I don’t think enough people know about this, so I decided to make a post here for those looking. You can connect to your average YSF (Yaesu System Fusion), DMR and M17 reflector using your computer and talk with any connected headset. Droidstar is openSource, and the source code can be found here.

Downloads

Grab the Windows 64 bit version of DroidStar from here:
https://dudestar.gw8szl.co.uk/Droidstar/DroidStar64-build-f050489.exe

Grab the Windows 32 bit version of DroidStar from here:
https://dudestar.gw8szl.co.uk/Droidstar/DroidStar32-build-f050489.exe

DMR ID Requirement

This build of droid star requires a DMR ID, even when connecting with other modes. The reason for this is unknown to me. If you don’t yet have one, you can register for one at https://radioid.net/register. Once you open the application, navigate to the Settings Tab and fill in the DMR Id there.

The post Connect to Ham Reflector with your Windows Computer and DroidStar appeared first on TheModernHam.

In 1985, I built a home-brew decoder and experimented with RTTY, but I never got it to work. I've since decided that I didn't know how to tune RTTY properly. Things changed in 2005 when I downloaded CocoaModem made my first RTTY contacts. 

Since I was involved in contesting, I naturally turned to RTTY contesting. Today, it is unusual to hear RTTY signals on the bands except during contests. Thirty or more years ago, RTTY was commonly heard on 80 and 20m. 

Characteristics

Principles

For effective RTTY contest communication, several principles apply. 

• Brevity - every character sent must have a purpose. There should be no wasted characters.
• Duplication - every important element should be sent twice. This contradicts the brevity principle. Because RTTY prints incorrect characters, sending important elements twice helps ensure correct reception.
• Scrolling - each message starts a new line, but ends with a space. This technique keeps lines from wrapping, and avoids the end of message being confused by garbage characters when the signal drops. 
• Shifts - avoid needless shifts. Any sequence involving the unprinted FIGURES or LETTERS characters takes longer to send. 

Messages

S & P

{TX}{ENTERLF}{MYCALL} {MYCALL} {RX}

or

{TX}{ENTERLF}* * {RX}

(For N1MM, the asterisk and {MYCALL} macros are the same)

Notice the message starts with {TX}, performs a carriage return / line feed with {ENTERLF}, sends the call twice, ends with a space and then {RX} to go back to receive. Sending the call twice helps to ensure the recipient receives it correctly.

If you are lucky enough to get a response, you'll have to send the exchange. The exchange will vary by contest, but it could be a message like this:

{TX}{ENTERLF}! 599 GA GA DE {MYCALL} {RX}

This is what I send in the RTTY Roundup. First is the recipient's call (!). Then 599 -- don't use 5NN, because that actually takes longer to send in RTTY -- and send it only once, because it isn't important. Then the exchange is sent twice, followed by the prosign DE and my call, followed by a space. 

N1MM's authors recommend you use the ! character rather than the {CALL} macro. The reason is that {CALL} isn't subject to correction -- it sends the contents of the Call field at the start of the message. The ! character will send the Call field as it is being corrected in real time. As a practical matter, most RTTY contest contacts involve pointing and clicking on callsigns, so there's less typing, and therefore fewer corrections involved.

A couple of things here. Notice I did not use the {EXCH} macro above. When there are multiple elements to the exchange, I put the repetitions together. So, I tend put the exchange information into the macro directly. For example, here's an S & P exchange for CQWW RTTY:

{TX}{ENTERLF}! 599 GA GA 5 5 DE {MYCALL} {RX}

GA for Georgia, and 5 for zone 5. For NAQP RTTY, it would be:

{TX}{ENTERLF}! 599 BILL BILL GA GA DE {MYCALL} {RX}

Some might balk at the use of the DE prosign, particularly for exchanges that involve a state or section, since DE might be confused with Delaware. However, I think this prosign is useful, as it establishes the callsign is of the answering station, and not the CQing station.

CQing

{TX}{ENTERLF}CQ RU {MYCALL} {MYCALL} CQ {RX}

Note that the important information -- the callsign -- is repeated. The other curious thing is the "CQ" at the end. This indicates I finished a CQ message. This is important because one cannot tell when potential callers tune in to your signal. If they do so during the first callsign, the can't tell if you are calling or answering a CQ. Putting "CQ" at the end establishes you are calling CQ. And it is shorter than "QRZ?".

Naturally, one indicates the contest in the CQ message. Here it is "RU" for Round Up. Use whatever is appropriate for the contest, or simply "TEST".

When someone answers your call, you send an exchange message:

{TX}{ENTERLF}! 599 GA GA ! {RX}

Note that the exchange is sent twice, and if there were more than one element to the exchange, I'd send those twice as well:

{TX}{ENTERLF}! 599 BILL BILL GA GA ! {RX}

Another item to notice is there is no {MYCALL} macro in this message. Instead, the caller's callsign (!) is sent twice, once at the beginning and once at the end. There are two reasons for this. First, it follows the principle of sending important information twice. It could be the caller's callsign printed incorrectly to me, or perhaps it will print incorrectly when I send the message back. If I only send the callsign once, the caller might or might not correct it if is wrong, or they may correct it if it printed incorrectly to them. 

Unnecessary corrections are a waste of time, but necessary corrections are desired. 

Second, it may be that during the response with the exchange, other stations may also be calling. This, creates a good chance that the initial callsign in the response will print incorrectly. If you don't send the callsign again at the end, it could be unclear who you responded to. 

Once you've received the exchange from the caller, one sends an acknowledgement:

{TX}{ENTERLF}! TU DE {MYCALL} CQ {RX}

Short and simple. Two features here. One is the DE prosign, to indicate this is the transmitting station's call, and ending with "CQ" to invite new callers.

Turnaround

{TX}{ENTERLF}! TU {LOGTHENGRAB}NOW..{ENTERLF}{F5} 599 GA GA {F5} {RX}

This message omits {MYCALL}, and uses the {LOGTHENGRAB} macro to first log, then grab the callsign off the automatic decode stack, then it follows with the normal exchange. If you use Single Operator Call Stacking, you can use {LOGTHENPOP} instead. See the N1MM manual.

Note that instead of using the exclamation point (!), we use the {F5} macro. Both the exclamation point and the {CALL} macro won't be updated by the {LOGTHENGRAB} macro, but {F5} will.

Short

{TX}{ENTERLF}! 599 BILL GA DE {MYCALL} {RX} -- short S & P exchange

{TX}{ENTERLF}! 599 BILL GA {RX} -- short exchange for S & P or CQing

{TX}{ENTERLF}599 BILL BILL GA GA {RX} -- repeat of just the exchange 

{TX}{ENTERLF}CQ RU {MYCALL} CQ {RX} -- short CQ

{TX}{ENTERLF}TU DE {MYCALL} CQ {RX} -- short acknowledgement

All these should be used when you have solid copy, want to get back to other callers quickly, or you are fairly certain the other operator already has your exchange information from a previous contact.

Tips

Practical Messages 

{TX}{ENTERLF}AGN AGN {RX}

Or perhaps you need a fill of one element:

{TX}{ENTERLF}STATE? STATE? {RX}

{TX}{ENTERLF}NR? NR? {RX}

{TX}{ENTERLF}NAME? NAME? {RX} 

 Before you open up with a CQ on a frequency,  this is good one:

{TX}{ENTERLF}QRL? DE {MYCALL} {RX}

 Maybe if you are not sure someone is calling you:

{TX}{ENTERLF}QRZ DE {MYCALL} {MYCALL} {RX}

Or the short version:

{TX}{ENTERLF}QRZ DE {MYCALL} {RX}

Every once and a while, directed call is useful, especially when two stations are calling CQ on top of each other:

{TX}{ENTERLF}! DE {MYCALL} {MYCALL} {RX} 

Conclusion

I wish I could make this one simple, but we are getting into complex territory. Please read the instructions and follow along carefully. This is not something I recommend doing without knowing your way around Linux, and so the basics are not covered(it would be too long). this should let you share the same soundcard between direwolf and other apps like VARA, and FLDigi as well. I ran into this when I wanted to have VARA and Dire wolf share a soundcard for my BPQ32 node on Linux. By default, Dire wolf takes complete control of the sound card interface, as well as VARA when ran within wine. There are several tweaks and changes needed to make this work, so buckle in. In this guide, I’ve used this post to install VARA within wine on Debian 12. I’ve used this post to install dire wolf.

Splitting the Interface

First, we need to grab your sound cards device name. Enter cat /proc/asound/cards to get a list of sound cards, pay attention to the “Device” or “Device_1” relating to your radios digital audio interface card. I my case, I needed both (one was used for 2m, the other for HF). Note the name somewhere, paying attention to the case as well.

Now, we need to open the “asound” configuration file (or make a new one if it doesn’t exist), and enter some information. First, check if one exists for your current user with : cat ~/.asound. If you get file does not exist, that’s fine. If you instead see file info, enter rm ~/.asound to get rid of it. The reason we did that was because the user configuration file overrides the global (which is the one we will now create/edit).

Enter sudo nano /etc/asound.conf to create/edit the existing global configuration. If your file is empty, awesome. If it contains content, remove everything.

What we will do now, is name our new split soundcard interface. In the following example, I’ve taken the soundcard listed as “Device” from above, and now named it “digirig” in this new interface, and split it into “digirig-rx” for the receive(audio in), and “digirig-tx” for the transmit (audio out)

We will now paste the following template:

Take care to replace the word “Device” with the name you found above (probably the same), and if you would like to rename the interface to something other than “digirig” like I have here, replace all instances of it with something lowercase and simple you will remember.

pcm_slave.digirig {
   pcm {
      type hw
      card Device
   }
   period_time 0
   buffer_size 8192
}

pcm.digirig-dmix {
   type dmix
   ipc_key 2023041901
   slave "digirig"
   bindings.0 0
}

pcm.digirig-dsnoop {
   type dsnoop
   ipc_key 2023041902
   slave "digirig"
   bindings.0 0
}

pcm.digirig-rx {
   type plug
   slave.pcm "digirig-dsnoop"
   hint.description "digirig RX audio plug"
}

pcm.digirig-tx {
   type plug
   slave.pcm "digirig-dmix"
   hint.description "digirig TX audio plug"
}

If you have 2 sound card interfaces, such as I do, you will just paste the above twice, one after the other. You will need to rename all instances of “digirig” (or whatever you called the first one) to something else (to refer to the second card). You will also need to replace “Device” once more with the name of the second sound card (probably “Device_1”).

Great, save that file. Issue the following command to have the changes take effect.

sudo alsa force-reload

If you get command not found, you’re better off rebooting before continuing.

Now, we will now make sure we’ve done this part right. Open up your direrwolf configuration file (probably nano ~/direwolf.conf) and find the “ADEVICE” line and remove it.

Replace it with the following. (Obviously replacing “digirig” if you’ve renamed it in the asound file we made/edited above.

ADEVICE  digirig-rx digirig-tx

Save the file, and restart Dire wolf. Dire wolf should start fine, and your audio device should be working as it did before. If not, stop here, somethings wrong.

Getting VARA to use the Split interface

Now that dire wolf is using our split interface, we now need to get VARA on board, which is a little more involved.

First, we need to get your wine prefix to be configured using ALSA. If using VARA in the default prefix, this could be as simple as running “winetricks sound=alsa“. Give it a try, as it won’t hurt either way. Otherwise, you will run the following command, replacing “.wine32” with the wine prefix you’ve made for VARA.

 env WINEARCH="win32" env WINEPREFIX="/home/aspect/.win32" winecfg

Another way you can try to achieve this is by running “winetricks” within desktop mode, selecting the prefix where VARA is installed, choosing “Change Settings”, finding “sound=alsa” and pressing “Ok”

Next we need to set some registry keys on the Wine prefix to identify our split interfaces. Similar to the above, we will enter the following command to open the registry editor for the VARA prefix:

env WINEARCH="win32" env WINEPREFIX="/home/aspect/.win32" regedit

You can also reach the Registry editor using the “winetricks” command, selecting the prefix, and opening the regedit from there.

You will navigate to the following key and leave it it open:

HKCU->Software->Wine->Drivers->winealsa.drv

Just as in the above screenshot, you will right click the empty space, and select new -> multi-string value.

Create one key called “ALSAInputDevices” and another called “ALSAOutputDevices”. In each of them, for the value, make a list of the relative -rx or -tx devices we made before in the asound file. (If you only have 1 sound card interface to use, you only need the one here). (-rx being in the Input devices, and -tx being in the Output.)

Save, and close it all out.

Starting VARA

Now start VARA as you normally do in WINE. In the soundcard settings, now chose the interface we specified in the registry relating to the one we created in the asound configuration file.

Direwolf and VARA should now be able to share the sound interface this way!

The post Share Soundcard between Direwolf and VARA on Linux appeared first on TheModernHam.

FT8 has been a revolution. The technology has made DXing really easy. Or has it? I continue to be amazed at how much difficulty people have working DXpeditions on FT8. 

Last year, there were DXpeditions to Bouvet (3Y0J), Crozet (FT8WW) and Sable Islands (CY0S). The most recent DXpedition to Glorioso Islands (FT4GL) has brought it all back to me.

Let's start off with a few observations on people trying to work these DXpeditions:

• Wrong Cycle - It's amazing the number of folks trying to work DX that are calling on the wrong cycle. FT8 has even and odd cycles. Even cycles start at 00 or 30 seconds, and odd cycles start on 15 and 45 seconds. You always call on the cycle the DX station is NOT transmitting. Indeed, if you double-click on a decode of the DX station, WSJT-X will set up the correct cycle. So how are people getting it wrong?

Or: Don’t Hate on FT8

One of the great things about amateur radio is that there are so many different modes to explore and avenues to pursue. It is an amazingly diverse technical hobby. There is something for everyone, and FT8 has become that something for many amateur operators, much to the chagrin of a few curdmudgeons.

Without giving air to the critics, I wanted to share why I like to use FT8 (and FT4).

Reason 1:

In February 2023 I was diagnosed with cancer. After two surgeries and six weeks of radiation treatment, I am currently cancer free. But during the diagnosis and treatment time, I needed a distraction – something that was fun, but intellectually stimulating. One can only play so many word games on their phone. I had cut back on work and was spending a lot of time at home to recover. I had never used WSJT-X before then, but decided to get my Xiegu X6100 on the air and try these new-to-me digital modes. So I set up the radio with an EFHW (End Fed Half Wave) and got it configured to do FT8. This also forced me to figure out a logging solution (I ended up using N3FJP ACLog on Windows, along with Logbook of the World, QRZ logbook, eQSL, etc). I also set it up so that I could remotely access the PC interfaced with the radio, and use my Android tablet while I was stuck in bed. I’ve also set up FT8 on my Android devices using the FT8CN app, which is pretty fun to use. This whole thing proved to be great fun to set up, tune, and refine. And it was fun to operate while I was recovering. I made hundreds of contacts and learned a lot about propagation and my antennas during this time. Which brings me to the second reason I love FT8.

Reason 2:

Once I was up and about more, and had more time, I began to experiment with different antenna solutions. I have a small backyard with no tall trees, and can’t really erect a permanent antenna. So I bought a couple of different telescoping poles (this one and this one). I started playing with different setups for the EFHW (sloper, inverted L, vertical). A great way to assess and compare the performance of each configuration was to change it, then call CQ on FT8 on a band of interest, and examine the spots from PSKreporter. It is really amazing how much this helps understand an antenna’s performance. I spent a lot of time doing this with the EFHW, a G5RV, and some dipoles. I now have a very good idea of how each of my antenna setups will perform on a given band, within ionospheric conditions and constraints, of course. This has really helped me to understand practical RF propagation and my available antenna solutions.

Reason 3:

The third reason I love FT8 is that it is like theraputic operating. And this realization came to me while recovering from surgery or when I was too tired from radiation treatment to do anything else. One can be very casual or very concentrated when operating FT8. But seeing those grid squares fill in and then get confirmed (I use GridTracker) is very satisfying. And I don’t mean satisfying from a contest standpoint (at least not for me), but from a sort of puzzle-solving standpoint. It’s pretty cool to me to see a real-time map of all the contacts you have made on a mode by band.

I operate a lot of other HF modes as well (Olivia, PSK, VarAC, JS8Call, packet, and even SSB!) but I still like FT8 and FT4. At the end of the day, it is a hobby and it is all about having fun. Do what you enjoy and strive to be good at it. What do you like about operating FT8?

Like many amateur operators, I have far too many handie talkies (HTs). I’ve cycled through many, and sold or given away many that I was done with. Some of those I wish I hadn’t sold (like the Kenwood TH-D74), but others I was glad to be rid of. I thought I would take a few paragraphs to talk about what I use day to day, and what I like and don’t like about these radios. I should note that I won’t discuss the HTs that I use in wildland fire communications as that is an entirely different purpose and topic.

On a regular basis and in addition to analog FM, I use DMR and Yaesu C4FM. To a lesser extent, I use P25 on amateur networks. Rarely do I ever use D-STAR any more, and then only via DVswitch and the mobile app on the phone.

I like using DMR. I’ve always liked the networks (specifically Brandmeister) and the architecture. I know, the digital audio is totally different than the richness of analog, but it’s still fun. And DMR was where I really learned about bridging and how I got into XLX reflectors.

For DMR, I mainly use the Anytone 878UV Plus II. I also use a Radioddity GD77 with the OpenGD77 firmware, and a Motorola XPR7550e. Of these three, I think the 878 is probably the best everyday choice. Yes, the 878 has its weird quirks, and the CPS (Customer Programming Software) is pretty bad, but the radio is fairly solid and easy to operate. And it sounds very good, both on receive and transmit. I also like the form factor and feel in the hand when operating. The OpenGD77 firmware is probably the most ham-friendly DMR firmware in existence, and is a pleasure to operate. But the hardware (Radioddity GD77) isn’t nearly as nice as the Anytone. I do like this radio as well, and keep one in the shed and use it while I’m out working in the yard. These radios as so inexpensive that you can have a couple and not worry about beating them up. In addition, both the 878 and the GD77 work very well with the Mobilinkd TNC4 for packet.

I don’t use the Motorola XPR7550e as much. It is a good solid radio, but is lacking a lot of the ham friendly features (like direct TG entry and persistence). I use it mostly on the Rocky Mountain Ham Radio region-wide DMR network where I am usually parked on one repeater/TG (Talkgroup) or roaming on a single TG.

For Yaesu C4FM (commonly referred to as “Fusion”), I use the FT-5DR. I also have an older FT-2DR, but it is relegated to my PDN (Personal Digital Node). The FT-5DR is a decent radio, and has a lot of APRS features. But to me, it feels pretty cheap. Indeed, mine has develoepd the dreaded case crack (or “mold line” as Yaesu likes to call it). It also goes through batteries very quickly. I always carry 2 extra batteries for this radio. I think my main gripes about this radio are the audio quality and the form factor. It does not sound very good, probably owing to the tiny size and small speaker. And it feels uncomfortable to hold an operate. I mostly use Yaesu C4FM because it is becoming more and more popular in our area, but I will admit that I am a bit of a reluctant user.

In my opinion, the Kenwood TH-D74 was the best APRS HT that I have ever owned. I should not have sold that. Kenwood’s APRS implementation and UI are much better than Yaesu’s, and the receiver in the Kenwood radios is much, much better than the Yaesu. I just wish Kenwood hadn’t gone with D-STAR as their digital mode of choice.

Finally, I use P25 a bit over a hotspot on amateur radio. For that I use a UHF Motorola XTS2500. I said I wouldn’t talk about wildland fire radios in this post, but I did it anyway. I also use this radio on fires, as it is one of the NIFC (National Interagency Fire Center) approved radios. This is a very solid older radio with great audio. The CPS is a real bear to deal with (read: it is horrible and not ham friendly), but the radio is awesome. On fires, I use it with a very large AA batttery clamshell that holds 12 batteries, but around the house I use an old rechargeable battery.

Anyway, as you can see I like HTs Maybe in a future post I will discuss some others, and talk about what we use in wildland fire.

DXer vs. TXTer. They are not the same. Dom, T32TT calling N0UN on "Phone" from East Kiribati: (video). Guess this picture says it all: Lazy is, as lazy does.

TXTpeditions (Formerly DXpeditions): Current TXTpeditions as of this Blog Post: T22T - 100,034 Q's: .5% CW, 1% SSB, 98.5% FT. ZD9W - 6,518 Q's: 0% CW, 0% SSB, 100% FT.

February 14, 2024, will be etched in the memories of a generation of Oregon residents for more than Romance. On that date Mount Doom, a little known peak in the

September 1985, I purchased a Kenwood TS-430S and became more active in amateur radio. In the apartment where I was living, I snuck wires out of a second floor window and began to make contacts. 

In October, I got the notion to try some Radio Teletype (RTTY). I built a demodulator using a circuit I've forgotten. Perhaps it used a couple of NE567 chips. Having a demodulator, I needed to translate the five-level Baudot characters into ASCII that I could display on the terminal.

(I purchased a Wyse 85 VT-220 emulator terminal in August of 1985, so I was no longer constrained by the 64x16 screen and 1200 bps limitations of the CT-64)

RTTY Decoder

I wrote a program for Flex09 to decode 45 Baud RTTY by bit-banging a PIA pin. I couldn't use the MC6850 ACIA, because it does not support 5 bit characters.

A delay loop established character timing: 

Each pass through the loop consumes 8 clock cycles. With the right value loaded in X, fairly precise timings could be accomplished. A value close to 250 would be 1 ms on a 2 MHz machine. By calling this loop repeatedly, timings of 11 and 22 ms are measured. 

I connected the demodulator output to PIA Port B, pin 0. The program looks at this pin, waiting for a zero. Finding one, it calls the delay loop for 1 ms and checks again. If the pin is still zero, it waits 10 ms and checks Port B pin 0. A continued zero at this point indicates a start bit. The 11 ms total delay places us right in the middle of the start bit.

The next sequence waits 22 ms and then samples of value of Port B, pin 0. It does this five times. These samples are shifted into a byte value, which used to look up an ASCII character in one of two tables -- one for letters, and one for figures -- according to the shift mode. This character is then sent to the terminal, and we go back to waiting for a start bit.

The resulting program is about 300 bytes long. Despite the simplicity,  I had little success decoding RTTY signals. 

In hindsight, there are several reasons for this. 

• Decoding signals off the air that might have been noisy.
• Demodulator circuit was completely untested and might not have worked.
• No experience with RTTY, so signals might not have been properly tuned.
• Precise value of the 1 ms time delay not known. I used values of 230 and 240, allowing cycles for other program logic. 

At some point, I distinctly copied "RY RY RY RY RY RY RY" from someone, but not much else. Later, I figured out this meant my program, at least, was working. 

Hardware Solution

In November 1986, I decided to use serial chip that could do five-level Baudot. The MC6850 only allows 7 and 8 bit characters, so I needed a different chip. The NS8250 could do 5, 6, 7 and 8 bit characters, and sports a programmable bit rate generator for all the common RTTY rates. Hence, I added an NS8250 UART to the baud-rate generator board. 

Funny, though -- I never wrote software to use the NS8250. In February 1989, I removed the NS8250 and its associated circuitry. 

I didn't become active in RTTY on the air until 2005, using Cocoamodem.

Portable Station for Greencube

We’ve been having a lot of fun with the Greencube (IO-117) satellite, so I decided to put together a portable ground station for activating grid squares. I wanted a station that –

• Has adequate antenna gain and power for reliable Greencube operation
• Uses solar-battery power so that it is quiet when operating in public places
• Uses computer management for Doppler correction
• Can provide accurate grid locator information via  a GPS receiver
• Is easy to set up in the field in less than 30 minutes

Station Components

We already have a solar-battery power system that we build for portable operation with a 100w transceiver as well as an IC-9700 transceiver that we use as part of our transportable satellite ground station. We also have Windows and Mac laptop computers that we can use as part of our Greencube (IO-117) portable ground station. With these components in mind, here are the hardware components that we are using as part of our Greencube portable station –

• Icom IC-9700 Transceiver (70 watts output on 70cm).
• M2 Antenna Systems 440-11X Antenna mounted on a heavy-duty video camera tripod.
• Advanced Receiver Research coax-powered LNA.
• A portable solar-battery power system capable of producing up to 180 watts of power.
• MacDoppler software running on a MacBook Air Laptop.
• Greencube digital client and logging software running on a Windows Computer.
• A GPS Dongle and Client Software is running on a Windows Computer to accurately determine the grid locator we are operating from.
• A Verizon Jetpack 4G Wireless Modem for Internet Access.

We are using the following software for our portable Greencube (IO-117) ground station:

• UZ7HO’s Greencube Soundmodem (download greentnc.zip).
• OZ9AAR’s Greencube Terminal Software.
• DK3WN’s Greencube Telemetry Decoder.
• MacDoppler to determine antenna pointing and to provide automatic Doppler correction on the IC-9700.
• N3FJP’s ACLog for logging contacts.
• NMEATime 2 Client Software to accurately determine the grid locator that we are operating from.

Portable Station in Pelican Case

We also purchased a case (Pelican Air 1555) to package the transceiver and accessories.

Antenna System

M2 Antenna Systems 440-11X Antenna

We choose the M2 Antenna Systems  440-11X Antenna for our portable ground station. This antenna has more than adequate gain for use with Greencube, and its lightweight rear-mounted design makes it ideal for use with our heavy-duty video camera tripod.

Portable Antenna System

The antenna is attached to the tripod using a Camera Tripod Ball Mount, a Handlebar Ball Mount Clamp, and a Double Socket Ball Arm. The Handlebar Clamp grips that antenna’s rear extension and allows the antenna to be easily rotated to align its polarity with Greencube’s antenna during a pass. A short section of water pipe with a cap, hook, and a 1,000-gram weight provides a counterweight to balance the antenna on the tripod.

Portable Antenna System Details

A Magnetic Digital Angle Guage is used to adjust the elevation angle of the antenna.

A coax-powered LNA from Advanced Receiver Research (an available alternative is the SSB Electronic SP 70 preamp) is attached to one of the legs of the tripod and is connected to the antenna with a short LMR-240uF coax cable. a 20′ length of LMR-400uF coax connects the antenna system to the transceiver. N-connectors are used throughout the feedline system.

Radio, Computers, and Software

IC-9700 Transceiver and Computers

Our setup uses an Icom IC-9700 transceiver and two computers. The IC-9700 transceiver is connected to the Windows computer via the radio’s USB port and to the MacBook Air via a CI-V cable.

The Windows computer runs the following software programs to provide the client terminal, modem, and logging functions required to operate with Greencube –

• UZ7HO’s Greencube Soundmodem (download greentnc.zip)
• OZ9AAR’s Greencube Terminal Software
• DK3WN’s Greencube Telemetry Decoder

The configuration of these programs is covered in more detail here.

NMEATime Software used with GPS Dongle

The Windows laptop also runs the NMEATime application and uses a USB GPS Dongle to accurately determine the grid locator where we are operating from. The grid locator from NMEATime is used to configure MacDoppler to ensure accurate tracking information for aiming our antenna.

MacDoppler Tracking Greencube and Controlling the Uplink/Downlink Frequencies

The MacBook Air laptop runs MacDoopler. MacDoppler is connected to the IC-9700 transceiver via a CI-V cable and controls the IC-9700’s uplink and downlink frequencies to provide Doppler correction. MacDoppler is also used to determine the azimuth and elevation of Greencube to enable manual pointing of our antenna.

Power System

Solar-Battery Power System

Powering a 100-watt transceiver in a portable application during extended operating sessions can present a challenge. I also wanted a setup that was quiet as we often operate portable in public locations. For these reasons, I decided to put together a solar-battery setup that consists of the following components:

• Two 90-watt foldable solar panels from PowerFilm (current model is 120W)
• Two A123 4S4P 10.0 Ah LiPo batteries from Buddipole
• An MPPT Charge Controller
• A RigRunner Power Distribution Panel

90W Foldable Solar Panels

The solar panels are wired in series and provide about 34 Vdc in bright sunlight.

MPPT Charge Controller, LiPo Batteries, and Power Distribution

The MPPT Charge Controller automatically determines the best balance between cell voltage and current to provide maximum power transfer to charge the batteries. The batteries provide the extra power capacity needed when transmitting. The resulting power setup can sustain the full power operation of our portable station, even on cloud days.

The laptops run on their internal batteries and are changed via automotive lighter socket power adapters between operating sessions.

Operating Using Greencube

Portable Telemetry from Greencube

My initial tests of the portable station were done using the station to receive Telemetry from Greencube. This allowed me to learn to steer the antenna and adjust it for the best polarity during passes. The station had no trouble hearing and decoding Greencube’s telemetry transmission from horizon to horizon.

Compass App on iPhone

It was relatively easy to point the antenna based on the azimuth and elevation information from MacDoppler. I used a compass app on my iPhone to set the antenna’s azimuth heading and the Digital Angle Guage to set the antenna’s elevation. Pointing the antenna to within +/- 10 degrees of accuracy was adequate for reliable operation with Greencube.

I turned the speaker volume on the radio high enough so I could hear Greencube’s signal while adjusting the antenna polarity. Finding the polarity that caused Greencube’s signal to be weakest and then rotating the antenna 90 degrees from this point worked well.

Portable QSOs with EA8ARI via Greencube

I was able to make 15-20 contacts on each Greencube pass with our portable ground station. The RSSI graph in the Greencube terminal is a good indicator to determine when to adjust the antenna’s heading and polarity to track Greencube during a pass. It’s best to have a helper with one person making contacts and the other adjusting the antenna, but it’s possible for a single operator to do both jobs and still make many contacts during a pass.

More Fun With Greencube

I am quite pleased with the performance of our new portable ground station for Greencube (IO-117). Anita and I are planning a portable grid square activation trip for later in the fall to make use of the station.

This article is the fifth in a series that we are working on. You view the other articles via the links below. This is a work in progress, and we’ll be creating additional Greencube-related posts in the near future:

• Greencube (IO-117) – A New Satellite for DX!
• Greencube (IO-117) – Station Setup, Software, and Operation
• Greencube (IO-117) – Completing a Satellite Worked All States
• Greencube (IO-117) – M2 Antenna Systems LEO Pack – Will It Work?
• Greencube (IO-117) – The Road to a Satellite DXCC?

You can also read more about our Satellite Ground stations here.

Fred, AB1OC

The post Greencube (IO-117) – A Portable Station for Activating Grid Squares appeared first on Our HAM Station.

W6PQL 2 Meter 1.5 Kw Linear Amplifier

I’ve recently upgraded the Amplifier for our 2m EME station to one that can provide full-duty cycle operation at 1500 watts. The digital modes used for EME on 2m (JT65 and Q65) require an amplifier that can sustain full output for periods of 1 minute or more as well as sustain full power operation at a 50% duty cycle over an extended period of time.

I’ve had great experiences with Jim Klitzing, W6PQL’s amplifiers in our station so I contacted Jim to build a new 2m amplifier for our EME station.

Construction and Setup

W6PQL 2m 1.5 Kw Linear Amplifier Interior View

Jim does an excellent job with the design and construction of his amplifiers. The parts are top-notch and the quality of construction and attention to detail are second to none. Jim provides components and sub-assemblies as well as some turn-key amplifiers.

He hand-builds each amplifier to his customer’s specifications and there is usually some wait time to receive a completed amplifier. The results are absolutely worth the wait!

W6PQL 2m 1.5 Kw Linear Amplifier Rear Panel

The connection and setup of the amplifier was straightforward. It is well worth the effort to hook up an ALC feedback connection from the amplifier to your exciter. In our case, we are using an Icom IC-9700 to drive the amplifier. This radio does not have a positive sequencing control input for the power stage of the transceiver. Our setup uses an external sequencer to manage transmit and receive changeover and protect our tower-mounted preamplifiers. We have had numerous problems where sequencing errors damaged our preamps.

One of the unique features of Jim’s Amplifier Control Board is the inclusion of an ALC hold-back capability. The amplifier can be configured to send an output limiting ALC voltage to the driving transceiver to prevent any power from being applied until the sequencer completes the final Tx changeover step by keying the amplifier. This feature requires additional amplifier adjustment (the adjustment procedure is well covered in the documentation). This capability has eliminated the issue of sequencing problems causing damage to our preamplifiers!

Power Supply

Meanwell RSP-3000-48 Power Supply

The recommended power supply for this amplifier is a 48-volt, 62.5-amp switching design from Meanwell (Model RSP-3000-48). Jim set up the supply and provided the cabling to connect it to the amplifier. The supply is 240 VAC powered and is quite efficient. Jim adjusted the power supply’s output voltage and tested the amplifier with it with the amplifier before shipping.

Controls and Operation

W6PQL 2 Meter 1.5 Kw Linear Amplifier Controls and Meters

The operation of the amplifier is straightforward. It is best to set the driving transceiver for a watt or so and perform some initial test transmissions to ensure that the antenna system is presenting a low SWR and that your station’s sequencing system is operating correctly. Note the LNA and Amplify Controls must be turned on for the ALC holdback feature to work correctly.

The amplifier provides PA Voltage and PA Current meters as well as bar-graph displays for Forward and Reflected power.

More Articles on EME

We are very pleased with our new amplifier! I’ve used it for quite a few contacts, and it performs great. It provides a full 1500 watts output with the digital modes used for EME work.

You can read more about our EME station project via the links that follow:

• EME Station 2.0 Part 1 – Goals and Station Design
• EME Station 2.0 Part 2 – Excavation, Footings, and Conduits for New Tower
• EME Station 2.0 Part 3 – Phase Tuned Receive Coax Cables
• EME Station 2.0 Part 4 – New EME Tower Is Up!
• EME Station 2.0 Part 5 – Control Cables and Rotator Controller
• EME Station 2.0 Part 6 – Tower Grounding System
• EME Station 2.0 Part 7 – Building Antennas
• EME Station 2.0 Part 8 – Elevation Rotator Assembly and Sub-System Test
• EME Station 2.0 Part 9 – H-Frame Assembly
• EME Station 2.0 Part 10 – Antennas On The Tower
• EME Station 2.0 Part 11 – Station Hardware in Shack
• EME Station 2.0 Part 12 – Station Software
• EME Station 2.0 Part 13 – H-Frame Enhancements

If you’d like to learn more about How To Get Started in EME, check out the Nashua Area Radio Society Tech Night on this topic. You can find the EME Tech Night here.

Fred, AB1OC

The post EME Station 2.0 Part 14 – New 1.5 Kw Amplifier appeared first on Our HAM Station.

LEO Pack Transportable Satellite Antenna System

Quite a few folks have the M2 Antenna System LEO pack antenna. I wanted to see how this antenna system would perform with Greencube (IO-117). Our LEO Pack is set up on a Glen Martin roof tower that we’ve modified to create a transportable ground station. Here are some of the specs for the setup we’ve tested:

• M2 LEO Pack Antennas (2MCP8A and 436CP16)
• Alpha-Spid Az/El Rotator
• M2 Polarity Switches installed in both antennas
• Advanced Receiver Research coax-powered preamps installed at both antennas+

The specifications for the 70cm antenna are as follows:

• Frequency Range: 432 To 438 MHz
• Gain: 13.3 dBic
• Front to back: 15 dB Typical
• Beamwidth: 42° Circular

The published gain number for this antenna meets the requirements for operation with Greencube, so we set up our transportable station in our backyard and proceeded to do some testing.

Transportable Ground Station

Transportable Ground Station Radio and Computers

The ground station setup includes an IC-9700 Transceiver, a Green Heron RT-21 AZ/EL Rotator Controller, and two computers.

MacDoppler Tracking Greencube and Controlling the M2 LEO Pack

The Mac laptop runs MacDoppler, which handles steering the antennas and Doppler correction, and the Windows laptop runs the modem and client software to access Greencube’s Digipeater.

The antennas are located about 100 ft from the rest of the ground station and are connected using LMR-600uF coax cable. This results in about 40 watts of power being delivered to the feedpoint of the 70 cm antenna.

Testing The LEO Pack With Greencube’s Digipeater

Greencube (IO-117) QSOs with the LEO Pack Antenna System

I am happy to report that the LEO Pack 70cm antenna enabled us to make quite a few contacts using the Greencube Digipeater. The setup required the remote preamp to be on and the use of the polarity switching controls to optimize losses due to mismatched polarity, which occurred frequently during Greencube passes. The LEO Pack antenna/preamp combination provided consistent decodes of Greencube’s packets. The challenge was getting our packets to be Digipeated by Greencube. On some passes, this worked very well. During other passes, we were only able to get reliable Digipeats during the approaching portion of a pass at elevations above 25 degrees.

Optimizing Our Station

MacDoppler Optimized Frequency Settings for Greencube

I spent a lot of time determining the best uplink frequency to use with Greencube’s Digipeater. The settings above are what I finally settled on for uplink and downlink frequencies.

Optimized Soundmodem Settings for Greencube (IO-117)

I also spent some time experimenting with the Soundmodem settings. The lengthened Tx lead-in and tail settings above helped Greencube decode our signals more reliably.

These adjustments also improved the Digipeating performance of the larger antennas used in our main ground station, so they are not specific to the LEO Pack.

Conclusions About The LEO Pack and Greencube

I probably made about 50 contacts using Greencube and our LEO Pack antennas. If you already have a ground station built around the LEO Pack Antenna System, I would encourage you to add a preamplifier if you don’t already have one and try Greencube.

If you are building a fixed ground station for use with Greencube, it might be better to step up to a larger antenna such as the M2 Antenna Systems 436CP30.

I have also found that antennas with circular polarity are not necessarily the best for Greencube. This is likely due to a combination of the lengthened path through the ionosphere due to Greencube’s altitude, resulting in stronger polarity rotational effects and mismatches with the circularly polarized antennas we are using. I am anxious to do some more testing with the non-circularly polarized yagi that we are using with our portable station to see if I can confirm this.

More Fun With Greencube

This article is the fourth in a series that we are working on. You view the other articles via the links below. This is a work in progress, and we’ll be creating additional Greencube-related posts in the near future:

• Greencube (IO-117) – A New Satellite for DX!
• Greencube (IO-117) – Station Setup, Software, and Operation
• Greencube (IO-117) – Completing a Satellite Worked All States
• Greencube (IO-117) – A Portable Station for Activating Grid Squares
• Greencube (IO-117) – The Road to a Satellite DXCC?

You can also read more about our Satellite Ground stations here.

Fred, AB1OC

The post Greencube (IO-117) – M2 Antenna Systems LEO Pack – Will It Work? appeared first on Our HAM Station.