[antennaware] antenna analyzers - Part 2

[Ian White, G3SEK]

>Thanks to all who responded to my first query. Extremely interesting.
>Due to large number of the responses I'm writing to the reflector.
>I used to have the MFJ259B and was very happy with it until I realized I
>need more than just the SWR - in fact I'd like to know both Z and +/- X.
>So I sold it.

The current version of the 259B does measure R and X and so too does the 
269.

I reviewed the 269 for RadCom, and the R-X accuracy was pretty good. 
That review is not available on-line, but I can e-mail the Excel 97 
spreadsheet of results to anyone who's interested.

The build quality of the 259-269s has got progressively better, from the 
old original 259s through the earlier 259Bs to the most recent 269. I 
found no real criticisms of the 269 in terms of build quality - the 
boards are machine-assembled SMD, the old problem with the battery 
holders has been fixed, and the case no longer uses self-tapping screws. 
If you use rechargeable batteries, there is also an option to connect an 
external  charger.

I'm not sure how many of those improvements in the 269 have been carried 
back into the latest production of the 259B.

>Then I went on to see the AEA products. I've downloaded
>their manuals - VIA and CIA - and one thing what I didn't like about the
>AEA was that they keep the owners of CIA in the dark. For the VIA they
>have, so called, commercial manual which I, personally, would call just
>a manual, covering what should be covered including accuracy etc. The
>manual for the CIA is just like an advertising leaflet treating owners
>of this cheaper version like kids. But what I noticed in the performance
>spec for the VIA is accuracy dependence on magnitude  of X or ratio of
>X/R. For the SWR >=2 the value of X can be almost +/- 40% . The sales
>guy at AEA told me that the VIA and CIA are practically the same so this
>, I understand, applies to the CIA as well.

I tried to review the AEA-CIA a few years ago, but could not get a 
sample that gave R-X accuracy worthy of a detailed test - despite much 
correspondence with the makers, a factory upgrade kit and even a 
complete replacement. Problems included the displayed sign of X 
dithering between + and -, and sometimes the X value jumping to zero and 
sticking there when it should have been changing smoothly. I suspected a 
firmware problem, but AEA seemed intent on blaming the hardware (which 
seemed most unlikely to cause problems of that particular kind).

I must stress that this was a few years ago, and they may have fixed the 
problems by now. The AEA-CIA worked fine as a graphical SWR analyzer, 
and of course the build quality is excellent. It's just the lack of a 
detailed accuracy specification on the complex impedance performance 
remains a drawback.

One other thing you may like to consider is the ease of making a VSWR 
sweep. The AEA has to be set up via the menus, but then you get the 
results plotted out, and can transfer them to your PC. With the MFJs, 
you just twist the knob and watch the meters - and often that quick 
general impression is all you really want.

>Now: how is it with the VA-1 ?

Dunno... except that it's the same nasty little plastic box as the RF-1.



-- 
73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                           'In Practice' columnist for RadCom (RSGB)
                            http://www.ifwtech.com/g3sek

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