This was taken at civic park in Drouin, hundreds of them in the trees… Click on the photo to open full size then click on it again to zoom in
So over the last 12 months the Twisted Shack of Mark VK3PKT has been getting a lot more test gear. Some of it was from the hamfest, some from people that I know and some from eBay.
I first aquired a 550MHz Freq Counter this is connected to a 10MHz GPSDO timebase to lock it to a known reference. It is then connected to a 10 MHz-520 MHz Marconi AM/FM Signal Generator to give an accurate display of the frequency of the RF Sig Gen.
So I have a lot of my gear, 3 Frequency counters and a Time Interval Analyzer hooked up to a GPS Disciplined Oscillator. This uses GPS satellites to create a very accurate 10 MHz signal to use as a reference for the test equipment. I also have a Rhode and Schwarz Frequency Standard that outputs 5 MHz 1 MHZ and 100 KHz. I use an oscilloscope connected to both the 5 MHz output of the R & S Standard and the GPSDO to get the FRQ standard on spec.
This scope is dedicated to the job of using lissajous figures to monitor the GPSDO and both the R & S as well as my OCXO Ovenized Crystal that runs off 12 volts and has a small SLA battery to keep it running while taking it from the shack to the car then to a mates shack to calibrate gear. I first adjust the transfer standard against the GPSDO using a Scope and then take it to the required location as needed.
Now when it come to calibrating counters and reference standards I start by using the GPSDO as the Master Standard, this is the one that for my shack I trust the most to be accurate. That is what I feed it into a lot of my test gear as a reference. To check the 5MHz R & S I could just use lissajous figures but I have a bit of gear I picked up dirt cheap on ebay. It cost me 160 bucks delivered and new was over US $8000. It is a Yokogawa TA320 Time interval Analyzer. It measures periods down to picoseconds. Here is a histogram of the the 5 MHz signal calibrated against the GPS 10 MHz signal.
As you can see the range of the window is only 2 nanoseconds, from -1 to +1. The average signal is 199.97958198 over 99.999999 Million samples. The gate time is set against the 10 MHz reference. Apart from setting standards what would you use such a beast for ? Well the manufacturer gives a few ideas with one being connecting it to a hall effect sensor counting teeth on a flywheel of a drag car engine it is fast enough to see a stretched pulse at full throttle if the engine misses a bit. It is also used a lot to measure jitter in optical drives for CD’s and DVD’s in a musical recording studio making master discs.
TA320 with Freq Counter permanently connected to it
Here is a photo of the Rohde & Schwarz Freq Standard and GPSDO mounted in 19 inch Rack, there are four 10 MHz outputs on the back of the GPS that break off to test gear in the lab. One comes to the a hole that was in the front of the R & S that had a broken neon lamp in it and was just the right size for a BNC connection to break out the 10 MHz from the back of the GPSDO to the front panel to make it easy to get to it.
So I was looking at commercial RF adapter kits and the prices shocked me so I decided to make up my own. The commercial ones I saw used a weird connector to join the adapters to each other. I decided I would use female BNC as the interconnect that way i could use male to male adapters to make short connectors or BNC patch leads for longer cables. Here is a commercial kit from element 14 it is pretty limited and is more than US$200.
I put together a much larger kit with two of all the adapters as well as to 50 dummy loads just small ones to use to match the load when connecting to a scope to match the impedance, you use a BNC Tee piece. Anyway here is my kit… It has double of each connector and should cover all my needs it cost me about 120 bucks Australian to put it together.
So I rebuilt a friend of my sons PC. It was a mess it had water cooling and the radiator was hanging lose. It was overheating from all the dust and when he brought it over in the car the radiator ripped the CPU out and bent dozens of pins.
It was one of the worst PC’s I had seen in a long time for dust and if it had gone to a shop they would have thrown the CPU in the bin and it was an AMD FX 8 core worth 300 bucks
Nearly an hour under a stereo microscope with tweezers that are so fine they are like needles was spent getting all the pins straight.
I pulled it all apart except for the motherboard, blew all the dust out, mounted the radiator to the top and put a HDD cage in as the hard drives were just hanging by the power cables.
It took Angus and I about four and a half hours to get it from the first photo to the finished product in the last two photos, one of the back which has a case cover over the cables and one of the front side which is missing the cover.
Some people might think it is to much to repair a PC like this and rebuild it but I actually enjoy this type of work, I just wish I could actually do this as a full time job but my health wont let me
This is the schematic, the battery is on permanent float but if the power goes out it isolates the battery bank until I flip the red missile switch. This is so the rigs standby current drain does not flatten the battery if I am away from the shack
Okay I was a geek at school, .. Nothing has changed… Just ask my wife
I run Linux
I am a licensed Ham Radio operator
I Own 4 Oscilloscopes
I also own 8 calculators including 3 graphing
3 slide rules
I have a glass world globe on my desk
4 Ham Radios in my shack
3 Radios in the car
2 Handheld ham radios
My phone and tablet run custom android roms
My bookshelf in my man cave has the following books…
Machine Tool Operation Book 1
Machine Tool Operation Book 2
Taps and tapping by sutton tools
The Australian Amateur lapidary handbook
Meters for measuring water
RCA receiving tube manual
108 uses for an oscilloscope
Audio Handbook No2 “Feedback”
Phillips Valve data book
Electronics Made simple
101 ways to use your signal generator
99 ways to use your oscilloscope
How to use grid dip oscillators
101 uses for your Vacuum tube volt meter
Transistor radios Circuits and servicing
The casio PB100 Computer manual
RCA Tube Manual
WIA Handbook Vol 1
Summary of lectures Automatic control systems
Faber castell slide rule manual
Hemi 40RK Sliderule manual
Icom ICT90a Manual
Transistor Transmitters for amateurs
Radio Data Reference book
The boys book of crystal sets
ARRL radio Amateur handbook
Electronics Principles Integrated and discrete
GIMP Graphics Package User Manual (Linux)
Tech topics radio handbook
Radiotron designers handbook
High quality sound reproduction with valves
Novice Operators Theory Handbook
Tektronics Scope 314 Service Manual
1972 Melways (Street Directory of Melbourne) from my birthyear
The ARRL handbook 1995 (Theory)
Sourcebook of electronic circuits
Yaesu FT707 Service Manual
Ford Falcon EA-EF Factory Manuals (We own 2 falcons)
Linux Sys Admin
HEMA World Atlas
Oh and I own two domains, twistedsouls.com and hamshack.org
Geek and proud
I went on the Gippsland Motorcycle toy run on Saturday. The toy run is a charity event to collect toys and food for the needy , I didn’t get to take to many photos as it poured down with rain most of the day but considering the conditions it wasn’t to bad as to the number of riders who turned out. Anyway here are the photos I did manage to take..
Okay so I bought a 30VDC Variable 3 amp PSU from Jaycar a few weeks ago. It is model MP3086 with CV and CC modes. I was expecting the one shown above with 3 pots, one for amps, and coarse and fine ones for volts.. Instead I got a new improved model, unless you like the coarse/fine pots!
|Cover off, transformer looks nice doesn’t it ?|
|IEC socket with integrated fuse holder, nice one !|
|Shake proof washer a point for Jaycar|
|Spring washers on transformer mounts with intake vent for fan, there is also vents on the sides with exhaust at the rear of the unit|
Okay now for the close-up internal shots, there are five boards
- Rectifier board Power transistor board with Relays to switch taps from transformer to transistors
- LCD Display board
- Keyboard Board for buttons
- CV/CC Control board
- Connection board for front panel outputs with current shunt for amps readings
|Is this a real Japanese Rubycon or a copy ?|
- RS232 connected DMM logging temperature
- Galaxy Note 2 Smartphone for dB readings (Not real accurate but okay)
- Incandescent 12V globe as resistive load
- Digitech QC1932 25MHz DSO
- Supply set at 6.9 Volts, this just switched to the second tap (6.8V) so max heat from transistors
All in all for the price I am very happy with it, well built steel case, the front panel is plastic but has steel rails running from it to the back panel for support.
So what don’t I like ? Well not much the only things are as follows.
- Earth Connection is in the centre, so I cant plug a standard spaced dual banana plug adaptor in to the – and + rails, I may re arrange the banana sockets and move the earth to one side.
- You need to short the rails to set the required amperage for CC mode, I am going to put a NO momentary switch on the front so i don’t need a lead to do it
- Switching on CC mode is a bit hit and miss, I dont know if it is key bounce or a slow micro but you have to press the CC button a few times before it locks in to CC mode, it is a soft switch