Just another Amateur Radio Operator

Author: ben

Packet Communications!

First Packet Connection

I’ve played about briefly with AX.25 in the past when tinkering with APRS, but never really had much success with it and with TNCs being both hard to come by and damn expensive for what they are, it has always been out of my reach. Recently I acquired a couple of second hand TNCs and have spent the weekend setting up and connecting.

The first TNC I attempted working on was a Paccom TNC 320. This meant creating a cable to go from the 5 pin DIN connection on the back of the TNC to the 6 pin mini-DIN connection in the back of my ICOM radio. The first attempts at this involved using the mini-DIN tails from old PS/2 Mice or keyboards, testing to see if their wired up pins were going to be any good for the TNC and then just soldering the 5 pin DIN on the other end. I spent an evening with VK7ZMS doing this and after much testing, we got to the point where we had PTT and 1200 baud AF working, but no RX. Even then. the AF out tones were low.

Over the weekend I bit the bullet and visited Jaycar and bought some more mini-DIN, 5 ping DIN and multi-core wire and created my own cabling. This time I was also armed with an MFJ-1270B TNC which was my fallback option if I had no luck with the Paccom.

Plugged everything in, fired up a Putty serial connection, got presented with garbage. Changed the terminal baud settings, still got presented with garbage. Thought at this point it’s probably a good time to read the manual. Interesting thing about the MFJ TNCs is that they use 7 bit words, not 8 bit like many other devices. Updated my settings and bingo, was presented with text that looked like a TNC.

Ran the calibration tests, PTT worked, I could hear tones being sent loud and clear, and most importantly I was receiving packets as well. I was in business. Finished assembling the cable, plugged everything back in and found I had Rx, PTT but no tones out. Back to workshop again and found in the final assembly I had caused a small short across some of the pins. I fixed the issue, liberally applied hot glue to hold it all in place and provide isolation and put it all back together again, and now it works!

As you can see above, I have managed to successfully connect to VK7ZMS. I have also connected to VK7HDM-9 using VK7ZMS as a via.

I already know of a few other amateurs getting interested in packet again, so who knows, we might see a bit of a packet radio revival in southern VK7!

Everything Old….

The last time I was active on air was a brief period in 2011. During this time, I just wasn’t that interested in radio and it took a back seat to other projects and interests.

Fast forward to July 2015. My lovely partner has gone overseas for a few weeks and I decided to spend a couple of evenings at my local radio club which holds amateur TV nights most Wednesday evenings. This wasn’t new to me. What was new however was a couple of work colleagues deciding to come up with me and the discovery that the stuff I couldn’t do before I now could, especially having bought a contemporary new transceiver.

So now I find myself not knowing which way to go first with many of these “old” things (and not so old) that are all new to me again:

  • VK3YT’s endeavours with High Altitude Balloons I find just amazing, and can easily see this becoming science projects in high schools or colleges, promoting amateur radio, electronics and further research.
  • JT65 Weak Signal Modes being used for high altitude balloons, HF communications, EME, Meteor Scatter and a whole range of other types of communications that are just not suitable for voice communications
  • Traditional Modes such as BPSK, RTTY and STTV, and more exotic modes like THROB, Feld Hell and Contestia. Previously I did not have the hardware available to do this at home. Now I do. Enough said there really.
  • Packet Radio. AX.25. One of the many projects I am currently running with. I have acquired an old TNC, and it’s just a matter of interfacing it with the radio.
  • Speaking of interfacing, I need to make a suitable new interface for my Icom IC-706MkIIG that includes PTT and audio in.
  • Amateur Satellite communications. It doesn’t seem as hard as it sounds remarkably, and I think that would be great fun.
  • FreeDV – The new digital voice mode on the block. it’s achieving some amazing things like FM quality audio with weak signals, and is definitely a QSO mode I want to try.

This, along with station maintenance and improvements is definitely going to keep me busy in the foreseeable future. I’ll touch more on the station maintenance in a later post.


Testing Coax for Faults

It’s been a while since I was regularly operating my station and much of the coax that is in use has been exposed to the outside environment for over 10 years. I know the best way of testing coax is by using specialised sweep tools, but having only basic testing equipment available I though I should ask the Ham Radio community over on Google+. I think Google+ is an entirely underrated social platform, and I find myself leaning towards it’s use more and more.

Some of the advice coming back I expected, such as investing in an MFJ-269 or FoxDelta Analyser (which is good advice by the way, I see an antenna analyser being next on my purchasing list). However, I think Tim (VK2XAX) provided me with some excellent advice to get started:

Yes there is a couple of things you can do with basic ham shack items:

  1. stick your power/SWR meter on a small patch cable with a dummy load directly on the output of a 2m radio. Set you power out to precisely 10 watts aka 40dBm call this p1. Remove meter from rig. attach suspect cable to rig. attach meter and dummy load to end of cable and measure power again without touching rig output power. call this p2.
    p1-p2 = loss for your cable.
    look up spec sheet for your cable e.g. RG213 has a loss of ~15db@100MHz for 100m so 15/100 = ~0.15dB loss per metre. e.g If your cable is 34m in length then it should have a loss of ~5.1db aka about 3.5w.
    If your 34m cable shows a different value to 3.5w then you should be able to calculate that loss and work out how much worse than the specs it is.
  2. If you have a big dummy load, stick that on the end of the cable with the SWR meter at the radio and pump up the power to max and see if there is any SWR – there should be none. If there is SWR then the cable is most likely damaged in some way that is causing reflection These are good “rule of thumb” tests to check your cables.

Tim then went on to detail in a separate Google+ post a demonstration of his testing.

I was quick to check out the second of the two items, as high SWR was my immediate concern (The SWR without ATU seemed a little higher than I remembered, ranging between 2-3:1). I was pleased to find that it is not the coax contributing to the SWR (which means I need to look at the balun next…). The loss measurement will also come later.

Other more obvious inspections I have done are:

  1. Continuity – just use a multimedia so find any obvious issues like open circuit, or short circuit  between the conductor and ground.
  2. Visual – Inspect Coax and connectors for any physical signs for deterioration such as oxidisation around the connectors and ground braid and  any indications that the outer jacket of the coax has been damaged or has become brittle, allowing water to enter the coax.

I have unfinished business with the Coax and dipole, so I am sure there will be a post in the future providing a continuation of the testing.



Rig Control with RUMlogNG

My workspace for my radio gear is pretty limited, therefore space is at a premium. The Toshiba Tecra M2 which I used as my station computer for many years finally reached the end of its life, with none of the major operating systems supporting non-PAE chipsets. Not ready to purchase a laptop just for radio operations, I was hoping that I could use a more contemporary platform for operations – an iPad.

A quick search around and I came across RUMlogNG, which is easily the best logging interface I have seen in a ham radio iPad app that is modestly priced.

RUMlogNG Logging Page

One of the more interesting features was that basic interaction with your radio was possible (reading of frequency, mode), with the suggestion to use one of Pignology’s Piglets. Reading the specifications of the piglet, it became apparent that what it was doing was taking the serial CAT interface of the rig control, and making it accessible over wifi network to connected devices by streaming the serial data out of a TCP port.

Armed with this information, went looking for alternative ways to connect serial interfaces to RUMlog, and happened across this forum post, talking about an app called remserial. After attaching a Serial to USB Converter to a Raspberry Pi, I was able to run the below command as root:

pi@raspberrypi ~/remserial-1.4 $ ./remserial  -p 7373 -s "9600 raw" /dev/ttyUSB0

The app did not crash when I tried this, so I assumed it was running, and then configured RUMlogNG to connect to the Raspberry Pi on port 7373. Success! RUMlog did not throw any errors and back on the logging screen, I saw that frequency and mode was being updated off the radio.

Rig Control with RUMlog

RD Contest 2015

This weekend I participated in my first radio contest in at least 3 years with the annual WIA Remembrance Day Contest. This is a 24 hour points based contest, open to all VK, ZL and P2 stations.

The first thing that was noticeably different was that the rules had changed. The biggest change is that the QSO exchange no longer swaps an incrementing serial number, but instead the number of years the person has held their license. I can understand why this was done (so people do not get discouraged when hearing people with serials of 400+ indicating 400 QSOs, and giving up), but it does introduce a new issue of knowing exactly what the report is going to be if you have worked that station multiple times. You could go to the extreme in saying that an exchange of callsigns would be suffice after the first contact!

As with every RD contest, I worked both HF and VHF/UHF, the latter being advantageous in that there are a local group of operators who are easy to contact every 3 hours.

Indeed this was a good thing, as conditions were so poor on HF this year do to a geomagnetic storm, some 15 of the 35 unique callsigns I worked were local, with VHF making up the bulk of my contacts, as demonstrated in the summary:

54 HF Contact vs 105 VHF Contacts


Working HF was just depressing, with pretty much nothing heard on 20m for most of the contest (VK4HH was the only one I heard regularly). Both 40m and 80m also seemed oddly bereft of people contesting in the evenings. I do hope that this is largely due to the solar storm impacting on operations, rather than less people participating.

I still enjoyed the contest, and met the goal of 150 QSOs I had set for myself as the contest was starting. This is a far cry from the 600+ contacts from the last serious contesting I did at Penstock Lagoon but as a first crack at contesting after I break. I am happy with the result.

I still remain unconvinced that my trap dipole is operating as well as it should (around a year ago someone cut the antenna element while I was having work done around the house, causing me to exchange some unpleasant words and having to replace a large section of dipole). This I will investigate in coming weeks, along with what I suspect will be the complete replacement of feed lines that have deteriorated from the many years in the sun.

Next year having a 160m antenna of some description will definitely be happening, or perhaps I will go portable in the North of the state.

It was good fun and I am looking forward to the next contest.

Back on 6m

6m Dipole

6m dipole finally in the air

I’m finally back on the 6m band. It wasn’t a cakewalk, with the dipole generally un-cooperative with the element parting ways with the Acro-bat insulator, and then finding the masthead pulley rope (pictured to the right in the photo) was no longer going up to the masthead, meaning that I needed to lower the mast to replace it.

1:1 coax balun made by VK7ZIF is the centre-feed, and I took the time to redo the PL259 connectors and waterproof them prior to reinstalling to make that particular joint a lot stronger than last time. It was this joint that led to the antenna’s demise a few years ago.

Plugged in, and tested, works a treat with low SWR, which was how I remembered it.

I’m looking at building a new and improved version of this antenna at some point using 2mm multi-strand stainless marine stainless steel wire, much the same as my HF dipole.

Attack of the RFI

After having a successful setup of the radio shack over the weekend, I took the HF rig to the local radio club, but when I returned, and plugged everything back in, BUZZZZZZZZZ. S20 over 9 noise. not good.

Troubleshooting kicked in. Whats changed? Earlier in the afternoon I had put up the 6m dipole antenna and finished working on installing an earthing stake and earth wires back to the rig. By process of elimination, I removed each. Noise still there.
It was late in the night by this point so I made an assumption that the noise was in fact being caused by nearby power lines having damp insulators, so went to bed with the though of investigating the issue if it existed the following day. Yes, it did exist the following day.

Read More

Day 1

Today is the first day of getting back on air. It’s been a pretty full on day actually as I never anticipated the amount of things I needed to do to get everything working. I guess before I continue, I should mention one of these arrived in the mail for me yesterday:

My new Rig

No complaints about this arrival

The Yaesu FT-DX1200 is quite an upgrade from the trusty Icom 706-MkIIG, which has now been relegated to VHF/UHF Duties.

The joy of a playing with a new rig on Friday night was short lived – the new Yaesu draws 23.8A @ 13.8V peak. My power supply was a fair way short of this at 15A. operating would have to wait until Saturday. In the meantime, I could start getting a PC ready for rig control.

Let me just say, you will reach an inevitable point in time when hardware, although suitable for the purpose will not be supported by modern operating systems. I found out that upgrading from Windows 7 to Windows 10 was not supported at 64bit, but was if I would find Windows 10 32bit. The problem here however is that the 32bit download tool will not work under 64bit Windows 7. joy.

I also managed to go out to Jaycar in the morning and buy a 40A switch-mode power supply. Some people will cringe, because these type of power supplies are notorious for causing RF interference (QRM). Fortunately I see very little QRM affecting the rigs.

Ham Radio Battle Station

The Battle Station. Win10 Installing

After installing Win10, I found that the drivers associated with the rig control interface cause the computer to crash. Dammit. back to Windows 7 I have gone. I think I have done about 5 OS install attempts in the last 24 hours.

Finally, I am getting around to configuring Ham Radio Deluxe to control the Rig. I am finding the lack of documentation in configuring the DX1200 quite frustrating and as I am writing this I am looking for information on how to sent PTT to the rig, which will probably take me into the evening.

After this, import my previous QSLs, set up VKCL for the RD Contest in a couple of weeks and start doing a more thorough configuration of HRD.



Reactivating the Station

Realistically, I haven’t been on air much in the last 7 years. Other interests and real life have seen tinkering with amateur radio come a distance last to everything else.

Occasionally I would have a listen around the band, make a half-hearted CQ DX call, or try to contact that station in amongst the pileup, usually turning off the rig some 30 minutes later.

However, thanks to a renewed interest by some of the people who helped me get into the hobby, and with some of my newer friends taking the opportunity to get licensed themselves, I find myself growing in enthusiasm to get back on air.

As part of this, I felt I would also bring back my website. Sadly much of the information from the original 2008 website has been lost, but some still remains and will make it up here eventually.

Thanks for joining on this new adventure!

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