[Amps] New SB-200 owner

[Steve Thompson]

Joe Subich, W4TV wrote:
> 
>>It needn't be. If you stay simple, a dropper from the anode 
>>supply with an uncomplicated active shunt regulator costs 
>>about a pack of beer. 
>>Regulation is more than adequate. I begrudge wasting 30W as 
>>heat, but it saves a transformer.
> 
> 
> High impedance droppers from the HV supply and "adequate" 
> regulation typically is not adequate from an IMD viewpoint 
> no matter what certain proponents of tetrodes would have you 
> believe. 
> 
> Karl is probably referring to the work by GW4FRX reported by 
> Ian,, GW3SEK at: www.ifwtech.co.uk/g3sek/cleansig/imd1.htm 

Perhaps I should have been more careful with words. By 'adequate' I 
meant good enough that it wasn't the predominant factor in IMD 
performance - in effect, giving the same results as John and Ian's 
regulators. That can be achieved with a fairly simple and inexpensive 
active shunt regulator - I was not thinking of a string of zeners.

 >
 > The bottom line: a pair of 4CX250s are good for maybe -30 dB
 > IMD3 with a very well regulated screen supply.

Yes, at 250-300W out.

Steve