Maybe you must look for simply one of early days HiFi audio amps.
Someone gave me recently a SONY F420 (1990 design!). 2X 70W @ 4 Ohm flat
response up to 100kHz.
I put the Ultimate 3S on it and indeed almost 200W @137kHz could be
dissipated in resistors here without any mod.
The unit has a "direct drive" mode, input full flat connected to the PA.
I don't have space/suitable antenna for 2200m :-(
Even 470kHz came thru but not at this power with some fiddling best 40W.
But assume when the circuit is modified (redesign feedback circuit), MF
can come in the picture.
Maybe you can have a look at a "recycle centres"
Some idea? http://www.w1tag.com/XESTX.htm
Jan/pa3abk
On 8-1-2016 23:08, Andy Talbot wrote:
No Graham -
I don't want an EER design - that may be for another project in the
future. And I'd certainly not do it by
trying to regenerate a signal using analogue techniques. EER has its
place, but only when the siganls are generated ion polar form in the
first place. Class E amps are just asking to be used in that way - my
measurements suggest they exhibit and impressively linear power out vs.
Vdd characteristic.
But for reproduction of signals generated via an upconverter, I'm
looking for a conventional proven linear type amp
Andy G4JNT
On 8 January 2016 at 21:59, Graham <[email protected]
<mailto:[email protected]>> wrote:
__
M0BMU from 2007
http://w4dex.com/projects/EER_Transverter_v2.pdf
G,
*From:* Andy Talbot <mailto:[email protected]>
*Sent:* Friday, January 08, 2016 9:45 PM
*To:* [email protected]
<mailto:[email protected]> ;
[email protected]
<mailto:[email protected]>
*Subject:* LF: Linear Amp for LF
Are there any proven reliably designed LF amplifier designs power
amplifiers for 137 / 475? Wideband, covering both ideally
Rated for at least 300 Watts output, and ideally a lot more.
I saw G3YXM's low-HF design, and it looks promising for low
frequency use, but he appears to have not gone that way and went for
a switchmode version at LF/MF
Of course, I could just redesign that, or something similar, using
suitable ferrite and a bit of feedback ,but it would be nice to
avoid reinventing too many wheels.
Using switching MOSFETs as linear amps still doesn't feel quite
right, but enough people seem have managed it now (including my own
design for a low power one) that it looks a sound-enough route to
follow up. The one thing that does bother me about the technique
is bias compensation with temperature. It is really asking for
active bias control, but in a class-B or -AB design, where bias just
affects standing current, that gets more-than a bit tricky as a concept.
Andy G4JNT
--
pa3abk <-> dordrecht jo21it
Sent by Philips STB-75 with T100
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