Hi Joe.
Just place a suitable resistor in the dc feed to the FET so that when the
max FET current flows there is 0.7v across this resistor, then connect the
base and emitter of a transistor across this resistor and use the collector
current to fold back the dc voltage so it current limits.
Regards
Ken
M0KHW
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Thursday, January 13, 2011 12:12 PM
Subject: RE: LF: VX9MRC 507.77 kHz
Thank-you Victor for the very clear copy. The TX shut down overnight when
a fuse became dislodged in the power supply. Also at one point during
an aerial tuning session, the TX keyed when the aerial was disconnected.
The FET fried and blew a fuse in the power supply. It seems this happens
quite frequently given the growing population of fried fets in the
semiconductor cemetery. Perhaps a current limiting stage in the power
supply is in order, if anyone can suggest one.
73 and thanks
Joe VO1NA
On Thu, 13 Jan 2011, [email protected] wrote:
Hello Joe,lf,
very good copy of your signal
73
Victor
PA3FNY
-----Oorspronkelijk bericht-----
Van: [email protected]
[mailto:[email protected]]Namens [email protected]
Verzonden: woensdag 12 januari 2011 17:39
Aan: [email protected]
Onderwerp: Re: LF: VX9MRC 507.77 kHz
Thank-you Warren and sorry Group,
Yes, 184 kHz is down for the moment. Any reports on
507.77 kHz will be appreciated. The TX is a class E
but only 100 watts. With Alan's spread sheet, it
was straightforward to design.
73
Joe
On Wed, 12 Jan 2011, Warren Ziegler wrote:
Joe,
Does this mean you are off 184kHz?
--
73 Warren K2ORS
WD2XGJ
WD2XSH/23
WE2XEB/2
WE2XGR/1
On Wed, Jan 12, 2011 at 7:05 AM, <[email protected]> wrote:
Greetings all.
VX9MRC will be on tonight 2359 utc with an 8 WPM CW beacon and
QSX 501 and 504 kHz on the half hours.
73
Joe
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