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+ The preamplifier can be any low-noise device of your choice. I use a lot of Ramsey SA7 preamps and Minicircuits MAR series MMIC chips - 10 to 20 dB is fine.
+ If you want a bare-bones version, the coax from the pickup loop can be fed directly to the output connector and the preamp and its associated switch omitted.
+ A cyber friend, Paul, has pointed out that a higher Q coil can be fabricated with the windings spaced out at least one wire diameter between turns. Paul is correct, and that is technically the correct way to make these things. Whether a bad decision or not, I opted to save space at the expense of selectivity. Some initial tests have been made with just the coil and caps, but I will hold off until the device is completed before publishing anything definitive. So far, mine has an edge on the Terk loop for sensitivity and the Terk has the best selectivity - both by about 1/2 "S" unit.
+ It looks like this will be a nice travel companion for (RF) noisy city AM receiption and for nulling those strong 50 kW flame throwers that every city seems to have.
+ You can see a properly built loop here.
+ If I am clever enough, I could make the coils swapable, but I don't want to loose sight of the initial purpose of this project. That's the reason I stopped throwing the Terk in my suitcase in the first place: The antenna needs to be mounted on a gimbal to perform correctly - the Terk doesn't do that. I will say that I could have lived with the Terk (as opposed to some of the better/more expensive table-top loops). My Terk has performed very well in the heart of New York City. I've used it both as a proximity and direct-wired antenna with the GE SR-III, CCrane, and Sangean 803A. One problem; no tilt feature. I'd usually end up propping up the Terk with an ashtray or something - awkward at best.
+ I'll try to start on the gimbal mount this week. (Maybe the boss will be out of the office.)
3-26-06
