[Amps] SS amps watercooling - was PowerGenius XL

[Roger (K8RI)]

A properly designed SS amp running Class A, AB1, AB2, B, and C uses 
about the same power and class as a tube amp may require less cooling 
than the tube amp as there is no heat from a filament.  Many tube amps 
in the legal limit  power range require fan cooling directed at the 
filament pins and lower seals.

Only SS amps using exotic modes require less cooling.

To me, it makes more sense to use modern devices that can run 2400 W for 
a pair of transistors per module, use a pair of modules through 
combiners, design the whole works for the legal limit and you will get a 
super clean amp for less than the cost of an equivalent tube amp and 
without the fan noise, without the need for a lot of complicated 
monitoring and protection circuitry.

Adding hardware predistortion gives an outstanding signal, while dynamic 
predistortion gives an even cleaner signal.

I've used several SS, air cooled amps in the 1 to 1.2 KW range and they 
did not suffer from excessive heat. In fact, they were very quiet, 
unlike my tube amps.

The only legal limit amp I have that is quiet is my old HT33B, but that 
legal limit was quite a bit less than today's.

73, Roger (K8RI)

On 2/21/2017 9:26 PM, Jim Thomson wrote:
> Date: Tue, 21 Feb 2017 20:11:42 +0000
> From: Manfred Mornhinweg <manfred at ludens.cl>
> To: amps at contesting.com
> Subject: Re: [Amps] SS amps watercooling - was PowerGenius XL
>
> Hi all,
>
> It's my humble opinion that this whole thread on how to cool high power
> solid state amplifiers, using water (or evaporation, oil, freon,
> whatever) is on the wrong track.
>
> Instead of using high power amplifiers built basically like small signal
> amplifiers on steroids, that is, transistors acting as RF-controlled
> variable resistors that drop more or less of the supply's voltage to
> produce the desired waveform, and thus incur in huge power loss that has
> to be removed as heat, we should be building high efficiency amplifiers,
> in which the transistors act as RF-controlled switches, so that the
> power loss is tiny and can be easily handled with very modestly sized
> heatsinks.
>
> The broadcasters have been doing it for ages. It's about high time that
> we "technologically advanced" hams do it too. A handful of hams are
> actually doing it, but most hams still cling to antiquated and
> inefficient technology, and that's really a shame.
>
> I don't mean to blame any individual ham. For a single individual it
> does take a considerable effort to think totally outside the box and
> come up with a good, highly efficiency, low distortion power amplifier
> that doesn't break the bank. But collectively we should be able to move
> standard ham equipment technology from class AB linear amps to something
> much better.
>
> Manfred
>
> ##  which broadcasters  are using SSB  ???
>
> Jim  VE7RF
>
>
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus