Ham Radio - Building the Cricket 40 QRPp CW transceiver kit.

[@Liberty4Ever]

Watching you solder a PCB is like me watching myself soldering a PCB. All the same tricks. :-) I recommend No Clean solder so the board doesn't need cleaning and the flux doesn't turn gummy and nasty crufty brown in a year or two. Hey, the switch does have a polarity. It bugs my OCD if a switch is moved to the left or down to turn on the power. I ohm them out before installing them. I'm an old tech guy too. I have a nice Luxo Wave lighted magnifier that I use for soldering, and now I need more powerful flip up magnifiers to read component values. Geezer Vision is my old man super power. I also have the Cozy Magnifier app on my phone that makes a pretty nice lighted digital microscope. Nice build! Thanks for sharing. I have three of the Pixie kits that I should build this winter, although the three inductors printed onto the Cricket's PCB was a very nice touch. That looks like a very nice high quality little kit.

[@johng7rwf419]

Kevin, I had to smile at the folding of the legs for D1. It was exactly as taught in the British Army, failure to use that method led to harsh penalties. In fact we were urged to employ that method with all components to prevent damage.

[@BoB4jjjjs]

we were taught to do it that way in primary school, we built little radios something the same with little wire antennas, they would transmit across the school but that was about it. It was done just to introduce us to electronics and radio. A toy walkie talkie had more power, but it was fun building the radios, even if we didn't have a clue about Morse. In fact a walkie talkie someone brought in to school (some kid with rich parents) had Morse on the front as it also had a Morse key tone on it. The sets we built were clearer than the walkie talkie by the way, but it could transmit voice. No idea what frequency it was on, it was just a walkie talkie and the kits were just Morse radios to us. But we had fun building all four kits between us. I ended up doing a kit on my own as the girl I was supposed to build the kit with was not interested. That is how the teacher told us how to bend component wires (I wonder if he had been in the army, maybe he was during the WW11, but he never mentioned it. Anyway, all worked but one radio, even the teacher couldn't work out what was wrong with it, I suspect it was someone a bit heavy handed with the soldering iron and to much heat on a component.

[@n2jmb]

Cool looking kit, Thanks for sharing with us. One thing I've found helpful is using the camera on my cell phone to zoom in on the small part that my diabetic eyes cant read without a little help. 73!

[@loughkb]

That's a good idea.

[@stevejones8665]

I think the odd Arrangement for the Audio is just using the IC in Push Pull and they are using the headphones as acting like an audio transformer..Push Pull usually has 2 amplifiers that have a centre tapped transformer with center tapped ground or it can be left floating. Interesting way to get a bit more audio out with less components, I also think the dual op amp would be a lot cheaper than say an LM380 or similar Audio amp ic.

[@loughkb]

He did a few clever things in that design, didn't he? :-)

[@stevejones8665]

Hi Kevin, Great Video and the little kit beats surface mount stuff for sure when the old eyes don't work as well as they use too. I always find English is a Crazy Language when listening to the US version versus UK version, I kept having images of Plywood with a Veneer every time you said Sodder the Veneers 😊 in the UK we call it Solder the Via,s.. I understand what you Dad was saying about leaving the leads of the Transistors long, I always remember as a kid holding onto each Transistor leg whilst Soldering it with a pair of long nose pliers so the heat didn't destroy the Junction inside the Transistors. Heat was a No No when it came to those early Transistors especially the Germanium ones. Its amazing how hot the New Electronic components can get, hot enough to burn your fingers. Very Best Wishes for a great Christmas and a Prosperous and healthy New Year.

[@Cardassiaprime]

Good build Kevin, very in-depth view of the schematic at the start. some great tips as well for the general build. As for reading the small print on caps and suchlike, been there lots of times and not just electronics. So I have a tip for You- doesn’t take but a moment to be sure of your print, I take a good light photo with my I-phone and then zoom in, Wowzers it’s clear as day. Thanks for sharing 👍🏼 Barnie.

[@GeezerDust]

Built my Cricket 40 kit as I watched you build yours. Got the same results as you. Would like to see video on any mods/improvements that you make. Thanks for the help.

[@Joe-KN4IFI]

Now that's a kewl idea doing the toroid inductors are on the board. Great video as always Kevin 73s

[@chasiu75]

I enjoyed all the helpful tips that are good for any build.

[@johng3929]

That's the best audio amp electrical isolation trick I've ever seen.

[@acestudioscouk-Ace-G0ACE]

This was a great video for me as beginner at these things. The tips and reasons for doing things a certain way are really helpful.

[@TheMikeDarling]

Nice video, great step by step process of soldering in the components, and some great tips along the way. Thank you for taking the time to record and make this video. N7GND

[@JennyEverywhere]

The little board strip and the extra jack let you connect an external keyer and paddle instead of the straight key.

[@loughkb]

Yeah, I figured that out later in the video and pointed it out. :-)

[@ryanv7075]

Would that allow an iambic keyer?

[@loughkb]

@@ryanv7075 an electronic keyer, sure.

[@ryanv7075]

Kevin Loughin I just purchased the keyer produced by TheCheap3DPrinter on Etsy, but am unsure if it is electronic or not.

[@loughkb]

@@ryanv7075 You might be using the term "keyer" to describe a paddle. A "Keyer" is an electronic circuit that you plug your paddles in to. It then converts the paddles switch closures into strings of dots and dashes and has an output line that goes to the radios key input.

[@eddy2561]

I just built mine, 1 hour and easy since there's no torrid's to wind....TG!! Performance is as expected for simple design, no AGC so watch your ears and rock bound so QSY tuning. Fun rig, but not one I would take to a SOTA peak. ~ k6sdw

[@Peter-W1]

To tap off audio try to connect a smal transformer över the outputs and Conect line amp on the unbal side.

[@loughkb]

I have another idea. I have in-ear microphones I use for binaural recording. I'm going to put those in and the headphones over them.

[@derrick_builds]

Nice build. Now I want one.

[@Snarky_Radio]

nice video Kevin. Thank you for breaking down the circuits. I built one of those, and had some problems getting the receive volume and with the side tone. First, I used a little amplified computer speaker, then found that a cheap pair of earbuds was better but not great. I guess it has something to do with the way the audio is wired up. I would like to beef up that receive sensitivity, and selectivity, put it in a lunch tin, and improve that hand key a bit. I look forward to any additional videos you might do with this radio. I have learned a lot more about how it was designed. Did get some reports from the reverse beacon, but have yet to make a contact with it. 73.

[@Steve-GM0HUU]

Thanks Kevin. Hope you manage some QSOs. Interested to know what mods you were considering. Few things are as good as the satisfaction of building a radio and finding it works :-).

[@thomasmillar6261]

Kevin, great video. Thanks for the hard work putting that together. Did you ever do a part about the CW filtering off of R4? I looked in your channel but I must have overlooked it. I could use a simple design if you got one that you think would be good for this little QRP kit. Best regrrds and 73

[@owlcricker-k7ulm]

Kevin, did you ever do your upgrades to the Cricket and put it in a box?

[@loughkb]

I ended up giving it to another ham that collects these small simple transceivers.

[@kd5inm]

For the audio, could you use an audio transformer?

[@loughkb]

Sure. But I have simpler idea for it with the next video.

[@nobounds156]

Friggin cool! Did you ever make any contacts with this? I’m big into QRP kits..even one medium distance contact would be worth it to me lol. If so, what sort of antenna did you use?

[@loughkb]

I used it on my doublet and made a couple of contacts. Ultimately I gave it away to another ham that enjoys these little radios. I didn't like the broad and low sensitivity direct conversion receiver. There's no filtering on it so it brings in the full audio range which makes it hard for my ears to pick out single signals.

[@claudem.p.7969]

I liked the video so much, I bought the cricket and change the crystal to 7.055. Claude VA2SOB

[@MickeyD2012]

I'm going to assume the reverse diodes are for shunting stray currents and reducing noise.

[@ElectroNeutrino]

I figured it was reverse power supply voltage protection.

[@loughkb]

I considered that as well. However, very odd placement if that's the case. A single diode at the power connection would do the same. However, that strategy is almost always accompanied by a fuse. The reverse diode will blow the fuse before the diode and the rest of the circuit is destroyed. This has to be something different. I'm still betting on reduction in interference from strong broadcast signals coming in through the antenna.

[@janetwinslow2039]

@@loughkb Are the two diodes for clamping the voltage swing at the gate of Q2? Have you had a reply yet from the designer?

[@compassman54]

Great build video it’s my first kit and am ready to tackle it ! Question will standard iPhone ear bud work ?

[@claudem.p.7969]

Just checking are these HC-49-U Crystal ?

[@jeffreyeide7512]

Yo Kevin: Great video! I look forward to your mods involving this kit. Did hear broadcast in the audio you presented in the video, hopefully you'll tackle that in your mod. Hopefully spice up the sensitivity too. Carry on guy! 73's! de seeker/Jeff WA7LFP

[@loughkb]

Getting rid of the BC component would require some kind of pre-selector filtering on the antenna input. The only way to up the sensitivity would be with an addition of an RF amplifier between the antenna input and the mixer. Maybe down the road. I've more to do with it as is for video yet.

[@idontneednostinkingchannel6848]

@@loughkb No! In fact this could be improved upon by switching to a Hi-Q mag loop antenna! Sounds "out-there" but you might be surprised with the results. Excellent application - with QRP output levels there's minimal concern for the high-voltages at the tuning capacitor and the selectivity of a "tuned-circuit" antenna will help cut out adjacent QRM. - 73 - N3BNQ/KA1FWW

[@loughkb]

@@idontneednostinkingchannel6848 You probably haven't seen my many earlier vids on magloops. Quite familiar with them. However, my previous suggestions will work, no need to say such a strong "No!" to them. And sure, the narrow bandwidth of a magloop would cut out the BC noise coming through.

[@brettany_renee_blatchley]

*Thank You Kevin* 😊

[@eminusipi]

How does it sound on the air?

[@loughkb]

Weak and terribly wide on RX. If the band is busy, you'll hear four or more stations at once. On TX, nice and clean with no chirp or click.

[@eminusipi]

@@loughkb Thanks Kevin. Several years ago I built a 40m RockMite and put it in a Altoids tin. Never had a good enough antenna to get out though being in an HOA. James AD6LP

[@charlesschindler1971]

Cold here in the land of the Indian. Enjoy the warmth Kevin. ✌️out! ⚔️🇺🇸⚔️

[@Billblom]

reversed diodes will help with hooking up the battery backwards.. as in not killing the transistors..

[@loughkb]

Someone else suggested that as well. The thing is, that's usually accomplished by a single diode at the power feed, not within the circuit and also usually accompanied by a fuse that will blow before the diode. If that was the intent in this case, hooking the battery up backwards, difficult with the polarized plugs, would blow the diodes and then destroy the circuit in short order. I'm pretty sure they provide some other function.

[@Billblom]

@@loughkb Very true, but I can see the need for two of the smaller diodes if he tested an "oops" and it blew the transistor down around the oscillator during his test.

[@charlescompton4495]

That is neat; I have to say I like my Pixie 2 type a bit more. It only puts about 1/4 watt but it fits in an Altoids tin including a 9 volt battery. I did build three , three channel models including a keyer chip, three position crystal switches but used external power through a coaxial power jack. All these Pixies would drive earphone fine. I don't remember how I did it but I added RF gain to one of them to throttle down the real strong signals so I could hear them better. I'll check on the Cricket, thanks for the great video, Greg KA8ZAF

[@ElektroLUDIKITS]

Even without the tone the "CQ" was obvious when you tested the key at 46:08 :)

[@loughkb]

Kind of like the early telegraph sounders. The timing of the clicks was all they had to work with.

[@tim46767]

I think there is a fault in the schematic. I don't understand how the colpitts crystal oscillator works. Normaly the crystal is attached to + and ground. But in this schematic botth ends of the cristal are attached to + via 1 M ohm. This make no sense.

[@Stuff_happens]

I put together the cricket 30. Haven’t used it. Are you on vacation?

[@loughkb]

Nope. I live full time in the RV now. Home is where I park it.

[@kb6dxn]

D2 D3 are protection incase the battery voltage is applied in reverse from what I can see..

[@loughkb]

Nope. See the more recent video titled measuring the cricket for the answer.

[@tedmead465]

Shorten the leads on the chrystal.

[@paulschmolke188]

Thanks.

[@rohnkd4hct260]

not bad for a $30 kit.

[@YourOldDog]

Sounds like a Cuban station ! LOL

[@nr3rful]

Just like "paint by the numbers "

[@jamilsouzagodoisouzagodoy1099]

Traduzir para o Português

[@tim46767]

google for Diode Protection Circuit

[@loughkb]

Which wouldn't make sense the way they are placed in this circuit. Diode protection against reverse power supply connection is almost always implemented at the power supply point of the circuit and usually includes a fuse that would blow, saving the circuit. In this case, if the battery was connected backwards, difficult with the polarized connectors, the diodes and then the other components would all blow.

[@tim46767]

@@loughkb Not the battery voltage, but HF voltage protection. The gate is pretty delicate.

[@tim46767]

@@loughkb goggle: I/O pins protection diodes

[@loughkb]

@@tim46767 Ah. OK, now I can see that. When the mixer is in RF amp mode during transmit? No, that couldn't be it.. Or high RF voltages from BC stations coming in the antenna as I guessed toward in the video?

[@tim46767]

@@loughkb I'm stupid! I was thinking that the gate of q2 is the HF input. To be honest I have difficulties to read a schematic if not make in the usual way. Ground at the bottom, + at he top, input left, output right, gate on the left, drain top, source bottom. In this schematic you have literally any way to draw a transistor ;-)

[@johng7rwf419]

Thank you..

[@edel7339veis]

73 ! RA3YV ex .....

[@stephenwilliams5201]

I don't like the af amp.

[@tonywright8294]

Stephen Williams I don’t like Mondays

[@fatbikejamie]

I discovered this kit last night... how timely for this video! Great job... now I'm pretty sure i have to order one. 73 vy2js

[@ryanv7075]

Jamie Smith similar here, just got my license last month and have been looking at this kit during the last couple of weeks! Good to see an in-depth video on it.

[@justinelliott3529]

Ryan V did you build the kit? Make any QSOs?

[@forthy62]

Really nice kit. You can grab an old big book, cut most of the pages off and use the book as enclosure for your "paraset" spy radio :-) Don't use a bible for that. Bad karma :-) 73, Stephan, DF6PA

[@loughkb]

Well, the bible is Christian, and Karma is Hindu/Buddhist, so maybe they'd cancel each other out... ;-)

[@forthy62]

@@loughkb Guess you are right :-)