Triple PN2222 Class C Amp

I did not have a lot of bench time tonight... but I did not really need much given the low parts count for this project.

I look forward to hooking this up to the signal generator and power meter. It will be interesting to see how much drive it takes to turn these on in Class C.

73 de NG0R

Triple PN2222 Class C Amp

Tonight I got back to the work bench to work on one of my projects.


The image below is an old schematic and the three 50 ohm resistors were replaced with a single resistor so that the circuit presents a 50 ohm impedance to the signal generator.

I had to hunt for the schematic and the image below so that I could remember what I was thinking when I came up with this experiment.


This is a Class C amp using three parallel PN2222 transistors. The idea was based upon some schematics that I saw doing something similar with FETs. If it can be done with a FET it should be possible using something like a PN2222.

I printed up the board about a month ago but had not gotten around to finishing the project. So tonight while participating in the "Builders Net" on EchoLink (using my Netbook+Qtel at the work bench) I drilled the board using my dremel-press. I recently bought a bunch of BNC right angle PCB connectors. My original design assumed that I would connect the board to the BNC via a short lead or some mini coax. I decided to mod the PCB tonight to accept the new connectors right on the board.

When time permits one evening this week I would like to stuff the parts. Once that is completed I can connect the signal generator and power meter. There are three things that I would like to measure:

• Power consumption
• Input drive level limits/requirements
• Output power level
  

73 de NG0R

The Retro 75 has arrived!

My package from Dave Benson arrived this afternoon.


As much as I might like to build it tonight I think that I will wait a couple of days. Maybe I can get Jacob (N0AEA) to help work on this one with me at the workbench.

SDR-Shell

Here is an interesting look SDR tool for Linux. (SDR = Software Defined Radio)

http://ewpereira.info/sdr-shell/

I am looking for forward to at some point focusing on my SDR project and getting them built and operational. Ideally my Softrock will drive a 28mhz to 144mhz transverter which will drive 902mhz, 1296mhz, and 10ghz transverters.

There are not too many people doing this on Linux so it should be an interesting voyage.

73 de NG0R

Svxlink, Qtel, and EchoLink

EchoLink will work on Linux using WINE. It works but sometimes can be a little flaky. I am not a huge EchoLink user but I do want it work properly as I talk with some other folks that are interested in building radio and electronics gear.

There is an Open Source project call SvxLink that offers a client (QTEL) and a server component.
http://sourceforge.net/projects/svxlink/

The challenge that I have is that they only have pre-built packages for Fedora based distros that can use RPMs. I use Ubuntu which is based upon Debian which uses DEBs for installation packages. In theory this should not be an issue because they list the sources files and give you instructions for how to compile it for your platform.

http://sourceforge.net/apps/trac/svxlink/wiki/InstallSrcUbuntu
sudo apt-get update
sudo apt-get install g++ libsigc++-1.2-dev libgsm1-dev libpopt-dev tcl-dev libgcrypt11-dev libspeex-dev make alsa-utils
sudo apt-get install libqt3-mt-dev
wget  http://downloads.sourceforge.net/svxlink/svxlink-090426.tar.gz
tar xvzf svxlink-090426.tar.gz
cd svxlink-090426
make
sudo make install

In theory that is pretty simple... until you throw an error!  I am running Ubuntu 9.10 32bit and it appears that some important things might have changed since the instructions were written for 8.04 and 8.10.

--- Compiling AsyncSerialDevice.cpp...
AsyncSerialDevice.cpp: In member function ‘void
Async::SerialDevice::onIncomingData(Async::FdWatch*)’:
AsyncSerialDevice.cpp:299: error: ‘perror’ was not declared in this scope
make[3]: *** [AsyncSerialDevice.o] Error 1
make[2]: *** [all] Error 2
make[1]: *** [all] Error 2
make: *** [all] Error 2

It appears that a couple of folks are talking about tweaking this install and then creating a deb.  So what does a person do until that is available?  --Of course... you Google to see if you can find someone that already has made a deb for testing. I found an old build at: http://hb9hli.radioamateur.ch/public/ubuntu/svxlink/ Install the couple of debs that are listed and you should be in business. I was able to get this to run on an ASUS EEE 900HA with Ubuntu 9.10 in about 2 minutes.

The images show the QTEL client.


This version appears to be pretty old. It runs and appears to be pretty stable based the initial testing that I did with the EchoTest conference room. At some point I would like to get the newer client running so that I can get visual feedback on my audio levels.

This tool is not as full featured as the standard EchoLink client but it appears that all of the important pieces are there and it appears to be more stable than running EchoLink under WINE.

Ok... enough time playing computer for this morning. I need to run some errands. Once I get those done I hope to make it back to the work bench and work on some radio and electrical projects. I will probably test QTEL out tonight on the QRP conference around 8:15pm central time.

73 de NG0R

PS... Here is another location to try: http://www.chrisronk.net/ham/linux.htm
Chris has converted the RPMs to Debs with Alien. It was on my to-do list but it looks like he might have it working. I am going to try it on another laptop that is headed to workbench but is not critical around here.

Wind Train CP 9704 - Cutting Snow

Here is a delayed photo....

A Canadian Pacific train hauling wind farm components across central Minnesota. The photo was captured on 2/15/2010 a few miles west of Watkins, MN as the train is headed eastbound.

New Kits on Order

Since I did not buy anything at the Mid Winter Madness hamfest I went with my backup plan. I had been waiting on ordering these until I knew if I had spent my allowance in Buffalo.

http://www.qsl.net/k5bcq/Kits/Kits.html

You can never have enough signal sources on hand. This one is pretty small and covers a nice range. It is WAY smaller than my HP606 and Wavetek 3000. It will make a nice addition to the work bench with the other test gear.

---

http://www.aade.com/lcmeter.htm


 I have been looking at ordering the LC meter for about 6 months and had always found a reason to avoid spending the money. I have a LOT of variable capacitors on hand that are unmarked. I also tend to homebrew quite a few of my inductors. Both of those reasons keep reminding me that it would be handy to have an LC meter on hand. (I will build a couple of additional test fixtures for it once it is assembled.)

I will see if I can get N0AEA and N2BEN to help assemble them once the kits arrive in a week or so.

73 de NG0R

Polyakov's Russian Mixer (N2CQR & AAITJ)

Kind of a neat circuit and article on the SolderSmoke Blog by Bill.


That is what you call "homebrew"... no SA612/NE602 blackbox mixer there.  :-)

That picture has a high "cool" factor for knack victims. I should try brewing up a diode mixer sometime soon. I need to starting working on a 30m receiver to go with my 30m transmitters/components that I am testing. (You need both pieces to complete a QSO. )

73 de NG0R

Photo Projects

It has been a while since I experimented with HDR photos.

Some examples of what an HDR photo is:
http://www.hdrsoft.com/gallery/index.php
http://www.vanilladays.com/hdr-guide/#onevsthree

I have been pondering some ideas for new photo projects. (Like I really need more projects in my life at the moment.) I have been feeling self aware that I have not been shooting nearly as many photos over the past 12-24 months. One of the things that I miss from my film days was shooting Velvia E6 slide film with polarizing filters and/or gradient/split neutral density filters. I was always trying to push the available latitude of the E6 film.  Back in the day, I shot primarily two different styles.... B&W and ultra contrasty E6 chromes.

It might be time to revisit HDR as a way to bring a similar feel to my digital work.

In the past my most rewarding photos (to me personally) were rural America route 66 style images. Travelling the roads of places like North Carolina, Oklahoma, and Colorado shooting a wide angle lens with some chrome loaded in the camera was pretty magical.

Thinking out loud... some photos projects might be slowly bubbling near the top of my to-do list.

(Yeah.. Yeah, I know that I need to get the photoblog and gallery up on the new web server after the migration.  It is buried on the to-do list some place.)

Here is a non HDR image from a couple of years ago. --Spring on the North Shore of Superior

The Flake Equation

Humor from xkcd


Click on the picture for a larger version.