Mon DU1FV

A forty seven year old trick. Some of the readers here may remember the post I made on the Pioneer tuner I converted from Japanese to local standard. Before I made the mod. I had to repair the tuner. Right out of storage, when turned on, the tuner audio out would produce what I would described as a loud crackling sound intermittently. To many radio techs, the word "intermittent" is a dreaded word. An accompanying symptom included diminished sensitivity. I had just repaired the oscilloscope the day before. I had to replace a resistor in the focus section of the CRT circuit as the normal dot trace was as big as a grain of corn. The 'scope is the best instrument to track down the source of the noise. Poking the 'scope probe here and there lead me to a AM section IF amp stage which had an odd reading of voltage. So the immediate thought was that the transformer was shorted. I took it off the PCB and examined using a good magnifier. There was no apparent short between t...

(Long) Many years ago, I went to Paranaque to visit a guy who advertised used Japanese HiFi equipment and a smallish Pioneer AM FM tuner caught my fancy. Since it is a digital tuner and the FM band can only receive a couple of local stations (because the Japanese FM broadcast band is from 78 to 90MHz, while ours is from 88 to 108 MHz) and haggled with the shop keeper to get a good price. Unfortunately back then, no information can be obtained even from the internet on this particular tuner model. Two weeks ago, I got a small 40W p.a. and thought I'd dig up the old Pioneer tuner and listen to AM. By the way, it turns out it is one of the rare models that could receive AM stereo (C-Quam standard -used in the states and Japan. Unfortunately, AM Stereo boradcasting has been on the decline and Japan stopped AM stereo broadcast a few years ago. DWWW at 774kHz still lights up the stereo indicator but the audio received is monoraul. I don't know why but maybe the engineers at...