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Gangue,

I just discovered this tool a couple of days ago...

It is a de-soldering iron which is a 40watt soldering iron with build in solder sucker. Brilliant! I just wish I had thought of it! I'd retire and just play with my QRP stuff all day.... Oh wait! I am retired and play with my QRP stuff all day. Well, if I did invent it, I would at least have some money in the bank....

Anyway, I ordered a few for me and made sure my order was processed before I alerted you guys. I haven't got mine yet but the reviews looked real promising so I bought some!

Rex? W1REX

?

OK, YOU have your amateur license, so what's next?

In this build-a-thon, we will build a very simple 40 meter transceiver that anyone with the desire and a minimal amount of equipment should be able to complete in a single 2 hour session on Saturday March 25th, at 10:00 PDT (1800 UTC). This is a very simple design that should get you on their air on 40 meter CW. A Morse code key and antenna wire is included in the kit. The builder just needs to supply a battery and some headphones.

Assembly should be completed during the 2 hour session with enough time afterwards to try the complete working station on the air. We will coordinate this operating with the hope that we will all make contacts with a followup session on Sunday morning. Of course band conditions, propagation and lots of other factors will attempt to thwart our little on air event but the prospect of a hundred of the same rigs with the same output to the same antenna all operating on the same 7110 Novice frequency should increase the odds that somebody will be contacting somebody else during the event.

Click on this link to order your Simple Station Kit:?

On 2023-02-02 8:04 p.m., Daniel KK4MRN via groups.io wrote:

So, on the calculator, enter: 25 ± ÷ 10 = 10x
The 10x really is 10 to the x power but I do not know how to show

subscripts or superscripts here.


The standard way to indicate exponentiation when all you can do is type in a straight line is this: a^b means a raised to the b power. So you want 10^x.

So, is my dB math correct?

It's fine.

Will this work?

Yes. But when you flip several switches on your attenuator do not expect extreme accuracy. If you flip the 20 dB, 10 dB, and 2 dB switches you're going to get something close to 32 dB of attenuation but not as close as you might think. The 2 dB attenuator will be pretty close to 2 dB, and the other two will be pretty close to 20 dB and 10 dB, but if your luck is as bad as mine the errors will all be in the same direction and the total error in dB could be as much as 3 times what it is for any one part. Realistically some errors will be on the high side and some on the low side so it probably won't be that bad, but it might be. What you can have reasonable confidence in is that when you've already called for 20 dB and 10 dB attenuation and then flip the 2 dB switch, you're going to have pretty close to 2 dB more attenuation than you had before you flipped it. But the total attenuation might be further from 32 dB than you might think. However it's not going to blow up your tinySA; the error won't be that bad.

David VE7EZM and AF7BZ

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Daniel,

OK lets take your problems 1x1......

I can hear the TTT on my receiver on 7.110 when I key down, but that is probably the crystal oscillator.? I got 2 crystals: 7.030 and 7.110.
Congrats, you have confirmed that your oscillator circuit is oscillating. You can usually 'hear' the oscillator oscillation on any and every nearby receiver tuned into the crystal frequency.

I took out the final, nothing changed.

Congrats again... looks like you have narrowed your problem down to the final or output filter...

I hooked it up to an an oscilloscope, nothing.?

OK. Nothing where? Did you check the output of the oscillator circuit? You should be able to see a small rf signal on the output (collector) of Q1....and you should check that it makes it past capacitor C2 (220pf). If it doesn't make it to the final side of C4 then the final transistor Q2 will have no signal to amplify.

Well, I wanted to use my TTT EZB for an education - well, looks like I will be getting one figuring out what is going wrong and trying to fix it.? LOL
This is one of the benefits of building a project and NOT having it work! You now get extra FUN diving into the guts...and learning how your project works.

The LED was missing or I lost it.? So, I found a red LED.? ?The LED never lights up.? I think I got A and K correct.? K is the flat side.? Or the LED consumes too much power.?

Use a jumper to bring 12v power down to the top of the 1K resistor R10. Check it directly. If it still doesn't light, you need to check the orientation ( A&K ) and the soldering job.

And one of the coils did not match what was mentioned in the documentation.? L2 in the docs:
L2 = 10uH = brown black black (large tubby)

There were 4 coils included in the kit.? I found the other 3.? I used what was left for L2.
NO.... That's not a good idea. You really need to use the right parts. What exactly was left over?

Or it's my bad soldering skills.?

How about a close up pic of the back side for possible debugging....

Rex? W1REX

Hello all,
Rex updated the QRPme web site the other day to include to the following link:

QSO Today BUILDATHON KIT (#9) SST+ on Mar 25 2023
$45



From the QRPme web page:
The Sea Sprite Transceiver + is a new re-working of the Sea Sprite currently in the QRPme tuna can line. The original Sea Sprite was reconfigured into a larger sized tuna can, spreading out the parts a little for an even easier building experience.

Scroll down and see the "Additional Included Items" for the buildathon.? ?
Also, see a previous message from Rex where he said this kit would be a good way for a new ham to get on 40 meters.

Features included in the NEW Sea Sprite transceiver+ are:

Bigger pcb has more space between components.

Bigger pads

Wider traces

Larger clearances around pads

Higher probability of completion without soldering errors

Latest low insertion loss low pass filter

Reduced parts count for faster building time
Added antenna coupler for instant hookup to 1/2 wave End Fed Zepp antenna

Additional included items for the QSO Today Expo Buildathon are a straight key kit and enough wire to construct a 1/2 wave End Fed Zepp antenna
To GOTA (GetOnTheAir) with everyone else, the builder will need to supply a 12V battery and a set of Walkman style headphones. Of course you will have to have a minimal about of construction tools to build the kit.

We are encouraging an online operating event on Saturday night and again early Sunday morning. A whole Buildathon*s (well almost whole) worth of transceivers all operating on the same 40m frequency (7110) at the same time and with the same antenna should provide a practical real time test as to the performance of this QRPp rig.

A second QSO Expo session is scheduled on Sunday in which we will discuss the results of the event, provide info as to how to improve your HF operations and also hold a Q&A session as time allows.

Docs for the ORIGINAL Sea Sprite are shown below. The new Sea Sprite+ boards are on order and new documentation will be posted as soon as they are developed....

Original message from Rex:
/g/QRpmeKits/message/328

Note, the original Sea Sprite transceiver Kit is found here in case you want to build it instead for $30

Hello Russel,
Not sure why this topic morphed into something else.? I am still trying to fix my radio. There is improvement.

I am getting a signal on my oscilloscope now while the rf output goes into a 50ohm dummy load.? Not sure if the signal looks ok considering what I see at the top.? Two peaks.
If I remove the final, so signal on the scope.
And I can still hear it on a receiver on 7.110 MHz.

Nice to see the red light glowing when I key.

I still need to build my peak detector, but the weekend is almost over...??

73 Daniel KK4MRN

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Rex,

Interesting. Your TT2-EZ has a 2N3866 final transistor where the current 
design of the Two Tinned Tuna -EZ build uses a 2n2222a for the final. Is that a change? would a heat sinked 2n3866 give more output power? would that be an possible modification?

   Thanks,

---John AC9UV 

Gangue,

From the very beginning of QRPme kitting, I have included a SIP socket in my kits for not only using as a crystal socket but also as a transistor socket for the final transistor. Easily replacing a final or even better...experimenting with other transistors as finals has been a hallmark of my efforts to enable others to have FUN with their kits. So the EZB does come with a pair of PN2222 transistors for the oscillator and final. It also comes with a SIP socket and very clearly in the builders guide shows how to use it as sockets for both the crystal and final transistor.

I like the 2N3866 as I have plenty due to getting them for a VERY good price from the GQRP Club! I pop them in my builds and some kits primarily because they are TO5 cans and finding heat sinks for TO5 cans is much easier than finding sinks for TO18s (2N2222A) or TO92s (PN2222). Consulting the datasheets:

transistor? pkg?? Max collector current watts dissipation

2N2219A?? TO39??? 600mA/800pk ?? ??? ??? ??? 3W

2N2222A? TO18???? 600mA/800pk ?? ?? ??? ??? 1.8W

PN2222A? TO92??? 600mA? ????? ??? ?? ?? ??? ? ?? 625mW

2N3866??? TO39??? 400mA??? ??? ??? ??? ??? ??? ??? 1W

I'd rather 'push' a whoosier final WITH a heat sink than a marginally better transistor without one... AND trying to find obsolete 2N2219A s and 2N2222s in cans is a challenge along with coming up with the coin to buy them! Jameco Electronics has 2N2222A transistors at $1.29ea which is a little cheaper than they used to be but no heat sinks for them. But their performance in the EZB is not that much better. I yanked the 2N3866 in my EZB that I tested last night and plugged in a PN2222. Power readings were pretty much the same without touching the trimmer pot. I suspect that if you wanted to run higher supply voltages you would start to bump into the collector current and heat dissipation limits and start to melt epoxy.

I really wanted to be in Orlando this weekend for the Hamcation! When my dad was alive and less than a hour away, I would take in the show nearly every year. The low rent building out back was my GOTO source for things like NOS heat sinks etc. Another GOTO place is Skycraft Surplus. Apparently they have moved into a bigger space since I last visited them....and bought every TO5 heat sink in their bin. I had 150+ in my suitcase on the way home. Long since used up but more easily findable than a TO92 or TO18 heat sink. They sell online but not as much FUN as being there in person and getting the full touchie feelie experience. They make the old RS stores look like an end cap in a truck stop convenience store!

Rex? W1REX

Rex,

Interesting. Your TT2-EZ has a 2N3866 final transistor where the current
design of the Two Tinned Tuna -EZ build uses a 2n2222a for the final. Is that a change? would a heat sinked 2n3866 give more output power? would that be an possible modification?

Thanks,

---John AC9UV

Gangue,

I just hosed up my early TT2-EZ Build transmitter to my fairly accurate PM-1300a dummy load/power meter. Powered from my portable Jackery, the input voltage to the TT2 was 13.4 volts. The key down power was approx .18W. I typed approx .18 on purpose. My college physics professor taught me something very important in Physics 101. You can't read something from a meter and write it down or say it is fact unless you can prove it is fact. I'm looking at an un-calibrated analog meter with an unknown full scale accuracy and see that the needle is between 150mW and 200mW and slightly past the middle point between the two scale markings.? So the .18W is MY best GUESS as to the power output from the transmitter. I thought that the output was a little on the low side so I twiddled with the power pot over by the crystal. Holding the key down while twiddling, I raised the output power to about .48mW with minimum resistance on the pot. I had no heat sink on the 2N3866 final transistor so I didn't key down for too long....

I could have said my power readings were 180mW and 480mW but THAT would convey accuracy that I can't actually read on my meter. YOUR mileage may vary depending on kit parts, load variations and your technique of measurement.

Rex? W1REX

I replaced the LED and the LED works now when I key.? ?I noticed the trimmer resistor was not soldered well, so i soldered it better.

C8 and L3 is ok to flow together when you see it on the schematic.

When I hear it on my receiver, the tone sounds better.

And I made double sure that the transistors are incorrectly inserted.? Unless, I blew a final.
I have extras of those I got from mouser.??

And where would I stick an oscilloscope probe to read from the oscillator?

I have an RF Probe kit I've been meaning to build.? And I was supposed to home brew a peak detector today but have not gotten to it.? I assumed my TTT would built like last time years ago and i would already be playing with it...

I will keep going part by part...

Not sure what to check for voltages.

73 Daniel KK4MRN

Hello,
I was wondering if I can get some insight into why my Two Tinned Tunas EZBuild is not transmitting.

I can hear the TTT on my receiver on 7.110 when I key down, but that is probably the crystal oscillator.? I got 2 crystals: 7.030 and 7.110.

I took out the final, nothing changed.

I hooked it up to an an oscilloscope, nothing.??

Well, I wanted to use my TTT EZB for an education - well, looks like I will be getting one figuring out what is going wrong and trying to fix it.? LOL

The LED was missing or I lost it.? So, I found a red LED.? ?The LED never lights up.? I think I got A and K correct.? K is the flat side.? Or the LED consumes too much power.??

And one of the coils did not match what was mentioned in the documentation.? L2 in the docs:
L2 = 10uH = brown black black (large tubby)

There were 4 coils included in the kit.? I found the other 3.? I used what was left for L2.

Or it's my bad soldering skills.??

73 Daniel KK4MRN

Please ignore.

No part is missing.

Brain fart in the morning.

My last cap was a 22uF electrolytic cap.

My apologies.

I am missing a 22pF capacitor in my TTT EZB kit.

Can I use 2 count of 10pF ceramic capacitors instead?? These either came from Jameco or Radio Shack.
I used my multimeter against a 1000pF capacitor which has a value of 1.031nF +/- a few .001nF
I added on 10pF, I get 1.043nF
I added another 10pF, i get 1.052nF.
That last digit is not reliable because it bounces around each time I measure it.

So, will these 2 x 10pF work?

I have a 33pF ceramic 100V C0G/NP0 I got from digikey.? Or would this work?

Or do I need to get the actual 22pF capacitor???

I am asking so i can go ahead and build the kit.

Thanks,
Daniel KK4MRN

Dan,