Update on Electronic noise during recording

After we moved to a new home, I had not been able to record vocals on my computer due to a constant electronic noise in the background, something like a high-pitched whine and chatter.

After a lot of troubleshooting, I purchased a Ziocom Ground Loop Noise Isolator from Amazon ($9). It is a small non-powered device that plugs into the microphone input (3.5mm) on the computer, and the output from the mixer board plugs into the ground loop isolator. Just that quickly, all the chatter stopped and the recordings are clear again, except for a background hiss. I’m going to try a DAC to convert to USB digital prior to the PC and see if that fixes it.

The concept is that the ground point of my computer and the ground point of the mixer board are different, even though they are in the same room. This creates a slight “potential” (DC current) which is then amplified by the mixer as electronic noise. This gizmo filters out that current and lets the audio signal through.

I used an XLR female to 3.5mm audio cable from the mixer to the isolator.



(NOTE: I am not an electrician. I am familiar with basic wiring, having done simple projects for about 30 years. If you are not entirely comfortable doing such a project, please hire a licensed electrician who can easily do it for you, or just change out the entire fixture.)

The light fixture in my closet was under-powered so much that I couldn’t tell the colors of the shirts. I removed the glass cover and discovered that it was using orange-colored compact fluorescent bulbs with an odd base I hadn’t used before (GX24Q-2).

I searched online to see if there were LED lights that used this base, and found that while there were some, there were also adapter bases made to allow a standard bulb to be used. I purchased 6 off of Amazon and looked at the wiring description which wasn’t a lot of help.

It said to remove the fluorescent ballast entirely, but leave the wires attached to the GX24Q-2 sockets. On each socket there are 4 wires, 2 wires will be unused, 1 will be attached to the 120V white neutral wire and 1 will be attached to the 120V black hot wire.


I shut off power to the fixture at the breaker to prevent accidental shock. I removed the fixture from the ceiling and unscrewed the 3 wire-nuts holding the fixture to the house wiring (Ground, Hot, Neutral).

I used my multimeter to test which of the pins on the new adapters went to the screw socket and which went to the base contact. The side of the screw socket will be connected to the white neutral, and the base contact will connect to the black hot.



I found that 2 of the pins on the adapter were not connected (these correspond to the 2 unused wires), and then labeled the 2 remaining pins either B or W for Black or White. I also labeled the sockets attached to the light fixture so I could easily match them. (I’m not sure that it really matters for a bulb, but since I’m not sure, better to just err on the side of caution).

I used a marker to put a dot on each wire that went to either the B corner or the W corner. The other two wires I bent down and attached a wire-nut to keep them from touching anything electrical. I arbitrarily decided to make the yellow wires attach to Black 120V and the others to attach to the White 120V.


I used wire-nuts to attach the colored wires to the house wires. I turned on the power again and tested the lights which worked perfectly. I reattached the fixture to the ceiling.

All in all, the directions that came with the adapters left a lot out. It would probably have been easier to just get a new fixture, but it was a lot cheaper to do it this way. As I said at the beginning, if this is beyond your skill and understanding, please do not attempt to do it yourself. Hire a licensed electrician to do the work.

IP Cameras – trouble with plugins for viewing

I install rather a lot of IP cameras for security. I’ve been seeing a recurring issue with manufacturers using plugins in order to view the camera feed. For example, when viewing a Samsung (now Hanwha) camera via its IP address, it first pops up a screen with a link to install a plugin. Once this installs, the browser is supposed to close and reopen and be able to view the camera. Sometimes that works, like on my laptop. But other times, it keeps going back to the plugin install page. On those computers, I’ve never been able to get the browser to view the camera. I can view an RTSP stream, just not the built-in program for configuring the camera. No idea what the difference is between the two systems. If Samsung would drop the plugin and go with HTML5, then the program would be compatible with any browser.

Vicon uses built-in Java for viewing and configuring their cameras. But the version of Java on the camera is older day by day, and so Windows quickly does not trust it and each camera has to be entered into the Java exception screen in Control Panel. Java then wants to reset this list for safety reasons. Ridiculous waste of time just to be able to configure the camera.

Netgear switches (GS110TP) that I use to hook the laptop to the IP cameras also use a Java plugin to view the switch layout. Clicking the link doesn’t install the plugin, it just redirects to the Sun Java homepage, which is useless. Besides 64-bit Firefox cannot install such a plugin. Browsers are moving away from such approaches and going with HTML5. Thus there is a part of the switch I have that I cannot access due to the manufacturer deciding to use a plugin instead of a standard web page or HTML5. I can’t get my laptop to install the plugin because I have 64-bit and Firefox. I can still do most functions on the switch menu, but am blocked from other sections.
I’ve read on Netgear forums that this problem is marked “solved”, but all they said was “please open a trouble ticket” and then closed the thread. Yo Netgear, that isn’t solving the problem! So what if you “are aware” of the issue. You’ve “been aware” for YEARS now. Hire some programmers and dump plugin entirely.


Moz-extension entry in Firefox history

Recently I noticed an odd thing appearing in my Firefox history. Whenever I would first start the browser, a line would appear in history:


A search yielded no result. I did find one discussion about a similar case where an add-on (extension) was causing this. I did other searches based on just “moz-extension” and “blank.html”. Eventually, I disabled a handful of add-ons and restarted Firefox. No odd entry! One by one I enabled them until I found the one that causes this entry:


I am writing to them to see if they know why this is happening.

Android g900vvru2dpf4 update, no Linux connect

After I upgraded to the latest Android g900vvru2dpf4 software, it no longer wants to show any files when I connect via USB to my PC. Tried reconnecting physically several times. No joy. I’ll keep messing with it in case I missed something.

EDIT: Had to go into developer mode and change USB setting from charge to connect. It will still charge but now the computer sees it as a device and can connect.

Form colors in Firefox 46

When I updated Firefox to 46, I noticed that something odd happened. The browser now had an odd brown/gray color and some forms (like on Yahoo news) had white text on a white background. I had recently used an addon called Stylish that allows the colors for certain websites to be changed, which I had done for the bright white of Google, changing it to a darker theme. But after the upgrade, Firefox continually had a dark upper menu area and the forms on Yahoo had white text. I even removed the Stylish addon, but the changes remained.

The most pressing part was the form text color. It made them basically unusable. One person suggested using a CSS file, and I tried that and it worked once and then not. No idea why it stopped. But Firefox has its own way to set form text colors, and that always works.

In the about:config page, I typed in browser.display to see the various options. These are the ones I set:

browser.display.focus_background_color;#FFFFFF (sets form background to white)
browser.display.focus_text_color;#000000 (sets the text color to black)
browser.display.use_focus_colors;true (tells Firefox to use the colors I specify)

The effect is immediate.

I gotta go, someone is wrong on the Internet… 🙂

Update: As of FF 47, all the coloring returned to normal.

Nurse call station replacement

I was asked to repair or replace an old nurse-call station in a medical room. The current device was discontinued back in the 1980s (Rauland PCS-7351A), but has been working fine until the pull-string was pulled too forcefully. The purpose of the unit is simple: If a patient needs help, pull the string and a switch clicks and turns on a light and buzzer in the nurse station corresponding to the room number of the patient. A light on the switch also illuminates, indicating that it is working.

Rauland PCS-7351A 1

I took it out of the wall and realized that I had already repaired this unit once before, and it was likely going to break again. So I went online to see if I could find a replacement. I found a variety of call stations from various vendors that said they were equivalent. I finally settled on a suitable model and bought it. I knew the biggest challenge would be getting the back wiring correct. Since nobody who installed the original system had labeled anything, I had to guess at the purpose of some of the wiring.


Happily, the new unit came with a diagram that should give a 1-for-1 idea of where the wires should go. But I noticed a difference in how the old one was wired compared with the diagram. I guessed that it was simply a slight difference and made up my own diagram to take with me to the room.



I hooked it up according to my handwritten diagram and it worked! Happy camper. The new unit is a much simpler toggle design than the old one. Time will tell whether it will withstand use and abuse. The most obvious flaw I saw was the simple nut on the face plate that keeps the switch in place on the new unit. A disturbed patient could unscrew that, push the switch into the cavity and cause a repair call, though the switch would probably still work.

old unit

new unit

If it turns out to be a problem, I may have to find a smooth surfaced unit to replace it. I did see one such unit in service in the same ward, but haven’t had time to examine the wiring. This is the Rauland PBS113, also discontinued, though we have a spare or two. No idea what the various wires do, and no diagram to help this time. However, an old tech at Rauland kindly sent me a PDF with text that describes which wire goes where on a call station, and that will prove useful.

Rauland PBS113


I did find a waterproof (WP on the diagram) design by Crest that uses a magnetic reed switch. I am guessing at the wiring, and show it here as a possible solution since I haven’t had a chance to try it yet.