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.

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Mt Beerburrum VK4/SE-112

Getting to Mt Beerburrum is easy: proceed along the Bruce Highway from Brisbane towards the Sunshine Coast for about 55km. Look for Exit 163, which will take you to the Glass House Mountains Tourist Drive. At approximately 4.8km take the Beerburrum Road turnoff and look out for the sign for Mt Beerburrum Lookout. There are a few car parks here, but rather continue along the gravel road for about 800m to the end, where there is ample car parking.

Park your car here and begin the walk to the summit.

The path to the summit is concrete all the way, but be aware, it is very steep. Classed as a Class 4 climb, the going is unrelenting all the way to the top. But there are many resting places along the way.

The concrete track may be only 700m long but it is deceptively challenging.

Allow an hour for the return journey and be sure to take frequent breaks.

This is a Class 4 climb.

It took us 40 minutes up and about 19 minutes down. And enjoy the views.

Take advantage of the many opportunities to take photos.

There is a small fire tower at the summit. As soon as you spot it you’ll know you are just about there.

The fire tower at the summit.

There is not much open space on the summit, especially if you want to erect a long wire antenna. I made use of a wooden pole to attach my squid pole to. Be sure to put out calls on 2m FM as well as there is excellent reception on the summit. I was able to talk to local hams easily from there.

There is also good phone reception from the summit.

Mt Beerburrum is part of the Glass House Mountain range and is within the Glass House Mountains National Park (VKFF-0200).

Matthew Finders mentioned this summit in his journal.

Climbing Mt Ngungun in the Glass House Mountains, QLD.

One of the most recognizable mountain groups in Queensland would have to be what is known as the Glass House Mountains. Named by Capt James Cook during his voyage of discovery, these remarkable geological formations are what remains from ancient volcanic activity.

Getting to Mt Ngungun, the northern most mountain in the group, is easy. Drive up the Bruce Highway and turnoff down Steve Irwin Way. Then follow the signs to the Glass House Mountains National Park. You’ll find a good place to park your car at the car park in Fullerton Road.

Plenty of parking available.

The track to the summit is well maintained, with good dirt surfaces and rock steps. It is a Grade 2 track all the way to the top. However, there is a short section where there is a warning to beware of cliff edges.

Signposting is good.

The walk up is interesting, through open forest with fern understory. There is also an interesting rock that features an overhang.

Looks much like a cave.

The walking track is excellent but care needs to be taken in wet weather as the rocks could be slippery.

The going is steep at times.

There are excellent views of the local area to make the journey up even more enjoyable. Photography is a must as there are good close-up views of nearby Mount Tibrogargan, Mount Coonowrin and Mount Beerwah.

There is plenty of space on the summit but little shade. And there are lots of visitors; this is evidently a popular mountain for day excursions.

The small trees and rocks provided me with a good spot to erect my antenna and operate my low-powered radio station while enjoying spectacular views.

The round trip took about 2 hours, not counting time spent on the summit. The walking distance was around 2.8km.

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.

Building SOTABeams’ PowerPole PP-4 Way power distribution board

One of the challenges I was having while operating portable was making sure that my power polarity was correct. Fiddling around on a mountain peak with red and black connectors on a 7a/h gel cell is fraught with danger. And when I have two or more components to connect, well …

The answer I found on the SotaBeams web site (http://www.sotabeams.co.uk/).

I placed an order for their PowerPole PP-4 Way power distribution board.

A week or so later, a padded envelope arrived in my mail box.

The contents of the envelope.

Construction was easy as the kit is very simple. All that was needed was a soldering iron and some solder.

 

The power poles ready for soldering.

I ordered the kit only (without the enclosure), so I headed to the local supermarket and bought a cheap plastic sealable container that would do just fine. All I had to do was to cut out a piece wide enough from the lid for the connectors to stick through.

The PCB sits under the lid with the connectors sticking through. I secured it into place with four nuts and bolts.

The power supply connects to one set of power poles and the radio, atu and other items connect to the others. Simple.

Works like a charm. Will make a difference in a park or on a summit.

Activating Fort Lytton, VKFF-0179

I decided to activate Fort Lytton National Park  on Sunday 23 April 2017 for two reasons: firstly it has never been activated before and secondly, it’s considered to be the birth place of Queensland’s military history.

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The above picture is of the Fort’s parade ground.

This coastal fortress served as Brisbane’s primary defences from 1881 until 1965. It was even used during WW11, when some 89 US submarines were docked here for repairs during the war.

There is an interesting museum there now, including a good display of military radio’s, which I particularly liked.

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I was fortunate in finding an excellent operating position, right alongside the river under a gazebo. The picnic bench was just perfect and it was unoccupied.

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Being a first activation meant that I was able to make a quick ten contacts, on both SSB as well as CW. The rig I used was my FT-817 that tuned an end-fed long wire by means of an LDG auto tuner. My key was my new pico paddle, which worked beautifully.

The weather was perfect, the exhibits were wonderful and the activation was a success. Will need to revisit this site again sometime.

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Samford Conservation Park VKFF-1639

Easter Saturday was the day I decided to activate Samford Conservation Park, VKFF-1639, which is situated around 40km from my QTH. This time I had insect repellent in my go-bag and I’m glad I did.

I set up my equipment on a park bench that was at the far end of Iron Bark Gully, a picnic area in the park. As usual, I had my FT-817, LDG Z100 Pro ATU and endfed antenna held up at the far end by a 7m squid pole.

All set up and ready for calls.

I could hear lots of SOTA action but even though I had self-spotted, I was getting nothing. So I decided to pounce on a SOTA QSO. The first one I came across was VK2HRX operating fromVK2/NW-019, which also happened to be a National Park, VKFF-0111, so when he completed working a chaser, I pounced. He replied and I was up and running. And with a park-to-park QSO at that. Then I heard my old mate John, VK4TJ working him so I tail-gated that QSO and worked him too. Two in the bag, but that’s as far as I got.

I think my position in the gully was not the best, so I decided to pack it in and head off for a restaurant for lunch. Also, using only 5W could have been the problem. Mean time, Scott VK4CZ posted on Facebook that he would like to visit my operating position as he lived nearby. But I had already hit the road. Along the way I stopped to admire the view from McAvee’s Lookout in Mount Nebo, which is situated in the D’Aguilar National Park VKFF-0129. As luck would have it, he called me on 146.500 FM (simplex calling frequency) so I was able to add that to my log, and from a different park.

So I was happy with the way the day turned out. But there is unfinished business. I will return.