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MFJ Antennae analysers? VNWA?
On Sat, 26 Dec 2015 12:24:54 -0000, "gareth"
wrote: Anyone have an inkling of what you get for your £350-odd? You can probably get a fair idea of what's inside and how it works from the following links. The major limitations of the MFJ-259/269 analyzers is the inability to sweep a frequency range and the tendency for static electricity or too much RF to blow out the front end diodes. MFJ-269 repair: http://802.11junk.com/jeffl/MFJ-269-repair/ MFJ-269 schematic: http://802.11junk.com/jeffl/MFJ-269-repair/mfj-269-schematic.pdf MFJ-259 calibration: http://www.w8ji.com/mfj-259b_calibration.htm http://www.ok1cjb.cz/pdf/390_kalibrace.pdf Build Your Own Antenna Analyzer for under $50 http://www.hamstack.com/project_antenna_analyzer.html http://www.hamstack.com/hs_projects/k6bez_antenna_analyzer.pdf For single port measurements, I prefer to use a return loss bridge: https://www.google.com/search?q=return+loss+bridge&tbm=isch http://www.qsl.net/n9zia/wireless/pics/rtrn_loss_bridge.png It doesn't give reactance information or draw a Smith Chart as with a real VNA. It also requires an RF sweep generator and an oscilloscope. With a collection of small bridges, I can sweep and measure most anything from VLF to wi-fi: http://pe2er.nl/wifiswr/ -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
MFJ Antennae analysers? VNWA?
On 26/12/2015 23:25, wrote:
In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: On 26/12/2015 22:41, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: wrote in message ... In rec.radio.amateur.antenna Ralph Mowery wrote: wrote in message ... Despite its high price and snazzy interface, does it provide any more useful information then the tried-and-trusted (transistorised!) GDO? That depends on whether or not you have the skills to utilize the information such devices provide. Most of the hams I have seen with the MFJ do not have the skills to really use it and a simple swr meter would do just as well or beter for them. That's a sad comment and contrary to my experience, though most of the hams I know are also engineers or technicians in real life. professionals should take up another hobby ...... Why? because they are a pain in the arse trying to lord it over non-professionals trying to enjoy their hobby ... You mean like when they disparage old wives tales that have been passed down from the days of spark but contradict the laws of physics? yes...and boy do they love to make you feel small.... -- Moderated groups kill abuse No spare wheel isn't progress The latest model is not always the best A rubber cam belt is not acceptable Cheat your way through life, join the Freemasons DIGITAL just doesn't work |
MFJ Antennae analysers? VNWA?
On 27/12/15 06:21, Jim GM4DHJ ... wrote:
On 26/12/2015 23:25, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: On 26/12/2015 22:41, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: wrote in message ... In rec.radio.amateur.antenna Ralph Mowery wrote: wrote in message ... Despite its high price and snazzy interface, does it provide any more useful information then the tried-and-trusted (transistorised!) GDO? That depends on whether or not you have the skills to utilize the information such devices provide. Most of the hams I have seen with the MFJ do not have the skills to really use it and a simple swr meter would do just as well or beter for them. That's a sad comment and contrary to my experience, though most of the hams I know are also engineers or technicians in real life. professionals should take up another hobby ...... Why? because they are a pain in the arse trying to lord it over non-professionals trying to enjoy their hobby ... You mean like when they disparage old wives tales that have been passed down from the days of spark but contradict the laws of physics? yes...and boy do they love to make you feel small.... You are simply blaming others for your own lack of knowledge, hardwork, and self-esteem. Take some responsibility for your life. -- Why you should not ignore animal neglect and cruelty: http://www.caar-uk.org/why.html |
MFJ Antennae analysers? VNWA?
"Brian Reay" wrote in message ... On 27/12/15 06:21, Jim GM4DHJ ... wrote: On 26/12/2015 23:25, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: On 26/12/2015 22:41, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: wrote in message ... In rec.radio.amateur.antenna Ralph Mowery wrote: wrote in message ... Despite its high price and snazzy interface, does it provide any more useful information then the tried-and-trusted (transistorised!) GDO? That depends on whether or not you have the skills to utilize the information such devices provide. Most of the hams I have seen with the MFJ do not have the skills to really use it and a simple swr meter would do just as well or beter for them. That's a sad comment and contrary to my experience, though most of the hams I know are also engineers or technicians in real life. professionals should take up another hobby ...... Why? because they are a pain in the arse trying to lord it over non-professionals trying to enjoy their hobby ... You mean like when they disparage old wives tales that have been passed down from the days of spark but contradict the laws of physics? yes...and boy do they love to make you feel small.... You are simply blaming others for your own lack of knowledge, hardwork, and self-esteem. Take some responsibility for your life. ........political and contentious sig deleted ..... No I blame others for being conceited and big headed ......thank god for the moderated group where you can get a reply to a technical query without the snide comments ... |
MFJ Antennae analysers? VNWA?
"gareth" wrote in message
... These questions are raised by the possibility of resurrecting a project with a former colleague from uni 43 years ago, now that we are both retired, although it will be dismissed cynically as vapourware by some nasty individual, to produce a speccy covering up to 10GHz together with tracking genny but based aroind COTS components that feature more and more in domestic white goods. There are two aspects of vector analysis under consideratiom; the first, as for antennae measurement is to assess the amplitude and phase of reflected power from various circuits, which is where the interest in the VNWA arises, but the second is the analysis of complex modulation, particularly where there are constellations. |
MFJ Antennae analysers? VNWA?
In rec.radio.amateur.antenna Jim GM4DHJ ... wrote:
On 26/12/2015 23:25, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: On 26/12/2015 22:41, wrote: In rec.radio.amateur.antenna Jim GM4DHJ ... wrote: wrote in message ... In rec.radio.amateur.antenna Ralph Mowery wrote: wrote in message ... Despite its high price and snazzy interface, does it provide any more useful information then the tried-and-trusted (transistorised!) GDO? That depends on whether or not you have the skills to utilize the information such devices provide. Most of the hams I have seen with the MFJ do not have the skills to really use it and a simple swr meter would do just as well or beter for them. That's a sad comment and contrary to my experience, though most of the hams I know are also engineers or technicians in real life. professionals should take up another hobby ...... Why? because they are a pain in the arse trying to lord it over non-professionals trying to enjoy their hobby ... You mean like when they disparage old wives tales that have been passed down from the days of spark but contradict the laws of physics? yes...and boy do they love to make you feel small.... Sounds like sour grapes to me. Most hams I know are eager to learn new things. -- Jim Pennino |
MFJ Antennae analysers? VNWA?
In rec.radio.amateur.antenna gareth wrote:
"gareth" wrote in message ... These questions are raised by the possibility of resurrecting a project with a former colleague from uni 43 years ago, now that we are both retired, although it will be dismissed cynically as vapourware by some nasty individual, to produce a speccy covering up to 10GHz together with tracking genny but based aroind COTS components that feature more and more in domestic white goods. There are two aspects of vector analysis under consideratiom; the first, as for antennae measurement is to assess the amplitude and phase of reflected power from various circuits, which is where the interest in the VNWA arises, but the second is the analysis of complex modulation, particularly where there are constellations. I can not think of any antenna that modulates signals. -- Jim Pennino |
MFJ Antennae analysers? VNWA?
On Sun, 27 Dec 2015 18:46:42 -0000, wrote:
I can not think of any antenna that modulates signals. I talk to my antennas all the time. I only worry when they talk back. DAM (Direct Antenna Modulation): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5464640&url=http%3A%2F%2Fie eexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber% 3D5464640 http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1339221&url=http%3A%2F%2Fie eexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber% 3D1339221 https://www.google.com/search?q=direct+antenna+modulation -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
MFJ Antennae analysers? VNWA?
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