S . Would be interesting to see how far OP30 would go with 1 w
Ae feed , would you reach Gary ?
G.
--------------------------------------------------
From: "Stefan Schäfer" <[email protected]>
Sent: Wednesday, January 11, 2012 2:02 PM
To: <[email protected]>
Subject: Re: LF: QRP 1W /PA circuit
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
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