Briarty Hill VK3/VC-029

Briarty Hill, VK3/VC-029 is located in the Warramate Flora and Fauna Reserve located near Seville East in Victoria.  This was my first visit to Briarty Hill, it’s only worth a point and you do have to work for it!

After parking at the gate on Yarralock Way, its a rather indirect hike to the summit.  On the way up, I took the “scenic” route which was about 4km and a rise of about 335 metres.

The return trip was 3.2km and slightly more direct taking a few goat tracks back.

img_20161112_143653From the gate at the entrance to the reserve, it is about 575 metres to the narrow track on the left at S37.73818 E145.49209.

The track didn’t appear to be in regular use, there were a few trees down here and there and some bracken growing over the track.

See the map below for the GPS track of the hike.  The highlighted route is the way down from the hill, the lighter deviations show the way taken on the way up.  track-down

It was raining very lightly on the way up which was nice to keep the walk cool.  We have a mosquito plague at the moment due to the wet spring, and this made operating difficult at the top.

At the top there is a radio tower running from a noisy generator, so I set up just down the road a bit for a bit of quiet.

Despite the warm temperatures, I put on a beany and jacket with hood to protect myself from the mosquitos.  The loaded 40m / 20m / 10m End Fed Half Wave was erected on a 7 metre squid pole.  The rig used was an Elecraft KX2.  40m was not much good for close in NVIS, although signals from VK2 and VK7 were strong.  On 20m ZL2AJ was worked.

I used Peter, VK3ZPF’s Portalog app for logging and found it to be very mozzie proof!

After about an hour, the gear was packed up and I left for the car via a more direct route!

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Posted in Hiking, SOTA | 8 Comments

Yet Another EFHW Matcher

While on the lookout for a more compact housing for the End Fed Half Wave matcher, I came across this perfectly sized enclosure at Altronics (Hammond 1551).  At 50mm x 35mm x 20mm, it is just right to hold the FT-82-43 core, a BNC socket at one end and a terminal at the other. The case is just a bit too small to fit a banana jack as it would protrude too far inside, so a 4mm bolt, washers, nut and wingnut make the antenna connection.  A 4mm nylock nut holds the wingnut from coming off.

The toroid is the same one as used here, with a 3 turns bifilar wound primary over a 24 turn secondary.  A 100 pF and 45 pF capacitor are in parallel across the primary to improve the match.

This is quite a bit smaller than the earlier versions and is a better fit with the KX2 and antenna in the case.  Total weight is 38 grams.

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Posted in Projects, radio communications, SOTA | 9 Comments

Thoughts on Elecraft KX2 Transceiver for SOTA

After some time getting used to operating the new Elecraft KX2, it was time to take it out on a SOTA activation.   With a break in the weather, Federation Range, VK3/VN-029 looked like a good choice as it qualifies for the current winter bonus.  It is also a nice walk of around 9 km return from the Lake Mountain car park.

Trying to keep things light, the only antenna taken was the 40/20/10 metre trapped/loaded End Fed Half Wave which was supported by a 7 metre squid pole (of course, the usual medical pack, emergency shelter and water were packed as well).  Two sets of home made,  3 cell 18650 packs came along for power, one internal and the other as a backup.  The radio, spare battery pack and microphone fit pretty well in the Action Cam case from Target.

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Once on air, the KX2 is very easy to operate with a big display, it’s nice to see the ALC, SWR, RF power out and S meter all at the same time without switching functions.  The battery capacity display is a real help for pacing the activation if you are short on power.  One thing that has always annoyed me about activating is getting the UTC time each time you put an entry in the log, the clock on the radio makes this easier.  I guess one solution is VK3ZPF’s portalog, which have used a couple of times.  Other solutions for UTC in the past have been GPS Navigator display, mini LCD clock  and mobile phone.

Reported audio was good and a comment was made that it sounded much like previous activations with the FT-817.  The microphone is a bit disappointing as mentioned here. I had heard that the internal speaker of the KX2 distorts at lowish volumes, but found it fine during the activation.  The KX2 has a few little gaps an a few holes in the case, I might have to make a few bungs or covers for these.  I can see ants filling up the radio (Mt. Selma or Mt. Reynard) or moisture splashing in while operating.  The FT-817 is better in this regard, despite having Mt. Reynard ants exiting for days later after an activation.

On the weight side of it, the KX2 with internal battery weighs 535 grams.  The FT-817 with internal battery weighs 1170 grams.  The overall physical volume of the KX2 is a bit less as well.

After the activation and a following short activation at Mt. Gordon, the battery capacity used was 0.6 Amp Hour (of a 2.2 Amp Hour pack).

Despite the FT-817 and KX2 being very different radios, here are some noted pros and cons of each radio:

FT817 Pros:

  • Cheaper.
  • 160m, 6m, 2m and 70cm bands.
  • Pretty durable, only problem after 4 years of SOTA was the power button rubber.
  • Good TX audio.
  • Two antenna sockets. (useful for two bands)
  • Nice mechanical construction.
  • Versatile radio.
  • Proven radio.

FT817 Cons:

  • High receive current consumption.
  • Heavier.
  • Small display is hard to read.
  • Small knobs and buttons.
  • Getting quite old now but holds up well.

KX2 Pros:

  • Low receive current consumption.
  • 10 Watts output.
  • Easy to read display.
  • Larger controls widely spread out.
  • Rich software features such as filters, voice memories.
  • Battery amp hour + current display, clock.
  • Metering in general
  • Nice form factor.
  • Lightweight.
  • Can use hand held with internal mic and whip antenna.
  • Good support for software updates and utilities on the Elecraft website.

KX2 Cons:

  • Price. (at least in Australia)
  • Gaps in mechanics.
  • Microphone a bit sup par in mechanics for price. (gaps in plastics, wobbly pressel)

The KX2 is certainly going to get some use in future SOTA activations!

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Hut ruins at Federation Range

Posted in radio communications, SOTA | Tagged , | 2 Comments

New SOTA Rig

The new Elecraft KX2 arrived last week.  So far it looks like just the thing for SOTA activations.  A battery pack was not ordered for it, so one was constructed from 3 x 18650 2500mAh cells with a protective polyfuse.  A 3 cell protection module is on order from Ebay to complete the battery pack.

An action camera case from Target ($6) is just the right size to house the radio, mic and a few small bits and pieces.

Looking forward to taking it out to the mountains.  Its quite a bit lighter than the FT-817 at 380 grams without batteries.  The display is big and easy to read compared to the squinty 817 screen.  The radio case has a few gaps here and there around connectors and joins, so it will need to be protected from the elements carefully.

kx2-case

So far, the radio performs nicely, the controls are well laid out and fairly intuitive.

The microphone for KX2 is pretty expensive at nearly $100 Aus.  Mine had a something rattling in it so I opened it up to have a look.  The rattling turned out to be a blob of solder.  While apart, I noticed that the braid wire from the cable to the internal connector was very tight and might break away if the curly cord is tugged.   There are some reasonable gaps between the PTT pressel and the shell sides, and it wobbles sideways a bit.  The mic. lets the radio down a bit in my opinion.

As its hard to avoid things getting wet with SOTA, so I wired up another smaller microphone.  This mic is well sealed with a gasket between the shell halves and the PTT switch completely sealed from moisture ingress.  The PTT switch strikes a rubber membrane with the switch is on the other side.  Being a smaller mic., it will pack better as well.    The schematic from this page was followed, although my mic. had a 2k resistor and 0.33 uF cap in parallel.   The level from this mic is much higher than the original, so a 10k resistor was placed in parallel on the cord side of the mic wiring.

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The audio from the small mic seems OK, although I did add a piece of fabric behind the mic aperture behind the case to reduce popping.

The battery pack was built with 3 x 18650 2500mAh cells.  In this case tagged 18650 cells were used.   I have had good service from Samsung 18650 cells from Ebay.  There are many dodgy cells out there though.

The 3 cell protection pcb for the cells was obtained from Ebay for $4.00 delivered.  The pcb limits the charge and discharge current and voltage to safe levels for the cells.  After the cells were connected in series, double sided rubber tape was put over the exposed cell ends.  The protection pcb was stuck to one end of the pack to the rubber tape and wired up.  Silicone wire connects the power from the pcb to the DC connector.  The silicone wire is very flexible and wont melt.  Some Nitto tape holds the cells together until the heatshrink will cover the pack.  In the mean time the pack is going to get some charge and discharge cycles with the cell voltage monitored to make sure the cells stay in balance.

Note that if you make one yourself, you are doing so at your own risk.  Utmost care has to be taken to ensure no possibilities of a short circuit can occur in the wiring, during assembly and in the completed pack.  A short circuit inside the radio could cause extreme damage to the radio, not to mention a fire risk.  Photos below show the pack before heat shrink applied.

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Just to check that the protection PCB was working, I put a dead short on the output and as expected, nothing much happened.  For another test, a potentiometer was put between the battery negative and the junction of the second and third cells.  The slider of the potentiometer was connected to the PCB input for the junction of first and second cells.  This allows a wide voltage simulation of the input to the PCB for testing how it behaves when a cell goes high (above 4.2V) or low (below 3V).

With the pack charging, the pot was slowly rotated from 4.0V to 4.3V while watching the meter on the slider.  As expected, as soon as the voltage went higher than 4.2V, the charging terminated.  Also, when then voltage went below 3V, the charging terminated.

At least I know if the cells go out of balance as the pack will not charge.  The charger used with the pack is a Hyperion RC charger.

Posted in radio communications, SOTA | Tagged , | 18 Comments

Castle Hill VK4/NH-136 Last Minute Activation 1 Point

Castle Hill is a small hill close to the Townsville city centre in North Queensland.  It was about 5:30pm when the opportunity presented itself for a quick activation.  I had the FT-817, an end fed for 40/20/10m and the RHM8B telescopic loaded vertical.  As there wasn’t much time before sunset, we parked the car at the bottom of the short stepped path to the top, walked up the steps and set up the FT-817 with the RHM8B on 20m against the railing.

Surprisingly, there were some reasonable signals coming in from VK3, so answered a general CQ and made the first contact.  Shortly afterwards after spotting, I worked Peter, VK3PF and Tony, VK3CAT.  Both stations had reasonable signals, well clear of the low noise level.  Not bad considering the antenna and the 2000 or so km distance.

After working another non-SOTA station, the summit was qualified for 1 point and we started to notice that the mozzies had arrived.

A few photos were taken of the sunset before we left.

Operating from the lookout

Operating from the lookout

Posted in radio communications, SOTA | 2 Comments

Mt Fuji JA-SO/001

Our plan was to set off from the 5th station car park at (2300 metres) around 2pm and hike the Yoshida Trail to the 8th station hut (3400m) before dark.  We would then sleep in the hut until 2am and then set off for the summit (3776m) to catch the sunrise at 4:30am.  Our group consisted of wife Sarah, daughter Meagan and her boyfriend Koyu.  My Japan callsign allocated was JP3PBQ.

I had a backpack with 3 litres of water, some clothes, lunches, dinner, breakfast, torches and of course, SOTA radio equipment.  The SOTA gear consisted of an FT817, Lipo batteries, 20/15/10m End Fed Half Wave antenna, log book, hand held and usual SOTA bits and pieces.  I didn’t really want to carry all that stuff, as the MTRV2 would have been much lighter, but it was not approved by the Japan radio authorities.  Koyu had more stuff than I did, not sure what his pack weighed, but it must have been heavy.20160702_165524

The car park was very busy and we had to queue for cars to leave the car park to provide spaces for us to enter.  The delays meant that we finally departed the car park for the hike at 3pm, a bit later than planned.  The temperature was in the high 20s at 5th station.IMG_1203

20160702_171832Its a pretty demanding hike and not made any easier on this day by the strong winds that was whipping up gravel and dust and blasting us with it.  We had a late lunch at 6th station and admired the views.  After lunch it was a long slog to 8th station with many rests in between.  You could feel the thinning air at 7th station making the going a bit slower.IMG_1199

We finally arrived at 8th Station hut at 8:30pm in the dark where we had some dinner and were shown the 90cm or so width allocated to us to sleep in.  It was very “cosy” and I don’t think any of us were able to sleep.
At 2am the lights came on and we all had some breakfast and continued the slog to the summit.  As we left the hut, the wind speed was 28m/s or 100km/hr at the summit.  This combined with -1 degrees was a chill factor of -20 degrees.  On the way up you could hear bullets of wind coming and hikers would crouch down and hang on to rocks.  A few were blown over.  It was an amazing sight to look back down and see the snaking line of hikers with head torches in the dark.

We arrived at the summit at about 3:45am to a howling gale and freezing temperatures. There is a small building with steel plate walls, which provided a little shelter while we waited for the sunrise.   The clouds eventually parted and we were treated to a stunning view of the sun and scenery below.  Sarah took some great photos.IMG_1294

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At about 6:30 local time, I ventured in a clockwise direction from the top of the Yoshida trail to get to the activation zone.  This part was very exposed and care had to be taken when wind gusts came through.  I found a spot against a stone wall and tried the 2m hand held.  It was not possible to spot on SOTAwatch as no cell phone coverage for some reason. Erecting the squid pole was out of the question due to the winds.    After about 30 minutes of calling, I decided it was becoming unsafe with the wind so aborted and went back to meet the others.

IMG_1333The trip back was uneventful although the winds were still strong and we were regularly pelted with gravel and dust.   We arrived back at fifth station about 1pm.

So, not a successful radio activation, but as they say, its all about the journey!

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Posted in Uncategorized | 4 Comments

HF1 QRP Transceiver Project

This project is based around the recent HF1 QRP transceiver by Ashhar Farhan, VU2ESE. The transceiver is an interesting SSB design with wide tuning range from 0-30MHz and should cover several amateur bands.  The schematic for the transceiver can be found on the Minima mail list in this post with a PDF attachment.
After a front end 0-30MHz filter, the  transceiver uses a 45 MHz first IF and a 10 MHz second IF.  The famous bi directional amplifiers are used in the bi directional SSB sections of the radio.
The first cut will be built as modules to test it out in sections.  If successful, a much smaller version will be made for SOTA use.

The mixers will be swapped with Mini Circuits SBL-1s as I have a few in the junk box.
The main LO and second LO will use an Si5351a oscillator so the second 55MHz oscillator unit will not be required.

The Si5351a, controller and display will be taken from the earlier QRP 40m rig.

First part is to build up the bi-directional amplifiers as modules.  The boards are SMD and designed on Eagle.  They came out fairly well, although the laminator sort of jammed during the toner transfer and the board had to be coaxed through.

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The boards were sprayed with lacquer before reflowing the components.  This turned out to be a slight mistake as the flux spread out with the melted lacquer under heat. Anyway, they are fine electrically, just had to be brushed up a bit.

The controller / oscillator board is finished now.  The Si5351 has three clock oscillator outputs.  CLK1 is planned to be used as the main VFO from 45-73 MHz.  CLK2 is planned to be used for the second mixer at 55 MHz, although there is some conjecture as to whether this will provide acceptable performance due to clock output crosstalk.  CLK3 is planned to be used for the BFO at 10 MHz.  The controller will switch it between upper and lower sideband.  If the crosstalk becomes a problem, the 55 MHz output will be replaced by a separate crystal oscillator.  The next job is to check the clock output crosstalk to see if it will be a problem.

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The controller / clock board is single sided with a top ground plane and much the same as used for the 40m QRP rig.  An 8 pin header is for connection to the LCD display.

The cross talk between the 1st oscillator and 2nd oscillator was tested by programming CLK0 with 52 MHz (45+7, simulating a 7MHz receive) and programming CLK2 with the 55 MHz second mixer frequency.  CLK2 was terminated with 50 Ohms for the test.  The results weren’t as bad as I thought they would be.   As can be seen below, the 55MHz cross talk is down 59.5dB.  Of more concern is a spurious at about 62.5 MHz which is just over 50dB down.

Si5351-52-55Some more tests need to be done as this was just a quick look.

For the moment though, I will use the 55 MHz CLK2 output for the second mixer.  Also need to look at the 10 MHz output from CLK1.

Out of interest, the 52 MHz output was moved to CLK1 with the 55MHz still on CLK2.  The cross talk increased considerably to -45dB.  So  1st oscillator will stay on CLK0.

The bidirectional amps work fine with a voltage gain of about 12 or 21.5dB @ 5MHz.

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Progress has been a bit slow due to work and other things.  Have been working on a main RF PCB that will accept the bidirectional amps and mixers.  Things aren’t as modular as originally planned for experimentation, although the bidirectional amp boards are socketed, so it will be easy to tap into the input and outputs.

The power amplifier and digital boards are separate.  So far the main RF board is 80 x 103 mm, and everything looks like it will fit in.  This is the layout so far, not much will happen in the next few weeks due to some travel.

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Posted in Projects, radio communications, SOTA | Tagged , , , | 9 Comments