Tuesday, May 10, 2016

Really slow CW

I've taken an interest is QRSS, super slow CW. A sound card DSP program, like Spectrum Lab, or Argo, is used to listen on a certain frequency. The "visual decode" is continuously posted on the internet as a picture.

Right now, I'm looking at the main center of worldwide activity, 10.140 MHz, 30M. When we finally get access to one of our LF bands, I'll probably move there.

My Grabber receiver can be "seen" at : http://www.qsl.net/w6iee/

Monday, January 4, 2016

Well, 2015 got away. ;)

But I am still tinkering, just really bad at documenting!

Here is a little Hartley oscillator I kludged together, and demonstrated it in the video:


Wednesday, December 31, 2014

QRP guitar amps!

Taking a break from radio tinkering to do some guitar tinkering. I'm going to build a tube guitar amp in the coming weeks, I mean it this time!!! ;)

Figures, after I haven't picked up a guitar in years, and just sold off a bunch of my stuff, I get the urge to play with it again.

While clearly in "toy" territory, the LM386 still earns some respect with ~ 1/4 Watt output! Thats's whats in both of these. The commercial unit on the right is a "Smokey Amp,"  (www.smokeyamps.com) as the first units were housed in empty cigarette boxes instead of the polycarbonate shell.

The one that I've slapped together utilizes a gain control (to back the gain off of max!) and a crude tone control, a switch that selects one of two electrolytic caps on the output. It's driving the big stereo speaker both are sitting on. Hey, it doesn't sound super, but it sounds impressive for one cheap chip powered off of a 9V battery!  Link the the circuit I built here, scroll down to "Smokey Tone Gain Amp."

Happy New Year!

Thursday, December 4, 2014

"Let's build something" receiver progress.

This is a construction project that will appear in the upcoming Winter QRP Quarterly, authored by N6QW and KK6FUT.

Progress in that it's been started, and that it looks like it might work... but it performs pretty unsatisfactorily so far. ;) Very little recovered audio.

At least I think I know why, my (semi-informed) hunch is that the bandpass filter I used, (this one) instead of the one Pete specified, likely has too much insertion loss. I have the instruments to prove this out, just haven't bothered yet.

This has got to be the problem, I've ruled just about everything else out!
At first I thought, could I have messed up in my construction of the mixer? I swapped the homebrew mixer module for another with an SBL-1, nope, exact same poor performance.

Then, I considered the possibility of insufficient LO drive. So I added a N3ZI-style buffer amplifier between the DDS and the mixer, as 250mV p/p going into the mixer straight from the DDS may have been a bit anaemic. Nope, didn't help either.

Also tried this RF amplifier  between the BPF and the mixer. This helped a little... when it didn't take off and oscillate, which wasn't very often.;) Now I know why there was supposed to be an attenuator in that amplifier circuit, need to go back and put that in!

Its definitely not the audio module, that thing is HOT!

I need to quit procrastinating and fire off an order to Mouser and obtain the proper IF cans to make the specified BPF. I also need to put the thing on a bigger breadboard, build a voltage regulator/power distribution module, clean up the Arduino/DDS section and switch to one of my new Pro-mini-328's instead of the big old clunky Diavolino.

I may yet work a deal with Santa in that Adafruit sends me a couple of those really nifty tiny OLED displays!

Thursday, November 27, 2014

Severe blog neglect!

I apologize for not updating my project antics since January! Life, and the day job simply occurred, free time was in short supply, and blogging is a low priority. ;)

This past August, I finally completed, er no... I finally got my 10 Ghz to 2M transverter into working shape, and successfully participated in the second weekend of the ARRL 10 Ghz and Up contest. Best DX were a trio of QSO's between the hilltop I was on above Sylmar, CA, to Mt. Potosi, near Las Vegas, a distance of 318.6 km! Done with about 300 mW @10 Ghz. ;)

So, its a work in progress, and I'll certainly have more detail when I dig back into it to improve it's performance. For now, a couple of pictures of the contest setup will have to suffice. The gray and black box under the FT-817 is the transverter.


Back in early May I made my first, and so far only (CW) QSO with a Rockmite. Worked AC7KL in Oregon on 20M with 400 mW... Over 2000 miles per watt, (!!!) have the QSL card and the certificate from QRPARCI to prove it!!!


What am I working on now?

Mainly fiddling with DDS modules as VFO's I'm presently working on building the direct-conversion receiver that is the first stage of Pete, N6QW, and Ben, KK6FUT's "Let's build something" series that will appear in QRP Quarterly in January. The first prototype can bee seen at Pete's YouTube page:  https://www.youtube.com/user/N6QW/videos

 I still have not worked anyone on 3579 kc's, but I'm hoping that Winter will bring a quieter band and better conditions!


Happy Thanksgiving, and have a "safe and sane" Black Friday!

I will be busy at work tomorrow, so no shopping for me. Earlier in the week I picked up a $39 7" Android tablet, for the sole purpose of seeing if I can find any state-sponsored malware inside of it. ;) I already have a really nice Nexus 7, so this one will be the "beater" I take to work.

Saturday, January 4, 2014

CBLA Technical Manual, beginning draft

ColorBurst Liberation Army
Field Operative Technical Manual

Chapter I:
Obtaining Materials for
Improvised Equipment
for the Suburban Operative.

Step 1: 
Once material source has been secured, gather the necessary tools. Standard Phillips screwdriver may be substituted for the drill motor for the non-homeowner. 

Warning: DO NOT plug in AC cord, or "Victory Against Ignorance" will occur!

Step 2:
Remove rear housing, saving screws, as they will be replaced.

Step 3:
Connect High Voltage discharging tool to chassis ground.
Step 4:
Discharge Anode.
Step 5:
Discharge power supply filter capacitor.
Step 6:
The internals are now safe for handling.
Cut ground wires and zip ties, and any other necessary non-connectorized interconnects.
Remove electron gun driver board, main board, and degaussing coil.
Remove speaker.
Remove deflection yoke it is not the bonded type.
Bonded yoke shown, do not attempt to remove unless CRT has already been shattered into 1000 pieces, and you enjoy handling jagged glass.
The following pieces should now be Liberated, shown from 12:00 clockwise: Degaussing coil, outboard transistor and heatsink,  Main Board/electron gun driver board, (this unit had integrated VCR.) and speaker at center.
Step 7:
Remove main board from components from plastic board carrier. Re-install board carrier back into main plastic housing. This will stabilize unit when reassembled, and give "Electronic Waste Management Specialists" a false sense of security that nothing is amiss with the unit, and therefore avoid arousing suspicion and unnecessary questioning.
Step 8:
Replace rear housing, using all available screws. Save for power cord and rear connectors, the unit will appear at first glance undisturbed.


Ideally, unit should be turned over to local municipality recycling apparatus. However, if you happen to have a QRP-L list troll/whiner in your neighbourhood,  these units make for an excellent petunia-bed flattener, property-value enhancer, or HOA-Stasi magnet/decoy.

Find a washer/dryer combo instead. 

Step 9, optional, but recommended:
Soap, rinse well, shake excess water, dry in sun. Do not wash speaker.

Step 10:
Identify primary objective:
Liberation complete:

To be continued...

***Thanks to K6FWT for the logo!