iPad app for Discord

 Here are some annotated screenshots that show some features of the app as seen on an iPad. This user interface is nearly identical to the interface on a desktop or laptop computer. Click on each image to view full size.

John

RV Net - 10/8/2020

Below you can listen to an MP3 file of audio from my FLEX-3000 transceiver, recorded during the second hour of the RV Service Net. I edited an 18-minute recording to remove long periods of no usable signal. I left in a few short segments where a signal was marginal. The result is less than 15 minutes long.

RV Net - part of 2nd hour

The stations heard include: AI1N,W5BUY, W8MQ, N0JHX, KC4GO, and W4BXI. You'll hear W4BXI as net control station transmitting from the following sites, in order: N4GYN, WA5MLF, KC4GO, W4UOA. W4BXI connected to each station via the Internet, using software from RemoteHams.com.

When transmitting from WA5MLF, there is no background radio noise, since the recording captured the VoIP audio coming into the transceiver from the RemoteHams software components.

I have a few other short recordings, from that same net session, that also may be worth sharing.

73,

John WA5MLF

Ionosonde sweeps the 40 m band

 

 

 

 

 

 

 

While viewing the 40 m band with my SDRplay receiver I saw a strong ionosonde signal sweeping across the band, as shown in the above screenshot. The top part shows the signal on the panadapter view (horizontal axis is frequency, vertical axis is amplitude). The bottom part shows the waterfall display (horizontal axis is frequency, vertical axis is time, progressing downward). Signal amplitude is represented by brightness. The sweep shows here as a diagonal line. Other stations on the band are operating on fixed frequencies.

Data collected by the ionosondes around the world are publicly available. See my blog posting: Graphs of Maximum Usable Frequency from Ionosonde Data for more information. The collection and analysis of data from ionosondes is managed by the GLOBAL IONOSPHERE RADIO OBSERVATORY.

I captured a video of the SDRplay window that includes a sweep, as seen below. There is no sound in this recording. Normally one hears only a short chirp as the sweep passes through the receiver's audio bandwidth. On this view the 2.8 kHz audio bandwidth is the thin vertical column in the center. Other active signals on the band are seen as the up-and-down white vertical spikes.

 

RCForb testing with foot switch

W4BXI is using a custom circuit to interface an ordinary foot switch to the TX function of the RCForb client program on his Windows PC. We have observed occasional stuttering in his transmit audio during the first 2 seconds or so after the foot switch is pressed. Today I made a recording of his contact on 40 m, transmitting from W4UOA, with a Virginia station. The full 3.5 minute recording is available below for listening.

QSO on 7193 kHz

You can hear the audio stutter just past at about 2:24 in the recording. Below is a 2-second excerpt from the recording along with a screen capture of the audio waveform that shows several quick drop-outs as received in Baton Rouge. 

2-second portion with audio stutter

Additional testing is being arranged to isolate the cause of the drop-outs.

RV Net - 9/24/2020

Here are 5 audio clips from the second hour of the 9/24/20 (East-Central-Canada) RV Service Net on 7.191 MHz, recorded from my Flex-3000 transceiver in Baton Rouge. Any long time segments with no readable audio have been shortened or edited out. The stations heard are identified above each audio clip. 

John WA5MLF

AI1N

W8OI, WK1F, N4JLR

N4JLR, W8OI, WW1SS

K9JWJ

K9JWJ, W4BXI (via N4GYN), K4ICZ, W4OWT

WU5E (Korea) to RVNet -- 9/17/2020

 WU5E checked into the RV Net from South Korea using an Internet remote connection to his Flex-6600 in Tennessee. Below is part of his exchange with net control W4BXI. The audio was recorded by WA5MLF in Baton Rouge on his transceiver.

The figure below shows that WU5E and W4BXI use the Internet to connect to separate transceivers remotely. There is no direct Internet connection between their computers.

Sloper Antenna for 20 m thru 10 m

A sloper dipole antenna is planned for evaluation at W4UOA to supplement the two horizontal dipoles and one horizontal loop antenna. The hyperlink in the previous sentence has a very nice analysis of the sloper antenna. I offered to do some modeling of the new antenna at W4UOA, and some results are presented below. The antenna is sized (length = 29 ft)  according to W8JI guidelines for a multi-band dipole. The radiation plots are oriented for a westward direction of greatest gain. The heights of the antenna ends and the slope angle are arbitrary starting points. The antenna is to be fed with 450-ohm balanced line that transitions to 50-ohm coax cable thru a balun.

Click on any plot to magnify.

This plot shows the total gain (horizontal and vertical polarization) of the antenna at 14.25 MHz in the horizontal plane. The blue curve maps the gain (dBi), with the scale progressing outward from the center of the plot. The labels around the plot are azimuth, like compass bearings, going clockwise around the circle. 0º is North. The antenna is in the plane oriented east-west. The maximum gain is 2.25 dBi at azimuth 334º.

This plot presents the total gain in the vertical plane. The labels around the circle are elevation (above horizon) angles. This shows the maximum gain (2.25 dBi) occurring at 46º at azimuth 338º.

This plot shows the vertical gain in the horizontal plane. The maximum gain is 2.11 dBi at azimuth 270º and elevation angle 72º.

Here is a 3D view of total gain with colors to signify the gain according to the scale at the left side of the figure. The slanted white line represents the antenna structure. The web link at the top of this article has a very nice animation of 3D and 2D views showing how the gain varies with the angle of the antenna from vertical to horizontal. The author of the article uses the same modeling software as I have used for these plots.





The W8JI article with guidelines for multi-band dipoles recommends balanced feed line of 300-ohm characteristic impedance.  Since Carl has 450-ohm balanced line on hand, I ran comparisons of the design using both feed line types, for the frequency range of interest -- 14 to 30 MHz. The modeling software generated tables of data including: SWR, gain F/B ratio,impedance (R, X, |Z|, phase). I made graphs to compare the SWR vs frequency and impedance (magnitude) vs frequency for both feed line impedance values. The graphs below show that for most frequencies there is not a large difference between the results of the two impedance values.  The SWR data are based on a 50-ohm source impedance. These results do not include the coax cable that will extend the balanced line to the antenna tuner. That detail can be added to the model at any time.

I would prefer to start these graphs at 14 MHz, but I don't know how to prevent Excel from starting at zero on the x-axis.

It will be interesting to see how this new antenna performs at W4UOA in comparison with the other antennas.

73,
John WA5MLF

Radio Propagation Issues for the RV Service Net

During several months of observing the Eastern/Central RV Service Net and providing remote station access to W4BXI, the ability of net participants to communicate was analyzed.

The results of our study are presented in this document (PDF), which is focused on the 40 m band propagation during the time frame of the morning net on 7191 kHz. Marginal radio propagation at the current low point in the Solar Cycle makes it difficult for net participants to hear each other.

Our presentation combines observations of signal levels, net participant reports, ionospheric "soundings" and propagation modeling.

John WA5MLF
Dan KC4GO

RV Service Net - 11 April 2019

During the second hour of Thursday's net I captured some audio and screen shots of the activity. The net control station, Sam WA4ICK, was S9+10 to me (in Baton Rouge) and painted a strong image on my FLEX-3000 SDR waterfall/panadapter view as shown below.

Click on image for an expanded view.

Improved propagation noted by several net participants can be attributed to an active region (with sunspots) on the Sun that has rotated back into Earth view and is raising the solar flux. On April 11 the sunspot number was 13.

A sample of the audio recording from around the middle of the second hour illustrates the reception here of signals from WA4ICK and W3TOM. Below is a screen shot of a portion of the audio waveform. You can see how the signal-to-noise (S/N) ratio changes after the hand-off from WA4ICK to W3TOM at about 1/3 of the way from the left.

Click on image for an expanded view.

The first third has a narrow baseline between syllables, indicative of my receive AGC turning down the gain in the presence of the strong signal. The remainder of the waveform has a lower S/N ratio as indicated by the thick baseline. Some fading is evident. The signal improved after the first few seconds. In this later 2/3 of the waveform the AGC opened up to allow more signal, but the noise was also higher. Click here for a 47-second recording that includes the portion represented by the above waveform.

 I have two longer recordings that I can share with interested parties upon request.

73,
John WA5MLF

RV Service Net Reception at WA5MLF

During the last half-hour of yesterday's RV Service Net the signal from W4UOA was solid at Baton Rouge. The distance from my station to W4UOA is 430 miles.

Below is a screen shot captured at 0751 CDT, while W4BXI was transmitting on 7191 kHz  from W4UOA. Another strong signal can be seen below 7188 kHz.

Click to enlarge view.

A little earlier (0728 CDT) I recorded KB0BH checking into the Net and acknowledged by W4BXI. The recording (click here) was made from my Flex-3000 transceiver in Baton Rouge.

73,
John WA5MLF

Open Wire and TPARCA

Click above to enlarge image.

Here's the cover of the March 1989 issue of Open Wire, the news bulletin of TPARCA. Note that the dial-up bulletin board system was in use at the time. For a bit of nostalgia you might like to listen to the sound of a dial-up modem connecting on this YouTube video. It offers explanations and waveform views of each stage of the connection process, starting with dial tone -- something that young folks rarely hear.













Among the contents of this issue was the following certificate from the ARRL:

   

The back page of the issue includes the Telephone Pioneers emblem:

N4AHJ has provided a large volume of historical Open Wire and TPARCA material that I can make available to any interested members.

73,

John WA5MLF

Chat Room Tips

Here are a few tips about use of the new chat room:

Right after you log in, the window below displays briefly. Note the short-cut keys for quickly switching chat rooms. You can also use the 3-dot menu and click on the chat room that you want to use.

You can identify which chat room you are currently using by looking at the colored stripe at the top of the chat window. See the two cases below.

Also, note that the chat time stamps do not identify the date. If there a few entries on consecutive days it is hard to be sure when the date has changed.

John WA5MLF

CQ TP and CQ WE 2018 Results

CQ TP results are at: http://www.tpqso.com/2018/results-2018/

CQ WE results are at: https://cqwe.cboh.org/2018.htm

Chat Apps

Various free chat/messaging services are available for those who are willing to sign up for a free account. Examples include, but are not limited to: WhatsApp, Signal, Telegram, GroupMe, Wire, Skype, Twitter.

Google also has a chat app that can be used at https://hangouts.google.com/ by clicking on the MESSAGE icon. 

John WA5MLF

RV Net Stations and Remote Transceivers

Observations of received signal strength from various participants in the daily East Coast RV Net on 7.191 MHz has revealed a daily pattern of reception range during the 2-hour period of the Net. Below are map views that show distance (as a circle) from each remote transceiver site that is used by W4BXI. Click on any map for an expanded view.

500 mile range: During the early part of the Net, stations within about 500 miles of a remote are not readable from that remote, unless within ground wave range.
300 mile range: During the later part of the Net, stations within about 300 miles of a remote are not readable from that remote, unless within ground wave range. 

500 mile radius from W4UOA

500 mile radius from KC4GO

500 mile radius from WA5MLF

500 mile radius from W6SFG

 

300 mile radius from W4UOA

300 mile radius from KC4GO

300 mile radius from WA5MLF

300 mile radius from W6SFG

Antenna Spotting, by Jim N6TP

A Great Antenna Location

Antenna spotting is somewhat like the other spotting hobbies such as Bird Watching or Train Spotting.

If you enjoy amateur radio, and if you are like me, I am sure you keep an eye out for amateur radio antennas. Several years ago, on a vacation trip to Europe with my family, I indulged myself with a little antenna spotting plus some technology observations. Actually, I did not see many identifiable amateur radio antennas, but did hear and see other interesting sights.

Our itinerary took us to London for four days. London was fascinating with many changes in the last thirty years. Then we flew to Copenhagen from London via Stockholm. We picked up our bus tour of Scandinavia starting in Copenhagen, Denmark. For the next two weeks we enjoyed a two-week tour to Denmark, Sweden and Norway. By the way, we had great weather all during the trip.

You have heard a lot about airport security recently, which is mostly true. You can expect to be checked several times every time you board a flight. I suggest you wear new socks with no holes in them, as you want to avoid any embarrassment. We transited through Frankfurt Airport on the way back to home. As far as I could tell, we went through four security checks, just to get into the boarding area.  So be prepared to show that passport at all times.

My portable AM-FM short-wave radio was somewhat useful to keep up to date on the news and observe radio conditions. This particular radio has a long wave band that covers from 160 to 290 kHz. In London, I heard several broadcast stations in that part of broadcast band but not in other parts of Europe.

It is interesting to note, that there were very few English broadcasts on short wave. There were no BBC, Voice of America or Armed Forces Radio Network services that I could hear. Maybe they have all gone to the Internet or satellite. I did hear the Voice of Russia World Service occasionally in their English language programming.

In Scandinavia, the broadcast stations were on FM. There were signs posted along the highway giving the local FM frequency (e.g. 93.1 MHz) and the program service (P1, P2). The roads in Scandinavia are excellent. There were not many four lane divided highways, but the surfaces of the roads were well maintained and in good condition. Norway has gone to a great deal of expense to build an extensive system of tunnels through their mountains in the last twenty years. The tunnels have cut hours and even days of travel across the country.

TV satellite antennas were seen everywhere. Since we were above the 60-degree north parallel the faces of the dishes were nearly vertical. You may recall that the feed on the satellite TV dishes is offset, so that the beam reception angle is actually not perpendicular to the face of the dish but elevated. But it is startling to see the face of dishes apparently pointed into the side of a hill.

I did notice five or six large log-periodic antennas in Stockholm. Two were located downtown on large commercial or government buildings. The others were on embassies in the surrounding residential areas. Perhaps they were back ups for the landline communication network. Norway has a number of microwave links, connecting towns in the bottom of a valley. Many towns in Norway were isolated by land until recently.

Scandinavia has a dense personal communication service network (PCS). Our tour director used her PCS many times, checking on arrangements for lunch and accommodations. In many cases she would make the call from her front seat in the bus, in some very isolated areas. Then if you looked carefully, you would see up on the ridge somewhere, a tall tower providing PCS service for that area. It might not make economic sense in all cases, but it sure helps the economy in general.  Powering these remote locations must require some interesting solutions.

My old Garmin II Plus GPS provided some entertaining moments. I would sit in the back of the bus near a window and take readings on our speed and position. The tour buses in Europe have a recording device, which measure the speed and distance traveled each day. There are European Union regulations governing the time that the driver can spend on the road. The bus had a speed limit of 100 kilometers per hour as marked on a sign on the back of the bus. The GPS confirmed that the bus’s maximum speed was right up there at 100 km per hour. He never seemed to exceed it. The GPS was useful. I made a point of marking the hotel locations. On a couple of occasions, I led the family back to the hotel by using the bearings from the GPS. Maps are great but unless you are familiar with the scale and the names of where you are then, you may be in trouble. The more recent versions of the GPSs could have built-in maps for Europe.

The most northerly point of the trip was in Norway at N62.46 degrees. The far north longitudes of course are much closer together as they converge the closer you get to the North Pole. So, it does not take much east-west travel to go from one longitude to another.

The scenery was wonderful. The family took hundreds of pictures and everyone had a great time. The flying was not fun but worth the hassle and inconvenience.

Jim N6TP

Magnetic Loop Antenna Tuning

Dan (KC4GO) shared a video of his magnetic loop antenna being tuned across the 40 m band. The narrow bandwidth of the antenna can be seen as the peak in signal level moves up and down the band.

The occasional large vertical jumps in the panadapter display (upper half) are caused by distant lightning activity. Each of these signal bursts also appears on the waterfall display (lower half) as a very thin, horizontal line, since the lightning energy is very broad-banded.

While the video is playing, you can type f or click on the box near the bottom right corner of the player to switch to a full-screen view of the video. 

Thanks, Dan

Volume control on multiple RCForb clients

My previous post showed 3 instances of the RCForb client running on a single computer / monitor setup. The receive audio from all clients connects to a single set of speakers. Although the receive volume sliders on the clients can be used to select the best audio for a given received signal, this is not the most convenient method. An alternative is to use the Windows Volume Mixer.

The (Windows 10) screen shot below includes 2 RCForb client audio sliders.

Any audio source can be adjusted independently from this mixer panel. Any source can be muted by clicking on its blue speaker icon at the bottom of its slider, as shown in the screen shot below.

Send me any questions or comments.

73,
John WA5MLF

3 Remote Rigs on One Screen

During today's RV Service Net (2nd hour) the net control station W4BXI had the use of 3 remote stations, connected via RemoteHams software.  At my location I arranged a display of the 3 remote clients on my wide screen (2560 x 1080) monitor.  Below is a screen shot of the arrangement.

Click to enlarge.

The RemoteHams RCForb client software provides a single user interface that resembles an Elecraft K3 transceiver, regardless of the brand and model of the transceiver it controls. Each station owner can choose which controls to make available to the remote users.

I closed some of the extra elements of the RCForb client windows, and slid the bottom parts (chat window and list of users) below the bottom edge of my desktop. I could still move a window up temporarily to take a peek at the user list.

The 3 client windows, from left to right, are connected to: WA5MLF, W4UOA and KC4GO. 

The upper left corner of the screen displays the KE9NS version of the PowerSDR program that controls my Flex-3000 transceiver. There I could view the strength and quality of the received and transmitted signals, and access settings that I have not enabled for the remote users.

The upper right has my Firefox web browser window where our Bell Ringers chat window is seen. I have other browser tabs (e.g. email) available for quick viewing with a single mouse click.

Send me any questions or comments.

73,
John WA5MLF

Remote Station Operation

Here are two articles, with diagrams, that I wrote recently for use in the RV Service Net newsletter.  Any feedback and suggestions are welcome.

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Many regulars on the RV Service Net recall that John, W4BXI, served as the second hour net control station on Thursdays, operating from his home at Fort Payne, AL. After moving to Asheville, NC, he now lives in an apartment that has no provisions for HF radio operation. John’s friend Carl, W4UOA, (at Mentone, AL) established a new remote interface to his own station for John to try from his new home. Carl has used other configurations of remote access to his station over a number of years.

Initially John used a single laptop PC, equipped with free software from RemoteHams.com to connect to Carl’s station. After getting familiar with the software interface (RCForb client), and finding it satisfactory for continuing his presence on HF radio, John resumed operation as a net control station. W4UOA is an excellent station for John’s participation in the RV Service Net.

Over a short period of time, John discovered other stations that are using the same RemoteHams software. This provided an opportunity to access other receiving locations, to hear stations that are too close to W4UOA for good reception during the early morning propagation on 40 m. John accessed the Richmond, VA, club station W4FJ that is available for receiving and transmitting, for club members. John also added receive capability provided by his RV Service Net friend Dan, KC4GO, of Casselberry, FL .

Around the same time John asked if my station in Baton Rouge, LA might be able to provide transmit / receive operation using the RemoteHams software. Previously I sometimes provided receive audio from my transceiver to John via a web interface (Google Hangouts), during his time slot on the RV Service Net. I set up the needed RCForb server software on my Windows PC that operates my Flex-3000 transceiver. This enabled John to use another remote station farther to the southwest.

The diagram below shows the current group of remote stations (in 4 states) that John uses from his operating location in North Carolina. Although these remote stations make it easier to hear reports from the many stations that check in, they don’t replace the excellent help provided by relay stations who are often located in even better locations for hearing and talking to the widely-distributed participants.

Click above to enlarge.

In a separate article I will provide additional details about how the RemoteHams software connects to radio equipment and the Internet.

John Krupsky, WA5MLF

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W4BXI and friends have tested various software and hardware approaches during the past several years for remote operation of ham radio stations. We are currently using software from RemoteHams.com. In a single software package, RemoteHams includes both rig control (along with CW keying, memories and DX spotting) and audio transport. Some previous approaches have required the use of separate audio transport (e.g. Skype) and control software.

The RemoteHams software was designed to interface with the Elecraft K3 transceiver, but currently supports many other brands and models. A single, universal interface is provided for control of any supported transceiver.

For anyone thinking about remote station operation we suggest installing the free RemoteHams (RCForb) client program and using it to listen to any of the online stations listed in the RemoteHams directory. You can find many on this Online Map. The client software runs on Windows computers and Android devices. The RCForb client enables the remote operator to receive and transmit (depending on permissions granted by the station owner) and to select frequencies, modes, power levels and other parameters that are configured at the remote station. The diagram below shows the components at the location of a remote operator. The Documentation section has a good “getting started guide” along with client and server manuals. 
 

Click above to enlarge.

The diagram also shows a RemoteHams server that is used for:

• registration and authentication of licensed remote operators
• publishing a directory of online stations that can be used with the RemoteHams software

The server is contacted each time a remote station’s server software or a remote operator’s client software is started, but is not involved in the client-server traffic.

A remote station is not required to be listed online. Many owners of remote stations choose to operate on a non-listed basis, but can allow their friends or club members to access their station with a non-listed link.

To set up a station for remote operation requires interfacing a (supported) transceiver to a Windows computer that is running the free RCForb server program. The diagram below shows the components at the location of a remotely-controlled station. Transceiver interfacing for operating the many digital modes (PSK, FT8, etc.) provides the same capabilities needed for the RCForb server program.

If you decide to explore this mode of operation, we recommend consulting the server manual in the Documentation section and the Support Forum section of RemoteHams.com for additional documentation and tips from other users. The RemoteHams software also provides remote operation of supported amplifiers, antenna tuners and rotators.

Other topics that must be considered for the establishment of a remotely-operated station include:

• Control of electrical power to radio and computer equipment
• Ability of radio and computer equipment and software to restart if power is interrupted
• Protection from lightning and electrical surges
• Remote access to the server computer if changes to the server software settings are needed

Remote control software provided by the radio manufacturers for their radio products may provide additional capabilities that are not available through the RemoteHams software, such as SDR panadapter views. We suggest that you evaluate the capabilities of any remote control solution that control your radio equipment, and decide based on features that are most important to you.

John Krupsky, WA5MLF