Kit Building

ToddDubya

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Months ago I bought a RockMite kit for 40m CW. It came with two sets of crystals for 7.030 and 7.040 MHz. I've put it off and put it off, but I think I'm going to at least get started building it today. I don't remember exactly how much power it puts out as is, maybe 500-750mw. There are a few common mods I might do, but mostly I just want to build it and get it on the air.

I also have in my head I want to build a little audio filter/amplifier for CW that knocks out the higher frequencies. There are kits available, which is what I'll likely do, but it's really not a super complicated design.

Anybody else into kit building?

Edit: RockMite, not Mighty Mite
 
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Not kits per we but I’ve been playing with a raspberry pi and some boards from mikroe.com. It’s fun writing device tree and drivers to get the leds flashing and buttons to put.

I did buy an audio oscillator kit off eBay figuring I’d use it to learn CW. I haven’t built it yet.
 
I've built a few kits in my day and several things from scratch. Been a while since then, but still have some of them.

The kits I've built were, a frequency counter, AM transmitter (100mw class), a couple of FM PLL synthesized transmitters (Ramsey Kit....now out of business), a few AM transistor radios, a grid dip meter, a Heathkit SB-220 amplifier, a Heathkit SB-200 amplifier, the old Heathkit also out of business.

The scratch built stuff (including fabrication of the metal chassis, metered face plates, and cabinetry) include an 833 RF amplifier deck, a couple of 4-400 Rf decks, a couple of audio modulators for plate modulated AM, several high voltage power supplies ranging from 600vdc to 7kv dc.
A couple of 10K rated Pi network tuners, dozens of RF filtering modules for telephone line filtering. Some audio tailoring filters.
A couple of small regulated battery chargers.

It's a great feeling to turn something on that you've built and it works.
 
Hoo lordy. I went through the parts list and taped every part to a piece of paper with the value and ref des. Now I'm trying to wade through the directions which have a lot of options and alternatives. I'm sure once you've built one it is easy the next time, but I'm no stranger to schematics/PLs and this needs some thought. I do appreciate the they tell you what the part says on it, for example resistors have both 1R2 and the color bands.
 
Hoo lordy. I went through the parts list and taped every part to a piece of paper with the value and ref des. Now I'm trying to wade through the directions which have a lot of options and alternatives. I'm sure once you've built one it is easy the next time, but I'm no stranger to schematics/PLs and this needs some thought. I do appreciate the they tell you what the part says on it, for example resistors have both 1R2 and the color bands.
Depending on the age of your eyes, good lighting and a good magnifying glass always helps with reading chip numbers and resistor color codes, especially on the small fractional wattage ones.
 
Depending on the age of your eyes, good lighting and a good magnifying glass always helps with reading chip numbers and resistor color codes, especially on the small fractional wattage ones.
Yeah, I had a little handheld magnifier but I'm considering one of those lighted magnifiers. I got by this time, but barely. I have a better light at my "workbench" but I needed some room to spread out. The diodes were the worst until I realized the text is along the length, not the around the part.

That reminds me, I need to clear off a workspace.
 
Haha, from the directions:

Diodes:

Since the lettering on these is teeny-weeny teensy-tiny,diodes in each section may be equated by quantity tocorresponding entries in the parts list. For positiveidentification, use the lighted magnifier!
 
I'd just use a multimeter and use a sharpie to mark which is the cathode.
It's more trying to read the part number.

I'm not certain but I think the tape I used took the part numbers off some of the components. I'm fairly certain I got everything right before I taped it down, but I'm paranoid.

Tonight I got about 1/4 of it soldered. Some pins were giving me hell and I think those might be ground pins. Gotta crank the heat next time and see if that helps. I did as much as I could before my eyes gave out. But I've made progress.
 
It's more trying to read the part number.

I'm not certain but I think the tape I used took the part numbers off some of the components. I'm fairly certain I got everything right before I taped it down, but I'm paranoid.

Tonight I got about 1/4 of it soldered. Some pins were giving me hell and I think those might be ground pins. Gotta crank the heat next time and see if that helps. I did as much as I could before my eyes gave out. But I've made progress.
well that sucks about the part numbers. Some companies used to buff the numbers off of chips in their electronic devices so an end user couldn't repair it.

Ya, sometimes the plating on the component legs is lousy and won't take solder well.
 
Not doing kits now but lately any fine work I do (soldering, component placement, etc.) I find the need to wear a headlamp for focused light.

Old enough to remember Heathkit? Then you will appreciate this guy's website (VE5JL) with his catalog collection.

Open a catalog and take the reader to full screen, the presentation is excellent.

Edit: 1967 an SB200 amp was $200 :p

🐯
 
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Yup, heat was the problem. I slowly turned it up until I could solder ground pins without having to leave the iron on the pad forever. 800 is the magic number. I was just going to do a couple components this morning to see what worked, yadda yadda yadda, it looks like I have all but the external connections finished. There's a little figuring to do, so I walked away for a bit. I'd love to at least power it up this weekend/today.
 
Hide your daughters, my transceiver is "done". I got the external connections all wired up temporarily, threw caution to the wind and fired it up.

The first test was not very successful. I had a dummy load so I didn't expect to hear much, but I thought there'd be some beeping or something to let me know it was on. Nothing. I plugged in my paddles to see if I could hear the sidetone, nothing. Hmm. Upon closer inspection I hadn't installed any of the ICs or the crystals. D'oh.

Second test, with ICs and crystals installed, it powered up with a "73", followed by a horrible constant tone. A check of the connections and the paddles weren't plugged in all the way, so it thought I had a straight key installed and it was just key down. Thank God for the dummy load.

Third test with the headphones plugged all the way in and the paddles plugged all the way in and I was making dits and dahs. Backwards, but I was making them. There's a setting in the PIC that controls everything for that, so I fixed that, adjusted the keyer speed, and everything seemed happy.

Fourth test was to connect it to my main antenna. I carefully carried it into the shack, connected it up, and I could hear signals. There's an offset of about 500 Hz so you get two frequencies per crystal set. I turned on the main rig to see if it could hear anything without the antenna connected and it did. So those 500mW are blasting all the way across the yard 30' away and it could hear it without an antenna. Bazinga.

If you look closely you'll see on the waterfall where I was sending dits. For those of you who've been following my CW story, I'm using the homebrew sawblade and drill bit paddles with my left hand. And if you look even closer you'll see the tweezers I used on the headphone jack to jumper the headphone connections and get audio in both ears.

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The next step is to figure out the connector layout on the non-Altoids Altoids tin and get it all mounted up. First I'll probably see if any reverse beacons can hear me so I know it's actually working.
 
Nice Job!!! and glad you got it on the air.

I'd be very leery about mounting it in a metal Altoids tin.

Doesn't look like there would be enough room for one thing, and the possibility of shorting things out would be huge.

I'd find a plastic project box with sufficient dimensions so things aren't too crowded and there's enough room to mount the jacks in the sides without interfering with the circuit board. The tighter you cram things in, the more likely you'll have an issue.
 
Depending on the age of your eyes, good lighting and a good magnifying glass always helps with reading chip numbers and resistor color codes, especially on the small fractional wattage ones.

They even make some with little alligator clips to hold your work materials.


Nice Job!!! and glad you got it on the air.

I'd be very leery about mounting it in a metal Altoids tin.

Doesn't look like there would be enough room for one thing, and the possibility of shorting things out would be huge.

I'd find a plastic project box with sufficient dimensions so things aren't too crowded and there's enough room to mount the jacks in the sides without interfering with the circuit board. The tighter you cram things in, the more likely you'll have an issue.
How about one of these, to stick with the NES theme?

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I've got my heart set on the tin. That's pretty much how everyone packages these. It'll just take some careful planning to find homes for all the external components (jacks, buttons, knobs) where the leads don't poke into anything. If I'd left off the volume pot I'd have a much easier time.

I do like the idea of the .22 box though. Maybe the next project can go in a CCI box.

Here's an example of one. The guy even used the same cheat sheet idea I had for the menu settings. I can't believe this little thing even has a couple keyer memories.

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I couldn't wait, I had to try it. The reverse beacon network heard me 214 miles away. It took a few tries to get picked up, but not bad for ~500mW.
Where can I find more info about this reverse beacon network? What does it do, and how?
 

One of the neat benefits is the SOTA/POTA (and I'm sure others) can use it to spot you. So for example if you're going to activate some park/summit with no cell service and want to get spotted, those sites can use the RBN to spot you. For POTA you can pre-plan an activation (i.e. you tell the site you plan to be in park XYZ today), and when the RBN hears you calling CQ the POTA site uses that to update your spot.

There are also web SDRs that are different but also useful to see if you're getting out. They're receivers you can use, just set the frequency/mode and listen to what it hears.

 
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Kind of a cool specialized area of ham radio. Not really my thing right now, but cool enough. I'm hoping all these functions can be put on just a couple chips in another few years. Maybe then I'll look again. Meanwhile, I'm just dipping my toes in with 2M and stuff, but watching with interest.

Does this beacon stuff work with 2M?
 
I saw a video of this one. His takeaway was that it's the radio he wished he had as a teen. It works, but had quirks.

QRP (low power) and QRPp (very low power) are interesting areas. It's like sports: you achieve something, then start pushing the limits. In this case, how much can you do with how little power? Or can you build your own gear and still get it done?

Thomas Witherspoon (K4SWL) did a series of POTA activations with his Elecraft dialed back to 1/10 watt. He was inducted into the QRP Hall of Fame at Dayton Hamvention this year.


View: https://www.youtube.com/watch?v=YPiHd0K4MfY
 
Yeah, this stuff is not really for me. I'm too old to start learning or wanting to learn morse code. I saw this though, and thought you might like it. Have fun!
 
Yeah, this stuff is not really for me. I'm too old to start learning or wanting to learn morse code. I saw this though, and thought you might like it. Have fun!
I get it. QRP can be voice too, it just means low power. That's fun as well. One step at a time.

Back to the project...

I've got the mounting holes drilled for the circuit board, and: the headphones, volume knob, function button, and CW key connectors ready to go. I'm taking a break, then I'll do the antenna, power connector and power switch. After that, I have to shorten all the wires so they fit and I'll be good to go. I may have to grind a few things so the lid will close, too. And it doesn't really need it but I may make a knob for the volume just to class it up some.

Bonus prize to whoever notices the homemade washer to replace the one I lost.

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It looks like tomorrow, June 17 is International QRP Day. What timing!
 
All done. I had no luck with the RBN with the crystals removed. Then I put them in and still had no luck. My main rig was receiving (without an antenna connected), so I know I was transmitting. I don't know how wide the filtering is, so I may have had other signals too close.

I think I have about 6 hours into it tonight just getting everything fitted. Lots of trips up and down to the basement and a little swearing. For anyone looking to do anything similar, a small pilot hole (backed with wood) and a step bit did a nice job on the holes.

The guts:

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Left to right: Antenna, power, power switch.

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And yes, it closes.

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For cripes sake, the lock washer I lost and scoured the room(s) looking for and eventually had to make my own, poorly, showed up first thing this morning under the chair where I'd been working. When I say I scoured the room, I mean I shook out blankets nearby in case it somehow launched itself, crawled around on the floor with a flashlight, moved everything within range so see if it was under it or stuck to it. Nothing.

POS homemade washer removed, lock washer installed. It looks better now, and the case closes easier since the POS washer interfered with the lid a little.

Also, I had my first real QSO with it last night. By "real" I mean more than 5nn 5nn, MA, 73. It was sloppy, but my friend/elmer was on the other end so it was low risk. He just told me what to send next and it went good. He's only about 8 miles away as the banana flies, so it wasn't much of a range test, more like ground wave. But whatever, I built a transceiver and communicated with it!
 
I don't see anywhere on these pages where it says what frequency. Also, are these all Morse code ("CW") only?
Thanks.
 
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