Sideband harmonics 7mhz away...wheres your test tone?

[Robb]

I don't want to stir the pot here and compare one builder to another but I will say if you knew BBI, you would also know Luke does give a damn. While still in the learning process in some areas, his mind is not closed. His mind is open to technical discussion regarding things he understands and those he does not yet.

He proved this to me years ago when we had the same debate regarding single ended amplifiers versus push-pull that is taking place in another thread here. He took the time to build and measure the input and output power produced in both circuits. About a week later I received a phone call from him explaining that both the single transistor and the push-pull pair were producing nearly identical results. Don't judge the book by the cover.

I don't think that anyone here is judging your friend here, Shockwave.
Well; maybe a little . . .

But you must understand, that it is HIS OWN video that was brought to attention here. If he wants to come to this forum and debate and explain and possibly accept some constructive criticism; then no one more than me would be pleased with that result.



NOT a clean test radio.
That signal frankly is an example of what a radio output signal should NOT look like.
A worst case scenario - really.
See the large, flat spaces between the boxcar shapes? Well that is massive distortions of two differing kinds. That blank space line between the boxcar shapes is negative peak distortion, and the boxcars themselves should look like sine waves - not rectangular boxes. Also called 'positive peak distortion of the third kind.' They are both a clear sign that either he doesn't know that (doubtful); or he is not a radio repair guy that can set it straight. Can't be anything else. May I suggest that he uses a stock radio if he cannot set up his test radio correctly?

 

[Martian]

He is probably referring my my comment where I doubt he cares.

Based on the videos I have seen he does not.
There is more than one video where he makes reference to an old and respected equipment manufacturer needing to copy his designs - a very unlikely scenario based on what I saw of his design.

If he cared about what he was doing or for his "customers" he would leave his arrogance at the door and realize that he knows a lot less than he thinks he does.
There is absolutely nothing wrong with saying you don't know something as long as you take the time to try to find out what you don't know.

 

[TheRealPorkchop]

Hmm. Well.

I like Luke myself and maybe there’s a lot he doesn’t know but then again, there’s a lot I don’t know too. I think he cares and I’ll make that statement based strictly off his craftsmanship, he and Gatekeeper have done some nice builds.

Now when it comes to most of the discussion in this thread, a lot of it is over my head and I’ll gladly admit that, right here in the open for all to see. But as you said, what I don’t know, I want to learn and that’s why I’m tagging along in this thread.

The water hose thing was kinda bad though, the antenna thing... and this don’t look all that good either but I still like the guy.

 

[Shockwave]

You guys are right based on those waveforms shown on his scope. If you took a signal like that and put on 3.880 no one would talk to you other than complaining about how dirty it is. I think this has more to do with the customer rather than him not knowing what distortion looks like.

I say this because if you took a perfectly clean AM signal with nice round peaks and no RF cutoff and placed in on 27.025, no one would talk to you there either. Other than to complain that your audio is in the "mud". While this is the complete wrong way to operate a transmitter, it all comes down to what your customer base is willing to spend money on.

From what I've seen, he builds some of the highest quality amplifiers for this band with just about no expense spared. He doesn't sell or make antennas and probably should avoid posting educational videos on that topic until a deeper understanding is acquired.

 

[Robb]

There is more.

Since he used that radio; then why didn't the spectrum analyzer show that same crap coming out of the amp? ANS: it had to; unless something is amiss. That is the real question that others have already brought up. In fact, that is what started this thread off.

Sooo, we must conclude that he has set up incorrectly. The video plays all of these facts plainly out to see.

He can do better than that, I'm sure.

 

[Handy Andy]

@Martian - Since the beginning of this thread - in fact since the first time I posted out here - I've had to post, and "Brace for Impact". And then, survive the lashings, floggings, bloggings, and otherwise mud-slinging rivaling a local Political Race using Fist-to-Cuffs...it has been a leaning experience. To find this thread taking to the issue of the radio may be just as guilty of the mess as the amp itself - it proves the issue of Purity, New York Snow and Garbage In = Garbage Out - its nice to see someone else helping me process this correctly and even draw a conclusion based more upon fact and evidence than Reputation and Speculation.

it is unfortunate that the person whom really can use this information- is not here for us to help them understand it.

 

[ExitThirteen]

It shows him using a Ranger 2950DX for a radio into the amp, for starters.... bad idea. Since the radio is "designed" and then expanded to run several mhz below it's "designated" band, the passband circuitry in the radio won't filter out the "junk" like a CB will. Plain and simple. Use a REAL CB radio and that will fix the problem on the radio 's side of things.

The other thing I see is that the PSU on the amp is unregulated which will contribute to IMD and other distortion issues. Also, the amp is class B biased, which is also unregulated, and with all that voltage fluctuation, I guarantee that the amp is going into class C territory.

These two factors combine for a nasty looking and sounding setup. It's embarrassing.
Junk on junk. Two wrongs don't make a right.


~Cheers~

 

[Handy Andy]

But maybe three do...

I just had a interesting thought while cleaning dishes - some of my best inspiration comes from cleaning up someone else's mess - but that's another story for later...

What about...

What arrived UP from all those Boxcars? As you put it so well EXIT 13 - (which Happy thanksgiving BTW) the radio and the amp are both amplifying the "image" and spurs...

Meaning if he has "scaled down and Slowed Down" that imager - and then Zoomed on the 1Hz to say 8MHz - I wonder if the problem arrived from down below - not from above at the RF signal - but as an ARTIFACT of the leakage - I mean could we be seeing even the CPU's 7MHz PLL Clock? Far fetched but - broadbanded amplification is certainly present...

You could be a DB'er when...
The Radio and the Amp costs more to repair together than they're worth, separately tuned.

 

[Martian]

I have not watched the video.
Only seen the image. I did not feel the need to suffer thru another one after I lost 6 or 8 minutes of my life after his antenna video.

As I recall the 2950/70 etc radios all had compensation (varactors) in the bandpass filters. I would think that's enough to swing a couple Mhz.

 

[Martian]

Meaning if he has "scaled down and Slowed Down" that imager - and then Zoomed on the 1Hz to say 8MHz - I wonder if the problem arrived from down below - not from above at the RF signal - but as an ARTIFACT of the leakage - I mean could we be seeing even the CPU's 7MHz PLL Clock? Far fetched but - broadbanded amplification is certainly present...

Fair question, and ironically my territory
That would be a really interesting leak.
Schematics I grabbed show it uses an old 4 bit Hitachi CPU that maxed out at 4Mhz and they were using a 4Mhz crystal or resonator to generate the CPU clock.

I highly doubt it's anything with the CPU. Would be a helluva leak and a second harmonic to boot

 

[TheRealPorkchop]

Rollin’ with the Big Mack, the amigo with the big ego.

 

[Martian]

I see that as inherently dangerous for the hobby.

That may not be an endorsement, but it's certainly being used and interpreted that way already.
Comments are amazingly enabled on that video (I wonder why) and he is heavily moderating them to remove anything that is not an epeen stroking.

 

[TheRealPorkchop]

I grew up listening to Mix so I’m biased I guess. Illegal and all that yes but I still like Anthony Ray.

How do you know he’s moderating the comments? I was surprised he enabled them myself but he’s hanging out at Sir Mix-A-Lot’s house...kinda expected I guess.

I’d like to see the whole setup myself. I’d like to see what massive amounts of money could buy you to play with and be illegal. No wonder he can put a 25k slug deep in the cawnah. Haha.

 

[Martian]

How do you know he’s moderating the comments? I was surprised he enabled them myself but he’s hanging out at Sir Mix-A-Lot’s house...kinda expected I guess.

I saw a few comments vanish.
They were there and when I refreshed later they were gone.
I was watching to see if he removed them since some were not bad comments but they were not praise either.

If he was honest he would take the good with the bad.
Has to maintain that safe space, I guess.

 

[TheRealPorkchop]

That’s some crap. He shouldn’t be doing that. Opinions vary. I guess direct insult or something like that, yeah remove them but opinions, that’s just bs.

I’d like to know how he got to be friends with Mix, there’s got to be a good story there. And he mentions often that that Prime is his teacher so does that mean Prime should’ve stuck to rapping and not building boxes?