Message-ID: <4BD649516CDF4CE18041D66405E9F97E@WarrenPC>
From: "K2ORS" <k2ors@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
Cc: <g3kev.ham@virgin.net>
References: <pre$151.24.46.161$.NCEFLJLAMJBHGGACJJMDAEIFCEAA.pre@libero.it> <000401c83119$0c401990$3de4fc3e@g3kev>
In-Reply-To: <000401c83119$0c401990$3de4fc3e@g3kev>
Date: Wed, 28 Nov 2007 20:01:36 -0500
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Subject: LF: Re: Re: R: classs E
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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
>>
>>
>>
>>
>>
>>
>
>