Roof and cement

No 'ReadyMix' used here, but 24 bags of cement and 6m3 of sand/pebble mix, a simple cement mixer and wheelbarrow to transport each mix to the pad. The surface was leveled and smoothed using a plank of wood! Back breaking work, it took two days to complete. 

Fitting the roof tiles

HF Low Pass Filter construction

I've started building a LPF diplexer filter rated for a 1KW SSB/CW HF transistor power amplifier

The diplexer consists of 6 relay-switched units and covers 1.8 to 30 MHz amateur radio bands. It has 1 input port and 6 antenna outputs, so no additional ant-switch is needed.

Next comes the hard part - winding the toroidal ferrite cores, and tuning them for each band.

Carport Construction p2

The basic structure of the Carport is complete; now I just need to order the roof tiles to match the house and a few days without rain to install the pine ceiling. All the exposed Oregon Pine has been painted with a non-stain wood preserver. Ethan, posing for the camera, provides a good reference of scale.

Carport Construction

I took advantage of a short break in the rain to begin construction of a carport. The roofed parking area will span 8 meters wide x 6 meters deep - ample space for two vehicles. The carport will also double as a nice shaded area over-looking our swimming pool during the hot summer months.

GLCD Assembled

The weather has been quite cold and wet recently, so I've used the extra free time indoors to work on my HF Solid State Amplifier project. The assembly of the above Graphical LCD module (Designed by VK4DD), was completed over a couple of evenings .... I now need to perform a few basic checks before inserting the PIX micro-controller and display. 

When the Amplifier is completed, this display module will provide important status information, such as power-ouput, SWR, FET-Temperature, voltages etc ... 

FT-817ND 'wideband' mod

I've suddenly got the itch to do some portable QRP work with my tiny Yaesu FT-817 HAM Radio, which I picked up in the UK a few years ago ... it has been gathering dust for quite some time. So I charged the internal battery and checked it over. It's then I realized that since I purchased it in the UK, the 2m band was restricted to just 144 - 146Mhz which is pretty much useless in Chile as ALL of the local repeaters are located in the upper 146-148Mhz. Also, the 40m band is restricted to 7 - 7.100Mhz; again in Chile I can use up to 7.200Mhz, so this has motivated me to extend its TX/RX capabilities or 'wideband' modification. The original FT-817 was very easy to extend with free software on the Internet, but I guess the FCC didn't like that so my newer ND model, requires a fiddly hardware modification.

 

Basically you have to strip off the top and bottom covers in order to expose and release the front control panel from the main chassis. Then using a fine tip soldering iron and a steady hand, modify the jumper settings as shown in the picture above. Fairly simple, in my case I needed to close the far left jumper and remove solder from the middle jumper to complete the mod. After the the radio is reassembled, it requires a hard reset holding the F and V/M buttons whilst hitting the power on button.

I checked the 2m band, it's now fully open :-)

Doors installed

Exterior almost finished

Looking at this picture it's hard to believe that the temperature was well below zero (-4C) this morning! However the sun came out so we took the opportunity to paint on the wood preserve before the next wave of rain hits. 

The front entrance is now taking shape. I shall be fitting two 50cm wide glazed pine doors, that open outwards. The spaces above the door will also be glazed to provide more light.

The cement ramp at the entrance has been broken up, as I intend to build a small deck and stairs leading up to the cabin. 

Working on cabin front entrance

Finally I have removed the ugly front doors, it now looks less like a garden shed ;-)

Most of the outer structure has now been covered with new Oregon Pine siding, and the windows have been fitted to the bathroom and bedroom.

Making progress on the cabin

Wood Cabin - Roof Installed

The roof was finished this weekend, I had to ship extra tiles from Santiago as I could not source them locally ... just in time for the rain forecasted this week. The wood framing is also almost complete, just need to remove the old shed doors and siding at the front in order to frame in the new entrance and windows. 

Wood Cabin - ready for the roof tiles

Wood Cabin - roof & framing

The cabin structure is really beginning to take shape now. Whilst my helper is working on the roof, I'm focusing on the wall framing. 

The 'dog house' looking structure to the right, in fact houses the water pump :-) A 1000 litre tank is buried out of view behind it.

Wood Cabin - bathroom

The ground to the to right of the shed slopes away fairly steeply so a wooden platform was built supported by prefabricated concrete posts. The surface area is 6m2 (2m x 3m), ample for a bathroom. The space under the floor provides easy access for installation of drainage pipes etc ...  

Wood Cabin - adding bedroom

The area to the left of the shed is fairly spacious with a view and level so I decided to locate the bedroom there with a solid foundation. My design includes exposed wooden beams and 'cathedral' ceilings, so the roof of the old shed will be completely stripped and done again. I'm going to recycle as much of the materials from the old shed to build a smaller replacement shed for the lawn mower and other gardening tools.

Wood Cabin Project

The challenge is to transform this humble garden shed into a cozy heated cabin, with a small kitchen and bathroom. An extra 15m2 will be added bringing the total living space to 30m2

Plumbed in

I finished the plumbing last weekend, the Solar water heater has been running for about a week now without any problems. We have had a mix of Sunny, cloudy, cold and rainy days so these variable conditions have enabled me to tweak the settings for the most efficient use.

I was initially concerned by the single inlet/outlet connection to the tank; the advantage of this setup is that you only need to run a single pipe up the roof to the tank, but I was worried that refilling would conflict with hot water use - say in the middle of a shower!  In reality however this rarely happens, as the system waits a min 30mins before trying to refill once the water level drops below 25%.

As first, I set the system up to maintain a tank level of 75%, this has the advantage of introducing less cold water for each refill, but I found on non-sunny days that the frequent refills still caused the electric heating element to come on more frequently as I also have the system maintain a temperate of 60c.

After a few tests, I found it was better to simply let the system empty down to 25%, this proved to maintain a much higher daily water temperature, especially on sunny days when it would heat up to 80c+ and the refill would not even dip it below 57c which is the trigger for the electric heater.

The 1.5kw heater seems to work very well, in no time the water is back up to 60c on cold days or a refill from the 25% level.

The only real negative point about the system for me is that the water pressure is a little low (I like to shower under a waterfall :-), but adequate ... so not a show stopper, I guess in fact it saves water which is a good thing.

Boiling Hot!

Here's a shot of the digital controller of my new Solar Water Heater. As you can see the water has almost reached boiling point after a couple of days in the sun. The tank is very well insulated and so looses very little heat during the night. Steam and boiling water is intermittently spouting out of the tank's vent hole like a mini geyser!

In normal daily use it should rarely reach these temperatures, as fresh cold water is added to replace hot water taken from the system. However, I'm happy to stress test the system like this to see what happens should we be away from the house for a while.

Ummm, I'm going to have to wait for a few cloudy days now to finish the plumbing .... it's far to hot to work on at the moment.

Solar Heater - Tube Installation

Installation of the 24 glass tubes was quite a challenge for several reasons. The pitch of our roof is very steep, so I had to fabricate a wooden support system to provide reasonable safe access to the heater frame. The manufacturer claims that the tubes can survive hail etc .... but these tubes are glass and would certainly break if I dropped one! 

Each vacuum tube slots into a hole in the tank with a tight fitting rubber seal. I used undiluted washing-up liquid as a lubricant, and carefully pushed each tube into place. The sealed, far end of the tube sits on a rubber seat in the frame. I can tell you that I was very relieved to get all 24 tubes safely in place.

Since I've not had time to complete the plumbing work, I temporarily sealed the input/output and filled the tank manually via the vent hole using the garden hose. I wanted to check for leaks and functionality before ripping out my gas water heater!

Once full, I noted the water temperature was 15c and the sun was setting. The next day was cold (5c) and very overcast ... surprisingly the tank temperature had dropped by only 1c overnight and was hovering at 14c. Later on in the morning, the cloud began to break and we had some sunny spells, within several hours the water temperature had reached 40c - very impressive.

Solar Water Heater

Ideally this should have been a summer project to take advantage of the hot temperatures .... anyway, I finally purchased the components on a recent trip to La Serena. The kit comprises of a ~300 litre tank, 24 vacuum tubes, support frame, backup 1.5kw electrical heating element and micro control unit.  It sells for approx. $600 USD. Our gas cost per month to just heat water is around  $40USD, so the system should pay for itself in less that 2 years.

I assembled the support frame on the ground and hoisted it up to the roof. Next came the tank, which when empty is not that heavy, but very bulky and difficult to handle . The project almost ended in disaster when the tank toppled off its support before I was able to secure it properly, but the hoist rope was still attached and I was able to grab it before it bounced off the roof! A few scratches, but fortunately no serious damage.

The next steps are to plumb in the tank, add the temp/water level sensor and electrical heating element. The glass vacuum tubes will be installed last to protect them from possible damage. Care will have to be taken for example to prevent thermal shock. The system operates at atmospheric pressure, thus the tank must be mounted as high as possible, else an additional pump is required to increase the water pressure, which I wanted to avoid so that hot water is available even during a power-outage which occurs quite frequently at this location.    

It's summer!

Anita with baby Alison enjoying some relief from the very hot temperatures we have had this month.

Note to self .... must try and keep the pool clean this winter! ... it took a LOT of effort to get it back to pristine condition.