LF: Re: Re: R: classs E

["K2ORS" <k2ors@comcast.net>]

Mal,

 Why not post the schematic on the Lowfer forum?
http://www.kc3ol.dynip.com/forums/index.php

73 Warren K2ORS


----- Original Message ----- 
From: "hamilton mal" <g3kev.ham@virgin.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Tuesday, November 27, 2007 11:50 AM
Subject: LF: Re: R: classs E


> Hi Enrico
> The cct diagram is too large for the reflector, so would have to go 
> direct.
> It E pa is vy inter dependent on V/W/Q etc and pse refer to Tonne s/ware
> V2.01 for design criteria. Mine is qrp for 500 and works fb and reliable.
> No smoke etc hi
> Pse listen for me on 502.5 khz and call me on 3533/7033 khz for a xband 
> QSO.
> 73 de Mal/G3KEV/IO9SH
>
> ----- Original Message -----
> From: "Enrico" <pre@libero.it>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Monday, November 26, 2007 7:52 PM
> Subject: LF: R: classs E
>
>
> > Hi Mal,
> > can you please tell me what kind of PA are you using? Have you an
> electrical
> > scheme?
> > Thank you an Bye.
> >
> > IW4CXL
> > Enrico
> >
> > -----Messaggio originale-----
> > Da: owner-rsgb_lf_group@blacksheep.org
> > [mailto:owner-rsgb_lf_group@blacksheep.org]Per conto di hamilton mal
> > Inviato: domenica 18 novembre 2007 16.54
> > A: rsgb
> > Oggetto: LF: classs E
> >
> >
> > Hi all
> > I carried out some analysis on my fet pa today to check the waveform for
> > true class E. Monitoring the drain on a scope revealed that the waveform
> was
> > almost correct but needed a slight increase in capacity for C2 for an
> almost
> > perfect switch at 502.5 khz. Increasing/decreasing the voltage did not
> make
> > a big difference to the waveform, at the design voltage it was only
> slightly
> > better.
> > Using a DL I altered the freq and found the perfect waveform at 535.9 
> > khz,
> > so I expect logically increasing the value of C2 would correct the 
> > anamoly
> > at 502.5 khz. I have not altered it yet because I do not have a suitable
> > capicator.
> > I did observe some ripple on the waveform that is probably caused by feed
> > through from the driver, it was more pronunced at a V lower than the
> design
> > voltage, but improved with a V increase.
> > In spite of the above observations the PA performs well and seems very
> > robust.
> > The RF pwr out  measurements using the DL or the Antenna do not vary,
> > indicating that the antenna is well matched to 50 ohms via the atu at the
> > base of the inv L.
> > I thought the above observations might be interesting to would be class E
> > constructors.
> > Considering mine was built from junk box bits, including the 60 year old
> > ceramic ex TU5 tuning unit coil  it works very well. The fet is out of an
> > old marine tx.
> > Best dx to date VE1ZZ at 549 during ideal conditions last week.
> > 73 de Mal/G3KEV