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LF: RE: QRS600

To: "[email protected]" <[email protected]>
Subject: LF: RE: QRS600
From: Rik Strobbe <[email protected]>
Date: Fri, 10 Sep 2010 10:13:06 +0200
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Thread-topic: QRS600
QRSS600 (= 10 min dot rate) requires a TX, RX and propagation stability of 1mHz (milli Herz) so for that reason it will probably be used only on VLF (ie. 9kHz or less)
Class D transmistters on 9kHz can have an efficiency of 90% and there are plenty of cheap power FET's or IGBT's rated >300W  dissipation and > 700V (what means you could run them right of mains voltage).
A 2kW amplifier should dissipate no more than 200W, in an H-bridge amp this power is spread over 4 transistors, so 50W each.
 
73, Rik  ON7YD - OR7T
 

Van: [email protected] [[email protected]] namens mal hamilton [[email protected]]
Verzonden: vrijdag 10 september 2010 9:47
Aan: rsgb
Onderwerp: LF: QRS600

How many transmitters could stand this duty cycle, especially the QRO versions. The time needed to send a full callsign for ID could well burn the TX out.
Those using QRS 120 in the past for prolonged periods reported problems.
g3kev
 
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