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Hi Roy,
MFJ makes a nice 81 dB step attenuator for a very reasonable price (about $70.00 as I recall) for those who don't want to build. In either case (build or buy), one still has to know how to make good use of it, which to my experience is more demanding than either pocket book or soldering solutions. There are a LOT of neat things one can do with a 2 position switch and a step attenuator. For one thing, a lot of myths can be summarily dismissed (after getting enough data points...another problem that gets lost in the shuffle). One simple measurement on anything sky-wave based is completely meaningless. Things like path-length, time of day, etc. need to be "washed out" or "isolated" in order to come to anything even resembling a meaningful conclusion, and one is likely to arrive and multipe conclusions based on the array of variables one investigates. A step attenuator is an absolute essential for anyone who plays with gain antennas or wants to compare antennas. If expense is an issue, you have provided a great solution, otherwise, the MFJ works rather well for not a lot of money. 73, ....hasan, N0AN "Roy Lewallen" wrote in message ... Mike Coslo wrote: Roy Lewallen wrote: A step attenuator which is completely adequate for HF and can easily resolve 1 dB can be made from a few cheap slide switches, some PC board material, and a handful of ordinary 5% quarter watt resistors. Detailed instructions can be found in numerous sources, including the Web -- a Google search brought a large number of hits, the first of which was http://www.arrl.org/tis/info/pdf/9506033.pdf. But I'm afraid that this level of homebrewing is beyond the interest if not the ability of the majority of today's amateurs. Got it - Thanks, Roy! - 73 de Mike KB3EIA - You're very welcome. The reason for my rather grumpy comment at the end is that I've recommended countless times for many years that people interested in evaluating antennas build a simple step attenuator -- an evening project. It allows you to make direct, quantitative comparisons between two antennas -- yours or someone else's, as well as calibrate your "S" meter. But to date, I've never gotten an iota of feedback that a single person has actually taken the trouble to build one. Rather, they continue to debate, ad nauseum and without any meaningful data, whether one antenna is better than the other, or at best quote differences in "S-units" read from their meters, without the foggiest idea how many dB it might represent or how different it is from someone else's meter (or from the same meter on a different band or a different part of the scale). The conclusion I've reached is that A) Hams would much rather argue than actually determine the facts, or B) The vast majority are unable to build a homebrew project consisting of slide switches, circuit board material, and resistors. I'm afraid both are probably true. Maybe you'll be the first to actually build one. If so, please drop me an email and let me know -- it'll make my day! Roy Lewallen, W7EL |
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