Nice video from this years Tokyo Ham Fair in August featuring some views of the new up and coming IC 9100.
Aug
08
2009
Automatic Coupler
This week I have mostly been planning and designing antennas. As you know I have no HF capabilities in the condo as for one I don’t have an HF radio and more importantly don’t have the antennas needed.
I am a bit spoiled with access to the club station but feel usage of that is much better suited to contesting and cluster spotted DX hunting. For casual local/regional QSOs a small set-up at home would be much better.
So how to get on the air you say? There are many compact antenna systems that may adequately work from my condo balcony. You have shortened coil-loaded verticals like the the Buddistick or the SuperAntenna MP1. You also have shortened coil loaded dipoles like the Buddistick or SuperAntenna YP2. At the other end of the spectrum you also have compact High-Q small loops like the MFJ-1788.
All of these antennas are suitable and would work to some degree from the balcony. However I feel paying cash up front for one kind of antenna system would limit experimentation and the fun involved in building home-brew antennas. I need something that would grow with the station. Hopefully sometime in the future I may find myself with a backyard and plenty of room for antennas, a high-Q small loop or shortened dipole would be kind of pointless then, no? I’d end up having to invest more money into an antenna system then.
I am starting to look at automatic antenna couplers like the Icom AH-4 or any of the SGC models. They would allow my HF antenna to grow if the need arose. So this week I began modelling some small wire loops in EZNEC. I have chosen wire loops as this removes the need for radials and maximises the volume of space I have on the balcony.
A 2 turn loop approximately 8ft x 8ft brings feed-point impedance within the range of most feed-point mounted automatic couplers. Most of these couplers can handle in the range of 100:1 SWR, if 1 is 50 ohms, then a range of 50 to 5000 ohms. In fact the loop I have modelled presents very favourable feed-point impedances between 40m and 12m. Anything less than 1:50 SWR is favourable, this loop presents most bands below 30:1 SWR or 1500 ohm at the feed point. Placing the coupler at the feed-point as opposed to using a tuner at the radio reduces losses in the coax due to high impedances.
Radiation patterns will be an issue and I will need to experiment more in ENZEC with feed-point positioning. But here in lies the joy of a automatic coupler. I can experiment with any kind of antenna and feed it into the coupler and it should tune it to within 3:1 SWR, hopefully!
There is nothing stopping me from designing short coil-loaded verticals, helically wound verticals, dipoles or loops of various kinds and using them all with this coupler. Think of these couplers as more of a toolkit item than a specific antenna purchase.
Purchasing a compromise antenna like the above mentioned models, means just that, a compromise antenna built specifically for either restricted or portable use. Though initially a costlier item an automatic antenna coupler is a purchase that should keep on giving long after I’ve moved out of my current QTH.
Jul
08
2009
ARRL Field Day 2009
The North Shore Amateur Radio Club (NSARC) this year operated as a 2F emergency operations centre station. Usually the club organises a field event on Cypress Mountain but this year it was felt it would be better to showcase the communications room at the North Shore Emergency Management Office (NSEMO). NSARC maintains a number stations in the room as part of an agreement with the NSEMO, in effect creating our club station.
This years station, VE7NSR comprised of the following:
Icom IC 756 ProIII with a SteppIR 3 element yagi on 20m.
Icom IC 756 ProII with a inverted V dipole on 40m
Icom IC 7000 with an assortment of yagis on 6, 2 and 70cm.
We also operated the IC 7000 as a Get on the Air (GOTA) station with the callsign VE7EMR. This was radio fed into an N4PC loop operating on 80m.
This was my first field day as a licensed operator so I decided to jump straight into the deep end. I had signed myself up for a nice spot at around 9.30pm on the Saturday evening. Little did I know that I would remain the rest of the night, fortunes swaying with the changing band conditions.
I arrived early at 7.30pm hoping to sit around for a while and soak it all in. I hadn’t operated for over two months as work commitments had meant my weekends were tied up. As no other newly minted hams had showed up my first task was to fire up the GOTA station and score a few bonus points. I’m not sure of the exact amount of points but I believe it was standard scoring per QSO and then a bonus for each 20 QSOs. All the stations were using N1MM for logging but as I was switching the callsign to VE7EMR it was easier to paper-log than create a second instance of N1MM.
In about two hours or so with a few breaks I racked up about 25 QSOs on 80m. The band was poor at first, but around 9pm it came alive as more and more regional field day stations were switching over to 80m with the setting sun. I decided to call it quits on the GOTA station once I had filled out a page of a standard RAC logbook. This was my first time operating on 80m.
Switching to the 20m station things were a lot slower than I expected. The number of QSOs dropped considerably after 11pm. I kept plugging away logging a few Hawaiian and Alaskan stations and a few west US coast stations that had slipped under the radar earlier in the day. At about 12.30am I heard a Japanese station call CQ, he had a queue but an orderly one at that. Running 100w in poor conditions I knew I wasn’t going to bust the pileup.
I moved up the band and had a listen around but it seemed the band had gone long with little or no North American activity. At about 1am I decided to come back to the JA station. The queue was still there so I knew I would have to play the waiting game.
I have no problem pounding on the door of a DX station, but I’m more of a sly fox than a big gun. Its all about timing. Every station is going to call when the DX calls ‘QRZ’, there’s no point calling then. Listen to the rhythm of his QSO’s. Maybe the DX has a QSO that goes awry and the natural rhythm of the QSOs is upset, you should be ready to pounce on this ‘dead air’. At about 1am I bagged JE7YSS.
Throughout the event all of our QSOs were logged in N1MM. To highlight the stations contacted and provide a visual representation of the days proceedings club member Luke VA7LWE had designed a piece of software that interacted with the log in N1MM. His program ‘Visual QTH’ will listen for log traffic that N1MM generates over IP. (N1MM will send log contacts over IP to other instances of the software on the same network so as to keep the logs upto date on each station if running multi-multi, this avoids dupes).
Luke’s software extracts information from the log and correlates it with information from the QRZ.com database. Each QSO is presented as a point on a global map and with distances between your QTH and the station contacted calculated. The software also pulls up a QSL card and website of the station contacted (if available) and displays them in a scrollable list. To top it off the software announces each contact in cw and computer generated voice! We had the software running from a laptop projecting onto a large screen in a room adjacent to the radio-room. This allowed visitors to visualise the QSOs as they were being made. Read more about Visual QTH here.
At about 2am I switched over to 40m on the second 756 station. Things were slow here and once the Asian shortwave broadcasters kicked in around 3am the band became unusable except for a little sliver between 7150 and 7200. Having never operated at this time of day before I decided it would be beneficial to stick around and watch how the bands develop if only for educational purposes.
With sunrise calculated for around 4.20am I expected conditions on all bands to change considerably before, during and after this period. I was especially interested to see how 20m would shape at this time in the morning, but it didn’t. I kept monitoring 20m, up and down the band. Nothing. Around 6.30am some Florida stations were weakly heard but far too weak to work. It took another full hour before I could begin making contacts again, working a few in far southern Florida.
Gradually the pace of the QSOs quickened as the band opened up on the South East US. However what surprised me was how long it took for 20m to ‘warm up’. It was a full four hours after sunrise before the band would be what I would call ‘usable’ at about 8am. Granted I have never experienced 20m at this time of day before but it was a bit of a surprise.
With a only hours left in the event and a QSO hungry shift coming on stream in the morning I decided to call it quits and head for my bed. It was a very enjoyable night overall. I really familiarised myself with the ProIII on this event and I’ve found a comfortable operating zone with the controls I need the most, VFO, AF gain, noise reduction, passband tuning and notch. If every radio only had those I’d be happy.
Jun
27
2009
Number one with a gun……
Well it seems that the poor showing in the Georgia QSO Party (GQP) wasn’t so bad after all. Number 1 in BC for VA7DXC!!!
Or should I say the only 1 in BC!
http://gqp.contesting.com/Certificates.htm
Oh the humanity! 😉
Jun
17
2009
Phasing Stuns
The world’s first Sony AN-1 Phased Active Antenna Array?………..
So I purchased a second Sony AN-1 unit from Ebay last week. It had been in storage for over 13 years and had a lovely set of 1997 expired batteries inside! After a bit of a cleanup of the battery compartment it was ready to go. Funnily enough even though there were batteries in the pre-amp unit the actual antenna it seems had never been mounted outside at all. All of the mounting hardware was still in its plastic?
My original plan was to use the second antenna as the aux/noise antenna in a two element phased array using the MFJ 1025. Having the second antenna also allowed me to do some A/B tests in terms of antenna position on the balcony. The results of these tests were surprising but welcome.
I had placed my first AN-1 in what I thought was the best possible position, as high up and as far away from the building as possible. I usually tilted it out at an angle of about 10-12 degrees to get away from the building.
The building opposite blocks not only a good portion of sky but is also a metal clad structure, in effect a huge RF blocker. However I was aware of these issues already but felt getting the antenna up and away from my building was more important.
The second antenna position is right up against my building and underneath a concrete balcony. This should mean poor reception beneath all that concrete and steel. But here’s the catch. This second antenna position has a slightly clearer view of the horizon, just a sliver.
Hooking up the two antennas to the MFJ-1025 I found that Asian signals were booming in on the second antenna in what I thought was the more compromised location. Most were 2 to 3 and sometimes 4 s-units over the first antenna! Its seems having even a 10 to 15 degree better view of the horizon can trump the attenuation that the steel and concrete provides.
I will continue testing and hopefully find optimum combinations for European and S. American signals. But right now I looking forward to the fun that phasing these verticals will provide.
Next up on the list is whether or not to mod the MFJ-1025 for LF & MF work. The unit is heavily attenuated below 1.8 MHz to block strong BCB overload. I do love digging around in the lower reaches of the spectrum and NDB hunting in the winter months can be quite an interesting challenge. If I modded it I’d probably have to buy a bandpass filter for HF if I wanted to continue using the unit on those bands as well. The other option is to buy a second MFJ specifically for LF work.
