Monday, July 18, 2011

Retiring this call sign

Well, the call sign is a little over three years old. VK5FNET.

It has served me well, however I must move on, my new callsign has been allocated.

Sunday, June 26, 2011

Study for license upgrade nearly complete

I have been studying for the Standard license upgrade course with Paul Hoffman, VK5PH, for the last three months. 12 weeks on a Tuesday evening with a dozen other hopeful students.

Well the last class was last week and I have a few things I need to re-read. Given my results on the in class practice exams, Paul has suggested I actually sit the Advanced theory first instead of the Standard theory. On the Advanced practice exam I would just scrape a pass mark. Not confident enough just yet. Good news is I am pretty confident about getting 90+% for the Standard theory and the Regulations.

The exam in this coming weekend. So I have to make up my mind about which exam to sit. I would love to do the Advanced and be done with it.

I have a couple of topics that I am not confident yet, mainly Valves, transmission lines and antenna loading. I have four nights free this week, so I will read up and see how things go =)

The really hard part is choosing to let the ACMA/WIA give me the next available callsign or choose one of my own. $5 or $20 respectively. Decisions, decisions...


Big trouble in little Corolla

The little Corolla has been getting steadily worse in the starting on cold morning. Saturday it stopped working all together. Hey I can use a screwdriver and sand paper! This looks easy, the internets tells me this is a common problem with Corollas and is a twenty minute job. Famous last words!

So, after disassembling the solenoid on the starter motor of the car, including un-soldering the solenoid winding from the cap. I cleaned the main starter motor contacts. They were a mess, so I sanded them back and tried to clean all the black gunk off. I cleaned all the other conductors and reassembled. As you do...

Then bolted the starter motor back in the car, tried to start it. Nothing.


Fiddle around with key switch wiring, contacts, etc etc ... nothing. There was only 6 volts on the ignition key switch to the solenoid. Not sure if there is lots of lossy connections between the battery, switches etc. Bother.

Find battery is a bit low on the volts. Put the battery on to charge, went over to a friends place for diner. Got home, the battery seemed to be charged suitably. Went to bed.

Got up this morning, to ponder the issue of there not being enough volts on the ignition wire, scour the internet for more ideas. Walk to servo to find a relay and connectors, etc. They had nothing. Zip. Bother...

Go home, listen to the WIA broadcast and ponder other possible solutions.

After a couple of phone calls shuffling my calendar, I walk half an hour into town to find Sprint Auto to find these parts. Sprint Auto was closed. Was not liking my luck at this point. Walk to Repco. \o/ Its open! Speak to geezer about what my problem is and what I thought might be a suitable solution about not enough volts on the key switch. He suggested that it sounded reasonable, but I would be better off waiting until tomorrow to find an auto-electrician or get a reconditioned second hand one. I needed the car running today. Things to do. With a lighter wallet and a pocket full of parts I walked half an hour home.

Got home grabbed some lunch, had another look on the internets to see if I could find someone else with a similar problem or at least a circuit diagram and repair manual type information. At this point I knew there was something that I did that was amiss. Couldn't quite put my finger on it.

Build up a relay that is trigger by the ignition swith from the key, powering the solenoid from the battery direct to get more current through to pull the solenoid in. The solenoid wasn't moving, but the motor was turning. This was very, very wrong.

Realize that maybe the solenoid was actually dead, maybe a broken winding. Decided to pull the starter motor off the car and ponder some more. I couldn't actually find anything on the Bosch model at all. There were a lot of NipponDenso models that looked similar. At this point I started comparing any starter motor for the 4A motor I could find. At some point I noticed that the large contact studs on the back of the solenoid were wrong. The short stud was on the top, away from the motor and the long stud was on the bottom, closest to the motor and connected to the positive cable for the starter motor. Hang on a second...

So at about this point I looked at a service manual for an AE86, which is a different model, but gave me the most detail for an 1988 corolla I could find. The schematic on the AE86 go me thinking about why the motor was spinning without engaging the solenoid. You got it, I had put the thing in upside down and solder the wires in back to front in the circuit.

After another half an hour, I had assembled it the right way and put it back in the car.

Not expecting it to even move the solenoid, the car car started smoothly and ran! So I switched it off and added my ignition relay, and that started nicely too. So I tidied everything up and took the car for a lap around the block, to be sure.

Half hour job, eight hours later! At least its working properly now and we can now go do those things we need to do. =)


Monday, May 02, 2011

recycled steerable dipole

I rescued an old teevee antenna from Karl before he escaped the state. (he has gone to vk7 land).
it had a number of 'large' elements on it for VHF and lots of small elements on it for UHF. =D

I striped all the elements off the boom and started looking at useful arrangements using the longest ones. did some numbers and worked out that i could use the largest and third largest elements and reuse the 'egg' insulators for a reflector element, then wrap an inductor around the 'egg'.... =)

Did the measurements, rough numbers for the coil, should be good for the middle of 10 meters. \o/
Put it together, then spent the rest of the afternoon cutting firewood. consequently I ache all over! =/

So after the pot-belly stove is fired up and the dinner is on the boil, I test the antenna to see where in the 10 meter band it works ok.

So it fails as a dipole for 10 meters. Rather badly actually the SWR > 5:1 across the whole band =(
Not to be discouraged I tested it on 15 meters. Bingo! The SWR < 1.5:1 across most the band. \o/

So lesson for today, is my modeling/measuring concept is right out. However the consequence is that if I tinker with the coil I should be able to find a tap point suitable for 10 meters. A job for next weekend though.


I've added some images of the process and what the final center and loading coil looks like.
It is not particularly self supporting, as the final elements are much longer than the original teevee antenna.



Monday, April 18, 2011

Listening for Yuri's day ...

I was organised, got the ALICE pack all setup to record the commemorative transmission on the 12th and again on the 13th.

I listened for many passes ... Not a peep =(

Anyhow, found this today;

"The planned operation of ARISSat-1/RadioSkaf-V/KEDR on April
11 and April 12 from inside the International Space Station
as part of the commemoration of the 50th anniversary of Yuri
Gagarin's flight was not successful. No earth stations on
the ground reported hearing transmissions on the ARISSat-1
downlink(145.950 MHz for FM analog/145.920 MHz for digital).
The planned retransmission of the satellite's FM downlink
via the Kenwood TM-D700 transceiver --currently used for
ARISS contacts--was also not successful as no reports were
received of signals heard on 437.550 MHz. However, a
similar ARISSat-1 transmission test conducted in February
was successful, with 145.950 MHz signals being successfully
received by several ground stations. "

ANS-104 ANS Special Bulletin - ARISSat-1 Not Heard During Gagarin Commemoration

Thursday, March 03, 2011

Exciting developments in GNU Radio

The article; Exciting developments in GNU Radio, describes updates to the GNU Radio project.

I wonder if this can tie in to the SDRCube project that Erich VK5HSE has been tinkering with?

73, Kim

Wednesday, January 12, 2011

Land of Lisp

I have been getting into Lisp recently. Quicklisp has made the process a fair bit easier, so I took the plunge and ordered a copy of Land of Lisp.

What do I want to do with Lisp? Well the main reason is that I used to code in Lisp back at Uni. I would like to do some log processing and sensible matching against multiple rule sets. However I suppose the idea that Land of Lisp is learning Lisp through creating games was quite an attractive idea.


Monday, December 27, 2010

New key

This chrismas I received a key! Along with a vintage power supply and Morse sounder. It looks old and has some loverly green corrosion on most the brass bits. It sits atop a wooden base and that atop a steel slab with a rubber sheet glued beneath. It has PMG stamped on the front of the wooden block. Should scrub up well. Would like to find out more about when and where they were used. Will post pictures soon.

Monday, November 29, 2010

OSDC trip

This last week I flew off to Melbourne for the Open Source Developers Conference. I spoke to many people about a wonderful range of topics. The main things that I was aiming to be across was large or enterprise installations of any CMS that folks have experience with. There are a surprising number of options. Drupal came up many, many times. Varnish with one of Apache + mod_php or Nginx + FastCGI seem to be a common platform.

Although there were a couple of good Perl talks too; Schwern's Perl5i and Damian Conway's talk on Quantum Mechanics + General Relativity + Perl. Reading several of Richard Feynman's books in the last year certainly helped to keep on the same page as Damian as he galloped along with some complex ideas. The talk "git for age 4 and up" was great, certainly cleared up my misconceptions of labels in git =)

73, Kim

Wednesday, November 17, 2010

Monthly update, November

Well its been a little while since the last update and I've been busy. AHARS has been quite active, the good weather has brought about many good events.

The AHARS Symposium. Was a great day, its amazing that as I keep reading and tinkering that little nuggets from the talks start to fall into place. Little bits of wisdom finally making themselves understood. There was just so much to take in on the day... Note the microwave gear on the right hand table, along with the VK5TR loop, and HPSDR rig at the lower right corner.

We had the National Field Day. So I helped out at the AHARS tent. To aid publicity AHARS got a foot in the door of the Eden Hills Primary School Strawberry Fete. Its your usual spring fair; food, plants, books, cloths, stuff, junk, treasure, etc etc...

The great resistor packing day for AHARS. Folks in the club thought it wise to do a bulk purchase of resistors so that all the constructors, repair and homebrew folks had adequate parts in their respective junk boxes. I decided that I needed to stock up too, so I ordered a box. The bulk order was made, around 1.2 million resistors in all. The day finally came, we assembled and sorted out each 'decade', cut 100 of each value, then assembled a bundle of each of the 12 values into a roll, then each roll into a box. Thankfully many extra volunteers participated for a good day. Lots of radio talk. I learned a thing or two about boat anchors. Went home with a box of resistors =)

The AHARS Buy and Sell. I was up very early to help setup for the Buy'n'Sell. There was an amazing array of stuff. Old radio gear, new radio gear, test gear, computer stuff ... I picked up a few things.

With the holidays coming up, I hope to get more done...

73, Kim

Tuesday, October 26, 2010

Wireless Networking in the Developing World book

At lunch I was browsing through some old email and was reading some "help me learn about OLSR" type conversations.

There was a link to the book; Wireless Networking in the Developing World

Its now in second addition and in now translated to more languages, you can download it or buy it.

It has been a while since I have setup up new WiFi infrastructure. My network at home has been pretty stable. I should go see whats new in the second edition...

73, Kim

Sunday, October 24, 2010

National Field Day 2010

Yesterday being the National Field Day - NFD for 2010 in VK (Australia), I spent with the Adelaide Hills Amateur Radio Society.

AHARS setup a tent at the Eden Hills Primary School Strawberry Fair.

A number of contacts was made on HF and 2meters and 70centimeter. Some contacts were made through the cross band repeater on the project horus ballon, launched to coincide with the NFD.

I spoke to about a dozen people across the day and handed out pamphlets. That doesn't sound like many people, but there were at least six club members there across the day, who each spoke to members of the public across the day about Amateur Radio and the club activities.

There were a couple of themes across the day for me. The main one was the grey nomads, who use the travelers nets to update their location and journey progress with their net controllers, mainy for safety, directions and recommended stop overs. Folks who use UHF CB and or the four wheel drive net VKS737 already. It was interesting to see them explore the options that Amateur Radio could give them. Even if it was only a couple of more bands to listen to the various travelers nets and listening to the reports coming in about traffic congestion, etc. Its not something that I've really put a lot of thought into, but certainly created an awareness for me about how folks outside of amateur radio use radio and why.

Secondly was the HF verticals and how to set them up with automatic tuners, especially across multiple bands. I believe the original squid pole article was from VK3JJ in AR, but I will have check that. A few of the AHARS club members present had built up the JJ antenna and all spoke about issues with tuning and assumptions with measurements and materials. There is certainly a lot of room for experimentation and of course careful measurement - a topic that comes up so frequently, which of course lead on to the third theme for me... upgrading my license.

I spoke to several folks about upgrading my license, the study involved and stratagems for learning. All duly noted. I will be pulling my finger out over the summer break.

I bumped into a few old friends, picked up a few books and plants at the fair. Saw a new part of Adelaide that I hadn't seen before. Over all, even with a little sunburn, I enjoyed the day.

73, Kim

Sunday, October 17, 2010

Copper cactus J-Pole - part 1

For some time I've been wanting to get a decent antenna up for 2 meters. We have a good technical 'net on a Monday night by the AHARS guys. I used to regularly join in but my little HT's batteries died and it doesn't work without them. I do have a little 1 watt Kenwood rig and a 4AH 12volt battery, which works a treat. However the antenna situation is letting it down. It works quite well on receive, but I need to get the antenna up much higher to activate the repeater.

Quite some time back, I was given some scrap aluminium and a 2 meter slimjim. I used the slimjim alot. It was pretty fragile and I repaired several breaks from wind damage, but its just not very practical as a portable antenna for the rallies, eg ROSA or as a home base antenna.

Lots of digging on the Internet yielded lots of info on the copper cactus antenna. I didn't have any of the common materials, so a visit to the local hardware stores didn't have any hard drawn copper pipe either. Well, Home Hardware had six meter lengths of 1/2" for $98 and did not cut off lengths either =( I decided that a copper cactus was going to be out of my reach and put it off.

Then I picked up a little dual band 2m/70cm 3/8" screw on to mag mount antenna for the car, just before the rally. Its ok pootling around on the car, but with out any ground, it doesn't perform on the little Kenwood at home as well on receive as the rubber ducky on the HT. Its pesky to setup and use at home.

That was all some eighteen months ago. Since then Bunnings has opened and some of their stuff is cheaper than the other hardware stores. Bunnings also has more range, but quality varies greatly. However, they did have 1/2"/15mm and 3/4"/20mm hard drawn copper pipe, but only in 1.5 meter lengths. The HDCP 20mmx1.5m is $16 a length, with 20mm 90 degree bends $2, 20mm Tees $3 and one bag of 1" clamps/brackets $7. So last weekend I needed to get some other things from Bunnings, so I got all the bits I needed and some spare for future projects.

This evening I worked out the measurements and cut up, then sanded the pipe, bend and tee joiners. I have a little industrial hair dryer, which gets everything up to temperature and soldered the lot up.

What remains is the mounting to little mast and getting some coax set up to the clamps. Obviously matching and endless tweaking =)

Can't wait to get the antenna up and tested.

72, Kim

Wednesday, October 13, 2010

SolderSmoke 126.mp3 is out

Yes, thats right, SolderSmoke is back \o/ Head on over, download, listen and enjoy. Damn just got up and have to hop on the bus right now, but I'll be listening to is ASAP!

SolderSmoke 126.mp3
October 11, 2010
SolderSmoke returns!
Shack #7: The New Shack
Drake 2-B inhaling RF
Listening to 75 AM and SSB: WA1HLR, KM1A
Time signal on 3820 +/-?
Repairing DaVinci Code QRSS rig
UK test gear works fine on this side of pond!
Computer woes: First Linux SolderSmoke
Astronomy from inside the Beltway
Winter SPRAT: Great info, philosophy, inspiration
Charging up solar cells
Inbound Boatanchors: DX-40, DX-60, HQ-100, HA-600(A), HT-37