Recycled PC Power Supply - converted for use as a 'lab supply'.
An RF-activated "On Air" sign. This was originally from a QST article from 2004, but a more recent January 2007 article that referred to it got me interested.
Key Down or PTT turns on the "On Air" sign. This works for CW, AM, FM, Packet and even for SSB provided there is some modulation present in the SSB.
An ubiquitous headphone amp of the Chu Moy design. Now I'm hooked on Audio too.
Inside the headphone amp: very tidy, with some point-to-point wiring to the control, input, and output. Most of the components are right next to the OPA2134 op amp and solder right to it. Uses a TLE2426 rail splitter to save components.
Pretty much my first radio project - restore FM to an old Zenith Royal 76 radio (AKA a Royal 820). FM Test Oscillator on left, lab power supplies. Must've been in my pre-Amateur Radio days.
Close up of a repair of a Heathkit BE-5 Battery Eliminator. Ditched the terrible old selenium rectifier for two silicon bridges. Chassis is the new heat sink. Caps replaced. This is now a good worker.
5-Digit Frequency Counter (Wolf DL4YHF) using a PIC 16F628 in an ever present Altoids tin
This was a quick, Sunday afternoon project. I added an interface box to connect a plain old PC Headset to the FT-897D.
Two jacks are provided so the Headset is not hard-wired. Big-red button is PTT. Also the usual DOWN / FAST / UP buttons are provided.
Grey trim pot in foreground adjusts MIC gain.
A full CAT + Data interface for my FT-897D. This uses a Maxim MAX-232 ic to convert the FT-897's TTL serial data (0-5V) to a 'regular' RS-232 serial stream (-9-0-9V).
The two isolation transformers eliminate ground loops in audio between the computer and the radio's data port. An opto-isolator (lower-left) provides PTT. Version 2 will add a second Opto to provide CW Keying from the serial cable.
This is probably Version 1 - I've included a separate Parallel port CW key mechaism, but the whole design point was to eliminate 'separate parts', so that one interface can handle CAT (rig control), DATA (audio to data port), and both PTT and Keying.
Parallel Port CW Keying is opto-isolated.
Finished version combines Data and CAT cables and a separate parallel port CW cable. Housing is a Hammond Aluminum case.
"An Automatic Sealed-Lead-Acid Battery Charger" project from QST.
Alternate 'Universal Keying Interface'
Part 15 FM Broadcasting with the NS73M module, controlled by an Arduino.
LCD displays current frequency, Set, Down, and Up buttons, a 3.3V regulator, and the NS73. Above that, a bare-bones Arduino from Modern Device Company.
LCD displays current frequency, Set, Down, and Up buttons, a 3.3V regulator, and the NS73M on it's breakout-board from SparkFun. Above that, a 'Bare-Bones Arduino' from Modern Device Company.
LCD displays 102.5 Mhz. The frequency counter confirms just about that on the RF Pin. A short wire connected to the RF pin drives a Yamaha FM stereo tuner across the room.
