Tuesday, January 20, 2015

I Can Feel it Deep Down, Waaaaaay Down.

Gonna be up late, I can feel it.
Writing features out for a rails webapp that will help me track my blood pressure.
I'm using a spreadsheet now.
It's taunting me. I bet my father-in-law would like something like this. Login, record some metrics, send to Dr.
Will be that simple.
It's 5 columns of data, a user, a date/time, 2 columns for the blood pressure, one for the heartrate.
It's coming together.
now to follow through.
I bet I don't sleep much.

Watch my twitter feed and this post for commits.

Tuesday, January 6, 2015

Ham Radio New Year's Resolution

I made one new years resolution about ham radio. My operating habits during December greatly influenced the wording

I, KG4GVL, do resolve to do my best to operate a minimum of twice a week, with the goal of averaging one QSO per day for 2015, or may the Wouff Hong find me as I sleep.

I've tried the whole "QSO once a day" thing, and that quickly became work. I managed to go somewhere around two months with a QSO every day, and many days it felt like I made the contact because of the commitment, not because I enjoyed the QSO. Time is a precious commodity in our house, and I don't have a lot of it to operate radio. In December, I managed to operate a handful of days, spending about an hour of time at a time (sometimes less), and had a blast running stations that were calling CQ. I even managed to call CQ a few times my own self and snagged a few new countries. Part of that I realize was propagation, but I've learned through the years that it don't matter how well propagation is if you don't get on the air. Plus, the maxim "RF gotta go somplace" is a reality. When you QRV, the signal goes somewhere, and the RBN network is a testament to how well some bands do under what would normally be considered marginal conditions. I really enjoy operating when I can get several QSOs at once.

Other people have made their resolutions too, one of the coolest is to build a project from your birth month/year issue of QST. I didn't see much in that would really work for me in the October 1977, but if anyone has an extra issue that they'd let me peruse, I wouldn't mind. :) I do have an October 1953 issue of QST that looks pretty interesting, and I think it has part of a 222 MHz project that would be pretty neat to construct, if I could find the parts to construct it.

Also doing some investigating into ham radio with microwaves. If the kids ever get their license, I think they'd get a kick out of building stuff they can use to bounce a signal off a satellite, or even the moon. The local library has a copy of The ARRL UHF/Microwave Experimenter's Manual and while some of the math inside seems complicated, the projects/ideas inside seem pretty straight forward.

Monday, January 5, 2015

Je Suis Toujours Tout Seul

When you are the father of four little girls, certain truths become rapidly apparent. Some things you just know, some things you have to learn. One thing that has revealed itself over time is that no matter what you do to prevent it, one of them will get the itch for pop music.
The two common reactions to this tragedy are:
1. Deny it is happening.
Denying your child likes pop music will alienate her, and disengage you from her life, this is unacceptable, and will drive you nuts eventually.

2. Embrace the crazy.
learn the words, learn the music, sing along, and find yourself doing Just Dance 2015 on the Wii. The trick to not totally falling off the deep end is finding some song that doesn't completely stink, and specialize in being the best at it. That will make you cool. For Just Dance 2013, I chose The Chemical Brothers "Hey Boy, Hey Girl". I could get 5 stars out of 5 on that one 4 out of 5 times. Just Dance 2015 I believe it will be Dead or Alive "You Spend Me Right Round". As a kid, one of my friends and I would sing this song in the line for water in the 2nd grade. First time I did the song on Just Dance, I got three stars. That's a sign folks.

The crazy I've embraced it.

There is one primary drawback however. Embracing the crazy means that sooner or later, you'll find yourself waking up, pouring a hot cup of coffee, feeling really optimistic, and whistling Katy Perry.
That's just not right.

Saturday, December 13, 2014

The Lightbulb Came On When the Lightbulb Came On

Sitting on the floor with a battery, jumper wires with alligator clips, a small light bulb, she traces the circuit in the picture on the book. She'd seen me put the circuit together and now she wanted to do it herself.

It all started with a well intentioned mistake. She cares about making sure her mom and I understand when she's cleaning something up. Getting cooperation in picking up her room, or putting away toys is as big a challenge as it can be for any five year old, but sooner or later things start to click, and it begins to come automatically. In this case, she was very proud of the fact that she was taking the batteries out of their packaging and putting them in a smaller box.

Because I don't want the house to catch fire from a shorted battery, I had to explain why putting batteries in a box like this was a bad idea. A couple of years ago, I got a kit from Radio Shack that introduces kids to electricity, circuits, etc. She knew about this kit, and got it out to ask me how a battery works. For the next hour she discovered how batteries work, how motors work, how a lightbulb comes on, and that some parts only work in a circuit one way, and she even did Morse code with a piezo buzzer.

That brought us to the moment when she could do it all by herself, help the electricity make a loop so the battery could do some work.

She just had to hook the alligator clip to the bulb and...

The electricity in the battery made a loop and the light came on.
She of course couldn't wait to show Momma.

Thursday, December 11, 2014

Finding Obsolete Parts: Furthering This Idea of a STHR

In a recent Post, I put forward the idea of a Strategic Thru-Hole Reserve of parts commonly found in kits made in the mid 90s to today. There's been some good feedback about this, so the next step is to discuss what comes next. I envision a website where people go to share what they have and what they need. Let's say I need a 2SC2166. I should be able to search for the part, select a person with the part, and contact that person to make some sort of arrangement to acquire the part.
Sound about right?

Wednesday, December 10, 2014

Operation Rock Garden Update

While I wait for #3 to bug me about her radio again, I'm working on my 10DE7 project.

Here's the skinny:
I took some parts that look like this:

and turned them into this:

and in the processed learned something about phasing.

Some project notes,
I did make the connection between taps 9 and 7 permanent, that is, soldered the wire in place. I made a short jumper with spades so I could experiment with places to put them on the taps. The first time, I soldered a jumper wire between pins 8 and 9, and didn't get the results I wanted. I thought for a minute that I had a bad transformer. I learned a couple of things in the process.

1. Autoranging digital VOMs can mess with your head. I kept getting jumpy measurements in the milivolt range, and it kept making me nervous. Verifying some readings with an analog meter really helped me settle down.
2. When dealing with AC transformers phasing matters. I should have realized from the schematic of the taps that the phasing a the bottom of one set of secondary taps would be out of phase with the top of the next set, but it took a little experimenting to figure that out.
3. When dealing with an unknown quantity, don't solder things down. I know better, but sometimes I don't do better.
4. Alligator clips for VOMs have their place.

I got to bed pretty late last night, so probably no shacktime tonight.

I have to think some more about plate voltages anyway.

Tuesday, December 9, 2014

Operation Rock Garden Phase One: Supplies!

I've decided to call my One Tube MOPA project "Operation Rock Garden." Because it is another project that involves a crystal controlled oscillator, I figured, why the heck not?

Phase one deals with power supplies. Not supply in this case, but supplies. There are three distinct voltages for this project, 2 different DC B+ voltages, and an AC filament voltage. Each one needs to be able to handle a certain amount of current as well. bBcause of this, I'll probably need a few solid state parts, like diodes and voltage regulators, for creating a rectifier circuit, or voltage doubler.

Step 1 of this phase is to light the filaments. To do this I need a circuit that can supply 9.7V at 600 milliamps. The easiest way to get there is to take the massive milsurp filament supply voltage I have, and series up the proper combination of taps to get as close to 9.7 as possible.

It came from a homebrew power supply for a Heathkit SB-102, and other than that, I don't know much about it, but I figure if I connect tap 8 to tap 9, and take my voltage from tap 7 and tap 11, I should have somewhere in the neighborhood of 9.45 Vrms, maybe a little more, because this primary is listed at 117 Vrms, and I'm around 120 consistently here.

Backside, showing taps.

I don't see this as an optimal solution, but it can handle the current, and the voltage should stay reasonably under the max. The supply has this lug sticking out of it.

The lug is behind taps 5 and 3. I think it's there so the core can be grounded, but I'm not sure the core needs to be grounded in the application I'm using it.

I will take advise in this matter.

Here's the plan for tonight when I get home from work:
1. Hook up the Transformer, ground (or not) the lug.
2. Construct tube base breadboard.
3. Go to bed. Light the sucker when I'm sure I have at least 9.4 Vrms, and after I've rested.

I'll be listening to 3579 KC while building, and the NoGA Twin Tube 80 will be standing by...

General concensus is that the lug can be grounded with no ill effects, and the filaments should be ok at that voltage.
We'll see if I can get 'er done tonight!