Tom W8JI gives a lot of information on winding and testing plate chokes. He designed the ones for some MFJ amps. https://www.w8ji.com/rf_plate_choke.htm GL, .... Bill K3HZP The Ameritron plate choke
Hi Alex, When using an amp in semi-break in, it is quite common for the first dit or dah of each transmission to be shortened due to hot switching of the slow Amp T/R relay. The slow T/R relay causes
Don't forget that a toroid is a 'one-turn loop' that can couple to other things. .... Bill K3HZP I clearly understand that, and I'm pointing out how you and other designers can figure out which mater
There must be a resistance across the filament pins on the weaker glowing tube. Ohms law does not lie! Check the tube socket filaments pins carefully on the weaker glowing tube with an VOM with both
Here is some food for thought. In both my SB-220 and my HL-2200, I added a 10 ohm 10 watt resistor directly below the stock RFC and prior to the bypass capacitor to ground. Its purpose is to protect
Hi Jeff, Here are some thoughts on short circuit current that others may be able to expand upon. Let me use my SB-220 as an example. The plate voltage is about 3,000V and the effective power supply o
Conrad, The 90 deg angle of the two dipole elements is necessary to excite the 2 orthogonal polarities. For the radiation to be circular, the signals in these dipoles must differ in phase by 90 deg.
The relay diode does not affect the closure time. It only extends the relay opening time. .... Bill K3HZP Hello Jim Does that clamping diode across the coil affect the TX key up delay time? As in "sl
Hi Jim The best argument that I have heard about capacitors across diodes is that older diodes had uneven capacitance. Under certain conditions the capacitance would cause the voltage to divide uneve
Hi Dave, I have the TS-590SG. It does not have a keying loop for QSK. TenTec is the only rig that I am aware of that supports the keying loop. TS-590 TX Delay is fixed at 10ms according to the manual
Hi Wayne, My guess that the 60Hz is in the test setup, not in the amp. Depending on common grounds etc., you are likely picking up 60Hz from the house wiring. You are correct, ripple would be 120Hz.
Hi Ed, I don't know if this will help. I repaired an external QSK-5 for a SK's widow. I think it uses the same PCB as the internal unit. The problem was that Q4 2N6740 was shorted to ground. The devi
Hi Jeff, I think there are multiple reasons for the first character missing at the beginning of a transmission with an amplifier. Number 1 reason: The sender is using an automatic band selection ampl
Hi Jeff, I think there are multiple reasons for the first character missing at the beginning of a transmission with an amplifier. Number 1 reason: The sender is using an automatic band selection ampl
Nothing is free. Putting the secondaries in series and primaries in parallel doubles the primary to secondary voltage insulation requirement. 73 .... Bill K3HZP I think I would have rathered wired th