Sunday, November 24, 2019

QSO Today Podcast with W8TN

QSO Today is an audio podcast created by Eric Guth, 4Z1UG / WA6IGR.  It consists of audio interviews with hams from around the world.  As the host of the QSO Today Podcast, Eric poses questions to those being interviewed about their own personal ham radio story.  He asks questions about how the person being interviewed got started in ham radio, about their first rig, their Elmers, about what affect ham radio has had on their career, their family life, what they see as the most exciting aspect of ham radio today and a host of other things.

Each interview runs about an hour and can be listened to online or can be downloaded on Apple Podcasts.  Episode 200 is an interview with Eric himself as the subject.  All prior episodes can be accessed and a list of all the interviews is available HERE.

Eric has been doing this for 4-1/2 years as a way to document the stories and ham radio history for hundreds of individuals in our hobby.  As of today, November 23, 2019, Eric has produced 277 episodes.

Today's Episode 277 is with me, W8TN. The interview was conducted over Skype on November 10, 2019.  The image at the right is from the Skype app during the recording.

I consider many of those who have already been interviewed as being absolutely at the pinnacle of this hobby.  Looking at the list of hams who have already been interviewed, I am extremely honored and humbled to be included here.

Using the embedded player below you can listen to this Episode right from this Blog. Note there are buttons to rewind 30 seconds or skip ahead 30 seconds.

Friday, November 15, 2019

UPDATE - FA-VA5 Vector Antenna Analyzer

On October 23, 2019, I received the DG5MK FA-VA5 Vector Antenna Analyzer from SDR-Kits. I previously posted on this Blog my search for such a product - CLICK HERE - to see that post. My order was very well packed and included a BEAUTIFUL 40-page manual which is full of color photos.  The manual can be downloaded as a PDF from this link: https://www.box73.de/file_dl/bausaetze/BX-245_FA-VA5_Manual_EN_201908_w.pdf  The quality of the kit is top-notch and after checking the parts list, all components had been supplied.

I began the construction of the Analyzer which turned out not to be very difficult.  The hardest thing was to properly position the USB socket and solder it with a mica insulator between it and the circuit board.  There are 16 pads that need to be soldered so it's a bit tedious.  You can see that USB Socket on the left.  Once that is done, you need to screw the motherboard into the housing's lower shell with four M3 screws.  Here is where I ran into a problem.

USB Socket
I was only able to screw in three of the four M3 screws and those only with difficulty.  The holes in the motherboard and the fixed nuts in the lower housing just did not line up well enough.  The holes in the motherboard were just exactly the size needed for the M3 screw with no "play" to allow all four screws to be inserted.  I decided the simplest way to fix this was to drill four larger holes in the motherboard.

I measured the hole size as 3.36 mm which is 0.13228346 inches or ~17/128 of an inch.  I used a 5/32" drill which is 0.15625 inches to slightly drill out the four holes.  This provided just enough "play" to allow the motherboard to be screwed to the lower housing.

Inside Case View
The building instructions are quite detailed and I had no problem following them.  There is a 20-pin socket strip that needs to be soldered along with two 3-pin sockets and all of them must be elevated exactly 7 mm from the motherboard.  This is easily accomplished with the supplied cardboard strips.  See the image at the left.  A small tipped soldering iron needs to be used to prevent any solder bridges.

Three Videos have been produced by Joe Fellner - OE5JFE showing what is involved in Assembling, Operating the FA-VA5 either as standalone Instrument or when connected to a Personal Computer via USB. 

Video Part 1:  Assembling the FA-VA5 Antenna Analyzer:  https://www.youtube.com/watch?v=m67hDfm0XOE

Video Part 2:   Using the FA-VA5 - how to do a Firmware update and perform Master SOL Calibration on a the FA-VA5:  https://www.youtube.com/watch?v=Ad9gjQutxCw

Video Part 3:  Connecting the FA-VA5 Antenna Analyzer to a PC and how to use with the DG8SAQ Vector Network Analyzer Application: https://youtu.be/FnfoTX5_DBo
Socket Strips Spaced 7 mm

It took me 4 hours, 45 minutes to complete the build because of the issue with needing to drill out the holes in the motherboard and my need to be super careful with the soldering.  Once I had the unit built, the first thing to perform was a functional test.  This went well so I completed installing the unit in the case. 

However, when I tried to connect it to the computer - problems ensued.  The USB connector on the analyzer turns out to be a "USB 2.0 Mini-B 5-pin" connector.  That is not a common connector that appeared in my USB cable drawer.  But I did find a short (9-inch) USB cable with the proper connector and connected the unit to the computer.  Connecting the unit to the computer with this cable cause the analyzer to go into USB mode but no COM port showed up on the computer.  I tried this on two different computers with no luck.  The instructions say if there is a problem, it is likely in the cable or in the USB socket mounted to the motherboard.  I searched some more and found a second 9-inch USB cable but it did not let the analyzer work either.

My next step was to take the unit apart, unplug the display, and un-solder the USB socket.  As I said before, this is soldered with 16-pads so it was difficult to remove.  I then VERY carefully re-installed the USB socket but, when I connected it to the computer, there still was no COM port.

1.75:1 SWR Problem
I thought that maybe there could be an issue with the cable so I visited Amazon to look for a longer cable.  What caught my eye was some cables were marked as being a "5-pin" cable.  Why was it described this way?  As it turns out, there are identical looking USB cables (like my two 9-inch ones) which were meant ONLY for charging.  There were no DATA wires connected.  This turned out to be the entire problem in that power from the computer was supplied to the analyzer with my short cables but no DATA was flowing to create the COM port!  I sure wish there had been a note in the manual or in one of the videos I watched to let me know that I needed a particular type of USB cable, not just one with the same connectors.  Lesson learned!

Now that I finally had a working analyzer, I proceeded to calibrate it using the SOL (Short, Open, Load) Calibration Kit I had purchased.  This took a little time but was simple enough to do.  My next step was to use the Analyzer to troubleshoot a problem with my EME array.

1.11:1 SWR with New Feedline
About a month ago my SWR suddenly jumped to 1.75:1 and the amplifier was not happy with this.  Using the analyzer I checked the complete 2x13 array and found the SWR was indeed 1.75:1 (see the image above on the left.)

I then proceeded to take the analyzer and notebook computer outside and test each antenna and phasing line individually, the power divider, and the feedline.  Everything looked good until I tested the feedline by itself and it exhibited a high SWR.  Luckily I had a run of ABR400UF cable going from the shack to the EME antenna array.  I switched to that cable and the SWR returned to 1.11:1 as you can see on the image at the right.  Click on any image here to see a larger view.

When more time is available I will see what is wrong with the other feedline and eventually get it back in service.  And, since the analyzer shows both antennas to be resonant about 0.355 MHz low, I may tweak them as well.  It's super-easy to do this with the DG5MK FA-VA5 Vector Antenna Analyzer. But, for now, this little Antenna Analyzer has completely paid for itself by getting me back on EME!

DX Cluster Client Program - CC User

Many, if not all, logging programs have the ability to connect to a PacketCluster server to obtain DX spots.  However, if you want to control the spots that are coming into your logger, you need to issue archaic DOS type commands.  VE7CC has created a program called "CC User" which resides on your computer and easily allows "mouse click" changes to the spot information which is displayed in your logger.

This software, which you install on your computer, allows you to connect to the VE7CC PacketCluster or any other cluster you want.  You then connect to the "CC User" program from your logger.  "CC User" has the advantage of being able to supply spots to other programs like contest loggers (N1MM+ for example) at the same time.  Or, if you have other computers in the house, you can connect to the "CC User" program on your main computer and save on the usage of your Internet uplink/downlink while maintaining the settings you have created for receiving spots.  Plus, there are tons of ways to filter the spots coming from "CC User".

One of the main reasons I started using the "CC User" program a few years ago was that you can tell it to "Auto Reconnect" if the link to your chosen PacketCluster fails.  And, not only can you reconnect if you get dropped, but you can also automatically pull in all the DX spots you missed.

CLICK HERE for the page describing all the features of "CC User."  It is free software.  Once on the CC User web page, scroll about 2/3 of the way down the page to find the "Installation of CC User" instructions.  Under that heading you will find the link to download the program: "Download CC User Full Version (ver 2.421)"   Clicking on this link will allow you to download a ZIP file.  Just Un-ZIP and proceed as you normally would with any program installation.

There are tons of ways to filter the spots with just a mouse click (instead of sending an archaic DOS command to the Cluster.)  For example, on the top left of this Post is a window showing how easy it is to reject spots from certain bands. On the right is a snapshot of the screen where you can filter the station sending the spots, not only by country (as by telling it you only want to see spots from the USA) but you can drill down and filter only spots from a particular STATE or PROVINCE.  Again, on the left, is a screenshot of the "Set" menu with just some of the options available available in "CC User."  Click on any image to see a larger view. 

On the right is a "Tab" in "CC User" which I use often.  The screenshot is captioned "DX Tab."  Say I'm trying to work a station that I see spotted on 40-M.  But, the most recent spot only says "UP" with no indication of how far up he is listening or, the spot does not even SAY UP, it just gives the DX station and frequency.  So, I click on the DX "Tab" of "CC User" and select "40" for the band and I can then see all the spots that have come in on 40-M in chronological order.  I can then scroll up through the spots and look for any spots with good info for me.  Check out the spots for T33C on the "DX" tab screenshot and you can see what I mean.  Using this will also help me find spots with comments giving QSL information or the fact that the DX station changed bands, etc.  Your logging program may only show the most recent spot which may not give you this info and trying to scroll back through all the spots for all bands to find any useful info is a PITA and usually unsuccessful.

DX Tab
If you are serious about getting your spots or have questions about certain PacketClusters, you can run multiple instances of "CC User" to test various Clusters and answer questions like:  Which node should you connect to? Which nodes are faster? Are you missing DX by connecting to a certain node? Does the "Get Missed Spots" really work?  Just set up multiple instances of "CC User", connect to various nodes, and compare them side-by-side.

When you setup "CC User" you need to look at the "Port Setup" screen like what is shown next on the Left.  I've marked in Red the part that deals with your connecting to "CC User" from your Logging Program.  If you are going to use Telnet to connect to your logging program you can ignore the settings for RS-232.

With the setup shown, the program is waiting for incoming connections from logging programs on port 7300. If the logging program is running on the same computer, use the local telnet loopback port (127.0.0.1 :7300). If the logging program is in a different computer, telnet to this computer's IP address at port 7300. The number of logging program connections is unlimited. To enable or disable this feature, you need to go to "Configuration>Ports/Logging Program>Logging Program Connection>Telnet" in the "CC User" program.

To enable this connection in the Logger32 logging program, Right-Click in the Telnet window of Logger32 and choose Setup | Setup remote hosts.  You should then setup a remote host to look like the screenshot shown on the right for "Telnet connection setup..."

You can see the address for connecting to VE7CC-1 is the telnet loopback port address of 127.0.0.1 and the Port is 7300.  This Port has to be the same as what you set up in "CC User."  In my setup I was already using Port 7300 so I clicked on "Use Custom Port" and entered "7100" - then that is the Port I had to use in Logger32.

This may seem like a lot of work just to set up a source for PacketCluster spots but, for me, the other benefits of the "CC User" program are well worth the effort.  I let my computer run 24/7 and "CC User" is always running.  I may shut down and later re-start Logger32 but when I do, my VE7CC-1 Cluster is always there.


Friday, October 11, 2019

FA-VA5 Vector Antenna Analyzer

FA-VA5 Vector Antenna Analyzer
For a long time I have been wanting an Antenna Analyzer that is better than my MFJ-259B which I have owned for many years.  The 259B covers 1.8 to 170 MHz and is a nice little hand-held unit to find the SWR and resonance of your antennas.  It can read SWR, return loss and reflection coefficients simultaneously.  It has two meters (one for SWR and one for Impedance) as well as a 2-line digital display.  In addition to those normal functions, I have even used mine to as a Time Domain Reflectometer to find where I had accidentally cut a feedline.  I believe I paid about $250 for this unit several years ago and feel I have received my money's worth over the years I have used it.

However, it has (for me) a major drawback.  It is NOT a graphing device meaning that you can not see a visual display of the SWR curve or other measurements.  Also, it takes 10 AA batteries and that gets expensive if you use it a lot.  I always remove the batteries after I use it so that takes a bit of time.

Components in the Kit
I was now looking for a unit that would interface to a computer and allow me to save graphical images.  I have had an N8LP LP-100 Digital Vector RF Wattmeter for many years and have used that to save graphs from the data it acquires.  I have really enjoyed being able to create those graphs and save them for later reference.  I can look back at how my antenna performed on a certain date and see if anything has changed.  However, the LP-100, as nice as it is, is not a portable unit, it is just a piece of shack equipment that is limited in where I can use it.  Also, it only covers 1.8 to 54 MHz with the one directional coupler I own so that limits its use as well.

Charlie, N8RR, purchased a SARK 110 a couple of years ago and helped me tune my 2-M EME antennas with it.  That's quite a nice little unit which operates between 0.1 and 230 MHz.  Current price for this unit is $389 and I seriously considered purchasing one for myself.  It can save and transfer measurements and graphs via its USB interface to a computer.  Just what I want.  It has an internal Li-Poly-1000 mAh battery that should run the unit for 2.5 hours but it can be charged over USB so you can extend the operating time by connecting it to a computer.  It has a 3" Color display which is 400x200 pixels but having it connected to a computer with a larger screen makes it much more useful.
Presentation Case + Adapters

In addition to the cost of the unit, you need to purchase at least an OSL (Open, Short, Load) Calibration Set plus some SMA adapters since the unit only has a female SMA connector as it's antenna connection.  $59 will get you the OSL Calibration Set, 4 SMA adapters plus a rubber case.
Suggestions for Adapter Placements

So I began researching what type of Vector Antenna Analyzers were available.  WOW!  Prices can be VERY low.  You can buy a Chinese NanoVNA for only $79.99 from Amazon!  It has a 2.8" LCD screen, built-in 400 mAh battery, and covers up to 900 MHz.  Plus it can export files to the PC.  This could be just what I need.  But, could it be too good to be true?

I began looking at the reviews on the NanoVNA and several other low-cost units and eventually came to the conclusion that these were actually NOT precision pieces of equipment.  Many reviews mentioned problems with some of these devices including those who received units that failed to work out of the box.  While the price points were super attractive, I came to my own conclusion that "you get what you pay for" and decided against going the "low-ball" route.

Turn On Look
More research and I found the DG8SAQ VNWA 3 Low Cost 1.3 GHz Vector Network Analyzer available from SDR-Kits.  I really, really liked this unit.  It is indeed a precision piece of test equipment and it would cover the 1296 MHz band which was one of the things I was thinking would be nice for future UHF work.  BUT, it is not really a "hand-held" unit, it has no display and MUST be connected to a PC to operate, it has no internal batteries, etc.  But, BOY, did I like this unit!  The software written for it is really extensive and impressive.  I spent a lot of time figuring out how I could get this unit which would run me about $565 for the DG8SAQ VNWA 3 unit, presentation case, OSL Calibration Kit, and a 165 page "Guided Measurements" book.  WOAH!  This is one SERIOUS piece of test equipment.

Dual-Band Antenna Measurement
But, while reading and viewing YouTube videos about the DG8SAQ VNWA 3, I became aware of the DG5MK FA-VA5 Vector Antenna Analyzer.  This is a truly portable analyzer AND it uses the SAME wonderful software as the DG8SAQ VNWA 3!  It only requires 2 AA batteries (which should allow it to work for up to 40 hours), and has a large display with good visibility.  The unit measures just 5.9 x 3.35 x 0.87 inches so it will fit easily in one hand.  It contains a real-time clock with capacitor backup so measurements can be time/date stamped and it has an audible buzzer alert for minimum SWR.  And you can connect it to a PC for real-time measurements on a larger screen.  Doing this gives full control of the FA-VA5 to the software (like the SARK 110) so that measurements can be made much more quickly than by using the analyzer's simple controls.

The FA-VA5's graphic display shows the complex impedance, standing wave ratio, complex reflection coefficient, capacitance and inductance.  Using the DG8SAQ VNWA software it can also be used as a Time Domain Reflectometer (TDR) to help find defects in antenna installations, measure the length of cables, and other similar applications. 

TDR Measurement
Since this is a one-port device (unlike the DG8SAQ VNWA 3 which is a 2-port device), it is limited to only measuring the S11 parameter.  S11 is a complex reflection coefficient, made up of a real and imaginary component. A lot of other values can be derived from S11 like Standing Wave Ratio (SWR) and impedance Z. Very often those values will be displayed using a special chart type, the Smith-Chart. The Smith-Chart does allow solving a lot of matching problems graphically.

The unit does only cover 10 kHz to 600 MHz so I lose the ability to use it on the 1296 band but it does add the 432 MHz band to my measuring ability.  And, this is a band the SARK-110 does not reach. But I gain a tremendous amount of accuracy as well as the ability to use it with some really great software.  And, the antenna connection port is a BNC connection.  In my experience this is MUCH easier to use than the SMA connector and can speed up the measurement process significantly by keeping me from not needing to fiddle with the SMA connection. 

It is a "Kit" which will require a bit of assembly (approximately 3 hours) but the process looks pretty straightforward.  You can CLICK HERE for a 3-minute video showing the assembling of the unit. And, no small feature, the cost is MORE than reasonable!  The basic unit can be had for about $225 including shipping.  I chose to purchase the basic unit, a "Presentation Case", a 600 MHz OSL (Open, Short, Load) Calibration Kit, 5 BNC adapters, a BNC to BNC cable and a BNC to SMA cable.  Total price was $270.72 including shipping.  Obviously, the price / performance ratio is outstanding!  It is essentially the same amount of money I paid for the MFJ-259B so many years ago and about $200 less than I would pay for a SARK 110.  AMAZING!  Click on any image in this Post to see a larger image.

So, based on the high accuracy, low-cost, portability, great software and excellent documentation for this analyzer, I decided to order the FA-VA5 from SDR-Kits. When I first decided to buy the unit it was shown as being out-of-stock due to high demand and they were taking reservations.  I made my reservation and just 2 days later received an email saying the unit was now available.  I immediately made the purchase (paid for with Pay-Pal) yesterday (10/10/2019) and today received a tracking number from Deutsche Post.  I am really looking forward to receiving this Vector Antenna Analyzer and learning to use it and the software.

Tuesday, October 8, 2019

Messi & Paoloni Coaxial Cable

Two years ago when first building my EME station, I purchased through GigaParts a 75-foot length of 400-UF cable with Male N-Connectors on each end which was built by ABR Industries and supplied to GigaParts.  This is cable which is apparently built for ABR Industries and is supposed to be "similar" to LMR400-UF but is actually marked as "ABR400UF" cable and NOT a Times Microwave LMR cable.  

This was to be the Receive cable from my preamp down to the shack.  It tuned out that the installed N-connectors were CRAP!  One of them was so difficult to screw on that I had to put a set of a double-female N-connector and a double-male N-connector on the shack end of the cable to allow the cable to be easily connected.

As I made more and more EME QSO's, I began to notice that quite a lot of the time I was receiving better signal reports than I was giving.  So, I tracked the QSO's where I had signal reports to see if my impression was true.

Out of 174 EME QSO's, 71.54% of the time I RECEIVED a better signal report than I gave.  That RECEIVED report was an average of 5.2 dB better than I gave.  21.14% of the time I GAVE a better report by an average of 3.0 dB.  7.32% of the time the reports were equal.  Now that I proved there was a substantial difference between signal reports received and sent, I began to suspect there was an issue with the ABR400UF cable and/or the N-connectors from ABR Industries.

Since I am now moving to an XPOL system with 2 preamps, I will need two receive coax cables.  I did not feel like using the current ABR400UF cable so I decided to look for something else.

Searching around I became aware of coaxial cable which was built in Italy by Messi & Paoloni.   They have been producing cables since 1984 and have received very good reviews.

In looking at the specifications on the M&P website, I decided to go with the "ULTRAFLEX 10" cable.  The main reason for choosing this cable is that it has a very high (Greater Than 105 dB) "screening efficiency" which is reported to reduce background noise more than other similar cables.  The shield effectiveness of the ABR400UF is Less Than 90 dB.  That's a BIG difference.  Loss per 100-feet at 144 MHz is 1.4 dB for the ULTRAFLEX 10 while the loss of ABR400UF at 150 MHz is 1.8 dB.  Not really a big difference considering I'm only using about 75-feet.

The N-connectors I chose for the M&P cables are their new generation ones with double sealing that protects even more from humidity, condensation and water.  The model is CO.N.10M-S and if you CLICK HERE, you can see the description of those connectors as well as a couple of videos showing how to install their connectors.  Also, you can click on any image on this page to see a larger version.

25m Cable as Received

Currently two 75-foot lengths of ABR400UF with N-connectors costs $213.90 and GigaParts would ship them for free.  Today I purchased two 25m (82-foot) lengths of ULTRAFLEX 10 with SOLDERED N-connectors installed direct from Messi & Paoloni for a total of $259.50 including shipping and PayPal fees.  So for an extra $45.60 I will at the very least have peace of mind and possibly MUCH better receive cables.

UPDATE: My order was placed on October 8th, it was shipped on October 10th (from Italy) and UPS says I should expect it Monday, October 14th.  Not bad at all!

2nd UPDATE: On Monday, October 14th, as expected, my package containing two 25m lengths of "ULTRAFLEX 10" cable with N-connectors factory installed was delivered by UPS.  Only 6 days after I placed the custom order and, it was shipped from Italy!  Besides the coax, M&P graciously included a couple of lens cleaning cloths with their logo on them.  NICE!  This is VERY good looking cable and I'm really excited to check it out.  Stay tuned for the results!