// As I understand it, RF-actuated T/R bias switching is now in many MFJ/Ameritron amplifiers. This allows the 8877's bias to rapidly switch between (linear) Tx and (non-linear) Rx modes during soft
// I arrive at PEP by measuring peak RF voltage across the load R with a freshly calibrated oscilloscope and a x100 probe. For a sinewave, P-peak=(E-peak^2)/R and PEP=P-peak/2. This method works wit
I used a version of Pete's method and it works well: At c. a 45º angle, I tightly spiraled THHN #14 solid Cu-wire down about a foot of the coax. Then I wrapped it with black plastic electrical
An efficient way to ground-feed a 1 or more halfwave inverted V is with a remote controlled L-network. Fair Radio Sales sells a Collins c. 30uH DC motor driven variable-inductor that wurks well for
Amen, Mark. Balun + high SWR =s bad news, - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan towers,
// This suggests that you have been using a so-called "balanced" tuner that consists of an unbalanced - usually T - matching network followed by a balun. I used to run one of these, and I got singed
// For a station ground, I use 25-ft of Cu tubing buried just below the surface. For the remote-controlled 160m antenna tuner, I use a sheet of galvanized sheet metal laid on the surface of the grou
// Please describe your antenna tuner, Tom - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan towers
// I use an oscilloscope and HV multiplier to measure the output voltage on each side of the balanced transmission line. On "Ultimate Transmatch" type tuners, the imbalance is not small and not mode
// Please explain why to us, Mr. Rauch. . thanks - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan
// A neon bulb test paralled my measurement of the voltage to gnd on each side of an not-balanced open wire transmission line using an o'scope and a HV x100 scope probe. // so my college physics cou
// ... yet another stonewall? Can anyone explain why a (current) balun should be located at a point where high voltages and high SWR are known to prevail? tnx - R. L. Measures, 805.386.3734,AG6K, ww
// Neon bulb tests seemingly paralled my measurements of voltage to gnd. on each side of an open wire transmission line. // So my ancient 1960s college physics courses were understandably somewhat o
// One type of silicone rubber does but another type does not. - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
// Isn't Teflon an insulator? - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan towers, coax, hardl
The best D.C. earth/ground is a vertical conductor. The best RF ground is a horizontal conductor near the surface. Lightning is similar to c. 100kHz RF. There is no shortage of ham radio old wives'
// I use permanent-magnet DC gear-motors. They have enough torque, reverse direction by reversing polarity and require only 2-wires. Remote position-indication is done with either a multiturn-potent
// My guess is that it should be >5-times the wire-spacing. It won't work as advertised when fed from an unbalanced tuner with a 1 to 1 balun at the output. However, a Balanced L-network antenna tun
I have a halfwave vertical for 80m, The feed Z is around 1000-ohms. I match it to 50-ohms with a variable L and a variable C. This allows coverage from 3.5MHz to 4MHz with a 1.0 to 1 SWR. cheerio, D
// A 50 - approximately 1000-ohm L-network can be used to match coax to an end-feed a half-wave (Hertz) antenna. If one uses DC gear motors to drive the L and C from the shack, the SWR will be 1 to