Fred, KC4MOP

[WA3VJB]

The MOP-Man is BACK !!!

Heard him check in this afternoon down low out the ghetto.

Turns out this was the first flight through the airwaves with Fred's new "Class D" transmitter.

Take a listen: (1.5M file size, MP3)

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

K7DYY "Class D" transmitter website:

http://k7dyy.com/

[WA1GFZ]

Wow 600 watts peak on 2 FETs that is honking.

[KF1Z]

Wow 600 watts peak on 2 FETs that is honking.

Yes, doesn't seem to bad for a pair of 9amp 400volt mosfets.


Of course, $1.78 each...........

[flintstone mop]

Hello Folks
It's nice little box for $400.00 built. The kit is half but I can't see the dam components so I sent it back and gave money for the "upgrade" for a built Tx. I can old buzzard anywhere on 80M with the Class D final and no heat on the sink 180 carrier watts (designer says 200 Watts MAX carrier!!)  800 watts P.E.P...... the audio response is just ok HI-FI. I cannot hit it with extreme high end. The audio breaks up bad with excessive ssss or shhhhhh. 6KC is about it for audio and I guess for us that is acceptable. The filters used to keep the pulses out of the RF final also get into the audio range. I'm not very knowledgeable on the Class E/D modulation technique. Maybe with more agressive processing I could be louder. I'll play with it as time goes on.
Paul's MP3 sounded surprisingly good.........the HUZ and Dave were booming into Annapolis Md. I was a few steps down the dB ladder but commin' on through.
OK FINE. It was a nice QSO
Fred

[K4QE]

Paul,

That audio file sounds fantastic!  Was that made with your SDR-1000?

[WA3VJB]

Nah,
I don't have the Flex/SDR1000 but I've been damned impressed both on transmit and receive.

Fred, Steve/HUZ and Dave/ZRF were recorded from the Diode Load of a 1966 R390A, about 40 years before the SDR1000.
But thanks.

Up on 40m this afternoon I worked Dave W9AD, who DID make a recording of me on his FlexRadio.
He's got synchonous detection and assymetrical bandwidth to take the cleanest chunk.

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(mp3 file size 430K)

[steve_qix]

Wow 600 watts peak on 2 FETs that is honking.

Hey Frank - we (you and I) do that all the time, every day with our transmitters (at least I do with mine !! - I thought yours was similar).  I run 6 FQ111N90 FETs (real cheap price) at 400 watts carrier.  The transmitter EASILY makes 150% positive (it will actually do 200%).... so EACH MOSFET is doing at least 416 watts peak - 2 FETs do 832 watts and so on.  And that's running things fairly conservatively.  Aren't your parameters similar?

Regards,

Steve

[WA1GFZ]

Yup 22 FETs 1 KW carrier stone cold....well a little warm.
need to get back to the modulator this year if I can break away from SDR stuff

[flintstone mop]

Hello fellow Amers
For The Record. This IS the QSO part of the forum. Here is a pic of me and the Family

Thanks
Fred, Anna Liza, Adrian baby boy 8 mos.