KO4BB's Ham Radio Pages
Pipe Cap Filters for the microwaves
This page shows how to use 24 or 28V relays from a 12V battery without voltage converter.
MFJ-264 Dummy Load modification
This modification turns the MFJ-264 Dummy Load into a 40dB attenuator still capable of 1kW power dissipation (short term).
This interface is designed for a laptop with lower than normal serial port voltage and current.
Microphone Mute for sound card modes with the TS-440
This modification to the stock Kenwood microphone mutes the microphone while the PTT switch is open.
This interface works well with Logger32 (by K4CY) and QSORecorder.
This interface is designed to control 2 radios (alternately, not simultaneously) through a single serial port
(works with FT-1000/FT-817 and Logger32 logging program)
It uses the QRZ.com on-line database, so you need to be connected to the Internet for it to work.
This comes without guaranty of any kind. If it blows up your computer, wipe out the C: drive or anything else,
it's not my fault.
Check the Release Notes.
Make a similar map for your QTH using SM3GSJ's software.
The plot of AD4TK is different since Jack is my neighbor... It turns out his net on 7.165 MHz LSB is pretty much 1/7th of the calling
frequency on 6m. His powerful, yet clean signal causes severe overload of my 6m receiver (FT-817), worse when the 6m antenna
is pointed at Jack's dipole antenna, about 400 feet away. As shown on the picture, his signal is clean of intermod. Harmonic
on 6m is too low to be measured by the Tek 494 spectrum analyzer (no picture). Good thing the net is only once a week :-)
I think the fix is a high pass filter at the input of my 6m receiver to eliminate the fundamental 7 MHz signal before it
reaches the receiver.