Martin, Yes, at least the 20m W3NQN filter changed from the original QST article to what was shipped from Array Solutions about 6 months ago. I have a plot that I can send you of the measured differe
Steve, Look at Caddock type MG, TG, MX etc. resistors http://www.caddock.com/Online_catalog/high_voltage/high_voltage.html I have used them many times. I picked up a bunch of MX440 5.6meg parts which
Duane, Doing "it right" is a whole lot more than just matching the input and output impedances. Issues such as IMD, thermal heat transfer, and protection against overdrive and reflected power are mor
You might want to get your info from the "real" source. http://www.gigavac.com/products/relays/datasheets/gh1_3_5/index.htm They are NOT even close to the same relays. You draw your own conclusions b
Jim, What frequency? 16 bifilar turns on a FT-240 size core would be about 8' total of #12 wire. At 20m #12 Cu wire is about 4 ohms per 100' so 8' would be about 0.32 ohms. Put 5.5A of current throug
This is total BS! Electrical conductivities: Copper ~1.7x10-8 ohm-m Silver ~1.6x10-8 ohm-m Silver Sulfide ~1.8x10-3 ohm-m Silver Oxide ~1x10+9 ohm-m If you wish to call something that has 62,500,000,
I just did the test several people had hypothesized about in the past few days and the test was done with 2 different IR thermometers. 1.) Thermometer was aimed at a black anodized aluminum heat sink
Using 2 chokes in series and not switching them is not a "carte blanche" solution to not having any series resonances. It is probably easier to get 2 chokes to work over all the bands but be wary if
Vic, Look at my post of a few hours ago. Two non-resonant chokes in series can together be resonant. This is basic circuit theory and there is no way around the issue. Larry, W0QE ___________________
Vic, Shane, and others, Changing the circuit to be 2 inductors in series with a capacitor to ground at the connection point between the inductors changes things but does not fix the possible low over
Roger, You might be thinking of a program called "Front Panel Designer". http://www.frontpanelexpress.com/company/press/front-panel-designer-40/index.html http://www.schaeffer-ag.de/index.php?id=55&L
Is your Hi-Pot tester a DC tester or does it have some AC on it? The reactance of 1000pF at 50Hz is 3.2M ohm and a 10kV rms (14kV peak) AC only Hi-Pot would result in 3.1mA due to the capacitive reac
Joe, I made measurements on a lot of transceivers which can be seen at http://www.w0qe.com/amplifier_timing.html It needs a little updating but might be useful. 73, Larry, W0QE ______________________
Jim, I haven't seen a radio which brings T8 outside of the radio which may not be of importance to you. Additionally T8 and R8 control the radio mode so T8 might not actually coincide with the RF exa
A simple way to look at this is if the non-linearities/distortion are _symmetrical_ on both the positive and negative sides of the AC waveform only odd harmonics are generated. All other cases produc
Egads! Big time error. LTSpice is a product of Linear Technology and NOT Analog Devices. Adrian is correct on the URL! Sorry for the goof. Larry, W0QE _______________________________________________
Steve, Let's get calibrated: 1.) 1.5kW in a 50 ohm environment is 274Vrms (387V peak) and 5.48Arms. 2.) Add some SWR into the mix (still @ 1500W) and the maximum voltages and currents rise by the squ
Mike, Not sure how seriously you want to understand everything but here is what I believe is one of the better ways to do it. 1.) Go to http://tonnesoftware.com and download Jim's PI-EL software. It
Dan, I don't quite calculate the same number. If the source is 3 phase power and halfwave rectification the ripple would be 50%. This is most likely _not_ the case. In the more likely case of full wa
Mike, Look at Wikipedia for "mismatch loss" to see how there can be loss without heat in an RF system. There are 2 kinds of loss: dissipative (heats up) and mismatch (produces no heat). If a connecto