Sure I suppose... Electronic Communications Systems Fundamentals Through Advanced - Fourth Edition. Page 319.
Also I went to microwave101.com for some more info. Curious why your so interested in the sources, I'm not lying I swear! Jesse On 9/3/07, allan crites <[EMAIL PROTECTED]> wrote: > > Jesse, > I find six titles by Tomasi with "Electronic Communications systems " in > them.Could you be a bit more specific? And could you specify the pages > where you found the information you used? And could you provide the > information from which google searches? > I'm interested in your sources. > > 73 Allan Crites WA9ZZU > > *Jesse Lloyd <[EMAIL PROTECTED]>* wrote: > > My source was "Electronic Communications Systems" by Wayne Tomasi from > DeVry. Copyright 1998. Its my old collage text. Also I grabbed additional > information from google searches. > > Jesse > > > On 9/3/07, allan crites <[EMAIL PROTECTED]> wrote: > > > > Ron , > > Aw c'mon Ron, dig out those equations from your library so we can all > > see where you're comming from. That way we can get an idea how much > > reference materials you really have and who and what they are. And just > > because your name is Wright doen't mean you're "right" all the time. Jesse > > also doesn't ever bother to quote the sources for his statements. I'm > > begining to wonder if you as well as he have any. > > > > 73 Allan Crites WA9ZZU > > > > *Ron Wright <[EMAIL PROTECTED] >* wrote: > > > > Gary, > > > > I gave the reason for the statement...measured with HP piece of test > > equipment. Was quick and to the point. > > > > I did not think I had to dig into my libary and dig out the equations. > > Same with stating an SWR...thought most would take a reading from a meter > > and not having to give the equations. > > > > I did not see you giving your basis for rejecting the statement, but > > then again I really did not expect it, hi. > > > > 73, ron, n9ee/r > > > > >From: Gary Schafer < [EMAIL PROTECTED] <gaschafer%40comcast.net>> > > >Date: 2007/09/02 Sun PM 08:29:08 CDT > > >To: Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >Subject: RE: RE: RE: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > > > > > > >But it is your statement. > > > > > >73 > > >Gary K4FMX > > > > > >> -----Original Message----- > > >> From: > > >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>[mailto:Repeater- > > >> [EMAIL PROTECTED] <Builder%40yahoogroups.com>] On Behalf Of Ron > > Wright > > >> Sent: Sunday, September 02, 2007 6:46 AM > > >> To: Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> Subject: Re: RE: RE: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > >> Duplexers > > >> > > >> Gary, > > >> > > >> I don't know. Why don't you tell us. > > >> > > >> I don't know why gravity will pull me to the ground real fast if I > > jump > > >> off a bridge, but I have all the faith in the world it will. Einstin > > >> tried to explain it, but died before he got the results. > > >> > > >> Taking the word of good test equipment is a good engineering > > approach. > > >> Doing the math, I am sure I have here somewhere, and I am sure the > > >> defferential equations would take a while probably starting with > > >> Maxwell's, but as with gravity if you know it does what it does I use > > it. > > >> > > >> These discussions can at times go no where, hi. > > >> > > >> 73, ron, n9ee/r > > >> > > >> > > >> > > >> >From: Gary Schafer < [EMAIL PROTECTED] <gaschafer%40comcast.net> > > > > > >> >Date: 2007/09/01 Sat PM 08:48:03 CDT > > >> >To: Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >Subject: RE: RE: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > >> > > >> > > > >> >Ron, > > >> > > > >> >Maybe you could tell us why coax cable has a lower frequency limit? > > You > > >> >claim that it does but have not explained why or how. > > >> > > > >> >Why does the impedance change significantly at lower frequencies? > > >> > > > >> >73 > > >> >Gary K4FMX > > >> > > > >> >> -----Original Message----- > > >> >> From: > > >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>[mailto: > > Repeater- > > >> >> [EMAIL PROTECTED] <Builder%40yahoogroups.com>] On Behalf Of > > Ron Wright > > >> >> Sent: Saturday, September 01, 2007 8:49 AM > > >> >> To: > > >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> Subject: Re: RE: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > >> Duplexers > > >> >> > > >> >> Gary, > > >> >> > > >> >> Yes the HP meter was spec'd to go below below 0.5 MHz, it went > > down to > > >> 100 > > >> >> kHz. > > >> >> > > >> >> I don't know where the confusion is...all coax and feedline has a > > upper > > >> >> and lower freq limit. Might try to learn something about this. > > >> >> > > >> >> I know about low freq RF. Worked on a Navy program that used 18 > > kHz, a > > >> >> C130 aircraft with 30,000 ft of wire hung out the back as a > > platform to > > >> >> talk to surmerged submarines. Ran over 250 kW. It was called > > TACMO. > > >> Due > > >> >> to the weight the wings kept falling off...well they were > > continously > > >> >> inspected and replaced before they fell off, but the aircraft was > > >> >> deffinitly over loaded. Had generators on all 4 engines to get the > > >> power > > >> >> they needed. Now that was a repeater. > > >> >> > > >> >> However, AC power distribution is not trying to radiate power, but > > >> >> transfer it with widly varing loads. Totally different > > engineering. > > >> >> > > >> >> At low frequencies such as 1 kHz little radiation takes place. Far > > >> less > > >> >> at 60 Hz. The EMF returns to the radiator, wire, before the next > > cycle > > >> >> can force it out. This is a problem in some applications, but > > since > > >> most > > >> >> do not want radiation it is not. > > >> >> > > >> >> 73, ron, n9ee/r > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> >From: Gary Schafer < [EMAIL PROTECTED]<gaschafer%40comcast.net> > > > > > >> >> >Date: 2007/08/31 Fri PM 05:59:28 CDT > > >> >> >To: > > >> >> >Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> >Subject: RE: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > >> >> > > >> >> > > > >> >> >Are you sure that the impedance meter you used was speced for > > >> operation > > >> >> >below .5 MHz? > > >> >> > > > >> >> >Yes all capacitors have inductance. Lead length is particularly a > > > > >> >> problem. > > >> >> > > > >> >> >15 KHz can be treated as RF or audio it all depends on what > > transducer > > >> >> you > > >> >> >are using it to couple it with. Use a speaker and it is audio. > > Use an > > >> >> >antenna it is RF. All RF propagates the same on a transmission > > line. > > >> 15 > > >> >> KHz > > >> >> >or even 1 KHz propagates as RF just like any RF signal does > > through > > >> the > > >> >> air > > >> >> >and even thru the ground as in the case of low frequencies. Read > > about > > >> >> what > > >> >> >some of the VLF guys are doing. > > >> >> > > > >> >> >On a video cable remove the termination on the far end of the > > cable > > >> and > > >> >> look > > >> >> >at the reflected energy. It has the same effect at those > > frequencies > > >> as > > >> >> it > > >> >> >does at HF or VHF. > > >> >> > > > >> >> >Yes long runs of video cable can be a problem. Long runs of cable > > in > > >> the > > >> >> >catv industry have the same problems of frequency roll off. They > > call > > >> it > > >> >> >"tilt" and their amplifiers have compensation for cable > > attenuation in > > >> >> order > > >> >> >to make the system "flat". > > >> >> > > > >> >> >I have an HP signal level meter that measures RF from 10 Hz to 30 > > MHz. > > >> I > > >> >> can > > >> >> >feed an audio oscillator set to 1 KHz or 1 MHz into the same > > input as > > >> I > > >> >> feed > > >> >> >a 1 MHz RF generator into. The signal level meter handles it the > > same. > > >> >> Only > > >> >> >difference is the output impedance of the audio oscillator is 600 > > ohms > > >> >> >rather than 50 ohms. The instrument doesn't know or care if we > > want to > > >> >> call > > >> >> >it audio or RF. As far as it is concerned it treats it as RF. > > >> >> > > > >> >> >I have an audio amplifier that has just about a flat response > > from > > >> around > > >> >> 5 > > >> >> >Hz to 1 MHz. Is that an audio amplifier or an RF amplifier? :>) > > >> >> > > > >> >> >73 > > >> >> >Gary K4FMX > > >> >> > > > >> >> >> -----Original Message----- > > >> >> >> From: > > >> >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>[mailto:Repeater- > > >> >> >> [EMAIL PROTECTED] <Builder%40yahoogroups.com>] On Behalf > > Of Ron Wright > > >> >> >> Sent: Friday, August 31, 2007 7:12 AM > > >> >> >> To: > > >> >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> >> Subject: Re: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > >> Duplexers > > >> >> >> > > >> >> >> Gary, > > >> >> >> > > >> >> >> To measure the impedance of the RG59 I used an HP impedence > > meter > > >> which > > >> >> >> displayed Z and phase. I use to use it to determine where caps > > >> became > > >> >> >> resonant as a demo for many caps look inductive above a given > > freq. > > >> >> Mica > > >> >> >> caps did pretty good, but still hard to find a cap at 1000 pf > > that > > >> was > > >> >> a > > >> >> >> cap above 25 MHz. These become issues in bypass caps and also > > for > > >> >> >> resonant circuits trying to get higher Qs where the C is large. > > >> >> >> > > >> >> >> In a good lab one often has tons of test equipment for making > > >> >> >> measurements, even spectrum anal that go down to tenths of Hz > > and to > > >> >> many > > >> >> >> GHz. I've had the previdlege of working in such places and some > > was > > >> >> for > > >> >> >> my use in my work. > > >> >> >> > > >> >> >> I know RG59 is a most commonly used cable in video. However, > > one > > >> does > > >> >> not > > >> >> >> have to go far before it really affects video especially color > > where > > >> >> the > > >> >> >> phase is so important. Also the syncs get torn up so bad > > monitors > > >> >> loose > > >> >> >> sync on the veritical retrace and a portion of the picture is > > torn > > >> at > > >> >> the > > >> >> >> top. Many manufactures make line amps that not only compenstate > > for > > >> >> loss, > > >> >> >> but varied freq response and some for sync...the better ones do > > sync > > >> >> also. > > >> >> >> The vertical sync is at about 60 Hz and horiz at 15734 Hz which > > is > > >> in > > >> >> the > > >> >> >> audio freq where the signal is not really propergating like in > > RF. > > >> >> Many > > >> >> >> things change. Of course for a run of couple hundred feet this > > is > > >> not > > >> >> a > > >> >> >> problem, but long runs it becomes one. > > >> >> >> > > >> >> >> 73, ron, n9ee/r > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> >From: Gary Schafer <[EMAIL PROTECTED]<gaschafer%40comcast.net> > > > > > >> >> >> >Date: 2007/08/30 Thu PM 07:39:21 CDT > > >> >> >> >To: > > >> >> >> >Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> >> >Subject: RE: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > >> >> >> > > >> >> >> > > > >> >> >> >I wonder what you were using to measure the impedance of the > > cable > > >> >> with > > >> >> >> >below .5 MHz? > > >> >> >> >Some cable especially rg59 types have copper clad steel center > > >> >> >> conductors. > > >> >> >> >If the copper clad is very thin low frequencies can penetrate > > the > > >> >> copper > > >> >> >> >clad and get into the steel where the loss can go up > > substantially. > > >> If > > >> >> >> you > > >> >> >> >are using that cable to transform an impedance the additional > > lose > > >> can > > >> >> >> make > > >> >> >> >the impedance transformation something other than expected. > > The > > >> >> impedance > > >> >> >> >will be closer to the characteristic impedance of the cable > > rather > > >> >> than > > >> >> >> the > > >> >> >> >expected transformation impedance. > > >> >> >> >But to have the characteristic impedance fall apart at .5 MHz > > would > > >> be > > >> >> a > > >> >> >> >mystery. 75 ohm cable is used extensively in video base band > > >> >> applications > > >> >> >> >where flat low frequency response is needed. > > >> >> >> > > > >> >> >> >73 > > >> >> >> >Gary K4FMX > > >> >> >> > > > >> >> >> >> -----Original Message----- > > >> >> >> >> From: > > >> >> >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>[mailto:Repeater- > > >> >> >> >> [EMAIL PROTECTED] <Builder%40yahoogroups.com>] On > > Behalf Of Ron Wright > > >> >> >> >> Sent: Thursday, August 30, 2007 10:48 AM > > >> >> >> >> To: > > >> >> >> >> Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> >> >> Subject: Re: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > >> >> >> >> > > >> >> >> >> Gary, > > >> >> >> >> > > >> >> >> >> I've measured RG59 cable terminated into a 75 Ohm resistive > > load > > >> >> with a > > >> >> >> >> variable freq impedance meter. We found the coax stopped > > being > > >> 75 > > >> >> Ohms > > >> >> >> >> below about 0.5 MHz. The cable manufacture also verified > > this. > > >> >> Other > > >> >> >> >> engineers in our department knew of this as well. > > >> >> >> >> > > >> >> >> >> We were designing security systems using video and the > > vertical > > >> and > > >> >> >> >> harizonal sync signals became very distored over long, 2500 > > ft. > > >> RG59 > > >> >> >> >> cables and this was the major reason. We had to design > > circuits > > >> >> that > > >> >> >> >> corrected this, but the cable had the problem. > > >> >> >> >> > > >> >> >> >> I am sure different RG59 cables have different low freq > > >> bandwidths. > > >> >> >> RG11 > > >> >> >> >> would also be different as well as cable TV cable. > > >> >> >> >> > > >> >> >> >> All coax has a lower and upper frequency range. Since we > > deal > > >> with > > >> >> >> radio > > >> >> >> >> this is not much of a factor until one gets real low or GHz > > >> levels. > > >> >> >> >> > > >> >> >> >> Coax also has the problem of a upper freq limit due to it's > > outer > > >> >> >> shield > > >> >> >> >> becomes large enough to act as wave guide. One will see > > upper > > >> freq > > >> >> >> specs > > >> >> >> >> will be lower the larger cable. > > >> >> >> >> > > >> >> >> >> 73, ron, n9ee/r > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> >From: Gary Schafer < [EMAIL PROTECTED]<gaschafer%40comcast.net> > > > > > >> >> >> >> >Date: 2007/08/29 Wed PM 09:23:57 CDT > > >> >> >> >> >To: > > >> >> >> >> >Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > >> >> >> >> >Subject: RE: RE: Re: Re: RE: [Repeater-Builder] Re: > > Duplexers > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> >As far as bandwidth goes,,, where do you get this .5 MHz > > for > > >> rg59 > > >> >> >> cable > > >> >> >> >> as a > > >> >> >> >> >lower limit? > > >> >> >> >> > > > >> >> >> >> >Open wire lines begin to radiate as frequency is increased > > to > > >> the > > >> >> >> point > > >> >> >> >> >where the line spacing becomes an appreciable portion of a > > wave > > >> >> length > > >> >> >> >> due > > >> >> >> >> >to the time it takes for propagation of fields between > > wires. > > >> >> >> >> > > > >> >> >> >> >73 > > >> >> >> >> >Gary K4FMX > > >> >> >> >> > > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> Ron Wright, N9EE > > >> >> >> >> 727-376-6575 > > >> >> >> >> MICRO COMPUTER CONCEPTS > > >> >> >> >> Owner 146.64 repeater Tampa Bay, FL > > >> >> >> >> No tone, all are welcome. > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> Yahoo! Groups Links > > >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> > > > >> >> >> > > > >> >> >> > > >> >> >> > > >> >> >> Ron Wright, N9EE > > >> >> >> 727-376-6575 > > >> >> >> MICRO COMPUTER CONCEPTS > > >> >> >> Owner 146.64 repeater Tampa Bay, FL > > >> >> >> No tone, all are welcome. > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> >> Yahoo! Groups Links > > >> >> >> > > >> >> >> > > >> >> >> > > >> >> > > > >> >> > > > >> >> > > >> >> > > >> >> Ron Wright, N9EE > > >> >> 727-376-6575 > > >> >> MICRO COMPUTER CONCEPTS > > >> >> Owner 146.64 repeater Tampa Bay, FL > > >> >> No tone, all are welcome. > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> Yahoo! Groups Links > > >> >> > > >> >> > > >> >> > > >> > > > >> > > > >> > > >> > > >> Ron Wright, N9EE > > >> 727-376-6575 > > >> MICRO COMPUTER CONCEPTS > > >> Owner 146.64 repeater Tampa Bay, FL > > >> No tone, all are welcome. > > >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> Yahoo! Groups Links > > >> > > >> > > >> > > > > > > > > > > Ron Wright, N9EE > > 727-376-6575 > > MICRO COMPUTER CONCEPTS > > Owner 146.64 repeater Tampa Bay, FL > > No tone, all are welcome. > > > > > > > > >
