k7dyy new 300 watt class D transmitter

[KF1Z]

Looks like k7dyy has a new transmitter for sale soon....
300 watt carrier.
$680.


http://k7dyy.com/index.htm

[John K5PRO]

Wow, impressive small size for 1/3 kW carrier. Now we're talkin'. Oops, thats an ARRL saying.

[K6JEK]

I had a whole lot of fun building and using Bruce's smaller creation which he now calls the DYY jr.   The Junior is a great little transmitter 200 watts, two pounds (Bruce says 150, but I turn mine up to 11).   The external T/R  of the junior is inconvenient and 150  watts isn't enough for my tastes.  Three hundred is more like it.

This design is a descendant of the earlier design which proved to be quite robust.   After correcting my stupid construction mistakes, nothing blew.   However, if you plan to build this baby, plan on using an isolation transformer for bring-up.   Don't go poking a scope probe in there without isolation.   There is no HV transformer.   

I think I'll buy the boards since all my horsing around building the Junior as he was designing it and fooling around with Class E has left me with most of the parts.   Besides, I'll have to make mine look more boat anchor like -- black wrinkle, and some meters for something.

Jon

[flintstone mop]

You must super sharp eyesight!! When I bought the kit I had to "upgrade" and send it back for Bruce to build. I couldn't see half of the components. Soooo he's up to 300 watts now??? You are pushing 200 watts out? Modulation ok and no overheating??

The audio response is ok for a D104 input. I'm inputting the audio from my station and you have to watch the high end or it will splatter all over the place. The "junior" has a strange response curve. Definitely not flat. I have my mic processor set at very peculiar settings for "normal" voice response. I think by typing this that I have discovered the reason for the peculiar setting for the EQ. I'll recheck the setup of the Transmitter and make sure it is 600 ohms and not 5 billion ohms for the D104.
Fred

[WA3VJB]

That is pretty cool.
I've heard Fred's "junior" model and it sounded good.

http://wa3vjb.amham.com/sound/KC4MOP.mp3

[K6JEK]

You must super sharp eyesight!! When I bought the kit I had to "upgrade" and send it back for Bruce to build. I couldn't see half of the components. Soooo he's up to 300 watts now??? You are pushing 200 watts out? Modulation ok and no overheating??
...
Fred

I had done very little surface mount work before the various DYY transmitters.   I got comfortable with it after awhile -- lots of light, magnifiers, and tweezers.  I did it the hard way, though.   Bruce started with a class E kit which I built.  It worked great.   Then he hacked on that to make the class D.   I hacked in tandem and built my own RF board from his design.   Then I got boards from Bruce and threw away the mess that this thing had become (but it worked) and rebuilt it all over again on his .9 version boards.  All of them worked. 

Yeah.  200 watts.   He called the thing a 200 watt transmitter when he first designed it.   It does fine at 200 watts, 100% modulation.   At 150 watts you can push 125% or so, I'm told.   I don't do that. 

[ka2zni]

Looks like k7dyy has a new transmitter for sale soon....
300 watt carrier.
$680.


http://k7dyy.com/index.htm

You can hear one almost daily, Larry, W8ER, has been field testing one and not babying it either, 300-310 watt carrier, Modulating about 1200 watts, and the thing sounds amazing! 5 Amps/110 volts! I am contemplating one for a back-up in case my main AM rig goes down...

I havn't heard a guy yet that hasn't gone out of his way to compliment Larry's audio, the thing is fantastic.

[KL7OF]

I have been monitoring Bruce using the "300 watt" rig....He is testing it at 350 watt carrier output and it sounds very good and very strong...  I would really like to have one  but I don't think I would be able to build it with my size 16 hands... those dead bug parts are just too small...those with average size hands and eyesight should have no problems...one of the best sounding rigs around!

[AF9J]

I've been debating about getting the Junior (more in my price range) for some time, for some 160m capability.  Also, as you know, I'm hesitant to run much more power than the Junior puts out, where I live.  Of course considering my funds - it would be when I get the money.   OK, now a dumb question - like the Class E rigs, I assume that it has no oscillator/exciter section or a modulator (in other words it's not a really transmitter per se, but a final amplifier section)?  So, in other words, I'd have to come up with a modulator (or as I've been told, a cheap audio amplifier would probably do the trick), and an exciter?

73,
Ellen - AF9J

[KF1Z]

You don't have to worry about building it......

They are NOT kits..... only bare boards with NO parts, or a assemlbed/tested unit..

And noo more K7JYY  "JR".... he;s not making them anymore.....

[The Slab Bacon]

Ellen,
         IIRC, Randy N3LRX brought one of those by here one night, and I believe the one he had was a complete unit with switching poewr supply, modulator and all in one little box.
Just add crapstal, mike and antenner. It was a really small compact unit IIRC, just not my cup of tea.
                                                                              The Slab Bacon

[KF1Z]

Ellen,
Looks like the new SR model has 6 selectable xtal sockets....

So, yes, it is "self contained" transmitter.......

(Don't know why he wouldn't need FCC type acceptance...... but that's not my concern.)

[AF9J]

Cool!! Thanks for the info guys!  I've always been intrigued by the Class D & E stuff.  I know K7JYY sells them built complete (and in some cases, sells the boards).  Still, a kit would be fun to put together (I always enjoyed building my QRP kit rigs).  No more Junior!!?   

<Sigh!>
Ellen - AF9J

[The Slab Bacon]

Randy bought the "kit" version. IIRC most of the low level stuff was all surface mount, well squished together. (This was before my eye overhaul) I dont think at that time I could have seen well enough to build it. I remember that Randy had a pretty tough time with it, and I couldnt see well enough to troubleshoot it at that time.

I do remember that it had just about no tuning adjustments in the RF section, and none at all on the final amplifier board. It was a very small package for the rated 300w carrier outpoot.

But it will never take the place of the glow of some big firebottles behind a peek-a-boo window for me!!

                                                                              the Slab Bacon

[KF1Z]

Randy bought the "kit" version. IIRC most of the low level stuff was all surface mount, well squished together. (This was before my eye overhaul) I dont think at that time I could have seen well enough to build it. I remember that Randy had a pretty tough time with it, and I couldnt see well enough to troubleshoot it at that time.

I do remember that it had just about no tuning adjustments in the RF section, and none at all on the final amplifier board. It was a very small package for the rated 300w carrier outpoot.

But it will never take the place of the glow of some big firebottles behind a peek-a-boo window for me!!

                                                                              the Slab Bacon

I have that particular unit now.......

Randy sent it to me to finish, and test...
He ended up trading it to me for parts to build a QIX class-e....
Haven't heard from him for quite a while....


The "JRs" at first were rated a lot higher.... but then after a bit Bruce k7dyy, lowered the advertised/recommended carrier level.

[AF9J]

Randy bought the "kit" version. IIRC most of the low level stuff was all surface mount, well squished together. (This was before my eye overhaul) I dont think at that time I could have seen well enough to build it. I remember that Randy had a pretty tough time with it, and I couldnt see well enough to troubleshoot it at that time.

I do remember that it had just about no tuning adjustments in the RF section, and none at all on the final amplifier board. It was a very small package for the rated 300w carrier outpoot.

But it will never take the place of the glow of some big firebottles behind a peek-a-boo window for me!!

                                                                              the Slab Bacon

I like 'em both (hollow state & Class D & E).  The electronics I was taught in college was all solid state.  Tubes - well, that comes from using tube guitar amps, and the fact that all of my rigs until 1993, were either tube or hybrid.  Like I said, both are cool to me.  Tubes look cool when they're doing their thing.  Chronically having a lack of space, also makes compact stuff (like Class D & E) attractive to me.

73,
Ellen - AF9J
Using a notebook computer to type this

[N3DRB The Derb]

its an attractive tx for me, because I cant handle the big stuff anymore.

[w1pe]

Hi Guys...I don't often post here but thought I would today..My K7DYY 300 watt
will be here today. Bruce shipped it yesterday...Hope to have it on the air tonight..
Am going to use a K7DYY D104 to start with... Bruce said that it worked great over the weekend... Will let ya all know what happens


Bob W1PE
Mesquite, TX

[Steve - WB3HUZ]

Hi Guys...I don't often post here ...

Why not?

Please let us know how the K7DYY rig works for you. I think many are interested.

[AF9J]

Please do.  When I have the cash, I'm think about going the K7DYY Class D, or the Class E route, to get on 160m AM.

73,
Ellen - AF9J

[w1pe]

Well folks the K7DYY Sr is on the air. On the MFJ Peak Meter it is running about 320watts Cxr and peaking to 1200 plus watts. I am using the K7DYY D-104 pre amped
mike with it...According to Brian WA5AM I was running neck and neck with an RCA at 350 watts out and the audio sounded better then a lot of guys with full audio chains...
This puppy weighs about 9 Lbs...Good for us Old Guys that can not lift stuff... It has 6 Frqs in it.. Love that Big Red light when you key up... So far worth every penny paid...
Ohh By the way Brian said that it was about 3.5 Kc either side of center and dropped off well.. That is good as well...

That is the first report...

Bob W1PE

[W5AMI]

I heard Bob this afternoon on the new class D and it sounded really good, however at that time of day, about 4:00 PM, propagation was not that good between us.  Best I could tell, it had a nice roll-off right at 3600 or 3700 cycles each side of center, and audio seemed to be smoooooooth as it gets...

Yeah Bob, why don't you visit here more often man???!!!

I'll try to catch you tonight, just give me a one ringer, or send an email.

[Steve - WB3HUZ]

Nice! A Nine Pound Hammer. I love it.

[ve6pg]

...how is this thing programmed for it's freqs?....it wud appear it cant qsy down,or up 5kc, unless it is programmed?...channelized operation seems weird....tim...sk...

[KF1Z]

...how is this thing programmed for it's freqs?....it wud appear it cant qsy down,or up 5kc, unless it is programmed?...channelized operation seems weird....tim...sk...

It is crystal oscillator (dip) controlled.......
You order the frequencies you want put in it.
Anywhere in the band you want.......