[Amps] Expert 1k amp

[Steve]

The diagrams I looked at came from here:
ok1hra.nagano.cz/Expert_Schematic_diagramsII.pdf
I can't see any mains filtering, and no power factor correction.

The repairs on my friend's amp required no more than removing the lid, 
so I can't vouch for what's actually inside the box.

What's the power limit for when power factor correction is required?

Steve

On 07/03/13 10:05, peter chadwick wrote:
> Steve, How much filtering is there to meet EU regs on noise put on
> the mains, and is there any power factor correction circuitry? 73
> Peter G3RZP
>
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> ======================================== Message Received: Mar 07
> 2013, 08:50 AM From: "Steve Thompson" To: amps at contesting.com Cc:
> Subject: [Amps] Expert 1k amp
>
> Yesterday I did some minor repairs to a friend's amp - resoldering
> joints on the current sensing resistor. Looking at the circuits later
> I noticed that the main supply voltage is regulated by having SCRs in
> place of diodes rectifying the transformer secondary and the main
> smoothing capacitor is 47000uF.
>
> My friend tells me the amp runs over 40A at full tilt, which means
> something like 8.5V ripple on the supply (7V at 60Hz). That strikes
> me as quite high and I'd expect to see some difference in amplifier
> gain/output if I was running such an amp off a regulated supply and
> altered the voltage that much. Has anyone measured one? Is any
> 100/120Hz audible on a carrier?
>
> Steve _______________________________________________ Amps mailing
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