I re-wired an amplifier heater circuit to an external current-limited stabilised dc supply. We had to fit larger heatsinks and more fans to keep the supply cool and arrange for this to be switched wi
I've heard Power Point can be used and that it has a measurement gauge. Have not tried it myself. You can insert all kinds of pictures and drawings. One thing I discovered recently: you can copy and
One trick I saw on the web somewhere: buy a filing cabinet and put the RF deck in the top drawer and psu in the bottom drawer. Cheap and fairly sturdy, particularly if you screw it to the wall, with
Here is a site on which SPICE models of some valves (tubes) are modelled http://www.normankoren.com/Audio/Tubemodspice_article.html I'm sure there are others I've seen other 'difficult' models like l
The vending industry replaces its machines about every 5 years or so, from small table-top to large floor-standing machines. Some have rare parts removed for servicing and the rest is junked. This co
I'm told Dettol works well as a bug repellent, particularly the Canadian mozzy which have spurs and buzz saws. David G3UNA _______________________________________________ Amps mailing list Amps@conte
Following logically from what you both say, my guess is that the load capacitors are fed with current via a nut and screw or the like. The current running from one surface of the chassis, via the scr
Fascinating stuff, this. Each surface of the plate, then, has different currents flowing along it: take a large hole in the chassis and connect a thin wire from one side to the other only touching ea
The current is taking many paths across the surface of the disc to get to the other side. Not sure what this means, but if you used a strip to reduce the number of paths, that might demonstrate somet
Heat can be a friend but it's usually our enemy in so many ways. Yet, to prevent melt-downs and dangerous conditions it is the easiest indicator of failure to detect and manage. A carefully placed pt
Paul I posted a note a few days ago regarding use of ptc resistors, thermostats, et al as protection devices. It went unchallenged, so I guess folk are not interested much in safety, or, at least onl
Coupled to all those antennas, no wonder you are loud. David G3UNA Guess I´m an idiot then since I have an amplifier I only run at 50 percent of the possible output power. ___________________________
Some semiconductors I worked with years ago were rated for 25 years continuous operation at maximum temperature. It was said that the tracks inside the part migrated to the next nearest track over ti
I would have thought the folks that work at these sites have addressed the emc with their vehicles long ago. They will have an unprecedented wealth of knowledge, I'm sure. No doubt there will be a fa
Jim Thanks for the tutorial. I've often wondered about the movement of energy in and around a stub. Harmonic energy is delivered from the PA to the output feeder and onwards to the stub. Would I be r
Thanks for doing the sums, Jim, I was interested in the theory. I thought energy would be reflected in both cases of open and closed circuit stubs. Something new to learn every day. David G3UNA Get y
Download yourself a copy of MIL HDBK 217F and look at the section on aluminium electrolytic capacitors. There's a nice calculation for MTBF and it is influenced by, amongst other things, voltage and
Further to my email about MIL HDBK 217F: It is dated 1990, so, not as current as you might like, but a good reference. page 10-24 refers to some aluminium electrolytics with a table for 125C types. W
You might consider imbalance in each side of the primary which will cause a net dc to pass, saturation and over-heating. This may be rubbish but it could get others thinking along a different path. D
I've looked again at the jpg and I think you have used trifilar windings, so, that's my first idea more or less gone. Imbalance can be due to poor coupling between the windings themselves or imbalanc