Electronics

All electronics related. Some overlapping with various ham radio projects but for finer selection go for sub-categories.

Quartus files

One of the biggest issues that I have, in general, while learning different stuff is lack of properly-explained abbreviations. I am starting today a compilation of Altera/ Intel Quartus list of filenames and abbreviations. Source: Intel/ Altera Glossary .qws – Quartus Workspace File. The Quartus® Workspace File (.qws) is a non-editable file that stores user […]

Time Capsule Repair

Some time ago, my old Time Capsule died. It simply did not start. I read that this is an issue that plague all older (first and second generation) TCs. The culprits are four electrolytic capacitors inside the switching power supply, two 1,500 µF, one 1,000 µF and one 470 µF. The 1,500 µF were badly swolen. […]

AD8307 RF Power Meter III — build

This will be another short post. I also made the GitHub repo public, but please be aware, current design is flawed. If you use it, you acknowledge that you use it on your own risk. Today I managed to build the revision 1.0 of this power sensor, not without some lessons learned. It was my […]

AD8307 RF Power Meter II — boards from JLPCB

I ordered the boards for this project with JLCPCB in China. This is my first attempt of working with a professional PCB manufacturer and I am extremely pleased by the results.

AD8307 RF Power Meter

My first finished KiCad project is a prototype of a RF Power meter with input attenuation built around an Analog Device AD8307. An excellent tutorial about log amps can be read in March 1999 edition of Analog Dialogue. KiCad PCB: And the 3D rendering of the same PCB: The next step will be PCB ordering, […]

Altera Qsys, NIOS II and FPGA fun

One very interesting feature of Altera FPGAs is that almost any system can be created in its next-generation system integration tool Qsys using a standard library of reusable IP blocks. The system interconnect fabric is automatically generated by Qsys and binds the blocks together. The system interconnect manages dynamic bus with matching, interrupt priorities, arbitration […]

End of week — pin planner

This week was quite busy to complete my assignments for the FPGA Course. I was running out of time because I did not estimate properly my available free time and things got crowded at the office, at this end of week. With a lot to do there, I barely found any time to focus on […]

FPGA Course

I’ve been quite busy lately and neglected the blog. I enrolled on Coursera for a very interesting FPGA course, in what seems to be a FPGA specialization from University of Colorado Boulder. I have always had somewhat a reserved attitude towards FPGAs mainly because I believed that these are hard to understand and need a […]

Beacon with SiLabs module

This is a beacon project started by my friend YO5VAE. He faced some issues while programming of the Si4463-based module and I thought I might give a hand. I resoldered the entire project on an empty Arduino shield to allow expansion of the project with some additional modules. Below are some pics, but probably the […]

Ferrite beads

I ordered some ferrite beads for a RF circulator project I currently work on but these might also be very handy for the SWR bridge project. These are extremely efficient for RF supression, or at least this is what they say.

Boards for prototypes

For low frequency projects, a fast way to prototype is using a bare PCB and scratch some dividers that allow “manhattan” style prototyping. I am especially very fond of this prototyping technique and I believe that PCB design should be avoided in the early stages of prototyping. Jim Williams was an artist in such designs. […]

OCXO tests

A couple of months passed since I purchased two 10 MHz OCXO modules from eBay. And, to my shame, I didn’t even tried these. Yesterday I did a quick test and the devices are spot on. Both measured on my TTi TF930 3GHz frequency counter: The OCXO needs apx 10 minutes for proper warm up […]

Electronics from China — Pixie CW

Power supply: DC 9v – 12v Antenna: 50 ohms, is not balanced, 7MHZ band, standing wave ratio below 1.8 Receive the static current: 10 mA @ 9 v Transmission power: 0.8W @ 9 v, 1.2W @ 12 v Frequency range: 7.023 MHz launch, receive 7.023-7.026 MHz (7.023 MHz crystals) Stray (harmonic) inhibition: – 20 db […]

Electronics from China

I am pretty pleased by the outcome of my commercial endeavours on eBay. Purchasing seems to be a pleasure; until now — with just one exception — I was spared from any nasty experiences. After several small items that I ordered in part for my curiosity to evaluate speed and quality of shipments from chinese suppliers, I […]

Rigol Spectrum Analyzer !

I’ve kept drooling for this for several years. Today I finally got it ! Moreover, it seems it is fully-option enabled, which is kinda weird because I haven’t ordered for such. However, here it is: the Rigol DSA 815 TG Spectrum Analyzer with tracking generator. This will enhance my lab’s capabilities in RF electronics and […]

My first order from RF Parts…

I was looking for a RF power module for my APRS beacon project and stumbled upon RF Parts. They are somehow of a niche–oriented online electronic part retailers, specialised on RF and — it seems — mostly on Ham Radio RF parts. I placed my order for two Mitsubishi power RF MOSFET Amplifier Modules and the package […]

LTSpice Parameter Sweep

While designing/ working on my APRS project, I used LTSpice IV for some simulations. For those that don’t know, LTspice IV is a high performance SPICE simulator, schematic capture and waveform viewer from Linear Technology. It is a freeware and can be downloaded from this link. Versions for my both platforms exist, Win 7.0 and Mac. […]

Staedler pens

Red and Green

This will be a very short post. And only for the blog. I have a sweet spot (call it idiosyncrasy) for stationery. I mean, some people do heroin, some do alcohol, some do Oprah. I am addicted to stationery. Put me in a stationery shop — you can leave me there all day (give or take), […]

APRS Proto - 3

144.8 Mhz TX for APRS (3)

This is a quick update post. The road I took with this little project is slowly getting to a dead end due to what it seems to be a lack of available crystals for 144.8 (like 48.26 or 28.96 MHz, for using the third or fifth harmonic). I believe that, currently, all APRS modules are […]

144.8 Mhz TX for APRS (2)

More work today and yesterday on this project. Still locking on 144 MHz, but this is normal, the crystal I used is a 48 MHz overtoned, working on the third harmonic in this case, thus spot on 144.0 MHz: I managed to clean the output, at the expense of transmitted power. I used a 7-pole 2m bandpass […]

144.8 Mhz for my APRS Beacon project

144.8 Mhz TX for APRS

Been busy at work lately, but still had some time for myself. Latest idea: a low-cost APRS beacon, done with a classical 144.8 Mhz TX and a μController. AX.25 on air. Automatically. So these days I’ve been busy making this: Winding coils, soldering, measuring. Fun. The frequency is remarkable stable, given the rudimentary nature of this. For example, […]

The Indestructible LDMOS

Mailbag today 2 ! This time from NXP. OMFG, look what I got ! This baby will definitely end up in a power RF amplifier for my Ham Radio fun time. This will be a project. THANK YOU NXP ! Got them both today ! And I have to tell you, the girls and guys […]

Toshiba TRL330 RF Choke

Scavenging for electronic parts

Not very often I have the occasion to salvage some good parts from throw–away devices. Two days ago I found an empty TV set carcass lying on the sidewalk with some pieces left. The rest was — probably — savagely ripped off for copper and some other metals. It’s a bit of shame to see […]

Stuff to read

This is very, very short. Books I have to read. But I really, really have to read: Art of electronics book Art of electronics student book Masterminds of programming

AVRISP mkII unboxing

AVRISP mkII

Until recently I have extensively used my MacBook, AVRDude and USBTiny for my μController projects: Now I got myself a proper tool, the AVRISP markII, mostly because I wanted to use AVRStudio 6.0 features: Key features: Programs both flash and EEPROM Supports fuses and lock bit programming Upgradeable for future device support Supports target voltages from […]

JFET Circuit Analysis – great tutorials on YouTube

Looking for some detailed information about JFET circuit analysis, I ran today into three excellent videos posted by Bournemouth University. Already subscribed to them. The videos are part of Linear and Switching Circuits Series and target the following topics: Performing the DC JFET circuit analysis of a simple JFET self-bias amplifier (to find the circuit […]

Power MOSFET

Understanding Power MOSFET data sheet parameters

Fabulous piece of literature from NXP (here’s the link to a cool pdf). Nothing beats a well written material. So it seems that I have some very interesting thing to do this evening: printing this and have a good read. This comes on perfect timing for my MOSFET dummy load project ! Quoting from NXP’s material: […]

Dummy Load Prototype – breadboard closeup, view from above; detail;

Dummy Load Prototype – 2

Next steps for my dummy load prototype based on IRF830 N-Channel MOSFET, and a LM328 plus a multi turn pot.

Weller WD 1000M Review

There are good tools and poor tools. Weller WD 1000 M is a state-of-art quality instrument that looks good, feels good, has a plethora of gimmicks and is a pleasure to work with. Let’s find out some more about my new soldering station.