mjf.what can i say "made from junk"

I own both the MFJ-207 and the MFJ-259B analyzers. The MFJ-207 I use just to rough tune an antenna in the field, or as a cheap unit to loan out in case it gets damaged, lost, or stolen. For more intricate work, I use my MFJ-259B. If you can afford both, then by all means, buy them. If you can't, then personally, i'd wait and save my money for the 259B. With the addition of the built in freq counter and the digital as well as analog readout, the 259B is the best all around unit without question! As of this date, 03/13/2010, the 259B can still be purchased brand new from Gigaparts for about $250.00 USD shipped within the continental USA. Thank you for your review, and thank you for the opportunity to share my experiences with you and your readers. Gordon...........

Hi:

Was thinking of purchasing the MFJ-207. There was an old article by Kris KA2OIG that might interest readers. Couldn't find copy of it on the internet and don't have access to ARRL files but here is what I found:-

Title: HK5:Fine Tuning the MFJ-207 HF SWR Analyzer

Author: Merschrod, Kris - KA2OIG/HR3

Source: QST Sep 94, p. 95

Abstract: Adding padding and shunting capacitors to an SWR analyzer to increase bandspread on each range.

Digest: The MFJ-207 Analyzer relies on a dial calibration to indicate frequency, but the resolution is poor because the dial graduations are so close together. The author determined to rework the tuned circuit to provide more bandspread.

The front-panel bandswitch has ten positions, but only six are used, so he decided to use the extra positions to connect additional capacitors into the circuit to spread out the 15-, 20-, and 40-meter bands.

Using the digital indicator on his station receiver, he checked the position of the main tuning capacitor at the high and low ends of each of the bands with which he was concerned and found that each of the bands was covered with a rotation of only about one-quarter of the full capacitance range. From that, he calculated that a variable capacitor of about 35 pF. would cover the bands and require nearly full-scale dial rotation. He did not have a capactitor of that size in his "junk box" but did have one of 27-pF, which he used. He found that it spread most of the 40-, 20-, and 15-meter bands over the full dial, although it did not quite reach the low ends of the bands. This was adequate for his purposes.

In addition, he added coverage of the 10-meter band by switching a 10-pF. fixed capacitor in parallel to the existing variable capacitor, and a 22-pF. capacitor in series. This provided coverage from 29.7-MHz. down to 28.1-MHz.

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Cheers

Aryeh

Thanks Peter.

MFJ do have a bit of a reputation of low build quality, but generally for the price you get a pretty usable device that might just need a touch-up here and there (soldering in particular - although this unit was pretty good). With the target market being us HAMs who are well-known for being somewhat frugal (but also as avid tinkerers) this probably works well for them.

One thing I did notice in the 207 is use of what appears to be lead-free solder. I guess this is an RoHS thing. Makes it a little tougher to resolder if needed, as most of us as still using PbSn solder which isn't very compatible.

Regards,

Alan

Alan,

A very thoughtful and useful review. Clearly there is tension between designers and the accountants at MFJ. The designers are presumably being sent back to the drawing board to make a version with less components until performance suffers.

I purchased the MFJ-269 analyser but in reality the only feature I use is the one that the MFJ-207 performs - finding antenna resonance.

It's great that MFJ makes test instruments like these at an affordable price. It would be bad if they had not got the best performance out of the money spent on components, aside from your comment about "RF hygiene" it seems they have.