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April 13, 2010 - Baby, Updates and Year in Review

   Well, it's way over due that I announce Olivia's birth on unforgettability.net.  She was born March 9, 2010 and weighed 8 lbs.  The doctors thought she weighed closer to 9 so they attempted to induce labor before she got any bigger.  That didn't go so well and Aliesha ended up having a cesarean.  Nevertheless we have a healthy baby girl and Aliesha seems to be healing up well too.  Her second pediatric appointment was yesterday.  Initially she did have a bit of a feeding problem and lost some of her weight however we have taken care of that.  She has gained it back and caught up to where she should be.  We can already see her growing up a little. It happens so fast!
Olivia and Lady
   Olivia is pretty good about sleeping at night.  She sleeps from about midnight to 4AM when she gets up for a feeding then she sleeps again until around 8am.  The other day Aliesha nodded off while feeding her and she grabbed her own bottle and held it!  It is way early for her to do that and I wouldn't have thought she did it on purpose but she has done it twice since.  I think she will be doing things early.  Of course she can't crawl yet but she sure does try!  If I lay down and set her on my chest she will push with her legs, grab my shirt and pull forward with her arms and even makes herself move forward a bit.

   Of course the new baby keeps us busy however there should be new projects for me to write about soon.  Our renters on the other side of the duplex have moved out.  We have new ones who want to move in in August.  Meanwhile there are lots of repairs to be done including replacing the upstairs bathtub.  I'm sure I'll find something to write about there.  I also have a couple of new radio projects to talk about.  However, first what about the ones I already 'started'?  A year ago I wrote about a number of projects I was looking for parts for at Dayton.  I pretty much have the parts, actually I am just missing some zener diodes for one but I know they are just a quick bid on Ebay away.  So far the parts are organized in nice little plastic tubs just waiting for me to start soldering.  I only actually attempted to build the one and failed so what happened?

   The audio filter I attempted to build was from a schematic I copied by hand from a magazine when I was something like 12 or 13 years old.  I didn't even mark the polarity of the electrolytics.  I am going to set that one aside indefinitely until I am ready to fully understand the circuit myself and fix any errors in my copy.  As for the rest... I haven't forgotten it.  My main goal is still to build that SSB transmitter.  I have been reading a lot about construction technique and I've also been listening to the SolderSmoke podcast. I'm up to episode 82 right now.  Anyway, I wanted to jump right into SSB because that was what most interested me.  I am realizing however that there is a reason people don't usually start with that.  Like Olivia I need to crawl before I run.  Instead I've picked a new first transmitter, the Michigan Mighty Mite

   The Michigan Mighty Mite is an insanely simple device.  I probably could have assembled it in less than a day however since this will be my first homebrew ham transmitter I decided I wanted to put a little more effort into making it nice.  I expect that as soon as I am 'finished' with it I will move on to building something better after which I won't really use the MMM much so I want to look nice on a shelf as a conversation piece.  Actually, I have this big wrap around shelf in my office at work with nothing on it and I think it will go there.  This is after the second transmitter is completed of course, I do intend to make some contacts with it.  So far I have made the coil and started to varnish a piece of wood for the base.

   My plan is to mount a front plate to hold the 'variable capacitor' and key jack, a back plate for the antenna and power and the coil permanently to the board.  I ordered a small breadboard which I intend to temporarily stick to on with double sided sticky pads.  The reason for this is that after I build the original circuit I want to attempt to make a few changes.  I would like to add a buffer amp so I can key that instead of the main oscillator.  From what I have read and watched on YouTube the MMM isn't all that chirpy but the buffer will help ensure this.  Better yet, I want to split off the oscillator's output to send to a little direct conversion receiver.  I'm considering either the one Mike Caughran, KL7R (sk very sad) used in his Motley Special or the one Michael Rainey AA1TJ's Das DereLicht Receiver.  The other change I am considering is replacing the variable capacitor with either a rectifier diode or an LED used as a varicap.  I recently read Hans Summer's pages about this and I am excited to try it out.  I think this is probably a good solution for the hand capacitance issue I had with the BFO I wrote about previously and I will try it there too.  If it really works for me I like the idea of not running RF through any user handled controls.  Perhaps when I am done I will have a design which is truly my own that I can give a name to.

   Once I am done tinkering with the Mighty Mite or whatever it becomes I will pull the breadboard and rebuild the circuit in a more permanent form.  I am thinking I might build it ugly bug style on a piece of brass or copper with the same dimensions as the breadboard.  Then I can attach it where the breadboard was and have my showpiece, once I am done using it anyway.  I'm looking forward to actually making some contacts on a band lower than 10 meters.  I am building it for 80 meters using a colorburst crystal I took from an old TV so maybe you will find me there one day.

   The most difficult part of this project of course is that now I need to learn code.  I've been listening to Phil Kawa's Rythm of the Code either to or from work each day as well as practicing on lcwo.net.  Aliesha and I both recently upgraded our phones to Motorola Droids which run Android OS.  I'm sure I'll have lots to write about those coming up.  Anyway, I found an app, MorseRing for it which replaces my ring tone with the caller's name in Morse so I'm practicing that way too.  So far I am doing all right however I still expect to finish the transmitter before I am ready to make CW contacts.  I will probably add a relay so I can key it by computer as well as by straight key.  Then I can try it out as a QRSS beacon.  I'll have to get a different crystal though, I don't think other QRPers would appreciate me taking up the colorburst frequency in that way.  I know there are programs which would do CW QSOs for me but the Heathkit is still a bit too drifty and I have to keep re-clicking the waterfall a bit too often to track a signal.  I could probably do it with the receiver I intend to build but by that time I hope to be ready to do the code myself.

   Towards the other end of the ham spectrum I've been wanting some more antenna for VHF and UHF.  I built a really simple groundplane antenna for 2-meters that I found in the 1998 ARRL handbook.  It's just a UHF connector with 2 copper wire radials soldered to the ears and another soldered to the center conductor to be the radiator.  The ends are terminated in small loops.  I tied  a string to the loop in the radiator and hung it from a hook in the ceiling of my shack.  It isn't much, especially being indoors but it gives me something to play with.  I couldn't even reach the nearest APRS iGate with my ht's ducky in the shack.  It seemed like half a wet noodle would do that at the old house.  A group from TMRA has been meeting on the repeater before the Sunday net to discuss FM PSK31.  It will probably eventually evolve into a simplex FM PSK31 net.  I wanted to at least have something to try to get out with when this happens, besides dragging a laptop out to my Jeep that is.  My laptop's battery hasn't held a charge in years so between the laptop, inverter, soundcard interface and radio it gets to be a mess.

   I also got out the old quad band mobile which I ruined a couple years ago by driving it through a Taco Bell drive-through.  I thought if I removed the second coil and everything on up it might work for 2-meter and 70 cm.  I love my new, non-broken quad band antenna but I don't always need 10 and 6 meter.  I'd like to save the wear on the nice antenna plus lower the wind resistance to save gas.  The broken one does work for 70cm but not 2 meter.  I guess part of the broken coil must have provided some amount of loading for 2 meter.  I replaced the whip above the first coil with a straightened out coat hanger.  That should have been longer than necessary, I think.  I then proceeded to clip off just a bit at a time while checking the SWR.  Once I found the right length I was going to replace the coat hanger with a real whip.

  From this I managed to confirm one thing.  My meter for 2 meter - 70 cm is useless.  It is a cheap Workman model (don't buy one, ever) which has had lots of bad reviews.  Previously the forward needle had completely given out.  It came back after I took it apart and put it back together.  I suspected it was acting up again when I got most of the way through the coat hanger with very little variation in SWR.  Then it happened, the forward needle stopped again.  I took it apart.  Last time I noticed that all the solder joints were terrible looking.  Any one joint probably contained enough solder blob to have properly soldered the whole board!  This time I reworked all of the easy to reach solder joints.  That did not fix it.  This is when I noticed that someone had cranked down on one of the terminal screws for the meter and there was a hairline crack.  I will never buy Workman products again.

   I briefly attended the TMRA hamfest.  I felt a little bad for not staying and helping out since I have joined the club but this was only about a week after Olivia was born.  I was so tired... and was needed more at home anyway.  I looked at SWR meters but with a new baby, Aliesha off work, the renters moving out and having just bought an Oscilloscope I just wasn't willing to pay much.  A few meters had price tags which caught my eye but upon further inspection... Workman!  No Way!  It was then I decided I need to build my own.

   The next day I started looking online for SWR meter designs.  That's when I found Manfred Mornhinweg's Homo Ludens Homepage.  There he has a design for a Wideband SWR Meter which is basically a Wheatstone Bridge. The disadvantage is that with anything but really low power it will burn up.  Also you can't keep it inline as it eats the signal. This could actually be an advantage however because it means it works with low power levels, like what I expect from the Michigan Mighty Mite.  On top of that it should handle a very large frequency range. So far I have assembled the RF carrying portion of the circuit.  I used Shottky diodes equivalent to the ones he used in his copper pipe version.  I didn't assemble it in anything quite so tight as a piece of copper tube and don't expect it to work up to 1200Mhz like his did but I did put it in a pretty small box.  It was a box I picked up at the Monroe hamfest last year which had bnc connectors already on each end, one male one female.  I am hoping to get accuracy into the 900Mhz band but I will be happy with just getting to the upper part of 440 since I don't own any equipment for above that yet.

   I have a wire coming out to carry the DC, I will probably solder an inline headphone jack to that so I can use one meter assembly with multiple RF pickups.  I am going to put the meter and calibration resistor on a panel mounted inside a large hinged candy tin.  I will probably use just one meter with a switch.  The panel won't go all the way across, in the empty space I will have velcro for mounting the RF pickup box/boxes for storage.  I don't have a dual resistor with a linear tapper yet.  Also, all the meters I have measure milliamps, not microamps.  I am going to see if I can take one apart, if there is a shunt resistor I can replace to change the range.  Otherwise I will get a meter at Dayton.  I tested it with a multimeter and it does seem to work.  I get a much higher level from the forward side than the reverse when connected to a good load but pretty much equal levels when connected to no load.  I haven't actually done the math to check the exact SWR readings yet though. 

   Besides all of this, a while back I emailed SparkFun with a couple ideas of kits I thought they could develop and sell.  They tossed that right back to me and suggested I develop them and then they can sell them.  I have started working on one of them although I’m not 100% committed to finishing.  I’m not going to go into a lot of detail yet.  I do intend to make the design  freely available under an open source / creative commons type license if I complete it but only after it is done and ready to sell.  Currently I am stuck as I need to learn more about amplifier design.  If nothing else, this will be a good way to improve my knowledge of theory!

   I also have a friend who wants me to help him design and build a quiz bowl like game system for another mutual friend to use at kid’s magic shows and birthday parties.  He has a few requirements for locking out buzzers beyond just the basic  ‘who hit it first’ idea.  I suggested we just use an Arduino but when I used the words ‘like a small computer’ in describing it he was totally turned off at the idea.  He thought it would be less reliable and we would be getting support calls all the time.  I guess that’s what the word computer means to Windows users.  Yuck!   Instead we are building it using 7400 series TTL logic chips.  I should have insisted on the Arduino but I wanted to learn more about building with 7400 series chips anyway.  It has been educational but I hardly work on it because I would usually rather be doing a radio project.  One of these days we will get it finished and I will probably post all the details as a project here so long as everyone involved agrees.


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