Below are FRP downloads and links for PulCalc Program Tutorials including the PulCalc Spreadsheets Workbook and the PulCalc Laminate Program Workbook.
Also some ham (amateur) radio and DIY projects are listed below.
Ham Radio Links and Docs by N1PS
Below are PDFs of various projects. In most cases there are Youtube videos also.
I recently put this websdr on line. It is single band for now.
DC Filament Circuit
Here is a DC filament circuit for vacuum tube audio amps. It was developed for speech amps in an AM transmitter. The PCB is no longer available, but you can breadboard it. In some cases when using a high Z microphone, the high Z grid Z can be problematic and prone to pick up heater AC. This is especially the case in some vintage AM transmitters where the filaments are unbalanced and grounded at the tube socket.
Emergency Lights Controller
This board was installed in 2014 and has worked flawlessly since. It senses loss of AC power and energizes a relay to drive LED lights from backup power (like solar). I have LED strip lights around my house that tie to my solar battery backup system. The board is composed of just a few transistors and an IC. The PC board can be built in a few hours for most people familiar with soldering components.
Video is here: https://www.youtube.com/watch?v=Y9TNys8auQM&t=10s
Johnson Valiant Transmitter FET Driver
Johnson made a lot of these transmitters in the 1950s. Here is a modification for those that like to use it on AM. First the 6146 modulators are not that great. A better solution is to use a pair of TV deflection sweep tubes like the 6DQ5. But, it takes a lot to drive them. The poor stock driver transformer cannot handle it and a RC driver using phase inverters can work as long as we can get enough drive of about 150-200 VPP for each phase. So what I did is I use a variation of Frank WA1GFZ, FET driver and use it to drive the sweepies. But there is no free lunch as is said, hence we have to be careful to not over stress the low voltage transformer. I added a 10A filament transformer and solid state the high voltage rectifier to allow the LV transformer to run cooler. The FET driver uses the ubiquitous FQA11N90 MOSFET as is used in CLASS E transmitters (see my youtube channel). I have lots of them on hand and they are cheap. It is also possible to drive the sweepies with vacuum tubes. In that case I would recommend using the B- as a current source to add headroom.
Note on using the TV sweep amp tubes. This is quite a common mod for those who like to run good quality AM. The 6DQ5 has twice the emission of the 6146s and provides oodles of audio to the mod transformer. Together with the heising connected reactor, the transmitter has consistent positive peaks above 130%. The guys who are running their Valiants (Vikings, DX100s etc) have much more punchy audio than others.
D104 Mic Source Follower
Here is a Field Effect Transistor (JFET) source follower for the ubiquitous D104 microphone. The D104 element is a high output mic and a source follower is all that is needed. This allows the operator to use almost any transmitter input impedance for a transmitter first speech amp stage. I mike to use a 47K ohm input on the first stage of a speech amp (typically a 12AX7 on vintage transmitters) to reduce susceptibility to 60 Hz AC hum. Also it is a good idea to not run the mic signal through the shield. I have used this circuit for about 5 years with no failures and with various vacuum tube transmitters. The circuit is powered from a 9V battery, but a regulated DC supply with work too.
Note: Bear WB2GCR pointed out that the 47uF cap is a little large for a battery input. You could use just a 1-2uF cap in that case. However, I wanted maximum protection from transients with vacuum tube transmitters, so keep that in mind.
Rock-Ola Jukebox Parts and Wiring
Below are scans of the model 467 jukebox. See the video for a look at the project. I continue to chase small electrical connection issues as there are many contacts!