Borivoje Jagodić : OME Test oprema

[HomeMadeAudioProject]

<p>i ranije sam ja pokušavao ovo da pokrenem ali dosta bezuspješno,ali sam kasnije naišao na nekoliko savjeta na ESP <a href="http://www.sound.westhost.com/project16.htm">http://www.sound.westhost.com/project16.htm</a> ,tamo se radilo o istom projektu samo sa tranzistorima mada uputstva su poprilično univerzalna:</p>
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<blockquote class="ipsBlockquote"><p><span style="font-size:14px;">Enclosure-</span><span style="font-size:14px;">The case used must be all metal, since the attenuator and meter amplifier needs good shielding against noise pickup. This can be made from sheet aluminium or other metal (steel, brass, etc) if you have the tools to work with it, otherwise a suitable case may be obtainable from your normal parts supplier.?</span><span style="font-size:14px;">Another alternative is to use un-etched copper clad printed circuit board. Cut the panels to size, and solder together from the inside, filing off the outsides so the panels are all flush, and finally finishing the unit with a suitable coat or two of paint. There are many different finishes available in spray cans, so take your pick.?</span><span style="font-size:14px;">Cases built in this way can look surprisingly good if you take the time to finish them off well. ??</span><span style="font-size:14px;">Construction-</span><span style="font-size:14px;">Make sure that the 0V line (the junction of the batteries, bottom of the attenuator string and earth input terminal are all tied to a common point on the front panel, and that the remainder of the case is in good electrical contact. If the case is not earthed properly, this is worse than using a non-shielded case!?</span><span style="font-size:14px;">It may also be necessary to add shielding between the FET stage and the main meter, and a small cap (10nF should be connected across the meter output, as close as possible to the diodes. Keep all leads short, and ensure that the output leads are kept well away from the input.The meter amp is wide band, and has a full scale sensitivity of 3mV. It will oscillate if there is any feedback from O/P to I/P or between stages. ?</span><span style="font-size:14px;">Front Panel-</span><span style="font-size:14px;">Drill all holes first for the two rotary switches, the meter and its mounting bolts and the input connectors. I always use a BNC connector, but for audio an RCA connector might be better. One can also use "banana" sockets, so you can use ordinary multimeter leads, but being unshielded they will pick up noise - especially on the lower voltage ranges.Make sure that all panel components fit properly, and de-burr the panel on both sides.Mark the switch positions for each setting very carefully, since markings that do not line up with the pointer on the switch knobs look tacky, and can be confusing when you use the instrument.</span></p></blockquote>