[Repeater-Builder] Does anyone else think of Power Factor like SWR?
Since I'm way more into RF than industrial power distribution, I've always been able to think of power factor on the electrical power grid in terms similar to antenna system reflections, which are commonly measured in terms of SWR. After all, both are AC systems where the voltage and current bear a phase relationship to each other. When they are perfectly in phase the power factor is 1.0, and a 60-Hz SWR meter would measure 1:1. When they are out of phase (power factor 1) that SWR meter would read greater than 1:1. I suspect, though I haven't done the math or looked up the specific matahematical definition of power factor, that it would be direcly proportional to the reciprocal of the power factor. And as we know, when that happens the power generating end has more difficulty delivering power efficiently to the load. The main difference is that at 60 Hz, the wavelengths are EXTREMELY long. I'm wondering if engineers and technicians who deal with cross- country power distribution must have to consider SWR effects on the power transmission line. In practice in homes and small factories, I would think, the SWR on the line caused by a mismatch between the characteristic impedance of the transmission line and the load is an insignificant factor, like worrying about the SWR measurement shift caused by a two-foot RG-213 jumper on 160M. At least as far as the transmission line is concerned - no significant voltage and current nodes and loops developed along the line like on an RF transmission line. A simplistic or impractical way of looking at things? I don't know. Maybe. Works for me. I know this is veering OT, but I beg your indulgence. This reminds me of something I heard a couple hams talking about on HF several years ago when we had sunspots: The effects of the electrical energy circulating in the ionosphere during solar storms and magnetic storms. I understand the frequency of the oscillations can be quite low but very, very strong. Seems to me the only Antennas long enough to be a significant portion of a wavelength and therefore long enough to pick up a significant signal would be long cross-country electrical power transmission lines. Since they are close together in terms of wavelength at low frequencies, the signal would be common-mode. I've always wanted to ask someone who might have experience in this regard what sort of effects these ionospheric phenomena have on the power distribution network. Ramble off. 73, Brad KB9BPF --- In Repeater-Builder@yahoogroups.com, Eric Lemmon [EMAIL PROTECTED] wrote: John, You are correct that when the power factor is 1.00, the current is in phase with the voltage, as it will be in a purely resistive circuit. In this unique case, watts equals volt-amperes. However, when the load is reactive, the current either leads or lags the applied voltage.
RE: [Repeater-Builder] Re: Cavity interconnection cable length
SO what I'll do is use the VNA to measure the loop's XL, calculate a starting point for coax lengths based upon it, and make a few other cables which are slightly different in length. Then I'll see what works best. The problem is that the XL of the loop in free space (unloaded) really doesn't really tell you anything. The loop is a coupling element; it's not just a series inductor. Its effect in the circuit will vary with rotation, cavity resonant frequency, load Z on the opposite port, etc. It's really not as simple as you'd hope it would be. It it were, I'd have a spreadsheet that tells me everything I need to know without having to resort to line stretchers and a rack of dangling test cables... --- Jeff WN3A
Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
Spinning disk meters are becoming a thing of the past. However, I believe that very few utilities are billing residential customers for kVAR. Many do charge residential demand and time-of-day rates. Eric, you may want to comment further. Chuck WB2EDV - Original Message - As I stated in an earlier post, the rotating-disk kWH meter on the typical residence measures only true power. It does this magic by combining the magnetic fields of two coils: a voltage coil that is connected in parallel with the load, and a current coil that is in series with the load. The angular displacement of these coil windings is precisely set so that only currents that are exactly in phase with the voltage result in a torque to turn the aluminum disk.
Re: [Repeater-Builder] APC UPS Charging Power
At 9/15/2008 16:03, you wrote: Bob, All standard residential utility meters read out in kilowatt hours. That is the basis for their tarrifs and billing. You are charged on the actual kilowatt hour use. The ups reading lower on actual battery operation MAY mean the charger is disabled and all you are seeing is magnetizing current of the step down transformer in the charger. You pay for actual usage. So yes it is costing you money to have the unit on line. The bottom line is how much is it costing you per KWH. Your utility has filed and is authorized to charge under their approved tarrifs. Unless you are subject to ratcheting demand charges it is calculated in actual blocks or steps. They begin with a modest block at the highest rate per KWH and proceed to biggest block at cheaper costs per KWH. The higher the usage the less you pay per KWH until you reach the last and cheapest block. Out here in SoCal it's the reverse: the more you use, the higher the rate. Bob NO6B
RE: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
I have a site where for many years the only load was a battery charger feeding a battery to power up the equipment. For many years the power meter DID NOT MOVE! It started moving when I substituted a GE Mastr II base station power supply with backup battery. My theory (correct me if I am wrong) is that the very short duty cycle current pulses drawn when the sine wave is at the crest of the cycle (when the diodes conduct) is why the meter was not moving. The GE Power supply is ferro resonant and draws current over the whole cycle although the power factor is pretty bad. The GE supply also uses a filter choke which reduces the current pulsing when the diodes conduct to a minimum. 73 - Jim W5ZIT --- On Tue, 9/16/08, Bob M. [EMAIL PROTECTED] wrote: From: Bob M. [EMAIL PROTECTED] Subject: RE: [Repeater-Builder] Volt-Amp(Re: APC UPS Charging Power) To: Repeater-Builder@yahoogroups.com Date: Tuesday, September 16, 2008, 10:31 PM Thank you Eric. This was the explanation I was looking for. The UPS is saving me money when drawing 181 Volt-Amps, yet the electric meter is only recording and charging me for 31 Watts. I wonder if APC did this on purpose. I don't know how much current is actually being fed to the batteries; they've been in there for a couple of months and should be fully charged by now, so it should just be trickling them (eight 12V 7A SLA cells in series/parallel for 48V). Bob M. == --- On Tue, 9/16/08, Eric Lemmon [EMAIL PROTECTED] net wrote: From: Eric Lemmon [EMAIL PROTECTED] net Subject: RE: [Repeater-Builder] Volt-Amp(Re: APC UPS Charging Power) To: Repeater-Builder@ yahoogroups. com Date: Tuesday, September 16, 2008, 9:21 PM Albert, You are forgiven, because you pose an important question! The spinning aluminum disk in the kilowatthour meter found on most residential service-entrance panels measures true power in kilowatts versus time, which equals energy. Thus, your electric utility charges you for the true power you use, not for volts times amperes- known as reactive power. Although the utility must provide the capability to supply all of the amperes you need, some of those amperes are given back to the utility due to a lower than unity power factor. That is why many utility companies charge a kVAR Penalty to certain industrial power users whose volt-ampere demands far exceed their watt demands, meaning that the power factor is low. Industrial power users strive to keep their power factors at 0.95 or above, to avoid some really painful penalties! The power factor, or PF, is simply watts divided by volts time amperes. The issue of power factor is why large Diesel generator sets have ratings such as 1000 kW/1250 kVAR. In simple terms, any AC generator requires torque (engine horsepower) to meet true power demands, and excitation (field flux intensity) to meet reactive power demands. When the generator load is reactive, that is, it has a power factor less than unity, the generator must not only have the horsepower to supply the energy in watts, but it must have excess capacity to handle the additional current required by motors and other low-power-factor loads. In a nutshell, that is why a 1000 watt generator may be unable to keep running a refrigerator that uses only 900 watts; the fridge may require 1200 VA to operate because it has a low power factor, and the small generator has no ability to handle such loads. Because of its relatively small amount of spinning mass, such a small generator probably could not even handle the refrigerator' s starting current- which is about 5 to 6 times its running current. 73, Eric Lemmon WB6FLY ___
Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
More likely the meter simply failed to register well on light loads. It doesn't happen with the newer meters. Chuck WB2EDV - Original Message - From: Jim Brown To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 17, 2008 10:06 AM Subject: RE: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power) I have a site where for many years the only load was a battery charger feeding a battery to power up the equipment. For many years the power meter DID NOT MOVE! It started moving when I substituted a GE Mastr II base station power supply with backup battery. My theory (correct me if I am wrong) is that the very short duty cycle current pulses drawn when the sine wave is at the crest of the cycle (when the diodes conduct) is why the meter was not moving. The GE Power supply is ferro resonant and draws current over the whole cycle although the power factor is pretty bad. The GE supply also uses a filter choke which reduces the current pulsing when the diodes conduct to a minimum. 73 - Jim W5ZIT
Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
Thank you Eric Lemmon ! Your explanation is the most precise I've read thus far. The last line of your last paragraph said what folks want to hear. I started to respond to this thread earlier, but after a few minutes of organizing my thoughts, my aging pea-brain said, Forget this and go get another gin tonic ! What's another few brain cells anyway ? de WD7F John in Tucson - Original Message - From: Eric Lemmon [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 16, 2008 9:59 PM Subject: RE: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power) John, You are correct that when the power factor is 1.00, the current is in phase with the voltage, as it will be in a purely resistive circuit. In this unique case, watts equals volt-amperes. However, when the load is reactive, the current either leads or lags the applied voltage. A typical case is a lightly-loaded induction motor, which may exhibit a power factor around 0.65, which is considered to be a poor PF. Some of the current drawn by this motor is used to create torque and perform actual work, and this current is nearly in phase with the applied voltage. Some current causes heating of the copper windings and the field core, and this current is also nearly in phase with the applied voltage. Both of these currents consume true power and are measured in watts. However, a significant amount of current does nothing but magnetize the field windings during part of the AC cycle, and that reactive energy is returned to the source as the magnetic field collapses just before the field is built up with the opposite polarity during the other half of the AC cycle. There are additional reactive losses, such as eddy-current and hysteresis losses, but the magnetizing currents are lagging the applied voltage, so they are the cause of apparent power which is expressed in volt-amperes reactive, also known as VARs. As was discussed at great length in this forum several months ago, one cannot measure true power with separate voltage and current meters. That is because the readings of separate meters are not synchronized in time. Even if one uses two true RMS DVMs to measure voltage and current, one still winds up with nothing more than apparent power based upon volts times amperes, or volt-amperes. To measure true power, one must use an AC power meter that synchronously measures current and voltage throughout the entire cycle. This can be performed by a device called a four-quadrant multiplier which, as its name implies, performs the multiplication of current and voltage through 360 degrees of phase rotation. One such instrument is a VIZ Instruments WD-767 Digital Wattmeter, which sold for about $925. Another device which has become very popular with Hams is the Kill-A-Watt meter that costs about $20 from several Internet vendors. Although not as accurate as the WD-767, it does perform quite well. As I stated in an earlier post, the rotating-disk kWH meter on the typical residence measures only true power. It does this magic by combining the magnetic fields of two coils: a voltage coil that is connected in parallel with the load, and a current coil that is in series with the load. The angular displacement of these coil windings is precisely set so that only currents that are exactly in phase with the voltage result in a torque to turn the aluminum disk. A small permanent magnet is placed near the disk so that the speed of the disk is proportional to the amount of true power being consumed. Since speed is movement over time, the disk is geared to a register that accumulates the number of rotations, which represents power over time, which is energy. Thus, the meter measures kilowatthours. You pay only for the true power that you actually use; you do not pay for apparent power since volt-amperes is not true power. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of John Barrett Sent: Tuesday, September 16, 2008 9:13 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power) This doesn't mesh up with what I've learned about power factor -- the impression that I got was a perfect power factor was 1 (one) (current in phase with voltage, equipment using everything the the power company charges you for to do useful work). Anything other than PF=1 meant that the equipment was using the power less efficiently, and therefore you were paying more in KWH than the work actually performed. That description excludes the possibly that the equipment could use more power than the power company records as being delivered (heck, conservation of energy says that in any case). any load reactance (inductive or capacitive) and the very low PF numbers stated sound more like what I get off my linear power supplies
[Repeater-Builder] Re: Cavity interconnection cable length
Excellent points, Jeff, and well taken. Too many subtle interactions for a concise solution. Still, some night in the near future when things are running smoothly and all we're doing is babysitting things, I'll run some tests with the VNA and see if measuring the XL of the loop and subtracting it from the cable length helps determine a closer empirical starting point. Fiddling with these old cavities and testing them on the VNA at work has been a valuable learning experience. Like many people, I had never really applied the things I've read about the Smith chart to real life. Although I'd made feeble attempts to follow the Smith chart examples in Wilfred Caron's book, and I'd filled up sheets and sheets of notebook paper with complex equations trying to comprehend the math only to find a procedural error in the algebra somewhere that threw things out of whack, it was hard for me to truly get a feel, that is, gain enough familiarity with the process to develop an instinct to it. But in working with the VNA I quickly found that the Smith function could tell an elegant story. I got immediate visual feedback to my adjustments and experiments, and it all confirmed the principals that I'd been reading about for years. Great fun! (I admit it, I'm a nerd.) I wish I had $15k to buy one of my own, but I'm afraid the house needs siding, gutters, and roof... Thanks again, Brad KB9BPF --- In Repeater-Builder@yahoogroups.com, Jeff DePolo [EMAIL PROTECTED] wrote: The problem is that the XL of the loop in free space (unloaded) really doesn't really tell you anything. The loop is a coupling element; it's not just a series inductor. Its effect in the circuit will vary with rotation, cavity resonant frequency, load Z on the opposite port, etc. It's really not as simple as you'd hope it would be. It it were, I'd have a spreadsheet that tells me everything I need to know without having to resort to line stretchers and a rack of dangling test cables... --- Jeff WN3A
[Repeater-Builder] Re: Swap my CAT300 for your Zetron 38A
Any 'non-messers' out there? Cheers Dave UZN --- In Repeater-Builder@yahoogroups.com, dave_g7uzn [EMAIL PROTECTED] wrote: There may be some that think that I have lost my mind! but I would like to swap my working CAT300 with copy of manual for a working Zetron 38A. I will pay postage to you and you pay postage to London UK. Strictly replies direct and first come first served. Any takers? Cheers Dave UZN
[Repeater-Builder] Re: Cavity interconnection cable length
One of our engineers had a factory tour of EMR. They did NOT calculate critical cable lengths, rather they had a pile of various length cables that they swapped in until it met specs. They were NOT optimized. That same engineer finally got a SWAG from them that the loops in the EMR cavities are approximately 1/10th of a wavelength for calculation purposes. That figure seems to have served us well over the last few years. I'll ask whether I can publish the spreadsheet that we use for those calculations. We use an HP 8711C network analyser to setup the cavities for our UHF radio system, and various other users [VHF, UHF, 800]. Walter, KD7BJJ --- In Repeater-Builder@yahoogroups.com, kb9bpf [EMAIL PROTECTED] wrote: Hello, Many writings about the optimum length of cavity interconnecting cables mention that the length of the coupling loops needs to be taken into account, but they don't get any more specific. Does that mean the length of the conductor in the loop (circumference if it were round) or connector-to-end length (diameter if it were round) or something else? I find it pretty easy to get the cables cut to a pretty precise electrical 1/4 wavelength but this loop length thing leaves me guessing. 73 Brad KB9BPF
Re: [Repeater-Builder] Re: Cavity interconnection cable length
Hi guys .just been following this thead .When you talk about 1/4 wavelength is there a formula available to make these coax lengths. I found a calculator and I am wondering if this is the right one http://www csgnetwork.com/freqwavelengthcalc.html Going off that 1/4 wavelength for my coax's should be 0.15 meters or 6 inches which is very short. Does this 1/4 wavelength work between the transmitter and the diplexer as well as interconnection cable length or should we have a different length for it . Thank You, Ian Wells, Kerinvale Comaudio, 361 Camboon Road.Biloela.4715 Phone 0749922574 or 0409159932 www.kerinvalecomaudio.com.au ---Original Message--- From: ka1jfy Date: 18/09/2008 6:41:57 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Cavity interconnection cable length One of our engineers had a factory tour of EMR. They did NOT calculate critical cable lengths, rather they had a pile of various length cables that they swapped in until it met specs. They were NOT optimized. That same engineer finally got a SWAG from them that the loops in the EMR cavities are approximately 1/10th of a wavelength for calculation purposes. That figure seems to have served us well over the last few years. I'll ask whether I can publish the spreadsheet that we use for those calculations. We use an HP 8711C network analyser to setup the cavities for our UHF radio system, and various other users [VHF, UHF, 800]. Walter, KD7BJJ --- In Repeater-Builder@yahoogroups.com, kb9bpf [EMAIL PROTECTED] wrote: Hello, Many writings about the optimum length of cavity interconnecting cables mention that the length of the coupling loops needs to be taken into account, but they don't get any more specific. Does that mean the length of the conductor in the loop (circumference if it were round) or connector-to-end length (diameter if it were round) or something else? I find it pretty easy to get the cables cut to a pretty precise electrical 1/4 wavelength but this loop length thing leaves me guessing. 73 Brad KB9BPF
[Repeater-Builder] Double-checking Andrews connectors with CableWave Heliax
Howdy! We're getting ready to move a repeater to a taller, more robust home. We have access to a run of CableWave 1 5/8 Heliax. Here's our question: Will an Andrew H7PNF work with CableWave HCC158-50J170 Heliax? If not, what Andrew connector will work with CableWave HCC158-50J170 Heliax? Thanks! From the work QTH, Ray, KBØSTN
[Repeater-Builder] FS: MSF5000 VHF Repeater
Model C73CXB7106B with extra C23CXB7106BSP01 receiver. Please contact off list for more details. Randy WB0VHB
RE: [Repeater-Builder] Does anyone else think of Power Factor like SWR?
Yes, SWR is a problem for long power distribution lines, but only the very long ones. There was a case I think in Canada where they ran into this problem. The transmission lines from one side of the continent to the other was an odd multiple of a quarterwave (1,250 km). Since a quarterwave acts as an impedance transformer, when they put a low impedance load at the far end, the cable transformed this to a high impedance at the generator end and they couldn't get power into it. The solution? Either fit impedance correction devices along the cable, or transmit DC power and convert it back to AC at the load end (they do that with a power cable running between the mainland of Australia and the island of Tasmania). Cheers, Mark VK3BYY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of kb9bpf Sent: Wednesday, 17 September 2008 4:26 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Does anyone else think of Power Factor like SWR? The main difference is that at 60 Hz, the wavelengths are EXTREMELY long. I'm wondering if engineers and technicians who deal with cross- country power distribution must have to consider SWR effects on the power transmission line. In practice in homes and small factories, I would think, the SWR on the line caused by a mismatch between the characteristic impedance of the transmission line and the load is an insignificant factor, like worrying about the SWR measurement shift caused by a two-foot RG-213 jumper on 160M. At least as far as the transmission line is concerned - no significant voltage and current nodes and loops developed along the line like on an RF transmission line. A simplistic or impractical way of looking at things? I don't know. Maybe. Works for me. ... Ramble off. 73, Brad KB9BPF ---
[Repeater-Builder] Micor TPN1110A power supply parts ID
Good Evening, I am trying to repair two TPN1110 power supplies. One has bad caps; the other has bad rectifier diodes CR1 and CR2. I tried looking up the part #s in the manual via Motorola Online, but the numbers are invalid (no suprise!). Anyone have any recommendations as to a suitable replacement capacitor, and a 1N equivalent diode part #? Can they be purchased with the stamped mounting piece, or will I need to re-press a 1nxxx diode into the existing rectangle aluminum piece? Thanks Eric KE2D
[Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
Hi Mark, I'll weave some comments--- I've always understood poor power factor to be a problem because the generator and distribution system needs to carry higher currents to deliver the same energy into a poor load. That's a problem because the power companies either suffer higher resistive (and financial) losses in their systems, or they need to use heavier distribution wiring and thicker wires in their transformers and generators (increasing the infrastructure costs). Actually BOTH, not *either/or*. To offset these costs they financially discourage anyone from using poor power factor loads. Well, to put it a better way, they encourage higher PF by customer-installed PF correction capacitors or other means. It's the same in a generator set. The difference between the 1,000 Watt/ 1250 KVA rating is that with a bad load up to 250 Watts are wasted in resistive losses in the generator windings, requiring a bit more torque from the engine to provide the extra 250 Watts and some extra energy to further cool the generator. Well, close. The 1,000 watts supplied to the load loads the generator to 100%. The generator winding wire size and other design parameters allow the generator to supply 1250 VA. That extra current does not load the driving engine since it is not real power, only reactive power. There is a small amount of extra resistive loss in the windings caused by the extra reactive current flowing in them, but it is nowhere near 250 watts. Laryn K8TVZ
Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
Eric, Kudos on a great explanation Doug - Original Message - From: Eric Lemmon To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 16, 2008 11:59 PM Subject: RE: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power) John, You are correct that when the power factor is 1.00, the current is in phase with the voltage, as it will be in a purely resistive circuit. In this unique case, watts equals volt-amperes. However, when the load is reactive, the current either leads or lags the applied voltage. A typical case is a lightly-loaded induction motor, which may exhibit a power factor around 0.65, which is considered to be a poor PF. Some of the current drawn by this motor is used to create torque and perform actual work, and this current is nearly in phase with the applied voltage. Some current causes heating of the copper windings and the field core, and this current is also nearly in phase with the applied voltage. Both of these currents consume true power and are measured in watts. However, a significant amount of current does nothing but magnetize the field windings during part of the AC cycle, and that reactive energy is returned to the source as the magnetic field collapses just before the field is built up with the opposite polarity during the other half of the AC cycle. There are additional reactive losses, such as eddy-current and hysteresis losses, but the magnetizing currents are lagging the applied voltage, so they are the cause of apparent power which is expressed in volt-amperes reactive, also known as VARs. As was discussed at great length in this forum several months ago, one cannot measure true power with separate voltage and current meters. That is because the readings of separate meters are not synchronized in time. Even if one uses two true RMS DVMs to measure voltage and current, one still winds up with nothing more than apparent power based upon volts times amperes, or volt-amperes. To measure true power, one must use an AC power meter that synchronously measures current and voltage throughout the entire cycle. This can be performed by a device called a four-quadrant multiplier which, as its name implies, performs the multiplication of current and voltage through 360 degrees of phase rotation. One such instrument is a VIZ Instruments WD-767 Digital Wattmeter, which sold for about $925. Another device which has become very popular with Hams is the Kill-A-Watt meter that costs about $20 from several Internet vendors. Although not as accurate as the WD-767, it does perform quite well. As I stated in an earlier post, the rotating-disk kWH meter on the typical residence measures only true power. It does this magic by combining the magnetic fields of two coils: a voltage coil that is connected in parallel with the load, and a current coil that is in series with the load. The angular displacement of these coil windings is precisely set so that only currents that are exactly in phase with the voltage result in a torque to turn the aluminum disk. A small permanent magnet is placed near the disk so that the speed of the disk is proportional to the amount of true power being consumed. Since speed is movement over time, the disk is geared to a register that accumulates the number of rotations, which represents power over time, which is energy. Thus, the meter measures kilowatthours. You pay only for the true power that you actually use; you do not pay for apparent power since volt-amperes is not true power. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of John Barrett Sent: Tuesday, September 16, 2008 9:13 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power) This doesn't mesh up with what I've learned about power factor -- the impression that I got was a perfect power factor was 1 (one) (current in phase with voltage, equipment using everything the the power company charges you for to do useful work). Anything other than PF=1 meant that the equipment was using the power less efficiently, and therefore you were paying more in KWH than the work actually performed. That description excludes the possibly that the equipment could use more power than the power company records as being delivered (heck, conservation of energy says that in any case). any load reactance (inductive or capacitive) and the very low PF numbers stated sound more like what I get off my linear power supplies with big capacitance and no power factor correction. In any case, anything other than PF=1 should mean that you are paying for more power than you are actually using. Tell me where I goofed this up ?? Bob M. wrote: Thank you Eric. This was the explanation I was looking
[Repeater-Builder] Re: Does anyone else think of Power Factor like SWR?
To answer the question, I don't. Look at it this way. The AC supply to your house, for example, is a low impedance; it can supply hundreds of amps (the transmitter). The 100 watt lamp (antenna/load) in your house is a relatively high impedance compared to the supply. There is no impedance match between supply and load, not even close. SWR is very high. Do we care? No, we're not trying to transfer the maximum amount of power here as we do in an antenna system, only the amount of power required by the lamp. Hope that helps. Laryn K8TVZ
Re: [Repeater-Builder] Double-checking Andrews connectors with CableWave Heliax
Ray, Those Andrew connectors will not fit. The configuration of the inner conductor is different. I do not know if Andrew makes a compatible connector. I have a few Cable Wave N Male and female connectors. Contact me off the list. for what it's worth Andrew connectors will fit cable wave in the 1/2 and 7/8 sizes. Gerald Pelnar WD0FYF [EMAIL PROTECTED] McPherson, Ks Original Message - From: Ray Brown To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 17, 2008 5:10 PM Subject: [Repeater-Builder] Double-checking Andrews connectors with CableWave Heliax Howdy! We're getting ready to move a repeater to a taller, more robust home. We have access to a run of CableWave 1 5/8 Heliax. Here's our question: Will an Andrew H7PNF work with CableWave HCC158-50J170 Heliax? If not, what Andrew connector will work with CableWave HCC158-50J170 Heliax? Thanks! From the work QTH, Ray, KBØSTN
[Repeater-Builder] Kendecom Mark 4 crystals
Group, I have a set of crystals for a Kendecom (MCS) Mark 4 repeater which I no longer need. T145.210 - R144.610 Let me know if you are intersted maybe for trade or sale or... Collin
