Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> HI Terry and Bart and others,Im just curious. Seems like the H field from the toroid is tangental to the plane wave antenna. If so, it seems like eddy currents are not an issue. Terry, have you noticed a difference with the "fractal" version of you antenna vs the solid copper version??
Gerry R,
Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx> Hi Terry,Yep, I haven't used the current for much as well (other than to say "yep, 90deg separation"). I'll have to check on the FR4 at a typical .062" dielectric, but I don't think that will be problem.When I built my planewave, I used etching solution (you know, the Radioshack bottle). In my early electronic days, I built guitar effects boxes with the same routine (the planewave was super easy compared to that).I think a pcb antenna may would sure save some work there. I don't mind taping off copper clad and using the exacto to build the antenna, but a pcb would certainly make it simple and if your still using terminator to antenna components, that could also be easily incorporated for a very simple board.The pcb's I recently received were somewhat large (6" x 13"). The purpose of driving up to 20 DC motors (high current) via PLC logic, so the board had to be somewhat large (accommodating ANSI specs on trace width vs. current) all fused of course. You are right, large boards are higher priced and some of that includes the number of via's and pads (I had well over 1000 on the board with least real-estate).I might first just design your antenna on a pcb and give it a go myself. AT least I have a pretty nice home-brew to compare it to.Take care, Bart Tesla list wrote:Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx> Hi Bart, At 09:06 PM 12/20/2005, you wrote:Hi Terry, Query:I built your planewave (current and voltage hookup) many moons ago. It's been fantastic and has served many purposes. The new planewave looks interesting and I note only one feed to the scope. But my query is regarding your planewave antenna itself.I never used the current for much...It seems the planewave antenna could be a very simple 2 layer pcb with the groundplane on layer 2 and the antenna on layer 1.That would probably work fine. The fields are probably better controlled in the original design, but that is probably not a big deal at all. Hopefully, the capacitance of the two layers would be enough to eliminate the loading capacitor, but I think you would still need that. THE PCB material might not be a great dielectric at much higher frequencies anyway. The grid pattern is probably not all that important below 25MHz. Eddy currents and stray noise should be pretty small.Is this something that can be easily thrown onto a pcb design and maybe offered as a bulk buy?95% probably could just get the raw board and hack it a little without any PCB etching step.This crossed my mind mainly because today I received the 3 pcb's I just finished up for work. The company I work for was use to paying super high prices on their proto type boards. I used CircuitMaker 2000 to do the boards (not the best of programs for various trace widths), but it did have it's good points. I ended up finding that www.4pcb.com had proto's at 1/2 the price the other board houses were quoting (guess who got my work?). Well, they did a great job! Seems like we could throw your antenna into a simple pcb design unless there is a reason for the groundplane distance below the antenna.Small boards from mail order shops go for about $20 each. Large boards are really dependant on the quantity.Cheers, TerryJust a thought. Take care, Bart Tesla list wrote:Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx> Hi,The files you mention are up to date. The antenna will work with any scope. The antenna's ground plane is grounded through the cable to the scope chassis.Cheers, Terry At 06:31 AM 12/20/2005, you wrote:Hello Terry,I got interested in your "Large Wide-Bandwidth Plane-Wave Antenna", described here:http://hot-streamer.com/temp/PlaneWave.pdf and here: http://hot-streamer.com/TeslaCoils/MyPapers/planant/waveant3.htmlI`m going to take some measurements of my VTTC with this unit (I haven`t build it yet). Everything seems to be in order, but - you use Tektronix TDS210, as i see from the photos this o-scope is very small (battery-powered perhaps?) Mine o-scope was made in USSR, it has a massive _metall_ chassis (signal ground - one signal wire is tied to the chassis),and it`s energised by the mains.So, does all your system has the "floating" potential, or it`s connected to the ground anywhere? See - the whole capacitance of my scope chassis is not very small - can it influence the measurements anyway? And, maybe there`re some new revisions of thisantenna after this one:"The new one is larger, quieter, better bandwidth, tougher, easier to make..."http://hot-streamer.com/temp/PlaneWave.pdf ? -- Best regards, Grishka mailto:ghome@xxxxxxxxx