its getting smug in the shack

[steve_qix]

$20 and a handful of FETs
_{and a few hundred dollars of parts-on-hand}

This has always been the fact right from the start

[Pete, WA2CWA]

Well, in this case you might be mistaken    Watt for watt (between a few hundred watts and a kW), and for transmitters with similar audio performance, class E rigs are FAR less expensive than any other technology available.  This is a provable fact.  I can buy all the parts from conventional suppliers and build a 400 watt carrier output class E transmitter that's flat from 5 to 20kHz and will modulate 200% positive for about $600.  And that's buying everything.

I am rather sure I couldn't even buy the iron required for a similarly powered tube rig of similar audio performance for $600.  Then I have to buy tube sockets, tubes, filament transformers, etc.... No junk box parts allowed - everything has to be bought from conventional suppliers  

From direct, real experience in building multitudes of tube rigs and multitudes of class E rigs, the class E rigs are, by every measure available, significantly less expensive to build than anything else of equal power and audio quality.  That which can be proven by fact is not a myth  

Hey, we are holding a class E forum at NearFest on Saturday at 10:30AM.  Come and check it out!!!!!!  

Do these things operate 160 through 10 meters ?

[WA3VJB]

Or even on 40 meters ?

And I don't know how you can make a performance claim either. Running 50 percent reduced carrier as you boast, is actually incompatible with most AM receivers among radio hobbyists.

And every time you try to make those FETs glow like a real vacuum tube, they blow up, and then you've got someone making a necklace out of the little burned parts.  Doesn't sound very efficient to me.

[flintstone mop]

True but he gets a nice reciever with it!  I wish they made just the RXer.

C

I agree. I would buy an RX only version in a heartbeat. Just give me ptt muting on it so I can use it with a real transmitter and that would be perfect. Most of the flex's I've heard on the air sound great, they have nice smooth audio on am and ssb, but they totally lack the needed BA's when the band gets ugly and one needs to turn the wick up as Don would say. Not trying to start a flame or nothing, and it's just my opinion, but I know what my ears hear and what I read on the forums.

I would think most folks here use their Flex radio with a linear amplifier. Most of us are already running legal limit. You are saying turn the wick up more??? That would only be a slight increase in signal strength going from legal limit to 1 kw out. So are you saying we can go to 2.5kw or 5KW??? These are unmodulated carrier powers BTW.
There are some brave folks who show off their handiwork on YouTube and they have nice hi-power rigs. Tubes with handles,,,,6kv B+, three phase power.....it's scary

Most of the weak signals are folks with small lots or antennas 30 feet high or the 25 watt or 51 watt operator.
I think we have come a long way since the middle 90's with a much better on air presence with nice audio and mostly legal limit operation.

[W1AEX]

Do these things operate 160 through 10 meters ?

I think that's a big factor Pete. The class E stuff definitely sounds beautiful, and for guys who only want to work AM and hang out on 160 or 75 meters, then go for it.

However... like many other guys who work AM, I also like to work every other mode and band that's available to me. A Flex 5K will do that, and it does it very well. 20 Hz to 20,000 Hz TX (yah, it will do 40 kc wide AM) and RX audio, and the ability with the AM mode to create positive peaks well beyond 100% without straining. Built in compression and a 10 band EQ are an added bonus if you're cheap like me and don't use an external audio chain. You can make your TX audio sound as ear-splitting raunchy or as smooth as you like in every available voice mode. A linear gives you full legal limit output on all bands from 160 meters to 6 meters and the capability to extend that as high as 432 MHz (or above if you want to use third party hardware). The receiver offers AM, SAM, FM, SSB, CW, every digital mode, DRM with free software, and DSP filtering that allows you to create your own brick-wall filters from 20 KHz - 1 Hz. Throw in the panadapter that allows on-the-fly filter modification and a fairly impressive suite of built-in benchtest software inside of PowerSDR and what's not to like? That being said, there are people who simply don't like the whole SDR side of radio. No problem, nothing to see here, move along!

Like I said before, why does it matter what the other guy is running as long as they're having fun? The diversity of equipment used by the people in this forum is staggering and I really do enjoy hearing about what the other guy is using when I chat with someone on the air, but the smugness factor in every niche group is getting old. Make RF any way you like and get on the air and enjoy yourself. It's only a hobby!

Rob W1AEX

[Steve - K4HX]

How so? I said it never cost $20 as you've often claimed. $600 is a long way from $20. Let's get real here and stop with the funny business. And that's $600 for a single band rig that runs AM only. Do a cost analysis  over all of HF and multiple modes and class e cannot compare to other types of amps, both in cost and functionality.

Engineering is about tradeoffs. Class e trades of high efficiency and some lower cost for lack of frequency agility and mode diversity. The 5 Hz - 20 kHz  frequency response is nonsequiter. No one can hear it. Do you really think anyone has a receiver with a 40 kHz IF bandwidth and can use it on the amateur radio bands. It sounds impressive but is meaningless in the real world.

Once again, there's nothing wrong with this, let's just get all the parameters properly and fairly conveyed and then let people decide. Propaganda only undermines the real value of class e.

It never cost $20 at any power level. The reality is that meters, cabinets and power supply components cost the same, class B, C, D or E. The fact that most class e rigs I've seen use a vac cap immediately remove them from the realm of low cost. And that's OK. What isn't OK is perpetuating a myth that they are low cost.

Well, in this case you might be mistaken    Watt for watt (between a few hundred watts and a kW), and for transmitters with similar audio performance, class E rigs are FAR less expensive than any other technology available.  This is a provable fact.  I can buy all the parts from conventional suppliers and build a 400 watt carrier output class E transmitter that's flat from 5 to 20kHz and will modulate 200% positive for about $600.  And that's buying everything.

I am rather sure I couldn't even buy the iron required for a similarly powered tube rig of similar audio performance for $600.  Then I have to buy tube sockets, tubes, filament transformers, etc.... No junk box parts allowed - everything has to be bought from conventional suppliers  

From direct, real experience in building multitudes of tube rigs and multitudes of class E rigs, the class E rigs are, by every measure available, significantly less expensive to build than anything else of equal power and audio quality.  That which can be proven by fact is not a myth  

Hey, we are holding a class E forum at NearFest on Saturday at 10:30AM.  Come and check it out!!!!!!  

[w3jn]

To be fair to Steve, I think his original statement got a bit distorted... I think he originally said "a handful of FETs worth $20" not "$20 and a handful of FETs".   Steve's original Class E project did use about $20 worth of FQAN1190s.

As with any project, a class E xmitter can cost as little or as much as you want - depending upon your junkbox stock and/or ability to score the bones cheaply at a hamfest.

[W1ATR]

I hear ya Fred. I probably didn't express what i was thinking right, so I'll give it another shot. I generally like to have things twice as strong as they need to be, then run them at half of that potential for 2 reasons. First reason being nothing ever blows up that way.(Knocking on wood) I have yet to let any smoke out of anything I was running conservatively. Although there was this one time a big screwdriver rolled off my bench and landed on an uncovered 4200v supply I was working with. That was interesting.  

Second, being stuck to the higher bands, (small lot, tall house), bands like 20m on a Sun afternoon are like being in the mall on a busy night and trying to yell something to your buddy 50ft away. Sometimes that 3db from doubling up is the difference between a failed contact and an achieved one. I just like being able to do it easily and quickly with a knob or two. All I'm saying is that a $4000 computer controlled cutting edge radio should at the very least be able to keep up with the transmit capabilities of a 25yo YaComWood when it comes time for flamethrower mode to get the job done. Mind you, this is in regards to the 20m ssb weekend madhouse that happens once an a while. If they were all that in the audio dept, the essb guys would be all over them instead of modifying hard to find freestanding radio's. I know what hear, and what I read around the google forums, and the general consensus is that these rigs just lack a little in the talk power dept. They are some of the best sounding rigs out there when sigs are 50 over s9, but when the band is tough, the few operators I've heard try to turn them up resulted in the transmit audio getting ugly.

Again, that's all for ssb. For AM, I'll prob stick with hollow state till I can't buy toobs anymore. If I ever get the hell out of the city and into the country like I'd like to be, then I can get rid of the gpt-750 and 3000a7 ssb amp and bring out the big stuff.  

73            

[Steve - K4HX]

Fair enough. My cost/benefit analysis still stands. Class E is a one trick pony. If you have other than very narrow interests, class e represents a poor value.

To be fair to Steve, I think his original statement got a bit distorted... I think he originally said "a handful of FETs worth $20" not "$20 and a handful of FETs".   Steve's original Class E project did use about $20 worth of FQAN1190s.

As with any project, a class E xmitter can cost as little or as much as you want - depending upon your junkbox stock and/or ability to score the bones cheaply at a hamfest.

[W1ATR]

How so? I said it never cost $20 as you've often claimed. $600 is a long way from $20. Let's get real here and stop with the funny business. And that's $600 for a single band rig that runs AM only. Do a cost analysis  over all of HF and multiple modes and class e cannot compare to other types of amps, both in cost and functionality.

Engineering is about tradeoffs. Class e trades of high efficiency and some lower cost for lack of frequency agility and mode diversity. The 5 Hz - 20 kHz  frequency response is nonsequiter. No one can hear it. Do you really think anyone has a receiver with a 40 kHz IF bandwidth and can use it on the amateur radio bands. It sounds impressive but is meaningless in the real world.

Once again, there's nothing wrong with this, let's just get all the parameters properly and fairly conveyed and then let people decide. Propaganda only undermines the real value of class e.

Well said. But, I disagree with one thing. people will hear EVERY part of excessive bandwidth. They'll just be talking on different frequencies.


Edit, hey my 1000th post! Did I win anything??  

[steve_qix]

Or even on 40 meters ?

And I don't know how you can make a performance claim either. Running 50 percent reduced carrier as you boast, is actually incompatible with most AM receivers among radio hobbyists.

And every time you try to make those FETs glow like a real vacuum tube, they blow up, and then you've got someone making a necklace out of the little burned parts.  Doesn't sound very efficient to me.

Paul, Paul, get a glass of wine    Let's interject some reality here.  Let's see - frequencies.  We can make them operate anywhere - probably your cell phone uses a class E RF amp.  High enough    Go to the class E web site.  There are 40 meter transmitters there.  I use one; Bob K1KBW uses his and there are others.  10 meters?  Just haven't bothered yet - now that the band is opening up, I suppose I'll get something going up there.    Various vendors have 30mHz amps documented in their application notes.  Maybe someone else will be the lead on the 10 meter project.  I've been rather distracted with other things as of late.  I even have the parts here (someplace!)  That's pretty bad isn't it? 

Performance claims? Don't need 'em.  Got real measurements and they are what they are - hard numbers.  Efficiency: 90% or better.  Frequency response: DC to anything I want.  Linearity: perfect.  Reduced carrier?  This ain't no slop-bucket rig - full carrier only    Incompatible with receivers?  Hmm... haven't had a bad audio report yet 

Fets failing all the time (or ever)? now THIS is a myth.  About as often as mod transformers fail - doesn't happen unless the builder doesn't know what he/she is doing.  Like anything, you've got to build it right, or it will blow up.  Everyone knows this. 

The tech section is full of people talking about rig blow-ups, and they are not about class E rigs.  We know everything about how to build stuff right and prevent failures.  Those who do it right have rigs (like mine, for instance) that never, never fail - ever.  The broadcast band is virtually all solid state rigs.  They have to be 100% reliable.  And they pretty much are, now that the manufacturers have figured out how to do it. 

I've blown up a lot of tube rigs (WOW have I blown stuff up!)    At that time, I was new into building and of course I didn't have much experience with high voltage or high power.  Learned fast, that's for sure    Same with class E - build it wrong, it is likely to fail somewhere along the line.  Build it right - it should outlast all of us   

This got me thinking about that high voltage I used to mess with - sure don't miss THAT at all !!!

Hey, is the political campaign rubbing off onto ham radio and showing up here?  Gee, looks like some mud on my S meter 

Cheers!  Steve 

[steve_qix]

Edit, hey my 1000th post! Did I win anything??  

A beer at NearFest?  A WAP (worked all posters) award? Congrats!  That's a LOT of posting.

[WA3VJB]

Cheers !

They don't glow.

That's a performance issue!


Cheers !  Light-hearted, avoid defensiveness.

[steve_qix]

Cheers !
They don't glow.

That's a performance issue!

Cheers !  Light-hearted, avoid defensiveness.

[flintstone mop]

I guess the ultimate Class E Ham operator would build, coz some of these folks are stinkin rich. Some ops sink big bux into whatever they do.
Build a Class E for each band. They can handle the entire band, without tuning?? OR is this the issue??
I own a Class D K7DYY TX and it is capable of the entire 80M band....no tuning, 180 watts carrier......barely gets warm, old buzzard.
Class D advantages??? dunno.......Class E...night and day comparisons or what?
Then generate your digital VFO into the TX of choice and switch station audio to the desired TX.
Let's face it.......some folks here have a B'cast TX for 160M and 80M and 40M.
The Flex radio just does marvelous things using modern technology and computers (sorry for mentioning that)

[WD8BIL]

Class E driven by a Flex?
That ain't smug.

THAT"S SMUG SQUARED!

I can't compete...... that's it..... I'm selling out!

[steve_qix]

I guess the ultimate Class E Ham operator would build, coz some of these folks are stinkin rich. Some ops sink big bux into whatever they do.
Build a Class E for each band. They can handle the entire band, without tuning?? OR is this the issue??
I own a Class D K7DYY TX and it is capable of the entire 80M band....no tuning, 180 watts carrier......barely gets warm, old buzzard.
Class D advantages??? dunno.......Class E...night and day comparisons or what?
Then generate your digital VFO into the TX of choice and switch station audio to the desired TX.
Let's face it.......some folks here have a B'cast TX for 160M and 80M and 40M.
The Flex radio just does marvelous things using modern technology and computers (sorry for mentioning that)

Class D and Class E each have their advantages and disadvantages.  Class D transmitters are smaller and typically less expensive to build because there is no tunable output network.  However, you then must provide an antenna tuner somewhere (if using an antenna), because the transmitter requires a proper, resistive load.  I cannot speak to what happens in the class D amplifier if the load goes away or is shorted.

Class E will pretty much work into anything under a 4 or 5 to 1 mismatch, either way, because there's a tunable output network.  You can drive a coax fed dipole directly, no problem, and cover the whole band.  A serious load mismatch is typically non-fatal if there is sufficient headroom in the amplifier, and proper protections are part of the design.

I have seen class E amplifiers run at very high frequencies (such as in a cellular phone), where class D may not be applicable due to the energy required to switch the output capacitance of the devices.

The efficiencies are similar at frequencies where the devices can work in both classes.

Both are switching modes at the input (even if analog drive is used, because the device is operating in saturation mode).

I would certainly not categorize one as superior over the other.  It depends on the application and requirements. 

I have not seen a class D transmitter built for the ham bands that uses more than one output module, and I have not tried combining class D output stages myself, so I don't know how that would work out.  I'm sure it could be accomplished, somehow.  The harmonic rich, unfiltered waveforms may be interesting to combine at HF, but they do it on the broadcast band all the time - up to 50kW or more!

On the class E side, there appears to be no particular limit as to how many modules can be added together, and since the output waveform from a balanced class E amplifier is very smooth, using a power combiner also works quite well.  The output network is typically after the power combiner (if one is used).

I will be talking about this at the class E forum - I'm sure you're flying up just to see it 

Regards,

Steve

[WA1GFZ]

I don't care what you run
I do tend to spin the dial when the modulation turns to idiot content.

[W2VW]

The majority of people heard regularly nightly in the Northeast on 75 AM who can dust the frequency off are using Class E stuff.

Where's my fourth grade English teacher?

[Pete, WA2CWA]

The majority of people heard regularly nightly in the Northeast on 75 AM who can dust the frequency off are using Class E stuff.

Where's my fourth grade English teacher?

Reminds me of the functions of an abrasive hand cleaner