Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Scott Newell
At 07:38 PM 3/9/2019, jimlux wrote: Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V from one of those rechargeable USB power bricks. I was thinking about portable operation. My USB power bricks shut off the 5 V output if there's not enough load. Something to watch for.

[time-nuts] Accuracy/drift of Garmin GPS 16 HVS 1 PPS output under invalid fix conditions...

2019-03-10 Thread Steve Olney
Hi All, Just a basic question for an application with low accuracy requirements.  I only need an accuracy of +/- 1 ms on the 1 PPS signal. Does anyone have any data on the behaviour of a Garmin GPS 16 HVS (or be able to point me in the right direction to find such data) w.r.t. the 1 PPS

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Taka Kamiya via time-nuts
Let me try it.  I have a few of those 5V USB power supply.  I have on my desk, DC/DC converter that will take whatever to whatever.  Got a dozen from Amazon.  I'll set it to 12V.  I'm sure it will work in some fashion.  I've used unknown power supply (switching type) for various things, and I

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread ed breya
Jim said: The question is really more one of "how much filtering do I need to design into the downstream power supply circuits" The answer of course depends on the source and receiver of the noise. Common USB type systems and accessories are built to maximize cheapness, pass EMC testing well

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Bob kb8tq
Hi Part of the problem is radiated / mag coupled spur energy. One of the things that makes the fancier switchers more friendly is that they can contain this better. Bob > On Mar 10, 2019, at 12:10 PM, jimlux wrote: > > On 3/10/19 8:58 AM, Richard (Rick) Karlquist wrote: >> Check out the

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread jimlux
On 3/10/19 8:58 AM, Richard (Rick) Karlquist wrote: Check out the LT3045-1. Ive used the LT3042 in a space application, it is basically the same thing with lower output current. The really great thing is that the rejection extends up to 10 MHz. It is an ultra low noise (2nv) linear

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Gerhard Hoffmann
Am 10.03.19 um 15:54 schrieb jimlux: True.. but there are a plethora of the USB 5V power blocks around - in general, there are lots of USB 5V (noisy, I'm sure), e.g. Cars now have 5V USB jacks, so I was thinking about designing with that in mind. The question is really more one of "how much

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Richard (Rick) Karlquist
Check out the LT3045-1. It is an ultra low noise (2nv) linear regulator with very high PSRR that has a 1 MHz bandwidth. The -1 version can control an external switcher (or linear) regulator ahead of it, where the voltage drop across the LT3045-1 can be set to, say 1V, and the front end supply

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread Bob Camp
Hi If you use the typical eBay units, they have a *lot* of noise. There are devices like the Linear Tech “switchers on a chip” ( = Silent Switcher) modules that can be quieted down pretty well. You needed a good board layout to do it though. They claim to have reduced that problem with the

Re: [time-nuts] Power supply for OCXO using "USB power blocks"

2019-03-10 Thread jimlux
On 3/9/19 7:42 PM, Gerhard Hoffmann wrote: Am 10.03.19 um 01:38 schrieb jimlux: Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V from one of those rechargeable USB power bricks.  I was thinking about portable operation. In my case, the OCXO is something like a Wenzel

Re: [time-nuts] Query about Guidetech products

2019-03-10 Thread Bob Camp
Hi Used a lot of their gear back many decades ago. I also knew a few of the people who worked there back in that era. The stuff always seemed to do what I needed it to do. Bob From: AC0XU (Jim) Sent: Sunday, March 10, 2019 1:00 AM To: time-nuts@lists.febo.com Subject: [time-nuts] Query