Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

Jim, I will agree with you wholeheartedly, except for the RF Ground part --- In reality, RF ground has only to do with a zero impedance reference for RF at the frequency of operation. It can actually be up in the air (example - at the midpoint of a dipole, normally the dipole feedpoint), or at t

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

On Mon, 02 Aug 2004 10:38:52 -0700, Vic Rosenthal wrote: >The way I like to look at is that there are at least >four different 'grounds' that you have to worry about, and you need to >provide for them separately. It's OK to think of them as fulfilling four different functions. But from a safet

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

The nice thing about the Ten Tec kit, is that it can be easily converted to an "L" network tuner, if you switch the point where the pick up circuit monitors current, and substitute a coax jack for the connection in one original hole. That way, it can be converted back to artificial ground service

Re: [Elecraft] Like MFJ's 931 Artificial Ground

Artificial ground tuners are series resonant circuits with a current sensing metering circuit so that you can tune for maximum current in the series circuit, an indication of optimum cancellation of the reactive ground lead, (resonance). Stuart K5KVH __

RE: [Elecraft] Like MFJ's 931 Artificial Ground ?

That's exactly what the "Artificial Ground" does, George. When you have a ground wire going to a ground stake it makes a lousy RF ground, but it'll be a much worse one if the wire to the stake is more than a couple of feet long because the wire is an appreciable fraction of a wavelength at HF. If

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

Vic, You are entirely correct - and I have long advocated thinking about the 'ground' terms separately. It should be common knowledge (but it isn't) that one 'ground' can be at a different potential than another 'ground'. I learned early in my hamming days because we often referred to 'chassis g

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

George, W5YR wrote: At the risk of seeming to rain upon the parade, let's keep in mind that the 931 can at most provide a low-impedance path to "ground." Whatever that "ground" happens to be is what determines the success or failure of using the 931. George is correct. The way I like to look

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

At the risk of seeming to rain upon the parade, let's keep in mind that the 931 can at most provide a low-impedance path to "ground." Whatever that "ground" happens to be is what determines the success or failure of using the 931. In almost all cases, adding a simple ground connection to a station

[Elecraft] Like MFJ's 931 Artificial Ground

The April 1988 QST Product Review shows the schematics as well. -- 73 Fernando N2FQ/NNNØJYM San Jose, CA ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. S

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

Ten-Tec has a kit version ($59) that in my experience works even better then the MFJ http://www.tentec.com/Tk1251.htm Mike, W9WIS ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber

[Elecraft] Like MFJ's 931 Artificial Ground

Hi Bill Got one last year to use on a vertical in conjunction with a standard tuner and now as a conterpoise to a LW antenna. It resolved effectively a high SWR problem I had. It consists of a LC network which creates a low impedance path to a standard ground. An L and C network don't create

Re: [Elecraft] Like MFJ's 931 Artificial Ground ?

Hi, Bill- Unless I am mistaken, there is supposedly a schematic available for the MFJ-931 in Devoldere's "Antenna and Techniques for Low-Band DXing". I have the 931 and use if with my EFW, both in the shack as well as while portable. It works well for me, plus one cannot have too many gadgets con

[Elecraft] Like MFJ's 931 Artificial Ground ?

Is there a kit version of the "artificial ground" available? Even a schematic would be nice. I would assume that its just a series tuned L/C with a meter to measure RF current somehow, but if anyone has come up with a version of their own, or knows of a kit, I'd like to hear about it. Than