I would be interested in any experience/opinions with antenna analyzers. . I have read the E-Ham reviews and see mixed reviews on Autek and MFJ analyzers, mostly relating to build quality. AEA units are more favorably rated, but also more expensive. Does anyone have experience with the Micro 908 Antenna Analyzer kit? Thanks.
HOWARD W. ASHCRAFT, Jr. W1WF Direct Dial: (415) 995-5073 [hidden email] HANSON 333 Market Street, 23rd Floor BRIDGETT San Francisco, CA 94105-2173 MARCUS Direct: (415) 995-5073 VLAHOS Main: (415) 777-3200 RUDY, LLP Fax: (415) 541-9366 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Howard asks: Does anyone have experience with the Micro 908 Antenna Analyzer
kit? Howard, I have used the MFJ and like it a lot, however, for me the choice would be the Micro908. It does more than antenna analysis and has many more possibilities long run, plus you get to build it! Jim, W4ATK _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Howard W. Ashcraft
I just finished building a 908 for someone, and mine is coming in the
second round. It works pretty well in the limited testing I put it through, and you get a development platform for other projects as well. Plenty of detail on the site. Quality is totally in your control :) Parts are all fine, case fit is OK and looks pretty good (although I'm not sure why it uses a stick-on when there'll be different apps in the future). de John/W1RT On Mon, 27 Dec 2004 14:12:43 -0800, Howard W. Ashcraft <[hidden email]> wrote: > I would be interested in any experience/opinions with antenna analyzers. . I have read the E-Ham reviews and see mixed reviews on Autek and MFJ analyzers, mostly relating to build quality. AEA units are more favorably rated, but also more expensive. Does anyone have experience with the Micro 908 Antenna Analyzer kit? Thanks. > > HOWARD W. ASHCRAFT, Jr. W1WF > Direct Dial: (415) 995-5073 > [hidden email] > HANSON 333 Market Street, 23rd Floor > BRIDGETT San Francisco, CA 94105-2173 > MARCUS Direct: (415) 995-5073 > VLAHOS Main: (415) 777-3200 > RUDY, LLP Fax: (415) 541-9366 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Howard W. Ashcraft
I have the Autek antenna analyzer and think it's a good deal for the price.
A couple guys in our club have the MFJ analyzers, so I've had a chance to compare. The MFJ display has more information on it, so it's easier to use. I like the analog meter on the MFJ; it lets you more quickly find an antenna's resonant frequency. BUT, the unit is bigger than the Autek, and it seems to go through batteries a lot faster than my Autek. The Autek is cheaper, too. I've seen the AEA units, too. They are much fancier, but as you say, they cost a lot more. If you were putting up antennas every day, you'd probably want the AEA, but since you probably are not... Having said all that, I just took another look at the micro908. WOW! It's very cool. If I were in the market right now, I think I'd go with this instrument. One big reason is the computer control. Neither the MFJ or Autek analyzers have this feature. You could do a lot of cool things with this feature. As an aside, I swapped e-mail with the Autek guy after I purchased my analyzer. Since it's obvious processor-controlled, I asked him about putting some kind of computer interface on it. He answered that "nobody would pay extra for that feature." Bleah. 73! Dan KB6NU --------------------------------------------------------------------------- President, ARROW Comm. Assn. (www.w8pgw.org) ARRL MI Section Affiliated Club Coordinator CW Geek (FISTS #9342) Read my ham radio blog at www.blurty.com/~kb6nu ----- Original Message ----- From: "Howard W. Ashcraft" <[hidden email]> To: <[hidden email]> Sent: Monday, December 27, 2004 5:12 PM Subject: [Elecraft] Antenna Analyzer Opinions? > I would be interested in any experience/opinions with antenna analyzers. . I have read the E-Ham reviews and see mixed reviews on Autek and MFJ analyzers, mostly relating to build quality. AEA units are more favorably rated, but also more expensive. Does anyone have experience with the Micro 908 Antenna Analyzer kit? Thanks. > > HOWARD W. ASHCRAFT, Jr. W1WF > Direct Dial: (415) 995-5073 > [hidden email] > HANSON 333 Market Street, 23rd Floor > BRIDGETT San Francisco, CA 94105-2173 > MARCUS Direct: (415) 995-5073 > VLAHOS Main: (415) 777-3200 > RUDY, LLP Fax: (415) 541-9366 > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Howard W. Ashcraft
I have the MFJ and AEA antenna analyzers in use at this end.
Started with the MFJ-209 which only reads SWR from it's single meter and has a basic rotary analog frequency read out. Works OK, but had dificulties with frequency accuracy particularly on the VHF range. Had to either use an external counter or in conjunction with a receiver to find exactly what frequency you were on. Made up a stick on paper scale to give a correction on the VHF scale as this does not appear to be adjustable for calibration, unlike the HF ranges. Sold this on at the local radio club last year and upgraded to the MFJ-259B. This has the same frequency range from about 1.8 to 170MHz but has much more information available from it's twin meters and an LCD readout that also gives a digital frequency readout. Able amongst many other tests to measure simultaneously SWR and impedance at the frequency of test. There is the more costly MFJ-269 available that also covers UHF, though unless this coverage is needed the MFJ-259B probably the better option. The MFJ analyzers are able to be operated from AA dry or rechargeable cells or even external DC power. On the earlier version of the MFJ-259(B) one could replace the cells through a hatch in the rear of the case. Sadly MFJ have now seen fit to remove this feature, probably to save costs and it now requires 8 screws to be removed and dismantle the analyzer to get at the batteries. I use 12 rechargeable AA cells with mine that are charged via the inbuilt charger to save dismantling. The AEA SWR-121V/U I have is for VHF and UHF only though there is an HF version available. This works in a totally different way in that it allows the user to make a sweep of frequency against SWR and displays this as a graph on an LCD panel. The sweep width is adjustable in defined steps to cover the bandwidth required. Found this extremely useful for sweeping antennas to check their usable bandwidth. A function can be selected to display the center resonant frequency of the antenna on test. Is powered with AA cells or external DC power. There is an inbuilt problem with both of these antenna analyzers and which probably applies to the Autek as well in that they are totally unusable in comm sites or areas where there are other adjacent transmitters in operation at the time of measurement. They are unable to read the SWR due to also detecting the external TX at the same time and reading this as a poor SWR. Noted another method of checking SWR on a graphical basis using a spectrum analyzer and tracking generator. Contractors building some new comms buildings at the workplace had installed new antennas on our existing towers in readiness for existing equipment to be moved to the new buildings. As part of the commissioning work these antennas were swept with a spectrum analyzer and tracking generator in conjunction with a directional coupler possibly from HP that allowed a visual sweep of the antenna. I note that the Micro908 from AM QRP club is able to carry out a similar task. Not seen this device listed before the mention on this reflector. Website for info: www.amqrp.org/kits/micro908 Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I can attest that this is also a problem with the Autek. I was using my
Autek analyzer to tune an antenna at a multi-op contest station that our club was setting up. As I was tuning the antenna, every once in a while, the readings would just go crazy. I started thinking that my meter was beginning to fail until I noticed that the meter would start acting funny whenever one of the other stations was transmitting! :) Everyone got a good laugh out of it. 73! Dan KB6NU ----- Original Message ----- From: <[hidden email]> To: <[hidden email]>; <[hidden email]> Sent: Tuesday, December 28, 2004 12:49 PM Subject: Re: [Elecraft] Antenna Analyzer Opinions? > > There is an inbuilt problem with both of these antenna analyzers and which > probably applies to the Autek as well in that they are totally unusable in comm > sites or areas where there are other adjacent transmitters in operation at > the time of measurement. They are unable to read the SWR due to also detecting > the external TX at the same time and reading this as a poor SWR. > > Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Howard W. Ashcraft
I have the u908 (AA908) Antenna Analyzer. It comes as a very nicely packed kit, lots of SMT components with an excellent instruction manual. The case is approx 7" x 5.25" x 1.5" and made of ABS(?) plastic. The complete unit consists of a Mother board, a DDS daughter board, a microcontroller board and a (KK7P) DSP card. The software is user up-gradeable running a terminal program on your PC (which I have done three times), and can change the function of the unit. Right now it is configured as an antenna analyser. It has manual and automatic modes, and can scan between user selectable frequencies. On power up. It defaults to impedance mode but can be selected to run in inductance, capacitance or VFO mode. I have tested it on antennae, coax, discrete capacitors, inductors and resistors, and it seems to work very well. The unit will actually be able to run as one of five different configurations - currently it is an antenna analyser, next application to be released is (I believe) an DSP audio filter application (AF908) similar to the K2DSP (using Lyle's excellent unit), and then(?) a PSK31 software program for Portable PSK using a small accessory keyboard. Internal batteries are 8 AA's - if NiMH cells are used, there is a jumper in the unit that will permit them to be charged while the unit is plugged into an external 12V source. The only current limitations(?) I have found so far are; 1. frequency range is limited to 1 - 30 MHz in three decade switched bands, 2. SWR maximum indication is 10:1 3. Impedances greater than 600 Ohms cannot be accommodated. Usual disclaimers, no financial interest, just a satisfied owner Dave KK7SS Dave KK7SS AMSAT #35359 DN06ig Mail is Virus checked , both IN and OUT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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