Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: QRP 1W /PA circuit

To: [email protected]
Subject: Re: LF: QRP 1W /PA circuit
From: "Douglas D. Williams" <[email protected]>
Date: Wed, 11 Jan 2012 10:22:56 -0500
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; bh=5kFzyttk0KxwtMg7ncUhF8VADc5w7CyqhphXDa5skxo=; b=cfe45nMof0bQ102KzEcnUmAp4tlp3Y0Sivq/j0jBxCPAMlTqFX79CuuorssXqvQaR1 GGnLdHk+M4zqq5ZvAEsFyfH/XGa9c+kdBLsDPIgza+yQsQXpXay7/SEum7q05CJf5xAE 0DBvZ63fpdAiE8xbWBsbvNvuHpzzdjKTeyF6k=
In-reply-to: <[email protected]>
References: <CAA8k23Qqo4ZagVGLdEiUqGSU-HL_XNpues+rPAr7NwOhiyd1zQ@mail.gmail.com> <[email protected]> <[email protected]> <CABP+t7Y47ePqNug_tWozoBVux9MJKRd0gyWS-aNLsqnMndoWfQ@mail.gmail.com> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
Well, difficult but not impossible. We will see tonight if you are
still QRP. Unfortunately, the band has been noisy with QRN the last
couple of nights.

On 1/11/12, Stefan Schäfer <[email protected]> wrote:
> Hi Doug,
>
> Thank you for your continued interest :-)
>
> I enabled SpecLab's "beacon mode" so it will run endless until i stop.
> And i will stop when the new FETs arrived here :-)
> However i see no chance at all that you will receive anything at all,
> not even in DFCW-900000000000000 ;-). I'm transmitting 1W TX power, not
> 1W ERP!
>
> Iceland may be the best DX to be expected, if conds are good and QRM is low.
>
> Back soon! The new FETs have excellent data: Higher VDS, lower Rdson,
> lower input C, faster switching times. The recovery times and dv/dt are
> much better too (not really a FREDFET though) so i will keep the RC
> circuit...
>
> 73, Stefan/DK7FC
>
> Am 11.01.2012 13:40, schrieb Douglas D. Williams:
>> I'll give a listen tonight, Stefan, if you are still in QRP mode.
>>
>> Doug
>>
>> On 1/11/12, Stefan Schäfer<[email protected]>  wrote:
>>
>>> LF,
>>>
>>> Last night i shot my PA again :-( No replacement FETs were available so
>>> i had to stay quite during the night. Replacement parts are ordered now
>>> and will arrive tomorrow :-)
>>>
>>> During that time i will run a *LF beacon on 136.172 kHz running _1W TX
>>> power_ in DFCW-90*, starting in the afternoon. If someone can receive
>>> that weak *QRPP* signal, then a* report is very apprechiated :-)*
>>>
>>> Also i will do some optimisations on my recently posted PA output stage
>>> (http://dl.dropbox.com/u/19882028/LF/DK7FC_137kHz_TX_antenna_and_PA_schematic.jpg),
>>> just in case someone wants to build a similar design and is interested
>>> in general:
>>>
>>> -R= 100 Ohm/2W (In series with C, across  Drain-Source)
>>> -C= 220pF/WIMA FKP-1 2kV  (In series with R, across Drain-Source)
>>> -MOSFET: The IRFP460
>>> <http://dl.dropbox.com/u/19882028/Datenbl%C3%A4tter/irfp460.pdf>  will be
>>> replaced by a SPW20N60C3
>>> <http://dl.dropbox.com/u/19882028/Datenbl%C3%A4tter/SPW20N60C3.pdf>  :-)
>>>
>>> 73, Stefan/DK7FC
>>>
>>>
>>
>
>


<Prev in Thread] Current Thread [Next in Thread>