[time-nuts] Anybody want a Thunderbolt power supply

Gerhard Hoffmann dk4xp at arcor.de
Thu Sep 1 11:25:39 EDT 2016


Am 01.09.2016 um 16:36 schrieb jimlux:
> On 8/31/16 10:24 PM, Gerhard Hoffmann wrote:
>> Am 01.09.2016 um 06:07 schrieb Bruce Griffiths:
>>> I have a quad LT3042 PCB that I must get around to assembling.One
>>> potential issue with the LT3042 is the relatively high noise at low
>>> frequencies when the capacititve bypassing of the resistor that sets
>>> the output voltage is ineffective.
>>
>> I wonder where that relatively high noise on the LT3042 might hide.
>>
>> <
>> https://www.flickr.com/photos/137684711@N07/24070698809/in/datetaken/lightbox/ 
>>
>>>
>>
>
> what's the input source for these measurements? Batteries?
>

Either NiMH batteries or a R&S NGT20 with the post filter box as in page 
9 of

< 
http://www.hoffmann-hochfrequenz.de/downloads/Noise_Measurements_On_Some_Laboratory_Power_Supplies.pdf 
 >

That would not make much of a difference.

Prefilter/test box and preamp were isolated and  in an another large ALU 
cargo box with beryllium copper
finger stock on the door and BNC bulkhead feedthroughs. The preamp runs 
on NiMH batteries. It's input
connection is just one semirigid SMA cable. If the testbox & preamp box 
touch, the resulting loop
creates an explosion of interference.

I used "The Art Of Electronics V3" and Aldert van der Ziel's "Noise in 
Solid State Devices And Circuits"
as insulators. A good foundation to build upon, in every respect. :-)

regards, Gerhard





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