The John Moyle Field Day 2018: Another successful field day.

Another Field Day success. This time my main goal was to rake up a few contacts during the John Moyle Field Day, operating from Mt Coot-tha in Brisbane with my FT-817 and Buddistick antenna. But this time, instead of squeezing the most out of 5W, I hooked up my new HF Packer miniHFPA2 Edition linear amp that puts out a massive 30W. And the beauty of this is that I would only need my 7 A/H gel cell to power it.

My set up for the day, from left: Yaesu FT-817, HF Packer miniHFPA2 amp, LDG-Z100Plus tuner. Behind: Yaesu FT-70D, Sotabeams powwerpole distribution box on top of 7 A/H gel cell.

I mounted my Buddistick antenna to a BBQ grill behind the operating bench that looked as though it had seen better days. Fortunately the G-clamp just fitted.

The Buddistick did a good job and was easy to erect. I chose it over a dipole as there was no ready method to secure my squid pole close to the operating bench.

Well, at the start of my 40 minute activation, my battery showed 12.69 V and at the end, 12.60 V. And that was after continuous SSB work on 40m. So 9 QSOs later, I was content to pack things up and head for home.

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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.

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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.

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The LPF boards are professional quality.

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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.