Chat Placeholders

Here is a screen shot showing my use of multiple chat room placeholders during this morning's QSO on 3740 kHz. The placeholders serve as a reminder, to QSO participants logged into the chat room, about our friends on the radio who are not logged into chat.  A web browser's support for multiple tabs enables creating the extra placeholder log-ins within a single web browser window. My personal favorite for handling many tabs is the Tree Style Tab add-on, as seen in this screen shot.

Sound card controls for VoIP patching

Here is an updated graphic with notes showing the results of my further testing of VoIP phone patching. I found it convenient to keep both sets of controls open, side-by-side, while using my headset (connected to the PC sound card (analog) jacks. Click on the graphic below for a larger view.

In general, the Recording settings (right side of graphic) control the audio going TO the distant VoIP party, on a phone call or Skype session, for example. The Playback settings (left side) control:

• the distant party's VoIP audio going to the transmitter
• the local operator's headset microphone audio going to the transmitter
• the receiver audio going to the local headset and to the distant VoIP party

The sound cards in my older PCs use a "select" check-box in the Recording controls. Only one choice can be selected at a time. To enable passing both microphone and receiver audio to the distant VoIP party, I select one of the "mix" settings. The sound card on my newer PC has mute check-boxes in the Recording controls. In that case I could mute or unmute any devices, in the same manner as provided in the Playback controls.

VoIP Patch Update

I've done off-air testing of my previously-successful VoIP phone patching using a younger PC (Pentium 4, 2.8 GHz). Here is an annotated screen shot that shows the sound card settings along with Skype audio settings. I'll use the three control panels shown during on-air operations while I verify the best configuration. Previously I have used only the Gmail Call Phone VoIP application. The younger PC has the CPU power needed to run Skype. The older Pentium 3, 600 MHz PC could manage Gmail Call Phone (Google voice) at 76 to 100% CPU utilization.

Click on the image below for a full sized view.

Skype's floating toolbar

Here is a screen shot showing the floating toolbar near upper right side of my desktop.

Test Tone Waveforms

The test tone files shared by Carl can be used to illustrate the capabilities of the free, cross-platform audio editing program Audacity. Below is a screen shot showing the 3 individual tone waveforms and the composite waveform, as displayed in the program. The tones were of 30-second duration, but this display is zoomed in to about .06 second to make the waveform shapes clearly visible. Click on the image to enlarge.

Audacity also has a frequency analysis tool that produces a plot of amplitude vs. frequency for up to 23.8 seconds selected from a waveform. Below is a screen shot showing the analysis of the composite waveform, with the 3 peaks corresponding to the individual notes (C, E, G) or frequencies contained in the composite. Click on the image to enlarge.

This program, like others of its kind, enables a user to record audio entering a PC's sound card, and to perform edits on all or portions of a recording. Such simple edits as copy/cut & paste, and amplitude changes can be done with the same ease as their equivalents in a word processing program. Many other editing functions are included.

Toroid choke for VDSL modem

I noticed that my transmissions on 3740 kHz were often accompanied by a loss of sync on the VDSL modem that provides U-verse service to my home. This is not surprising, given the frequency spectrum used by VDSL and the proximity of my dipole antenna to the aerial service drop that brings phone service and U-verse to my home. I obtained a large diameter ferrite toroid -- FT-240-J from Amidon and installed it on the DSL line cord at the modem. The 'J' material is designed to provide excellent attenuation in the 0.5 to 20 MHz range. Below is a photo showing the installation.

This toroid is large enough to thread multiple turns of the DSL line cord with the RJ-11 plug attached. Since the toroid resolved my interference issue, I could install a smaller toroid with the RJ-11plug temporarily removed, and save the large toroid for future troubleshooting or other problem resolution.

Hurricane Irene's Track

On 8/22/11 I saved a screen shot of the forecast model tracks for Hurricane Irene. See below, and click on the image to enlarge.

It is interesting to compare this with the actual track of the storm as shown below.

Of the various forecast models, the NGFDL seemed to have a good fit as the storm approached North Carolina, while the GFS had a good fit during the later path of the storm. According to what I saw on TV, the model tracks were all pretty close together as the storm traveled up the east coast. Naturally, small changes in the track's position east or west made a big difference in storm surge at the local communities on the coast.

Note that 8/29/11 was the 6th anniversary of Hurricane Katrina's landing on the coasts of Louisiana and Mississippi.