Archive for the ‘tech’ Category


Thanks to Barrie VE7HBS’s recent presentation to the NSARC HF group, my interest in WSPR has been re-ignited. I used WSPR briefly when first setting up my shack a few months back, basically to see if my signal was getting out.

Now that the summer months are here I might begin to play around with it a bit more as means to test out some new loop configurations. With automatic transmission, WSPR would seem to be the optimum program to not only check propagation but also antenna properties and characteristics.

Spring Clean

Well I somehow managed to wangle a few days off work this week so I decided to tidy up the shack and antenna installation.

Paid a trip to a store here in east Vancouver that sells everything made from bamboo. They have a huge selection of bamboo poles in various widths and lengths from 6ft to 10ft and for the measly sum of $5.86 grabbed a half dozen 1/2″ x 6′ poles. The plan was to replace the ugly PVC poles I use for my balcony loop with something ‘prettier’ and a bit more stealthy.

I also dropped by Burnaby Radio and picked up some nice flex-weave antenna wire and a few other odds and ends. The chunky ugly speaker wire that usually forms my loop was about to go SK.

Within an hour or so, I had setup the poles and a new loop configuration. This configuration with the vertical sections folded back on themselves presented a slightly higher (though still tunable) SWR than normal but not by much. However not to worry as the new flex-weave wire is so much easier to handle that I decided to just try another new configuration. The goal of these new configurations is to present as much wire as possible to the open front of the balcony. Previous versions had the loop folding around inside the balcony but the more wire out and away from the building the better.

Though not scientifically conclusive by any means I ‘felt’ my latest configuration, with the loop criss-crossing at the front of the balcony, provides a better S/N ratio and more ‘get-out-ability’. I followed up the installation with a few PSK31 Qs on 20m with reports from two Asiatic Russian stations reporting a 559 and a 557. Not too shabby considering conditions on the band have been generally quite poor for the past few days.

New Rig Workout

So having received my gracious gift from St. Nick it was now time to set it all up.

I have also purchased an Icom AH-4 tuner and this will become the focal point for future antennas.

Setup of the tuner and radio was pretty straight forward. Power is supplied to the tuner over a control cable that plugs directly into the IC-7000 and all tuning functions are accessed from the front panel “Tune” button. I set up a simple 16m wire loop on the balcony and the AH-4 had no problem tuning it to 1:1.5 SWR from 40m to 6m. 40m prodced some RFI which tripped a GFCI in the apartment but other than that no other issues or complications arose.

The loop is bascially just folded around the balcony. Right now I don’t have the supports to fold it in the manner that I would like but that is something I will rectify after Christmas.I based the design on WX7G, Dave’s, 3d folded loop antenna for 10m, I’m hoping to perfect the concept for HF operations. Remember my balcony is only about 40sq ft or about 8ft by 5ft (2.4m x 1.5m), in a highrise apartment surrounded by concrete and steel in a downtown setting at 140ft up.

I patiently waited for the 20m band to open one Sunday morning and eventually worked a couple of stations in PSK31 up and down the west coast all easily on 25watts. If this was all I could do then I would still be a happy ham. Just being to get on the air in the apartment is a great for me, anything after that is a bonus.

It took a while before I got used to the macros in DigiPan and it has a couple of quirks that you need to be aware of, especially the RX and RXANDCLEAR functions. If you don’t use the RXANDCLEAR function you risk sending your last macro again as I found out a couple of times while transmitting. Other stations were still happy to work me as I fumbled with the mode. And this is the thing with PSK, as a relatively new mode, everyday I go on the PSK bands I always come across other ‘first time’ QSOs, everyday. I also love PSK63, I love the speed, I love the QRM busting nature of it. Sometimes PSK31 can a bit finickity if soundcards are not calibrated spot on, PSK63 being wider blows that problem away while still being a relatively narrow bandwidth mode. I may try other programs aswell but Digipan works well on my lightweight netbook and I think DM780 might be a bit OTT for this machine, might try FLdigi or PSK31.

I have exclusively used the IC-7000 on HF and have not done any TX on V/UHF at all. But I didn’t get the radio for the extra bands, I got it for the IF DSP which I feel is comparable to that in the Pro III. The IC7200 has the same DSP but doesn’t have the graphical interface that the clearly better IC7000 has. I love the interface, being an Icom man it took no more than an hour to find my around the rig, the screen is awesome, just awesome. I have it in the white screen mode as I find it more legible in variable light conditions and from odd angles.

So it was another Saturday afternoon I found myself on the PSK bands. It was the weekend of the PSK Deathmatch and I was working stations on the east coast US even though my balcony faces NW. At about 3.40pm a weak signal appeared in the waterfall, a JA station calling CQ, and nobody was coming back to him. I pumped up my RF out to about 35watts and gave it a go. He came back to me with a 529, weak but readable, he copied me better than I could read him, a product of all the crappy urban noise I must put up with, but the QSO was made none the less. The JA station was soon followed in the log by a UA Asiatic Russian station whose eQSL I already have in my Inbox.

In less than a week I have gone from no station or rig to intercontinental DXing with a compromise, temporarily installed antenna and 35w or less. HF dead, don’t think so.

An early visit from Santa……

Old St. Nick has paid a timely visit to VA7DXC and dropped off a shiny new Icom IC-7000 along with an AH-4 coupler and a host of other goodies.

Now the real test of ‘High Rise Radio’ begins!

My rig: IC-7000

My rig: IC-7000

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.