First C4FM SOTA contacts in Queensland

Going through the Activator Roll of Honour results for QLD recently, I noticed that there were no results for Digital Voice. Checking the state of play for the other states, I saw that the Australian Capital Territory and Victoria had one each.

It was time to put that right, so on Saturday 23rd June, I headed out for Mt Cotton (VK4/SE-115) with nothing more than my Yaesu FT-70DR hand held radio.

I had activated this summit more than a year previously, so if I logged at least four qso’s, it would count as another activation and my tally would increase by one point.

The climb up to the summit was uneventful and I headed to a clearing that featured a rather tatty picnic table and a good view.

I set the radio’s frequency to 147.400, the calling frequency for digital modes, and the mode to DN (Normal Digital Mode).

I had pre-arranged with Wal, VK4CBW, to listen out for me on simplex. His was the first contact I made. The distance between us was 26.33 Km (16.456 miles) and his Yaesu FT-2DR connected to a beam antenna sounded excellent. I ran a few quick tests too, to see what difference it would make to the signal if I placed my radio flat on the ground while he spoke. It made absolutely none!

Trying to get more height when calling CQ.

I am well used to using FM simplex on summits and noticed immediately that with C4FM there was no background hiss at all. The audio was as perfect as can be, very similar to that of a mobile phone.

I then had a long qso with George, VK4HGT, followed by Phil, VK4MOT and Bob VK4YA. All contacts were remarkable in that the audio was perfect. I think C4FM is far superior to FM analogue and it’s a mode I’ll be using more often in future.

 

 

Advertisements

First real test of the HF Packer Amp

HF conditions are terrible at the moment, so when could be better to put the latest version of the HF Packer Amp, the miniHFPA2 edition, to the test?

The amp is set to accept an input of 5W for an estimated output of around 30W. It also has the 60/40 and 30/20 Low Pass Filters installed.

OLYMPUS DIGITAL CAMERA

A side view of the amp enclosure with the side panel removed, showing the clip-in LPF board.

I chose to look for a station operating on 40m as this is the best band for local (VK) signals during the day. My luck, the band was dead. Then I heard Gerard, VK2JNG calling CQ from Lake Innes Nature Reserve (VKFF-1955). I returned his call and received a report of 5/9.

I was delighted as I seldom receive such good reports when using my Yaesu FT-817 at 5W into VK2. You see, a quick check on Google Maps told me that we were 445 Km apart. So I asked Gerard if he could give me another report, this time with the amp in bypass mode. He gave me a 5/3. He went on to say that with the amp switched on, my signal was “crisp and the audio nice and clear.”

So there we have it: the amp certainly does what Virgil, the designer, set out to achieve.

I have LPFs for all bands and will use them when the time is right.

OLYMPUS DIGITAL CAMERA

The LPF boards are professional quality.

OLYMPUS DIGITAL CAMERA

Each board is marked with the bands they are designed for. The while guides aid with slotting them into place.

Each LPF is a 2×1 inch plug-in circuit board that is interchangeable in the field with the entire family of same size modules. Each LPF has a unique ID, and the panel LEDs inform you which LPF is active. Two LPF boards are plugged into the enclosure, one on each side. To select the one you need, all you have to do is flip the LPF toggle switch on the front panel of the amp. Field replacement consists of removing a side panel, unplugging an LPF and sliding in a different one.

To find out more, visit http://www.hfprojects.com

Building a VHF Packer 6m Amp

I was given this kit by Wal, VK4CBW, as he had purchased it some years ago and knew he would not get around to building it.

The kit was produced and sold by http://www.hfprojects.com in America and came well packaged in a series of sealed plastic packets. Everything including the enclosure and heavy duty heat sink were included.

This little amp requires 1W drive for 30W output and features a Mitsubishi RF mosfet module mounted on the heatsink. There is also a filtered Anderson Power Pole DC input that takes 12V at around 6.2A. And measuring only 5.25 x 3 x 3 inches and weighing less than 1 lb, I figured it would be perfect for SOTA or VKFF operations.

I started my working on the well-made PCB.

Populating the PCB

Then I began making the power cable assembly, the RF cable assembly and the switch cable wiring.

The cables were installed inside the top enclosure case.

I had to fabricate a make-shift mounting plate for the Anderson Power Poles as this was missing from the kit. It has been ordered but hasn’t arrived yet. Eager to avoid delays so I could catch the 6m band opening, I made a replacement out of PCB material.

This isn’t perfect but it would do until the genuine item arrives in the post.

After a little fiddling it went in well and did the job.

The mounting plate in place.

Next, the circuit board and amp module were installed and the initial check carried out.

Ready for alignment and the first smoke test.

The bias current had to be set to 0.7A if the amp is to be used for SSB work, or 0.5A for FM. I chose the former.

The bias current set correctly.

I skipped the next step, which was to align the low pass filter as I don’t have the correct instrumentation. But as I had constructed coils L1 and L2 according to the instructions, this wouldn’t be too critical.

The power output test was more important. I connected the amp up to my Yaesu FT-817 (with power wound back to 1W) and attached my homebrew dummy load and an SWP/Power meter. RF output was shown to be a mere 16W. So I flicked the bypass switch and measured the output as 1W with an SWR of 1.0:1. All good there.

Tweaking the coils of L1 and L2 soon produced the required 30W, so it was time to disconnect the dummy load and attach my 6m monoband dipole antenna.

My homebrew 6m dipole strung up and ready for action.

Keying down produced the power output reading I was after.

RF out was now 30W with the SWR indicated as around 1.7:1. Not bad at all.

Next, I attached my LDG auto tuner to the chain and was ready for an on-air test.

All set up and ready for action.

The result was most pleasing. I worked a bunch of VK7 stations (SSB and CW) and well as VK2s and 3s. I am in business and ready to take advantage of the summer openings.

Oh, and all reports received were most favourable. Nice clear signals, good reports and clear audio were what most operators reported back: they were all impressed that I was only using 30W – most stations were in the 200-400W range.

QRP Hours contest

Sunday 22nd October was a good day for QRP in VK-Land. And even thougth HF conditions haven’t been good at all (especially according to some), I had success and a lot of fun by taking part in this short contest run by the CW Operators’ QRP Club Inc.

This year the contest was restricted to the 40m band and consisted of two sections: the first hour CW and the second Phone. I took part in the CW section only.

The rig I used was my trust Elecraft KX1, this time with 12v gel cell power as I didn’t have to worry about weight: I was to operate from the back deck of my home. The antenna was the Buddistick that I attached to the hand railing of the deck by means of my new Buddistick G-clamp. My key was the Pico Paddle. Power output was 3W.

My set up for the contest. All ready to go.

Tuning up the antenna on 40m was not easy. I couldn’t get a match at all with my Hendricks BLT Tuner, so I hauled out my LDG auto tuner, which gave me a 1.9:1 reading, which was the best I got. QRP is all about compromise, so I went with that.

The Buddistick mounted to the railing with my new G-Clamp.

I do think that the proximity of metal guttering didn’t help, but I had to make do with the situation I found myself in. At least there was some good height, facing south – which would be good for VK1 and VK2 contacts.

Nice height even though I needed to angle the whip.

Noise levels were high on the band but nevertheless, I was able to work VK2IG, VJ2GAZ, VK2FGBR, VK1DA, VK2JDR and VK2IO.

Next time I’ll try a long wire antenna.

New battery power for my FT-817

I have long wanted/needed to upgrade my battery power for my Yaesu FT-817. The prompt came when the internal battery died. My choice was the kit put out by Windcamp; a 3000mAh internal LiPo battery and new battery compartment lid for the radio that comes fitted with a PCB and charging circuitry that allows the supplied mains charger to charge the battery while inside the radio.

The parcel arrived from China beautifully packed. The battery and the new replacement lid came packaged in very nice plastic cases, which, together with the instructions and charger, all fitted into a compact cardboard box for shipping.

The contents of the parcel.

After extracting the individual components from their packaging, it was time to think about installing the battery into the radio.

It is a tight fit but the components plugged together as intended. Note the PCB on the underside of the new lid.

When the battery and associated wiring was all nice and snugly fitted, I popped the lid closed and got ready to charge the new LiPo battery.

The new lid in place and ready for charging.

The charger has a double-coloured LED to indicate the state of the charge: red for charging and green for a completed charge. The initial charge takes around 5 hours to accomplish.

According to the supplied documentation, the rated voltage of the battery is 11.1V, with the output voltage range stated as between 9 and 12.6V. The maximum output current is 4A.

Now to test it in the field.

Working F0-29

Now that I have worked an FM satellite (in my case SO-50) the next challenge was to try a SSB satellite.

The basics would be the same I figured, except I would need to use my Yaesu FT-817. In fact, all I needed to do was to switch rigs and take into account that I would be needing to run to 817 off my 7 a/h SLAB, which I would need to slip into a spare camera bag so I could carry it over one shoulder.

The battery is in a camera bag hanging on my left side, and the FT-817 is slung around my neck (I knew the strap would come in handy some day).

So that I could work the satellite single handed out in the field without the aid of computer software, this is what I did:

  1. Set the rig into split mode
  2. Set VFO A to 145.960. This is the uplink.
  3. Set VFO B to 435.840. This is the down link
  4. Make sure the antenna connection is set to the front connector on the radio
  5. Keep the radio set to VFO B

When I saw the satellite is within range (using Satellite Explorer on my PC), I went outside and pointed the antenna into the rough direction of the satellite’s approach. This was roughly north. Then I put out a call (the radio switches to VFO A automatically when the PTT is activated but returns to VFO B when it is released. Then I immediately began tuning down the band to listen for replies.

Sure enough, I heard Wal VK4CBW, George VK2WEL and Geoff VK2ZAZ. I had a very satisfying QSO with them, but it was challenging having to continually alter the receive frequency by hand during the receive cycle while altering the direction of the antenna to take into account changes to direction as well as height, all at the same time.

Next is to think about improving my operating setup, perhaps with some form of automatic tracking capability.

 

 

Working Satellite SO-50

One aspect of amateur radio that I am enjoying lately is working the FM satellite SO-50. To do so I use my Boafeng GT-3TP dual band hand held and an Elk log periodic antenna that I have mounted on a camera tripod.

My basic satellite communications setup.

SO-50 carries several experiments, including a mode J FM amateur repeater experiment operating on 145.850 MHz uplink and 436.795 MHz downlink. The repeater is available to amateurs worldwide as power permits, using a 67.0 Hertz PL tone on the uplink, for on-demand activation. The repeater consists of a miniature VHF receiver with sensitivity of -124dBm, having an IF bandwidth of 15 KHz. The receive antenna is a 1/4 wave vertical mounted in the top corner of the spacecraft. The receive audio is filtered and conditioned then gated in the control electronics prior to feeding it to the 250mW UHF transmitter. The downlink antenna is a 1/4 wave mounted in the bottom corner of the spacecraft and canted at 45 degrees inward.

The Elk was loaned to me by Wal, VK4CBW, an avid satellite fan who lives down the road from me. The antenna is basically a held-held job but I do find it gets a bit heavy after a while, hence the tripod.

Today SO-50 was within range at 4.56pm, so I put out a call and was answered by Roy, VK4ZQ, from Nundah in Queensland. And although Roy isn’t that far from me, the satellite is. The apogee height is 665km, which means at its furthermost distance from the earth, it is 665km away. Not bad for a two-way FM contact.