a significant difference when you go from a resonant cable to a non-resonant one, or from a 1/4-wave to a 1/2-wave, there is a problem with the load. Yahoo! Groups Links
[Repeater-Builder] Loaded Cat-1000 and 6 Micro Control Specialties Repeaters For Sale.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemrd=1item=320303629393 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemrd=1item=220285469977 Thank you
