Hi
> On Aug 4, 2020, at 5:23 PM, Poul-Henning Kamp wrote:
>
>
> Bob kb8tq writes:
>
>>> The "modern" approach to that is to modulate or dither with a
>>> good long PRNG to whiten the noise, and while good in theory,
>>> it is not _that_ easy to get right in practice.
>>
>> Of course o
Hi
> On Aug 4, 2020, at 3:50 PM, Poul-Henning Kamp wrote:
>
>
> Bob kb8tq writes:
>
>>> I have not given much thought to A11 yet, and I do find a certain
>>> elegance in the wien-bridge approach. It is worth noting that the
>>> actual heaters run of the unregulated supply, when I sta
Bob kb8tq writes:
> > The "modern" approach to that is to modulate or dither with a
> > good long PRNG to whiten the noise, and while good in theory,
> > it is not _that_ easy to get right in practice.
>
> Of course one could simply cave in to the fact that for the sort of
> gain required
Bob kb8tq writes:
> > I have not given much thought to A11 yet, and I do find a certain
> > elegance in the wien-bridge approach. It is worth noting that the
> > actual heaters run of the unregulated supply, when I stabilized
> > that, A11 worked less hard.
>
> The AC bridge approach cer
Hi
> On Aug 4, 2020, at 3:07 PM, Poul-Henning Kamp wrote:
>
>
> Bob kb8tq writes:
>
>> If a more extensive rebuild is in the works …..
>
> Yes, that's where we're headed eventually, but I prefer to do it
> incrementally.
>
>> +/-20V is (as has been observed) not an ideal voltage for
Bob kb8tq writes:
>If a more extensive rebuild is in the works …..
Yes, that's where we're headed eventually, but I prefer to do it
incrementally.
>+/-20V is (as has been observed) not an ideal voltage for “modern”
>electronics.
Right, and being able to drop that down later is in the
Hi
> On Aug 4, 2020, at 2:49 PM, Poul-Henning Kamp wrote:
>
>
> Bob kb8tq writes:
>
I would go for the LTZ1000 if you can. The LM399 has gone out of
fashion for a reason: [...]
>>>
>>> Yes, I know, being also a volt-nut :-)
>>>
>>> Problem is, the A15 PCB isn't all that big
Bob kb8tq writes:
>>> I would go for the LTZ1000 if you can. The LM399 has gone out of
>>> fashion for a reason: [...]
>>
>> Yes, I know, being also a volt-nut :-)
>>
>> Problem is, the A15 PCB isn't all that big, and if you want
>> cooling fins on two TO220's, a lot if it just got occu
On 8/4/2020 10:21 AM, cdel...@juno.com wrote:
>
> Back in Nov 2017 I detailed my A15 mods:
>
> Set Zener current to minimum TC (I achieved < 1PPM/C at the +20V output)
> This involved disconnecting the C-field circuit and replacing it with a
> dual (in series ) LM299AH and 1PPM resistors. Jumpera
Hi
If a more extensive rebuild is in the works …..
+/-20V is (as has been observed) not an ideal voltage for “modern” electronics.
If you dig into each of the boards, there is a lot of “drop it down right now”
regulation
done on a board by board basis. More or less what might be there:
A1 Synt
>> C-field polarity switch. An experiment. If nothing else
>> I will be able to measure the residual magnetic field.
There is no requirement to do any thing other than switch the C-field
polarity.
No optical stuff needed.
The PRS10 switches the C-field polarity at a 5HZ rate to reduce
Thanks for doing that, Steve. I've added your hpgl -> PDF files to
Rick's www.leapsecond.com/u/rk/ directory:
asdrawa-8.pdf
asdrawa.pdf
asdrawb.pdf
E1938_68001_51.pdf
/tvb
On 8/4/2020 9:00 AM, Steve Hendrix wrote:
I have tools to turn those into PDFs if it would be helpful.
Steve Hendrix
A
Decommissioning an old hard drive and found these> files. I don't
know if they are already in
circulation; I can't view the hpgl ones
See:
http://www.leapsecond.com/u/rk/
Rick N6RK
___
time-nuts mailing list -- time-nuts@lists.febo.com
To u
Hi Poul-Henning,
On 2020-08-04 12:35, Poul-Henning Kamp wrote:
>
> Magnus Danielson writes:
>
>> If that is the range you aim to improve, then I strongly recommend you
>> do re-read the postings I did about phase noise in detector range, as I
>> have showed that phase-noise get's mixed do
Magnus Danielson writes:
> If that is the range you aim to improve, then I strongly recommend you
> do re-read the postings I did about phase noise in detector range, as I
> have showed that phase-noise get's mixed down to DC and increase the
> noise there. With very ugly and hand-wavey h
Hi Poul-Henning,
On 2020-08-04 00:32, Poul-Henning Kamp wrote:
>
> Attila Kinali writes:
>
>>> The main reason I dont just repair/replace the A15 is that
>>> I want to find out how much instability the PSU contributes.
>> There are very few points where supply voltage (in)stability
>> co
16 matches
Mail list logo
