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: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft
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