after more than two weeks of not being able to start up the XJ, i was finally able to resolve the issue. turns out the ignition coil had gone bad. the Haynes manual gave guidelines for checking the resistance between the primary and secondary coils which all checked out with the coil. it was until…
PT2399: nuances…
i’ve been wrapped up in Jeep repair lately as there’s some sort of issue prevent the beloved XJ from firing up. i have, however, in the meantime had some time to work through my initial modulation tests on this version of the PT2399 circuit and nail down a lot of the bugs. the initial problems…
initial test of a modulated PT2399 circuit…
a breadboard version of some PT2399 modifications i’ve been working on. there are a lot of DIY schematics that utilize the PT2399 (Magnus Modulus, Echo Base delay, Rebote, etc.). i’ve been interested at trying my hand at modulation techniques recently. i made a simple LFO circuit based on the findings mentioned in a previous post….
MOSFET overdrive… final build?
i might add some labels for the pots and contact info, but it’s done for the most part.
simple LFO circuits…
i was reading over this thread on diystompboxes.com about building an analog LFO circuit for some wild noise idea i’ve got brewing in the back of my head. i started messing around with some of the schematics on there and got a drifting saw wave out of it after a while. i was trying to…
TDA2040 PCB layout…
backlit PCB layout of the TDA2040 solid-state amp i’ve been working on. i’m still using perf boards until i wrap my head around designing PCB layouts in EagleCAD. i do a lot of work in the dark.
TDA2040-based amp schematic with EQ…
well here’s the first draft of the simplest medium powered solid state design i could muster. TL082 can easily be substituted with a TL072 which is probably better anyhow (i just have all these TL082s laying around). the power supply i’m using more like 14-15V. both ICs should easily be able to handle up to…
Sinometer 10MHz oscilloscope…
simple. cheap. a thing of beauty to add to the ol’ workbench.
experimental PTT signaling switch…
this is an experimental circuit i threw together today. i’ve been working on getting a VOX circuit to work with the Yaesu FT-60R (VX-3R, VX-5, etc.) and Soundmodem on the ol’ Gentoo box. it’s working well, but test packets have been a little iffy.