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The LARC Kit Builders Interest Group - updated 2018-09-12

Welcome to the web page for the group of LARC members who like to build electronic kits. This group is led by Dave McCarter VE3GSO who teaches our Advanced course, and who has taught electronics at Fanshawe for many years. If you're a kit builder, or would like to become one, come out and see what we're doing.

Kit Builder Meetings - NEW: Solder Parties on Wednesdays

“HOT” NEWS: We're starting to have Wednesday night meetings where people bring in the kit they're working on, and their soldering iron and associated paraphernalia, and actually build kits. Various kinds of assistance will be available: technical consulting, test tools, moral support, and first aid for solder burns. If you're working on something, come on out to our Solder Parties!

Our get togethers are at the 427 Wing near the airport where our club station is, and are very informal. They run from 10:00 to 12:00 on Saturday mornings, and many of us attend the traditional “Hams & Eggs” breakfast before heading to the Wing. Participants are welcome to work on whatever kit they are interested in, and will find there are always people around to assist, help troubleshoot, make suggestions, test, and listen to your bragging when something actually works. We also have some test equipment available.

If you'd like to join this merry band of kit bashers, and get on our mailing list, contact Dave McCarter VE3GSO or Doug Elliott VA3DAE.

WARNING: Working on kits can result in solder burns, diminished eyesight, mental anguish when things don't work, and facial paralysis in a permanent grin when they do.

The inaugural meeting was on January 13, 2018, and more information on this and other meetings is available in the Meeting History section of this page.

Kit Builder Resources

One of the key roles of this web page is to share information that's useful to kit builders. Over time, we'll accumulate details here such as:

The Weekly Parts Shopping List

Here's the latest shopping list. (File may get fetched silently. Check your downloads.)

Electronic and Electrical Supply on Nightingale in London is a well stocked local source for most electronic parts. Doug is there at least twice a week, and can pick up parts that people need, to be delivered at the next Kit Builders meeting.

No need to pay in advance - we can take care of that at the meeting when there's an invoice with the prices to help me sort things out. I'm not looking to make any money on this, and in fact I'll probably take a loss rather than have to figure out what the tax was. Come to think of it, I reserve the right to guess at the tax and round your order total up to the next dollar to make giving change easier.

If you don't give me complete specifications for the part, I'll make a guess. If I have an equivalent item in my personal inventory that I'm willing to “part” with, I'll email you to see if you would prefer a new part, or my free one. If you're keen on getting a part quickly, but you're not going to the store yourself, I can grab it on Monday, and you can pick it up at my place Monday night, or later. I am definitely NOT going to get into delivering parts to anywhere other than our weekly meeting.

It dawns on me that someone might have a question about what is available at the store, so I'll accept part descriptions for queries as well as purchase. I'll let you know what is in stock that matches your query, and what the price is.

I'll post the shopping list for each week at the beginning of this section of the website. I have a list in progress, and I'll update it if there are more requests. If you want stuff added for you, send me an email.Hope this is helpful…

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Sources for general electronic parts

An online supplier listing for Canadians: http://www.island.net/~kdbrown/WhereToBuy-Canada.php

Top 10 USA Electronics Suppliers: https://www.instructables.com/community/10-Best-Electronics-Suppliers/

LocationStore TypeNameWebsitedeliveryknown OKComments
LondonBrick & MortarElectrical & Electronic Supply Inchttp://elelsu.com/you pick upyup501 Nightengale Ave near McCormacks
LondonBrick & MortarHardcore Electronic Supplyhttp://www.hardcore.supply/you pick upyup. new15 - 63 Clarke Road, London, ON N5W 5Y2
LondonHamDoug Elliott willing to share personal parts inventory with local hams
LondonHamDave McCarter willing to share personal parts inventory with local hams
LondonHamMitch Powell willing to share personal parts inventory with local hams
CanadaWebDigi-Keyhttps://www.digikey.ca/daysyuphuge. name comes from ham radio keyer
BC CanadawebActive Techhttps://www.active123.com/
USAwebJamecohttps://www.jameco.com
USAwebMouserhttps://ca.mouser.com/
CanadaBrick & MortarSAYALhttps://secure.sayal.com/zinc/index.asp yupTO, Markham, Barrie, Vaughan, Mississauga, Burlington, Cambridge
BC Canadawebrp electronicshttps://www.rpelectronics.com/
USAwebBG Microhttp://www.bgmicro.com/
USAwebSparkFunhttps://www.sparkfun.com/
USAwebNewark - Element 14http://canada.newark.com/ yup

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Sources for tools and test gear

( to be added - contributions welcome )

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Websites with tutorials, training modules, educational information

TopicInfo
SolderingIf you are new to soldering, there are resources on the web to help you get on the right track, soldering like a pro…
www.aaroncake.net/electronics/solder.htm (Don't worry about the steel wool stuff)
http://www.kpsec.freeuk.com/solder.htm

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Websites with reference information

( to be added - contributions welcome )

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Bragging from participants about current activity

Bragging is done on a separate web page, located at the brag board . To provide information (in any format that is convenient) about your projects, send an email to instructor@larc.ca

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Requested Assistance

You've probably had that sinking feeling when you go to put a chip into a socket, and inadvertently break off a pin, and there isn't a spare part in sight. Maybe you could add a nifty function to your project if you only had a particular part. Have you come to the point where you're ready to admit you have no idea how to do something that needs to be done to complete your project?

All of these situations are solvable by putting the word out to your fellow kit builders (or others who look at this web page) to find someone who can help you out. Several of us have inventories of electronic components that we are willing to share. Probably all of us have junk boxes with a random sampling of retired gear that still has usable components. There may even be some abandoned projects that can act as donors for those in need.

It doesn't hurt, or cost, to ask, so if you're looking for assistance, let me know. Send an email to instructor@larc.ca , and I'll get your request onto the following list.

PS: If what you need is described in the next section, “Volunteered Assistance,” just mention what you're looking for in a meeting, and someone is likely to be able to help you right away.

RequestorDateStatusDescription of the Request
Doug ElliottFeb 17openanyone take notes in Jan 27 meeting?

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Volunteered Assistance

One of the great things about groups like the kit bashers is that members can assist each other in various ways. When you're stuck on your project, having someone who can get you over the hurdle and on your way can make all the difference. Hams seem to have a natural tendency towards helping each other out, Elmering, and sharing. Following is a list of tools, techniques, skills, components, and experience that members have volunteered. How do you request some of this assistance? You show up at a meeting and ask. Please remember that this is all voluntary, and no one has a committment to work on your project for you or provide unlimited goods or services for free.

Volunteered assistance
Provision of small numbers of selected electronic components
Assistance with microprocessor work: Arduino, Raspberry Pi, PIC, etc
Troubleshooting a perplexing project problem
Use of specialized test gear like antenna analyser, etc
Use of Greenlee punches to make rectangular holes in enclosures
Use of a metal nibbler to make rectangular holes in enclosures

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Meeting History

Notes from our meetings at the Wing, in reverse chronological order, so the most recent meetings are described first.

Sept 12, 2018 - Solder Party

First Solder Party was a complete success, although there was as much yakking going on as there was building. In attendance were Dave McCarter, Phil Harris, Gord Baker, Shirley McCall-Nicholson, Al McCrorie, Tom Pillon, Doug Elliott, Ted Haynes, Dale Rex, and Mike from St. Thomas. 3 tables set up, and averyone enjoyed playing musical tools. Doug showed of the web page for the $50 LCD microscope that's in shipment (great for us geezers with fading eyesight). No serious injuries were reported, although there was a suspicious pool of what looked like blood on one of the tables. So much fun we're going to do it again next week.

Sept 1, 2018

-Ken and Karen from QRPguys were at our meeting, and showed off a tiny bail they've come up with, along with a bag full of new and interesting kits

-149 years ago today, the Carrington event occurred, a large Solar Coronal Mass Ejection (CME) that caused one of the largeest geomagnetic storms on record, sep 1-2, 1859

-tntalum capacitors that fail are usually shorted

-Dave's feedback on the Lydia radio has been submitted to the original designer

- youkits.com is coming out with a 1 tube receiver

-We're going to start up Wednesday evening get togethers at the Wing where we bring our soldering irons and tool, and actually build the kits we're currently working on. Doug will probably do the ARES net in the middle of the “solder party”

-if you're using a hot air gun, make sure the air filters are porous enough to let enough air through. Bad manufacturing, or clogged filters can cause lots of problems. These are good for heating SMT's mounted on solder paste if you use LOW heat.

MIke Toth, VE3TIT visited us. He's the son of Dr. Dave Toth VE3GYQ, a pillar of the ham radio community, now a silent key

-the name for the TTT repeater came from GYQ's work on the first phone patch in London. TTT = Touch Tone Toth

-GYQ was a keen astronomer, and had an asteroid named after him. He was always helping people and making friends. One activity was building a tower for a rural mesh internet connection.

-McCarter has stories about tricks they pulled on GYQ, adding Saran wrap, and paper place constrictor plates to his high end expensive telescope, and an internal condom.

-GYQ had a very full life. He was a busy doctor (occasionally sewing orange peels back together for practice, and had received commendations from NASA.

-Mike seems to have inherited some of his dads traits, and built and installed his own Yagi for internet access at the family hobby farm near Embro when the ExploreNet installer said it couldn't be done.
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July 21, 2018

-GSO: TCA magazine has a good article from the author from Whitehorse. Yukon has a great government provided VHF repeater network

-GSO looked at QCX and SoftROC

-Lydia is a slightly augmented Neophyte. Preamp is pointless, & antenna filter has a big impedance mismatch

-QCX is slightly more expensive, but much better. Uses a digital mixer, & digitally synthesized oscillator VFO.

-(high pass filters on antennas)

-Phil has his QCX almost built, and is impressed with the built-in test tools

-it would be nice to come up with a morse code generator for Stan and Susan

-GSO bought a reel of RG58 at Milton - available for .20 / foot

-Barry's 991 won't tune. GSO may lend a have with troubleshooting

-discussion of tuning methods for manual tuners

-saw large hevy duty mechanical tuner from MIlton with doubled up capacitor plates

-Doug's ordered QRPguys.com Antenna Analyser boards (3 @ $10). You get your own parts from their list “$50-60 US$

-followup email from Dave McCarter:

Today a few of us met at the wing to discuss kits to build.
Doug has ordered three boards from QRPguys.com for the antenna analyzer, and will now be doing parts sourcing.
Phil is still in need of a 1590XX enclosure for his kit.
I received the Frequency Reference Kit, a Regenerative Receiver Kit, and a Digital Dial/Counter Kit from QRPguys.

I reviewed my discussion about the Lidia Receiver, and then discussed Alan Worton's article in this month's TCA about the QRPLabs 5W kit
called the QCX. Phil and Tom already have this kit and their build is well along.

After reading about the type of RF mixer, opposite sideband suppression, and local oscillator generation, (a CPU controlled Direct
Digital Synthesiser which is very precise and stable) I'm convinced this is the biggest bang for the buck kit available. The kit is sold
for $49 USD, about $75 CDN. The Lidia receiver only was going to be in the $50 range, so there is a lot of functionallity, including full
QSK CW transmitter, for the extra money.

Phil is building his for 30m, and I don't recall which band Tom is building for. I am going to also go for 30m, as that is a great QRP CW band.

I wonder how many of you would like to join us on this journey. Do let me know as quickly as possible.

Also, after all this, if you do want to continue with a Lidia Receiver, please do let me know, and for which band.
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July 7, 2018

-Heads Up: Milton Flea Market is Sat July 14. GSO will be there on the lookout for various bits and pieces

-GSO's looking at using crimped PL259's rather than soldering. Military uses this quite a lot, but the crimping tool is quite expensive.

-last week, Ken the QRPguys principle was here. contributions are invited for a bulk order.

-QST reviewed the Lydia 40M receiver - good review

-Barry's Nixie tube clock has black marking on PCB

-flux on a PCB compromises insulation
-best to us isopropyl alcohol, and scrub with toothbrush, multiple times
-good flux removers: isopropyl and ethyl alcohol

-Phil is awaiting boxes for his receiver kits

-ribbon cable suggested as source of easily connected jumpers, with either male or female connectors

-Richard's working on a receiver kit

-magnets dropped onto a copper plate decelerate as current / magnetic field is induced

-Barry's antenna challenges:
-991 wouldn't tune, but 890 would
-991 worked well at field day
-antenna at home has wrong length pipe
- 7/8 * 3 feet scrounged from GSO
- found loose BNC connector
- antenna meter giving strange results

-Richard has an antenna analyser that shows 4 bands at once

-loop antennas need tuning for multi-band use, but are still more forgiving than dipoles

-Richard's crank IR has touchy tuning, and radial length is critical. To tune, adjust radial length. Has a 14 inch difference in radial lengths, front yard to back

-VOA (Voice of America) museum nean Cincinati is worth a visit

-better to spot weld batteries when making packs, that solder. You can easily build a suitable spot welder
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May 26, 2018

-balloon tracker (Byonix) analysis
-payload needs to breathe
-board wasn't conformally coated - vulnerble to moisture
-bees wax as a connector sealer
-one way valve (like on coffee packages) to release pressure

-future projects
-mobile helical antennas for 144.39

-Dave: work on packet capture, software
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April 28, 2018

-Phil: QCX CW Xcvr in progress. sockets and some components in place. Awesome manual prointed

-Doug's huge Power supply boards: need extreme heat sinking. Have opto isolaters = (LED + photosensor)

-ACW;s flat board: through the board transformer, hot/cold side, keep diodes and caps

-project kits: 1/16, 1/8 W transistors, position to read code
-.1uF - 2*C25 C25 above Amp → C28 (electrolytic)
-D1 is a safety diode
-winding toroids, binocular xformer, #34 red wire, 2 lengths
-wrap clockwise to match pads on PCB
-once through center = 1 turn
-want wire tight to toroid
-avoid kinks and loops
-binocular: fold wire in half, one for each hole
- 8 * #34 (red) , 2 * #30

-using aspirin to remove coating from wire
-lots of light, magnification. easier to read resistors in bright light
-finding enamled wire in different colours is nice
-wire wrap wire is good too - use exacto knife to strip

-GSO: GreenLee punches (will do 16 and 16 gauge steel) available
-Doug has a metal nibbler

-AL: 49:1 balum for end fed wire
-trick for counting turns: take a cell phone photo, and blow it up

-dead bug construction: PCB = ground, components glued to it. label pins carefully

-manhatten construction: punch small holes out of PCB, glue down pads. 3/16 inch = 5 mm

-point to point using terminal strips, “solder tags”

-wire wrap pins

-perf board - grid of holes. push a (split) pin thru, solder after

-vero board. prebuilt grid of holes, connected by cuttable stribs on either side

-proto boards. uncommitted general patterns of pads, islands and buses, OR completely uncomitted pads

-DIY PCB's - design circuit, photocopy to toner on paper, iron onto board, wash in water, fix holes with Sharpie, etch with chemicals, drill, populate

-outsourced PCB production. may have minimum, maximum board size. delivery in day$ if you want. can do double sided, plated through holes. Do research to see what's currently available - constantly improving

-Ferric Chloride acid is available at Electronic Supply on Nightengale.

-WARNING: Amonium Perchlorate is very volatile.

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April 21, 2018

-Al's just beginning to assemble 40M Universal receiver kit from Chuck Adams K7QO, from KitsandParts.com

-Toms 409shop discoveries: HF frequency counter for $10, Aliexpress: “49er” HF 40M CW XCVR $10

-GSO: projects: replace battery in baby monitor with switching regulator

-recommended: video series: Mr Carlson's lab, the Guy with the Swiss Accent, AVE on youtube

-discussion on soldering: 67/33 solder (“ectectic= same melting and freezing point). Apply solder with a hot gun, and do it fast

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April 14, 2018

-Barry's grain of wheat lights - tiny

-UPS approaches: London Life had incoming power run a motor that powered a large flywheel. The flywheel drove a generator that provided power for the mainframe and it's peripherals. If power flickered, flywheel smoothed it out, and saved a mainframe outage. When Great West Life took over, they decided it was more economical to get rid of the flywheel UPS, and just tolerate the MF outages

-Barry's NIXIE tube display works!

-Al's visit to 1st robotics competition at UWO: robots challenged to lift and place a box. Al's ephew's daughter is on the South team

-GSO: a “Megger” is a high voltage generator. Used for testing motors, cables, etc for leaks (shorts) at high voltage. Also known as a hi-pot (high potential) test. Video of a hi-pot test room: metal cage, huge capacitors, interlocked access, 150 K V test, remote discharge. GSO can test to 15 K Volts

-Tom's frequency counter kit from 409 shop. 1 Hz - 50 mHz. p/n 0014-0111, $12

-GSO: TNC with 4 chips - fits raspbery Pi, stackable. Coastal Chips, Newark

-GSO: SMT techniques: avoiding tombstoning where one end of SMT part is much higher that the other. Apply solder blob, then use soldder wick for miracle cleanup.

-desoldering gun simultaneously heats and extracts components from a PCB

-using heat sinks to avoid heating LEDS (or other stuff) while soldering

-Barry's challenges getting LEDs to aim into display. Use green SMD LEDs?

-GSO: do we want to have a student fixit class? TV with bulged capacitors: instant fix is replace the caps

-85 degree caps are bad - always use 105 degree caps

-China as a source of Anderson Powerpole connectors

-Potential fixes for unhappy Astron PS: solder joints, 85 degree caps, crimped wire connections are loose


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April 7, 2018

-discussion on replacing bulbs with LEDs. Hot glue as an easy mounting technique (doesn't work on horses). SMT LEDS are tiny and can be a form of self abuse. E=I*R to figure out resistance to use

-Robot contest @ UWO, in Thompson Arena. www.firstroboticscanada.org/event/

-Robot Olympics suggestion

-Using banks of Red LEDs to conserve night vision for Field Day, Astronomy…

-new guys working on their licenses:

Philip Jones (dad), pjones8@uwo.ca, (now VA3PGJ )
Tristan Jones (son) tgbj@icloud.com, (now VA3TGJ )
They're writing their exams today

-Barry has 2 microwave transformers, good for isolation transformers. 700V, 1 Amp. Potential to build an amplifier. 2 secondaries, filament in magnetron. 120 V inputs need to have opposite phase, outputs in parallel, push-pull style

-salvage magnets from magnetrons

-microwave ovens make good fume hoods.

-Al's taking order for single band receivers

-Sams looking for a bridge rectifier

-Barry's old speaker with electromagnet instead of permanent magnet. 2 coils, ripple cancel.

-CHIRP does geo-location to get local repeaters


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March 24, 2018

-Harry showed off his BitX 40m transceiver that came from HFsignals.com in India. XCVR kit @ $75 US$, plus red enclosure @ $35 US$.

-Dave was recommending a micro XLR connector (think he called it mini one time too, I may have that wrong) for connecting the microphone, with a switch to disable phantom power when a dynamic mic is being used.
-Harry commented that the volume control was pretty touchy, and DAve recommended a 10 turn 10K pot to improve the control
-this pot has a spiral resistive element, with contact that travels slowly as shaft is turned

Barry's collection of old digital multimeters
-one with a dead short
-one with old D cells, which have leaked
-can clean old boards with 50% isopropyl alchol, 50% distilled water, and maybe a drop of soap. use an old toothbrush

Barry's also working on an MFJ CW Keyer / Reader

Dave: If you want a good worksurface, get a big white cutting board. Easy to see parts, saves your table top

Tom's Tuner
-wafer switch from Bill McHugh
-what kind of wire between wafer switch and taps on coil?
-rule of thump is use same diameter wire as is in the coil - it gets same current
-in this case, “hookup” or “bus” wire, about 18 AWG, solid or stranded
-needs 12 conductors - Doug may have some applicable cable from salvage job
-discussions on tuner design

Antenna “Aperture” - amount of space occupied, or circumscribed. bigger is better

Code Practice Oscillator
-Dave's schematic is on this website now. default resister values are in Ohms, and Caps are microFarads

Circulator circuit
-shunts returned power to a dummy load in a clever way that Doug didn't understand
-comment that S9 is equivalent to 50 microvolts - pretty small to see with common tools

N connectors have a lot of merit
-constant impedance
-“Norman” after war, using UHF having 22 Ohm resistance
-built water tight
-QRP use a different one, a bit like a 9V battery contact

Using thermal heat transfer compound to improve cooling of a resistor

Discussion of meaning of BNC:
-Dave: Bayonet Norman Connector
-Doug: Bayonet Neill Concelman (who invented it). Neill also invented D connector, Concelman invented C connector

Doug's robot is actually balancing, for minutes at a time
-works a lot better on carpet than on concrete floor in the nerdpit
-work has started on next generation: cad/cam schematic, auto layout, PCB build either on CNC machine or outsourced

Discussion of salvaging gold from surplus electronics
-using mercury and cyanide is very dangerous
-hydrochloric acid & hydrogen peroxide to disolve other metals
-nitric acid and hydrochloric acid disolves the gold
-there's also a way to process iron
-sodium…(borax) to get gold
-fine gold wires are used to connect dies to their leads
-10 pentiums ahve about $400 worth of gold in them

Dave's adventures melting lead from lead pipes taken out of houses to make scuba weights

March 17

Doug was ill, and didn't attend. If anyone has any notes, or recollections of topics discussed, I'd be glad to record them here for posteriors - back references.

In the meantime, here's a document Dave GSO has supplied:

A nicely designed code practice oscillator, (updated version as of March 26) like the kit that Phil ordered. If you're thinking of building one, talk to Dave and Doug who can supply some of the parts you'll need.
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March 10, 2018

-Al's large coil - sizable inductance with 210+ tight turns (GSO coulted them by hand), but would also make a nifty mug. Calculated at 1900 microH. There's gott be a cool project that can use this baby.

-Tom points out the aliexpress.com is a good supplier: allows small quantities, free shipping, great prices, great kits, good selection of tools, but slow delivery - multiple weeks

-in the St. Thomas club meeting, they mentioned a kit called a “pocket pal”, which measures resistance, outputs standard currents, and will oscillate a chrystal

-someone mentioned a “volt Tattler” kit from QRPKits. Catches hard to see signal voltage pulses and gives a sound alarm. $25

-for Barry's challenges getting high voltage sources for his Nixie tube supply:
. -antique radio “B” battery, for tube plates
. -“A” battery for filaments
. -Dav sketched a circuit that would create higher voltages, using zener diodes where voltages add up

-Doug was looking for characteristics of various kinds of caps, and Dave explained:
. -mylar, mica, NPO cerfamin are very stable
. -electrolytics only come in big values
. -for audio, polycarbonate are best, mylar are bad, ceramic bad due to piezoelectric effect
. -metal film resistors are “quiet”, carbon composition add some hiss

-Barry's old Fluke multimeter stopped working suddenly
. -early bets were on a cold solder joint
. -on exmination, a blown cap ws located - large cap with visible leakage

-Schottky diodes react very quickly

-TCA has an article on Pixie kit

-Phil's keyer from GSO - beautifully refurbished

-Doug's power controller link, suggested by Sam from his PS rebuild project:
https://rdtech.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html

-DAve WHite is a new ham who is a truck driver. He sleeps in his sleeper cab overnight on some trips, and needs to power a bunch of devices overnight: small fridge, CPAP machine, fan, bunk heater. He can't run the truck overnight in residential neighbourhoods, and is wondering if we could help him come up with an approach using a battery pack of some sort. Doug & Sam are taking up the challenge, and have done all sorts of research. Some details on this web page: http://nerdpit.ca/doku.php Made some incorrect assumptions based on device specifications, and need to make actual measurements of power consumption. Looks like a relatively small lithium battery may be sufficient, along with some small load on the truck's battery.

-there's a nifty WiFi analyser app available

-Phil's had great success getting shipments of stuff from Newark quickly. Doug should make sure their website is on the suppliers list.

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March 3, 2018

(Doug arrived late, so didn't get notes for entire meeting)

-Barry's Nixie tube driver is giving him problems:
. -tiny surface mount parts need a stereo microscope to be able to troubleshoot
. -some voltages are really off

-Doug: syringes to apply liquid flux are hard to find
. -3 drug stores either didn't have them, or wouldn't sell them (hard to tell)
. -they suggested a hime improvement store like Home Depot - weird response?

-LARC website out-of-date kit builders link has been brought to the attention of the web masters (Tm & Jim)

-not bad idea to get the email address: <callsign> @ gmail.com , and forward mail to your main email account

-battery sources for robots or ham gizmos: model aircraft and cars, lithium batteries from portable tools, etc

-Doug's demo & discussion on the stepper motor based robot he's working on:
. -reducing subassemblies to one motherboard (MB) with a lot of cables hanging off it
. -MB is based on proto board with a fairly useful pattern laid on one side with copper etch
. -a lot of soldered jumper wires and testing
. -next version with be cad/cam schematic > board layout > CNC board creation
. -my buddy's getting a very expensive CNC machine for other purposes. We might farm out initial board production.

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Feb 24, 2018

-Sam: rebuilding Astron power supply, using nifty programmable control panel

-Phil's code oscillator
. -twin T oscillator R C R C R phase shift network
. -oscillator runs continuously, no chirp
. -adjustable pitch and volume
. -capacitor smoothes tone on and off to avoid harsh splatter
. -from Morse Code Express MX-TCPO

-Barry: CW key progressing
. -brass bolts as contacts
. -considering magnets to force centering

-Dave GSO distributed shim stock stainless steel pieces for desoldering SMT parts as described last week

-SMT soldering:
. -flux
. -blob of solder over everything
. -use solderbraid to remove most of blob.
. -solder pste has a short shelf life - 1 month
. -store in ethyl alcohol

-isopropyl alcohol good for removing flux

-liquid flux application
. -large bore syringe, AKA blunt
. -Q tip
. -fine brushes from Lee Valley

-Tom's tuner
. -recycled meter
. -large parallel air caps

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Feb 17, 2018

-Tom's tapping a large coil for his tuner. Needed threaded studs to mate with threaded nuts embedded in the porcelain coil form.
Facca fasteners ( www.faccafasteners.com), or Laurie's ( www.lauriesfasteners.com) are good sources for things like threaded studs

-Barry's project with large pixie tubes with 11 leads. Trick is to trim leads in a spiral so you can insert them into the socket one at a time
-he's also working with a control/base board with surface mount (SMT) parts. We shared our condolences.

-Tip on removing multi pin SMT parts: use a piece of stainless 2 thou shim stock, which solder won't stick to. Heat the pins one at a time, and slip the shim stock between the part and the board, pushing it ahead for each pin.

-Doug passed around the mother board for his robot project. It now has all sockets and headers, and wiring is barely started.
-Dave examined soldering & said there are only a couple of bad joints (so far)
-key to good joints is keeping your iron clean and shiny tinned, heating both parts, and putting the solder on the parts, not the iron
-when you're wiping the iron tip on sponge or brass wool, twirl it for even cleaning action.
-teflon coated wire wrap wire recommended for jumper work, since the insulation doesn't melt when they're soldered

-Phil Harris is working on a code oscillator kit, for CW practice purposes

-Bill McHugh has offerred access to his bucket of knobs to the kit builders. Bill is generally regarded as an expert in electronic stuff

-Yaesu has announced a replacement for the QRP 817 that runs on batteries
-popular for summit work
-a pair of 817's is good for satellite work

-had a discussion on working satellites & related procedures & antennas
-satellite operations would make a good LARC presentation
-it would be great if we could work an ISS QSO into LARC 2020 - might have to rent some students

-Dave reports 3 London teachers want ham licenses to be able to use APRS for balloon tracking
-want classes/club to build uprocessor based boards as payload

-Harry has received his BitX transceiver, but not all of the related bits yet.

-Doug's note to self: add a section to this page titled “Bits and Pieces We're Looking For”
-if you need something, email instructor@larc.ca and I'll put your request where people can see it.
-includes components (chips, resistors, diodes, etc, project boxes, cables, connectors…)

-Dave would like us to actually do construction in these meetings, so bring your iron, your parts bag
and your instructions to the next meeting. Might want to bring first aid kit, too.

-to recondition old electrolytic capacitors, give them some current overnight. Put a 10 KOhm resistor in series with the cap and let some juice flow through it. This rebuilds the cap in mysterious ways that I don't understand. If you hear occasional clicking sounds, it means the cap is recharging up to the point where a fault in the dielectric insulation is allowing the current to arc over. The way you address this is by throwing the cap in the garbage.

-the session ended up with Dave doing a demo on how to use an oscilloscope over by the club station. Unfortunately, the scope and it's leads aren't fully functional, but we did see evidence of the FT-8 transmissions happening 5 feet away, and other stuff. We might do some more scope stuff next week.

Post Meeting Notes

-The wiki-whacker apologizes for the delay in updating this page, and promises to do better ion the future.
-we're now up-to-date, as far as I know.

-I've added a section for requests (“Requested Assistance”) to see if anyone can help with a part that is needed
-includes components (chips, resistors, diodes, etc, project boxes, cables, connectors…)
-could include access to test tools, design assistance, etc
-doesn't hurt to ask - worst thing that can happen is that on one responds
-forward your request to instructor@larc.ca and I'll get it listed

-I might add sub-pages for each member of the group in the “Bragging” section.
-it's a place for you to describe your current project.
-description can range from a single sentence to a full document with diagrams, photos, etc.
-don't worry about formatting the info. get it to me any way you can, and I'll include it.

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Feb 10, 2018

- Barry VE3DVV is working on a power supply project

- Terry showed off a few projects:

  • -Direct conversion LM386 NE602

Chinese built, can be a beacon. micorprocessor based, programmable

  • Rockmite II from QRPme: built in keyer, tone at 700 Hz, crystals
  • Pixie Forty-9er

-VHF 1 Watt transceiver: SV1AFN.COM

-QLG1 QRP-labs.com. Digital Xcvr. has GPS, can do WSPR with accurate clock. built in CW decoder

-QRPme.com is great for low cost parts

-Doug's garage door won't close if it's below freezing - safety beam falsely believed to be blocked
-eventually fixed it by replacing a 470 uF capacitor inside the infrared detector

-Should Doug replace capacitors with tantalums? No. GSO's story of shorting / healing tantalum faults, and
using a tattle tale - a JK flip flop - to trap a transient pulse.

-scope discussion - PC-based vs dedicated. no concensus that one way is better, but dedicated are getting cheaper

-basic tools for a kit builder include some sort of scope and a signal generator

-maybe a VTVM - vacuum tube volt meter. Hi impedance probes. good wish list item
that makes rapid changes visible

-Barry showed his ganged 4 part tunable capacitor from an AM/ FM radio

-GSO spun a story of a missed bargain on blowers at Forest City because they were monitoring his VHF bragging

-QEX (as in EXperimenters) magazine recommended for great in depth articles. Available only in dead tree edition

-There's a Brittish magazine line QEX as well, from RSGB (Radio Society of Great Brittain)

-there's a German TV board that takes HTMI in, and puts RF out

-UBNT.CA ( https://ubnt.ca/ ) is an outfit West of Owen Sound that is a wireless equipment distributor. They have gear suitable for Ham mesh networks, and well as lots of other stuff
-3.3 GHz as a clean frequency suitable for the spine of a mesh network
-mesh as an emergency support facility
-2.4 and 5.8 GHz can interface to spine, but are relatively busy and noisy
-mesh support for MS Tour?
-not expensive
-mobile ops doable
-for Trillium grant, need to sell application, not technology
. - need a strong plan and an early demo
. - ARES as driver of Trillium application
. - Terry has experience with location mapping

-Farhi as a resource we might be able to use?

-meeting regressed into story telling about CW practice

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Feb 3, 2018

-Terry has experience with BitX kits (or maybe he knows Kevin who has the experience?)

-Dave's DIY portable QRP tuner is beautifully documented in this PDF file (which might download stealthily. Check your downloads for QRPTuner.pdf).

-Tom's tuner
-frequency independence
-there's a well known design called the “St Louis Tuner”
-might not need all the capacitance

-Barry has received a CW Key kit from QRPguys

-discussions about:
-Beverage antennas
-Doug's robot (see bragging section of this web page for more details)
-switching power supplies
-Harry's Bit40 transceiver

-building kits to loan for new hams, vs. helping them find used rigs
-think the consensus was that used rigs are a better route for HF - kits are mostly QRP
-need to get new hams (like Dave Devries, who was present, and a graduate of last course)…
-an Elmer. Doug's action: assign Elmers to all students in course on the first day.
-offload course student monitoring to elmers, and post course follow up ?
-shack tours, to immerse them in reality
-involvement with club station - ready to go and generally surrounded by Elmers
-help getting used gear, and guidance at Hamfests.

-Dave needs an Elmer, and so does Ian, VA3WOT, who joined us for first time today

-should we have a LARC blog to keep students involved and up-to-date?
-challenge is always sustaining it over time with continuing fresh content
-our Facebook page does this sort of thing, but some of us avoid Facebook

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Jan 27, 2018 (Winter Field Day)

Doug was outside, freezing his butt off getting ready for Winter Field Day, and missed the Kit Builders meeting, if there was one. If you have any notes on what was discussed, please pass them along and I'll add them in here.

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Jan 20, 2018

-Al described his Neophyte receiver:
-40 M,, direct conversion, from Feb 88 QST article (some copies are blurry, but Dave has the original article)
-Dave McCarter has provided documentation of a new and improved version of this classic. You can find the PDF file here. (If nothing happens when you click, check your downloads directory for NeophyteReceiverV3.pdf - it may download stealthily and silently)

-FARCIRCUITS.com has zillions of printed circuit boards for ham projects available

-Hendriks / QRPkits.com also have lots of PCB's, many of commercial quality

-on a PCB, the ground trace should be big (wide) and close to everything

-when you're working on a kit, it helps to redraw the schematic, figuring out how each portion works as you draw it

-Dave claims it's easy to lay out a PCB, or maybe he said use “EASY PC” rather than “It's easy peasy”
-use toner transfer paper
-use photocopier (heated) to may copy from artwork
-be careful about flipping the image inadvertently
-clean and dry copper side of board, using acetone
-iron quickly to transfer
-dump in water bath
-do repairs with a sharpie pen
-immerse in etchant, about 15 minutes, then warm water

-request from the crowd for a list of recommended tools for basic and advanced kit building
-temperature controlled soldering iron. Al showed his Weller WES51
-a good tip has a large thermal mass to allow heat transfer without quick cooling
-different solders cool differently
-Eutectic solder, with a 63/37 tin/lead ratio is strongly recommended. From Wikipedia:

In specific proportions, some alloys can become eutectic — that is, their melting point is the same as their freezing point. Non-eutectic alloys have markedly different solidus and liquidustemperatures, and within that range they exist as a paste of solid particles in a melt of the lower-melting phase. In electrical work, if the joint is disturbed in the pasty state before it has solidified totally, a poor electrical connection may result; use of eutectic solder reduces this problem. The pasty state of a non-eutectic solder can be exploited in plumbing, as it allows molding of the solder during cooling, e.g. for ensuring watertight joint of pipes, resulting in a so-called “wiped joint”.

-Mike Cook notes that wooden paddles are better than plastic or metal for morse code keys, because they handle perspiration better

-for those of us who can't keep the names of morse code keys straight:
-a bug has horizontal action, and a single paddle
-a straight key has vertical action and a single paddle/handle
-an iambic key has horizontal action, and 2 paddles
-a side-swiper also has horizontal action, and 2 paddles

-Tom did a show and tell of the large open air capacitors he's using in the tuner he's building, and notes that you have to isolate the knob shaft.

-electronics-DIY.com has a good capacitance meter kit. They're Australian ?

-Hockey rink boards (as in being checked into the boards) are periodically thrown out and replaced. They're made of plastic that makes a great insulator

-if you need help with stepper motors, talk to Doug. I've used them on a couple of robots

-measuring the gaps in air capacitors
-micrometer
-feeler gauge
-they can handle about 750 volts per mil

-Tom's tuner design considerations:
-decide on power level it will be able to handle
-multiple antennas? Bypass?
-include a voltage balun (4:1) for ladder line, longwire?
-have an SWR meter, SWR + Power…

-an “ugly balun” consisting of a length of coiled coax imposes losses due to the length of the coax used

-a good book on Baluns was written by Robert Styvick

-a toroid labeled T-240-31 has:
- a 2.4 inch outside diameter
- a depth of “0”
- a permeability of 31. (31 and 61 are the common permeabilities)

-to make a choke balun, put coax around a toroid

-I have a scribbled diagram that shows coax entering a choke balun, and continuing to a 4:1 balun.

-Kits & Parts is a good source for toroids

-Smith Charts
-for visualizing RF circuits
-horizontal line is pure resistance
-uses logarithmic scale
-curves show reactance
-constant SWR curves - center = 1:1
-travel along a line to center, maybe multiple times.
-you'd probably be better to do internet research than try to interpret my cryptic notes

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Jan 13, 2018 - First meeting

11 people attended our inaugural meeting at the 427 Wing, and it was a relaxed get together with lots of story telling, advice, and project ideas. Thanks to Frank Birch VE3FBZ for these photos of the perpetrators.

conspirators

conspirators

We covered a lot of topics, interwoven with tall tales, confessions, and wish lists. A few of the discussion topics follow, and I'm hoping Dave can fill in more details and correct anything I've got wrong…

  • packaging your project in some sort of an enclosure can be the hardest part of building something from a kit. Dave showed a crafty way he had repurposed some fancy office conduit into a project case. Altoid Mints tins are also a traditional case for homebrewed gizmos
  • sometimes you can use electrical boxes from home improvement stores line Rona for enclosures
  • Making the right sized and shaped holes in your enclosure for connectors, switches, lights, etc can be a challenge. Some techniques were suggested:
    • drill a series of holes that outline the opening you want, then use small saws, files, teeth, etc to remove & smooth
    • Greenlee punches can be used to make square holes. Some members have these, and can help others
    • Metal nibblers can be used to expand a drilled medium sized initial hole into a rectangular hole. Again, there are members who have these and can assist others.
  • Speaking of assisting others (which is one of the major goals of this group), help has already been offered in a couple of areas. A “Volunteered assistance” section will appear soon to track these helpful offers, but there are members who:
    • can supply some electronic components from their own inventory
    • can help with microprocessor work, such as the Arduino, Raspberry Pi, PIC, etc.
  • one source of kits is the Alibaba website where many Chinese manufacturers sell kits. As always, you need to do a bit of homework to make sure any outfit you order from builds a quality product.
  • Lots of other potential kit sources were mentioned, and we'll accumulate a list in the Kit Builder Resources section of this web page. I heard Hendricks, Kits & Parts, QRPme, and BitX
  • Dave described the lightning detection system he has that detects lightning via a light level sensor on his roof. When it detects a sudden dramatic rise in light levels (i.e. lightning), an automated coax switch changes his rig from his antenna to a dummy load. Cool!
  • We do have some testing equipment available near the club station, and we have experienced people who can assist in those frustrating time when you can't figure out why the @%!*$ing thing won't work.
  • For some reason, I didn't take notes when we did the round table on the kit projects people were thinking of working on. Going from my feeble memory, these are some of the ideas:
    • Keys and Keyers for the CW course that has just started up
    • battery chargers of various types
    • Baluns for antenna feedlines
    • Remote station operation
    • attenuators
    • various kits that were started in the past, but never quite completed
    • weather-proof radios

Post Meeting Notes

  • Thanks to AL VE3GAM for providing 4 more kit websites
  • thanks to Mitch Powell for volunteering to share his own parts inventory, and for pointers on soldering advice

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lig-kits.txt · Last modified: 2018/10/20 17:33 by admin