Re: My Two Tinned Tunas EZBuild - Transmit Issue
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Daniel--?
Also, if your LED isn't working, you can probably check it with the diode check on your meter with no power applied. Should see something like 1.5V-2.0V drop. Since you are able to key the radio and you hear the oscillator, I'm guessing the keying circuit is working ok. If you do key down with power applied, measure the voltage at the top of the LED (junction of the resistor and the LED) to ground. If it is 0V or 12V, look at the resistor and the LED for issues.
More in a bit-- dinner time.
-HRS
H. Russell Smith, N0QLT???
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On Saturday, February 11, 2023 at 06:10:04 PM CST, Russell Smith via groups.io <n0qlt@...> wrote:
Daniel--
Overall, it looks like you did a terrific job!? I should show you some photos of the abominations I built when I first got started. Uggh. I shudder thinking about them now!? Yours is 100000000000% better!? In fact, in the VERY early days, all I had was a roll of what was probably acid-core radiator solder or something my dad gave me. I had it for years to remind me of those days. haha. It had to be 1/4 thick.
More than likely, it's something VERY simple like a bad solder joint. Easy enough to happen to anyone--even those of us that have been doing this for 40+ years.
The very first thing I would do is check and make sure all the components are correct and in the right place.
Next would to be to look at your soldering. There are a few places where it looks like solder didn't flow as well as you might like-- C8, L3, for example.? You might want to make sure the parts are in and flat against the board, too.
Do make sure the final transistor is in correctly.
Next, I'd start looking at voltages. Check your parts and report back, OK?
When I build stuff, I typically follow a policy of direction-- I always point the resistor (or other banded components) so they can be read right to left or up to down. I also put any parts like capacitors with the values facing me or facing to the right.? That helps me keep everything easy to see and troubleshoot.? You'll develop your own policies, but that's what I do to keep things neat and in line.
-HRS
H. Russell Smith, N0QLT???
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On Saturday, February 11, 2023 at 04:57:24 PM CST, Daniel KK4MRN via groups.io <sqldan2000@...> wrote:
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
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