Good afternoon all, Here is a powersupply problem that needs a neat fix. When my wife runs the highspeed washing machine, the whine and hum goes up and down and also off and on when I am on my trusty
My first thought, having a similar experience with a sewing machine, is to determine the input source. In my case it was NOT the power line, but rather DPI (Direct Pickup Interference) on an IF frequ
Phil, many thanks for an alternative hypothesis - I should have built a Faraday shield around that laundry room :>) Now that you mention that approach, the problem of the changing pitches means that
Kris, There are no guarantees with line filters. If you can borrow one from someone, you try it and if it works you install it permanently avoiding long leads that might cause filter blowby. Is there
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Wed, 03 Feb 2010 14:14:43 -0800
Don't blame environmentalists -- it's lousy circuit design. This doesn't sound like a line filtering issue, but it DOES sound like possibly improper connections of neutral and the power system green
Author: "CSM\(r\) Gary Huber - AB9M" <glhuber@msn.com>
Date: Wed, 3 Feb 2010 17:21:59 -0600
And if you have more than one electrical panel, only the first panel (Main Distribution Panel) has a Neutral - Ground bonding screw in place. All sub panels are to have the neutral - ground bonding s
Step 1 - disconnect antenna to rule that out. Step 2 - try simple stuff, like wrapping the power cord around a ferrite core Good afternoon all, Here is a powersupply problem that needs a neat fix. Wh
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Wed, 03 Feb 2010 15:57:33 -0800
Right. Clarification for those who don't do this every day. There's a big screw in a breaker panel when you buy it that bonds neutral to the frame of the panel, and the green wires (and physical grou
The first thing to determine is whether the shack outlets are on the same side of the line or the same branch circuit as the washer! VSD motor circuits are elegant for what they do, but they distort
A brute force line filter for the power line. In older versions of the ARRL handbook a circuit was published for years which was simple to build in an evening. I built and used them with early comput
Until a few years ago (or maybe more than a few as I age) National Electrical Code only required a 3 conductor cable to feed a clothes dryer. There were two hot conductors (220 volts for heat) and on
Yea, you are right. But that actually changed quite a long time ago in fact. Talk about dangerous ! _______________________________________________ TenTec mailing list TenTec@contesting.com http://li
And, since were talking about electrical panels and washing machines, NEC states that the laundry must have a dedicated circuit for the washing machine, with it's own dedicated neutral and ground wir
Not so sure about this. I believe the present NEC allows three wires for 240 VAC service. Two hot leads and one ground. There is not neutral run on a modern 240 VAC service feed, because it is no lon
Author: "CSM\(r\) Gary Huber - AB9M" <glhuber@msn.com>
Date: Thu, 4 Feb 2010 08:35:32 -0600
NEC 210.4 Multiwire Branch Circuits. This is a circuit that "consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has an equal voltage between
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Thu, 04 Feb 2010 10:16:36 -0800
NO! It all comes down to how the 240V appliance uses power. Certainly 240V for the heating element, so that's two hots and a ground. It's easy to make a motor that runs on 240V, so no neutral would b
Ken and the group, I subscribe to "ECM", an Electrical Contractors' magazine. It has a monthly feature on Electrical Code application. Generally, in something like an existing electrical dryer instal
The reference to that is NEC Article 250.140. Specifically, it address the use of an external grounding conductor to the frame of a 4-wire dryer on legacy 3-wire service when several conditions are
Author: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Date: Thu, 04 Feb 2010 15:09:54 -0800
The problem is that such a connection DEGRADES SAFETY. That's why the code was changed! AND such a connection creates a magnetic field that can cause hum in electronic systems. 73, Jim K9YC _________
Yes....the newest code does indeed require this. Not all local inspectors do though. And of course the bathroom (and the kitchen maybe?) have to be on GFI circuits as I recall. Sure is different from