Modulated 5W NS40

[redhat]

I think what we have here is two ideologies that aren't going to see eye to eye, and I can see the points made by both sides.  My personal opinion is anything less than 100W carrier isn't really worth building because it wouldn't meet any of my goals.  On one hand, Antennnae is a budding hobbyist who isn't quite at the engineering level of myself or Stretchy, but given enough time will get there.  Rome wasn't built in a day, and neither is understanding this level of electronics by designing and building.  I too used to hate torroids, but with a little experience and some neat software tools, I use them in a lot of my designs for their versatility and small size.

Stretchy I can see your point as well, as I am in a similar position with regard to design principles and topologies, but I think it would serve the average hobbyist better to not be as condescending.  You've built things like this for a long time, the average joe these are aimed at haven't.  While I agree you've got a good product and it seems to be made well, it probably looks pretty daunting to the average appliance operator ham, or someone without a lot of construction experience.

I in the background have been working on something similar based on the current mode class D topology with PWM modulation and would like to scale this to the 5KW level at some point, but that maybe just be a pipe dream.  Using the Kahn method of envelope elimination and restoration it is possible to have these modern transmitters do SSB with high efficiency.  The basic building blocks are already going to be there in the stereo exciter, one needs only to add the appropriate 45 degree phase shift to the program audio before it hits the balanced modulators, full wave rectify the audio feeding the PWM stage and away you go.  This is how commercial shortwave transmitters do it, and it is possible to scale it down to something that the rest of us would find useful.

Keep tinkering and learning boys, it's how all of us advance!

+-RH

[EliteData]

everyone has their own opinion on what is easy to design and build, the question comes down to reliability, stability and proper operation.
anyone can weld a tube frame with two wheels, sprocket, seat and a chain and call it a bicycle, its how well you build and want that bicycle to operate and the type of operator that matters the most.
im not knocking anyones design for any circuit, ive seen some pretty good build kits out there and ive seen some that would explode like a fire cracker if driven just a tad above its design limits, everything here is strictly my opinion from a professional point of view, pros see things differently than a novice would.

[redhat]

Absolutely, and once you've settled in to one design philosophy or another and invested the time in doing to, it becomes hard to see things from the other side.  I look at a lot of these schematics people post on the web and find myself saying 'eeeuuuuu'  or 'that's kinda creepy' or even 'that works?' a lot.  To some extent I see this in many of the class E designs floating around the net, most of which give me the heebie jeebies... but that's another story.  I don't understand the why people build these things using long obsolete parts (11n90's and IXYS fet drivers) but its a part they know will work in their design.  I like to tinker and get frustrated when things don't work out the first time, but that is what prototyping is all about....learning.

+-RH


Ugh, 16 mosfets to get 375W carrier...really?

[Antennae]

I'm just sayin theres a market of LAZY people out there like the ones on the movie Idiocracy.  And they just want some simple boxes with knobs, and then some more boxes with knobs to hotrod their setup. Think of artists, artists make good pirate shows. But how many artists are geared towards electronics?

And to save my bar friend's mod tranny from dishonor:
There's a cartoon about what goes on in british bars:
https://www.youtube.com/watch?v=Hnczcw9P93E

[Stretchyman]

You're good guys, your right and I do not intend to be condescending but do get a bit miffed with the confusion surrounded radio.

I now sell a fully built and tested kit to take care of most folks requirements ONLY requiring the DC power and the RF COAX to be connected and YES some folk even have a problem with that, NO Problem, I can help!

Had a few requests to build and sell a boxed unit and have turned these offers down as I want people to wire it up and get a handle on how it works.

I aim to make it as easy as possible but am not into anyone buying an RF TX and making a nuisance of themselves, you should know how it works, I'm not talking deep RF theory here, just the basics, hence using this design and supplying a kit of assembled PCB, Mod and Tranny, it's all there!

10W aint gonna hurt anyone!

Re High Power (REDHAT) Cree SiC seem where it's at, 4 are enough for close to a KW pep so I'm concentrating on that design.

PCB's are what makes all this very simple BTW, OSHPARK have made it a very simple, cheap and reliable process.

Oh, ANTENNAE if you have a TX that runs on 24V or greater I can send you a PWM to try, OK.

Str.

[moof]

Yes many different points of view on this one and I can see them all.
Hey I'd be interested, but only if I could get a complete box with poles, so239, and some sort of mp3 plug...
I don't want to figure out an unfamiliar schematic, build a box, etc.  I already work 50+ hours a week, am Mr. Mom, I just don't have the time.  My time is worth a lot.
I have a little room for an oscilloscope in my house full of shit, money is not a problem, but again it comes down to time to learn something new.  I can follow a simple schematic and can whip out a Channel Z grenade that works first time every time with >5 watt carrier.  More with a couple tweak attempts.  No scope.
I don't expect patients to be familiar with chemistry, diagnosis, meds, labs.  You are lucky if the goobers can even spit out an incomplete list of the pills they take into their bodies every day.  Same deal here.  Oscilloscope.  Labs.  Chemistry.  We all spoonfeed them (PAY for them too!) and they are almost unaware of being alive, much less how stuff works.
Just my 2 cents.  Yes I am not in a good mood today.

[Stretchyman]

I hear you MooF and you would def be my target market but as stated I'm not willing to supply the whole thing boxed.

You WILL have to do some work yourself!

Soldering 4 wires and drilling a couple of holes in a box is not to difficult and will familiarise oneself with the layout and construction etc.

That's the idea as you will have build something yourself (at least finished it off) and can take some pride in that?

The schematic is not confusing and not even ness as all you have to do is solder on the wires to the PCB from a top down photo, if you can see, you can do it!

You plug you MP3 player straight in too.

How much easier can it be ?

You wont find anyone building the whole thing that way as it's not cost effective, I'd still rather sell kits at half the price but have sold far more built and tested (10 times?) That kinda says something about the hobby and I think it's a bit of a shame!

I work 12hrs days, 60 hrs a week, have to commute weekly by plane so work away etc and every spare minute is spent building these TX's and designing my next radio widget.

Maybe my passion for this comes over a bit snotty sometimes but FFS if you really want something you have to be prepared to put some work in!

This in not a popular commercial enterprise and even far less so these days, this I feel is the best you're going to get and if anyone feels it's not good enough, let me know. I'm more than happy to listen to what people want, that's why I made this in the first place.

I'll build anything, but it wont be in a box and it wont come with 'Poles' 

[redhat]

Think of artists, artists make good pirate shows. But how many artists are geared towards electronics?

Well, I am an engineer by trade, and a fairly decent DJ too.  Sometimes you get both  

+-RH

[Stretchyman]

I run Maschine + Komplete 10, VirusB, FS1R, homebrew dual 303, TC Fireworx, MOTU 828X.

Tidy set up for making repetitive noises!

 

[Antennae]

Either the inductance of the 'modulation choke' wasn't sufficient to keep the audio out of the power supply bypass circuity, or the turn on surge made its way into the amp and killed it.  My bet is on the former, because if the input impedance is too low, the amp won't be happy.  Its also possible that there is a shorted turn in the winding of the choke he's trying to use, and that will severely lower the drive impedance too.

Redhat, so are you talking about the input impedance where the .mp3 player goes into the amp, or the input impedance of where the amp goes into the transmitter?

[redhat]

My money is on the last theory, he drove the transmitter too hard and the reverse body diode in the RF output device began to conduct and essentially put a dead short across the amplifier.  A 2 ohm series resistor between the amp and transmitter probably would have saved it.

+-RH

[Pigmeat]

Gentlemen such as myself and my dear friend Al Fansome never lower ourselves to argue in such a vulgar manner. You all should be ashamed. Have our years as shining examples of virtue and civility gone for naught?

I lay the blame for this directly in the tiny hands of Putin's Great Pumpkin, Donald Trump.

[Antennae]

So, thanks to Stretchypants, I think I understand that this transmitter can only go up to 10w PEP.  Jerry was trying to modulate it at full power (10W carrier) and then shoving audio down its throat with a 100W audio amp.  But I guess he should be modulating a 2.5W carrier and then shove audio down its throat so it has room to go up to 10W on the peaks.  2.5x4=10  
Is this correct?


Hey, the Trumpkin's hands might be small, but he's got proven fecundity.  And he doesn't do drugs/alcohol either.
And Putkin is just trying to get by in the world. Its the elites that are keeping Putin down from an honest shot at his sphere of influence on the elite's turf.  The mass media is out to get Putin the same way they are out to get Trump.  In Russia its illegal to advertise during children's cartoons!  Who's evil now, eh? 
https://www.youtube.com/watch?v=0h7GILsLzV0

[Stretchyman]

Yes ANTMan, you have it!

BTW Donald's new home is just 'up the road' from where I'm working as I'm in Glenrothes just down from St Andrews, home of all things 'Golfy'.

Haven't seen him, maybe he's hiding in one of those bunkers or maybe he's too scared to come back now?

I bet you're all proud to be AMERICAN!

Ha, I can get you ALL on that one!   

Anyway we're no better with the likes of Blair etc but we'll keep it there on that one as we DONT WANT ANY POLITCS (or religion or RAP MUSIC) on here!!

You're a good bunch you lot and look forward to starting the day with an apt reply.

Brightens up my day it does!

 

[Pigmeat]

So, thanks to Stretchypants, I think I understand that this transmitter can only go up to 10w PEP.  Jerry was trying to modulate it at full power (10W carrier) and then shoving audio down its throat with a 100W audio amp.  But I guess he should be modulating a 2.5W carrier and then shove audio down its throat so it has room to go up to 10W on the peaks.  2.5x4=10  
Is this correct?


Hey, the Trumpkin's hands might be small, but he's got proven fecundity.  And he doesn't do drugs/alcohol either.
And Putkin is just trying to get by in the world. Its the elites that are keeping Putin down from an honest shot at his sphere of influence on the elite's turf.  The mass media is out to get Putin the same way they are out to get Trump.  In Russia its illegal to advertise during children's cartoons!  Who's evil now, eh? 
https://www.youtube.com/watch?v=0h7GILsLzV0

LOL! It's not fecundity when you've got to go get it frozen from the bank to do the job. And using little blue pills doesn't count.

BTW, I hear the term "the elite" all the time, there are many elites ranging from villages to countries to multinational corporations, religions, etc...  Who is this particular elite? Is it the elite of Possum Trot, KY., a very real place, that's keeping these two men down? Or is it someone or something else? Just who are they?

Mr. Trump is billionaire and has corporate interests around the world. Putin is very likely the richest man in the world, controls the media of an entire country, has the Russian opposition killed both at home and abroad, engages in active disinformation campaigns worldwide, and has a massive nuclear arsenal. I hate to tell you this, but on the national and multinational level, those two are very much part of "the elite" any way you cut it. Vlad sits at the big table for tinhorn dictators, such Little Kim, while Don is at the other end of the room hanging with Monty Burns.

It sickens me to hear a Presidential candidate of a major party praise a man like Putin. A man who with his annexations of parts of Georgia and the Ukraine single-handily reignited the Cold War due to a twisted version of a greater Russia, while showing unprovoked bellicosity to my own country. Trump's comments praising Putin make him a Quisling at best and a traitor to his own country at worst. We put the curs of Putin's type down 27 years ago, why elect a man who gladly let them up to do it all again?

BTW, do you think Trump sings, "My Heart Belongs to Vlady" in the shower? Perhaps while planning the Great Wall of Mexico?