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Author Topic: The Cliplead 400 transmitter lives!  (Read 22414 times)
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steve_qix
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« on: May 22, 2008, 07:19:27 AM »

This is the cliplead 400 - a 400 watt *output* transmitter.

The transmitter is ultimately to be packaged in a large briefcase (Zero case), and features an off-line (no power transformer) modulator-power supply.  The modulator provides an isolated and modulated 45 volts @ 10 amperes (carrier) output, and will deliver 130V at the crest of the positive peak.  The push-pull RF amplifier is self-contained, including the IXDD414 drivers, and takes a TTL level input at the operating frequency.

The modulator is a push-pull forward converter operating at 140kHz.

Cute little project !

Below is the overall transmitter:


Below is the modulator:


Below is the RF amplifier:


Here is the PWM filter (4 poles):


And finally, the modulator switching transformer (push-pull modulator):
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KF1Z
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Are FETs supposed to glow like that?


« Reply #1 on: May 22, 2008, 07:37:06 AM »

""Below is the overall transmitter:.....""

Don't you mean "all OVER"  ?!

 Grin


Sounds good on tha ayah!



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Mike/W8BAC
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« Reply #2 on: May 22, 2008, 10:20:04 AM »

let me know ahead of time when you plan to travel with this briefcase. I want to avoid that airport.  Grin

Looks interesting Steve. Will you have it on the air this weekend? What band/bands?

Mike

By the way, I have a small, empty Zero suitcase. Not a briefcase but it might do. Interested?
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W1FRM
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« Reply #3 on: May 22, 2008, 11:24:19 AM »

Yo Steve - You know that I think that thing sounds
great and as always, breaks some more new ground.

I think you got the name backwards, however.  It
should be the "400 Cliplead" transmitter.

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flintstone mop
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« Reply #4 on: May 22, 2008, 07:26:35 PM »

If I were an electron, I would be afraid to go through that maze. I might get lost!!

fred
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Fred KC4MOP
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« Reply #5 on: May 22, 2008, 08:04:00 PM »


Steve,

Another fine Cloutier prototype!!   Cheesy

Cool new design.  Full strap power, no PS transformer, isolated modulator...  As always, thanks for the great work Steve.  Looking forward to learning more details.  Just wish I could make clip leads work like you do.  Wink
Look forward to hearing the new rig.

73, Karl    KD3CN
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AF9J
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« Reply #6 on: May 22, 2008, 10:52:54 PM »

It looks like it's going to be pretty cool Steve.  I especially like the fact that it can fit in a  briefcase.

73,
Ellen - AF9J
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« Reply #7 on: May 23, 2008, 08:58:17 AM »

Oh the Humanity!!!!
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steve_qix
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« Reply #8 on: May 24, 2008, 08:18:01 AM »

let me know ahead of time when you plan to travel with this briefcase. I want to avoid that airport.  Grin

Looks interesting Steve. Will you have it on the air this weekend? What band/bands?

Mike

By the way, I have a small, empty Zero suitcase. Not a briefcase but it might do. Interested?

Mike,

I heard you on the air last night (Friday) talking with Don, K4KYV.  Good sound from your end (and Don's).  I was working on the Cliplead 400 - had it up to full power (450 watts) in to the dummy load, modulated to 200% positive.  So, the little modulator-power supply has to develop over 4000 watts peak output to do that !!  I still have only 2 MOSFETs in the modulator, but I need to expand that to at least 4, and probably 6 to leave plenty of head room.

So far, the circuit is fairly simple (for all that it does) and I am trying to keep it that way !

Oh, Mike, I would be interested in the zero case if you're interested  Smiley

If this circuit proves effective and bulltproof, I will probably make this the "standard" modulator for class E rigs of 500 watts and under.

Good stuff!!

Regards,

Steve
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« Reply #9 on: May 24, 2008, 08:46:25 AM »

The leading edge of Serbo-Croiation Technology! Brought to the satisfied masses by Muppet Labs!
I'm not on much this time of year but this stuff may even convert me to try the waters!!!
Cool!
Keith
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« Reply #10 on: May 24, 2008, 09:43:23 AM »

That is pretty darn cool!
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Mike/W8BAC
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« Reply #11 on: May 24, 2008, 10:27:35 AM »

Hi Steve,

I wish you had dropped in last night, I'll bet that thing sounds good. What will the power supply for the transmitter and modulator consist of? I'm wondering about the size, weight and voltages needed for the supply. Another question, is it a single band, tunable rig?

You can have the case for postage Steve. It's covered with worn security and other stickers from my international travel days. You'll have some cleaning and polishing to do but it's serviceable.

75 meters was in rough shape last night (early this morning). Don was strong for a change but I couldn't hear Skip (K7YOO). Usually it's the other way around. I think I'll try 40 meters later today and this evening. 40 is fun but activity isn't as common. Thanks for the signal report.

Drop me an email with your mailing address and I'll send the case soon.

Mike
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« Reply #12 on: May 24, 2008, 05:30:04 PM »

Pay no attention the man behind the curtain!   

I think Guy has it correct.  To sound that good (I heard you on 75), the clip leads must certainly be oxygen free. 

N1 Prime Suspect

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VE1IDX
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« Reply #13 on: May 24, 2008, 05:52:57 PM »

I just have one question,how do you calculate the stray capacitance and inductance of all the clip leads in order to know what values to insert in the circuit when it all comes together to make it work in a case?  Grin

BTW, good job.
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« Reply #14 on: May 24, 2008, 11:26:48 PM »

Steve:

Looks...er...good (?).

I'll hafta listen fer it.

Congratulations on another Frankenstein noise silencer!

Dan
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« Reply #15 on: May 26, 2008, 10:47:12 AM »

How does he keep the clipleads clean?? mine are all rusty and covered with rosin smegma. 

klc
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steve_qix
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« Reply #16 on: May 27, 2008, 01:01:21 AM »

Well, I've been doing some more work on the ClipLead 400  Cool

Doubled the number of MOSFETs in the modulator from 2 to 4 - which SIGNIFICANTLY improved the modulator efficiency.  Now, the heat sink is cold under operation...

Also, changed the output RF transformers in the class E output stage, and now these just get warm after an extended period of long buzzard transmissions.  The previous transformers became very hot after extended operation.  I used 8 cores in each instead of 4.  The cores cost under $2.00 each, so not a big change in expense.

The positive modulation capability is over 200% positive, not that you'd ever use that, but I was pleased with the results, nevertheless.

It's almost time to document it and perhaps lay out a PC board for the modulator Wink

Regards,

Steve
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k4kyv
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« Reply #17 on: May 27, 2008, 01:28:09 PM »

You could make it even more compact by replacing those bread-slicers with vacuuuum variables shunted with fixed micas.

Last weekend when I went to Dayton, I stayed up at Gary's, K4XK, at his QTH in the thriving metropolis of Shinbone, OH.  He demonstrated his class-E rig, which uses a power supply of several times the size and many times the weight of the transmitter.  But he told me that the cheap MOSFETS he uses, designed for applications as pulse-width power supply regulators, are getting harder to come by.

I don't understand why they would be discontinuing to manufacture them since it would seem to me that demand for that technology would be increasing, but what is going to happen if those MOSFETS become unobtainium like everything else we need for building rigs?
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Are FETs supposed to glow like that?


« Reply #18 on: May 27, 2008, 01:54:05 PM »

But he told me that the cheap MOSFETS he uses, designed for applications as pulse-width power supply regulators, are getting harder to come by.

I don't understand why they would be discontinuing to manufacture them since it would seem to me that demand for that technology would be increasing, but what is going to happen if those MOSFETS become unobtainium like everything else we need for building rigs?

Those are just the particular mosfets HE uses...

There are at least hundreds of mosfet types that will work, with new types coming out regularly....


CHEAP, well, that may be another story!

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steve_qix
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« Reply #19 on: May 27, 2008, 08:54:17 PM »

Oh, I'm familiar with Gary's rig - quite a piece of work.  Gary uses an analog modulator, which is why the modulator is rather large as compared to the RF amplifier.  Nothing wrong with it - kind of a "boatanchor" class E rig, so to speak  Cheesy

As far as the MOSFETs - the FQA11N90s that Gary uses are still readily available, although they are being replaced with newer designs.

The manuracturers are coming out with newer MOSFETs all the time, and this is great!

Think about this: My first class E rig used the Motorola NTP10N100E MOSFETs.  These were discontined by Motorola about 7 years ago... so I went with another device (better device) which was discontinued, so I went with a BETTER device.  Each time, the devices got better and less expensive.  The MTM4N85s that I used to use back in the 80s were SO BAD - and very expensive.  The same device today would cost under $3.00 each.  At the time, (and in 1980s dollars), the MTM4N85s were some $8.00 each !  These were used in a solid state audio driver I designed.

Another good thing about MOSFETs is that they are generally the same physical size (there are standard case sizes, thank goodness), making interchange very easy when using an existing physical design.

Regards,

Steve
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« Reply #20 on: May 27, 2008, 10:16:07 PM »

I caught a few transmissions this evening Steve. It sounds sweet and looks clean. Good job.

Mike
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« Reply #21 on: May 28, 2008, 12:48:29 AM »

Thanks !

I've really got it cooking along, and the positive modulation capability is over 200% positive.

I'm looking into using physically small parts for the tuning network.  I think I'm going to try one of the ATC 100E series capacitors for the series cap (with a small variable), and some variable mica caps I have for the loading.  Should be an interesting experiment.  If the series cap gets warm, I'll probably to to a vacuum fixed cap, with a small variable across it.  The tuning range of the variable capacitor does not need to be very large to cover the whole band.

This has been an interesting design project, for sure.  Now I start falling apart because the design part is done (my favorite part!), and now its a matter of details and implementation  Cool  Oh well, the necessary evils of building - you have to actually build something and not just design it and test with a clip-lead laden prototype  Cheesy Wink

Regards,

Steve
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Are FETs supposed to glow like that?


« Reply #22 on: May 28, 2008, 07:38:23 AM »

Steve,
 You might take another look at ATC's website...
They've "extended" the voltage range of the 100B, and 700B caps.
They are lower capacitance values , I think they have  an "extended" voltage of 1kv at 200pf.

The 100B is $275. for 100pcs...the 700B is $225. for 100pcs.

You can buy those right on line, without even picking up the phone...

Might be worth a shot!

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« Reply #23 on: May 29, 2008, 08:41:15 AM »

My first solid state rig used TO3 FETs 2N6766 that sold for $80 in 1882.
My first 4 fets came from used breadboards.
It took 4 of them to make 100 watts on 75 and ran quite hot. Dean KNX built one befor me with similar pigs. New die designs happen all the time but we all need to deal with the surface mount monster.
The bad thing avout vacuum caps is they don't like mechanical shock. Good old bread slicer can take a beating in a portable rig.
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« Reply #24 on: May 29, 2008, 02:11:22 PM »

1882 !
wow, imagine what they'll come up with next year.  Grin

sorry for lurking.
Rick
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