If I were to extend my 1/4-wave inverted-L to a 3/8-wave L, and tune out the inductance with a fixed capacitor at the base, what would this do to the broadbandedness of the antenna? Inquiring minds..
Hi Rob, The 2:1 SWR points on my extended 3/8-wave inverted "L" elements are about 70-KHz apart...I have no idea what those points might be in a "regular" 1./4-wave vertical. ~73~ de Eddy VE3CUI - VE
No, but if a variable capacitor is used the reactance nul can be moved up or down the band for resonance. This can also be done with a 5/16 wl inverted-L which usually comes in close to 50 ohms resi
Narrow it due to it being a bit less ground dependent plus the high Q of the capacitor. Carl KM1H _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
There is an old basic principle to remember about this, "The fewer the components in general, the broader the bandwidth." 73, Roy K6XK _______________________________________________ UR RST IS ... .
Another rule for this is "the lower the Q of the matching network the greater the bandwidth." Herb Schoenbohm, KV4FZ _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw
Thanks, gentlemen (Eddy, K8GG, ZR, Roy, Herb, et. al.), for all the feedback on this. So, it seems it's pretty much what I expected -- if you tune an antenna for better results on one frequency, you
I don't know how much bandwidth you could get with coaxial quarterwave transformer (say, two quarterwave lengths of coax in parallel to transform 12 Ohm of an inverted L to 50 Ohm)? In previous life
Roy, you didn't specify the vertical length of your inverted-L but I'll assume it is 50' and that your base-referred ground loss is 5 ohms. Using NEC-2 for the 1/4 wavelength inverted-L I get a 2:1 V
Rob: A typical 3/8 wl inverted-L antenna is about 65 feet vertical and 125 feet horizontal or sloping back downwards at a slight angle. This means that 2/3 of the wire is horizontal near the ground
Thanks, George. Actually, my intent isn't to perfect a DX antenna, but rather, to get the piece of wire with the current maxima up in the air. As it is, with the current node on the ground, I suspect