Having fun on the “Magic Band”

In April I installed a second-hand HB9CV for 6m, primarily for use in the UKAC VHF contests but I hoped to use it during the upcoming sporadic ‘E’ season.

Still a relative newcomer to the hobby (only licensed at end of 2013) I had little experience of the 50MHz/6m band and have been mostly met with static whenever I did turn the dial to have a listen but happily that has changed in the last few weeks.

I knew that 6m can be an interesting, unpredictable almost unique band.  Being at the lower end of the VHF spectrum it exhibits the usual characteristics of VHF communication, mostly short range line-of-sight contacts since 50MHz is usually well beyond the maximum usable frequency (MUF) for normal ‘F-layer’ ionospheric propagation utilised by the lower bands. However solar activity and other factors can trigger other types of propagation, in fact the band can support just about every form of propagation possible and is the main reason why it has become known as the “Magic Band”

One interesting form of propagation is sporadic E, or popularly referred to as Es. Small clouds of unusually ionised atmospheric gas form in the lower E-layer of the ionosphere (located at altitudes of  90 to 160 km). These clouds ‘bounce’ the radio waves allowing long-distance communication at VHF frequencies, sometimes multiple hops are possible giving extreme DX. One advantage of sporadic E over other forms of propagation is that it allows low-power QRP communication. As its name suggests, sporadic E is not a normal occurrence but can happen at almost any time. It does display a seasonal pattern with activity peaking in the summertime most noticeable in mid-to-late June.

I had turned the antenna to the East and have been running WSPR on and off over the last month on 6m with no luck, just the odd spot from the UK. I was in the shack one Saturday evening and was tuning around on 6m and heard some Italian stations calling CQ on SSB. I tried my luck and answered (using 50W) and was amazed to be heard, working a couple of stations in quick succession then suddenly the opening closed mid contact with another station. I was hooked!

Over the past few weeks I have caught a few more openings and have managed to work (in no particular order) Latvia, Croatia, Lithuania, Slovenia, Czech Republic, Slovakia, Serbia, Italy, Germany, Switzerland, Poland, France, Spain, Austria, Canary Islands and Finland – using a combination of voice on SSB and the JT65 digital mode.

Using JT65 has been particularly interesting since it allows me to ‘remote operate’ from work otherwise I would miss most of the ‘Es’. Being able to monitor the waterfall and see the signals gaining and falling in strength during the minute long transmission is particularly fascinating.

Using the PSKReporter website I can see the location of all the stations I could hear and was being heard by. This map shows activity over the couple of hours on the 26 May using just JT65.

I have joined the UK Six Meter Group (UKSMG) to find out more about this “magic band” and their website is full of lots of information and resources along with the magazine Six News for subscribers.

Poetic justice?

Following my last post it is perhaps ironic that for the last few evenings I have been plagued by an increase in QRM.

Trying some JT65 on 40m I was being plagued by S8-S9 of local noise, it is noise I have had regularly (even before the purchase of my PLT devices) so I reconnected up the WiMo QRM Eliminator, which has been collecting dust, to see if I could improve matters.

Using just a short piece of wire as the auxillary ‘noise’ antenna managed to null out most of it to greatly improve reception. No commentary on the video below but hopefully you can see it working.


Interestingly the noise seems to abate around 11pm when people are off to bed.

Logging and datamodes with PZTLog

Organisation isn’t one of my strengths and my logging of contacts has been pretty woeful. It consisted of a spiral bound note book full of various scrawls sometimes tabulated for contests but more often than not a free form mess. With good intentions I purchased a proper RSGB Deluxe log book months ago but that has remained pristine and has just become a handy band-plan look-up!

Until recently I had only made a small number of voice QSOs on HF and had entered those manually into the online eQSL, QRZ and HRDlog logbooks I maintain.  JT65 data mode logging was handled by the JT65HF program itself and for the UKAC and other VHF contests I have been using the MINOS logging program – all in all a bit of a mishmash.

Now my operating confidence has grown I am making more contacts and so I really need to computerise and centralise my logging. After  looking at a number of programs I opted to give Charlie Davy’s (M0PZT) freeware PZTLog a try and after using it for a couple of weeks I am very impressed.

http://m0pzt.com/?pztlog

The program has a multitude of features but at the moment I am using it to simply enter and log details of contacts, combined with the CAT interface to the FT857-D and the OMNIRIG control the mode, frequency, band and power settings are automatically populated.

The really nice selling point for me was the inbuilt data mode operation. I have tried PSK and RTTY before using other programs but I often found myself confused and intimidated by the interfaces and jargon.

PZTLog uses the MMVari engine to operate PSK/RTTY and it uses a familiar waterfall display. The TX/RX window and  QSO macros are easily accessible and I found the interface much more intuitive than other programs I have used. On installation, the macros are already populated and labelled sensibly and are easily editable. By double-clicking received text you can set Callsign, Locator, RST/Serial, Name/QTH quickly and with ease.

In a short time I have made a good number of PSK QSOs as well as a some RTTY contacts, even giving some points away in the fast paced SCC RTTY contest last weekend.

Importing and exporting of logs is very easy and it has inbuilt eQSL uploading, but at the moment I am having trouble making that work reliably but that I think is me rather than the program.

PSK is a great mode, running no more than 30W, often less I have made a number of nice DX contacts and countries including Argentina, Oman, Japan and the Dominican Republic.

Thanks to Charlie’s program I now have a better understanding of how the mode and QSO works so may try some of the more sophisticated programs, or I may just stick with PZTLog for a while. Check out Charlie’s page for lots more interesting information as well as some very funny light hearted audio features poking fun at the hobby.

In other news the VHF UKAC contesting is improving. Last week I made a last minute decision to lower the pole and put up my homemade wooden 6m MOXON but glad I did. Conditions weren’t good but still made a respectable number of contacts but not a lot of distance. I’ve climbed to 30th place in the 50MHz low power AL section.

A last minute decision to swap the aerial, but worth it! Shame missed out on some E’s when got called away 🙁 #ukac pic.twitter.com/TRarIikVpD
— Andrew Garratt (@nerdsville) August 26, 2014

Last night was the 144MHz UKAC and what a great night it was, conditions were brilliant and it was very busy on the band. Still operating search and pounce mode I snagged just 32 contacts, but with 13 multipliers giving me by best score so far on that band.  Operating in the low power AL section as M6GTG it is hard work getting through the pile ups but it was great fun trying.

Well that was fun, great conditions and some nice DX even operating as M6GTG #ukac pic.twitter.com/KwTLXiTPDD
— Andrew Garratt (@nerdsville) September 2, 2014

Finally I became a licensed ‘foundation level’ amateur a year ago this month (M6GTG), and have since become an ‘intermediate’ (2E0NRD) and have now taken the bold step of applying to take the ‘advanced’ examination next month. I say bold because I haven’t taken a course or studied for it per se but with my background and education I have covered most of the theory even if it was over 25 years ago – with a bit of serious reading, revision and dusting off of the memory banks over the next few weeks I hope to be ready!

Well here goes nothing.. best get studying pic.twitter.com/FTDPqTPKSa
— Andrew Garratt (@nerdsville) August 28, 2014

Been a busy boy

Been very busy with the day job and too busy playing radio so this post will be a bit of a catch up!

JT-65HF
I have been using my newly built datamode interface in anger.

As well as running WSPR on occasion I have also been active using JT65-HF.

JT65 is a communication mode developed by Joe Taylor, K1JT, (specification here) originally intended for amateur radio communication with extremely weak signals such as Earth-Moon-Earth (EME) contacts on VHF it has gained popularity on the short wave bands using JT65-HF an adaptation of the JT65A protocol.

Being restricted to 10W it is an attractive method of making contacts. The protocol includes error-correcting features that make it usable even when the signals are too weak to be heard or are being subject to interference.

There are several how-to guides available
Get On the Air with HF Digital (from the ARRL)
JT65-HF — an ‘Odd’ but Fun Digital Mode (from eham.net)

A number of software packages support JT65, the most popular being JT65-HF originally developed by Joe, W6CQZ. Sadly Joe is no longer developing the software, but the last version released still works, and is available at http://sourceforge.net/projects/jt65-hf/ 

Thankfully the project was open source and Beat Oehrli, HB9HQX as developed his own version with the catchy title JT65-HF-HB9HQX-Edition, available at http://sourceforge.net/projects/jt65hfhb9hqxedi/ This is the version I have been using with great success, the colour coding and simple button pressing makes a QSO straight forward and the built in logging and exporting make uploading to QRZ, eQSL and HRDlog painless.

Whilst to a traditionalist amateur operator it is perhaps a little slow, remote and impersonal (each exchange occurs during alternate minutes) I really like it! One advantage is I can set up the radio in the shack with CAT control via HRD and then have QSOs while VNC’ing into the computer from the laptop whilst in front of the TV with the wife and the dogs! (Thanks Tim G4VXE for that suggestion!)

I have been active on the 10/20/30 and 40M bands over the past few weeks making contacts with Bulgaria, Canada, Denmark, Germany, Greece, Iceland, Kazakhstan, Poland, Russia, Serbia, Sweden, Thailand, Ukraine, USA and Venezuela.

Contesting ‘DX’ Headset and Interface

I have become hooked on the RSGB UKAC VHF contests, operating on a Tuesday evening on different frequencies (50MHz, 144MHz, 432MHz depending on which week of the month) Whilst my results are small-fry compared to the big guns I have been more than happy with my modest antenna set up and less than ideal location (previous blog posts)

I soon appreciated that using headphones rather than the speaker made life easier but I was still using the stock supplied hand microphone. Several times I have found it difficult to make myself understood and suspected that not only am I plagued by my ‘Black Country‘ accent and poor enunciation but maybe the microphone wasn’t quite cutting it.

Not able to afford or justify the purchase of a Heil headset just yet I took inspiration from Charlie M0PZT and his recommendation for a budget solution using a £10 computer headset from CPC (product AV21444).

On the Yaesu FT-857D the microphone connector is a 8-pin RJ45 socket which is behind the removable front panel with the lead coming out of one of a number of openings. Whilst the panel is easily removable I didn’t want to keep removing it when switching between microphones, also re-purposing an obvious CAT5 network lead was problematic as they are often thicker than the openings.

The lead removed from MH-31, RJ45 on interface

A quick look at the supplied Yaesu MH-31 microphone revealed it can be unplugged, so what I needed was a interface box where I could plug in the headset and the microphone lead. This would also allow me to try different headsets in the future.

Mic lead connected and headset
The budget ‘dx’ headset

My solution as pictured above is quite simple, I won’t include any pictures of the interior as it is a bit messy and not my best work! It is built from salvaged parts, including the box. The RJ45 socket came from an old network adapter, but beware some sockets are only 6 pin not the 8 as needed here. The headphone part of the headset is a simple connection to the rear socket on the FT-857D (the grey cable on the picture above)

Yaesu FT-857D mic socket as view from front

Most microphones designed for computers use electret elements which require a bias voltage, this is quite simple as the Yaesu microphone connector supplies 5V, so a simple resistor (8.2K) will supply this, also by using a couple of different capacitors and a switch I can select a ‘thin’ higher frequency response (for DX work) or a more normal ‘fatter’ response. A circuit can be found on George Smart’s webpage, the bias is simply applied to the tip of the microphone jack.

The box also has a PTT switch, this could have simply grounded the PTT line but I wanted to have a LED indication on the box and again I could have just wired a LED and resistor to 5V and to the PTT line so it would light when the switch was closed, pulling PTT to ground and completing the circuit. I opted to use a simple transistor open collector switch to add a little isolation.

The interface works well and I used it for the first time last night in the 50MHz UKAC with my homebrew MOXON antenna…

6M/50MHz MOXON
My first contest back in January was the 50MHz UKAC and as I blogged I made a solitary contact due to antenna issues, i.e I didn’t really have one!

I missed the February contest so this month I really wanted to have a decent stab at it which meant building an antenna. I decided early on that a Moxon was probably the easiest to construct, so I downloaded the MoxGen program to calculate the element lengths.

Using 1mm diameter ‘garden wire’ for the driven element and reflector. I had various bits of flexible plastic pipe kicking about and decided to use them to construct an x-shaped spreader, unfortunately the pipe was obviously from different batches and as soon as it was tensioned by the wire it bent into all sorts of strange shapes due to the different elastic properties so I abandoned that design.

I had left the build to the last minute and needed a quick solution, so yesterday morning plan-B was to go an get some cheap timber from the local B&Q on the way to work and build a simple frame to wrap the wire round.

Moxon on garage floor
Coax and common-mode choke, and sturdy support!

I impressed myself by completing the construction of the frame in the short time I had at lunchtime!

One thing I hadn’t appreciated was just how big the final antenna was, it wasn’t heavy just big! So last night an hour before the contest started I fitted the choke balun and coax to the terminal block. To be safe I removed the other antenna from the mast and hoisted her up.

Up in the night sky

Moment of truth, thankfully the VSWR was around 1.5:1 at 50.2MHz, rising to nearer 2:1 at the top end of the band. Not ideal but close enough. The VSWR measurements would suggest that the Moxon is a little bit long, interestingly some online Moxon calculators suggested dimensions for a slightly smaller Moxon than the downloaded Moxgen program did? Something to tweak/experiment with possibly using some thicker wire to increase the bandwidth.

50MHZ UKAC 25 March 2014
I was sorted! Moxon antenna up, contesting headset and interface plugged in and a quick scan up and down and I could clearly hear several stations testing and setting up. I poured myself a beer and soon the contest started.

Time between QSOs for a ‘selfie’

I finished the night with just 14 QSOs, more would have been nice and it wasn’t through lack of trying I could hear many more operators but simply couldn’t make myself heard either because the antenna was in wrong direction or due to low power and getting lost in the pile ups to stronger stations.

I was not disappointed in fact I was quite happy with what my 10W, my new headset and home brewed antenna had achieved. The Moxon showed great promise and directional characteristics but for some reason just couldn’t get south as the map indicates.

Out of interest I wondered what the line of slight view from my mast looked like so I strapped a camera on to the moxon this afternoon..

Need more height I think, especially if pointing South and a rotator would be nice!
Well that wraps it up for the moment.. 73