Re: [time-nuts] WTB: GPSDO

At 03:52 PM 3/22/2017, Nick Sayer via time-nuts wrote: Just a little side query… For those using one of these sorts of splitters with a Thunderbolt, have you seen anything odd? My thunderbolt *insists* on being on the DC Pass port. If you put it on a DC Mine doesn't. I just swapped ports

Re: [time-nuts] WTB: GPSDO

On Thu, March 23, 2017 9:36 am, Nick Sayer via time-nuts wrote: > The splitters I’m using do have a 200Ω load on them. I know this > because PA6H modules recognize an external antenna and use it. I may have been thinking of a different receiver, according to the Thunderbolt manual I just

Re: [time-nuts] WTB: GPSDO

The splitters I’m using do have a 200Ω load on them. I know this because PA6H modules recognize an external antenna and use it. > On Mar 22, 2017, at 3:20 PM, Chris Caudle wrote: > > On Wed, March 22, 2017 3:52 pm, Nick Sayer via time-nuts wrote: >> My thunderbolt

Re: [time-nuts] WTB: GPSDO

Hi, On Wed, Mar 22, 2017 at 05:20:31PM -0500, Chris Caudle wrote: > On Wed, March 22, 2017 3:52 pm, Nick Sayer via time-nuts wrote: > > My thunderbolt *insists* on being on the DC Pass port. If you put it on a > > DC Block port (yes, something *else* is on the DC pass port and supplying > > DC

Re: [time-nuts] WTB: GPSDO

On Wed, March 22, 2017 3:52 pm, Nick Sayer via time-nuts wrote: > My thunderbolt *insists* on being on the DC Pass port. If you put it on a > DC Block port (yes, something *else* is on the DC pass port and supplying > DC for the antenna and splitter at the time - other connected devices work >

Re: [time-nuts] WTB: GPSDO

> On Mar 22, 2017, at 12:40 AM, Thomas Petig wrote: > > > The special GNSS splitters forward DC only from one port and provide > some 200 Ohm DC termination together with the DC-block on the other > ports to keep the receiver happy, i.e., it seems current consumption and >

Re: [time-nuts] WTB: GPSDO

Hi Tim, On Tue, Mar 21, 2017 at 06:36:51PM -0700, Tim Lister wrote: > [...] > I have a Symmetricom 58532A GPS antenna which has a N female connector > but my 3 current GPS receivers all have SMA female connectors. If I > want to provide capacity for at least 4 receivers fed from the same >

Re: [time-nuts] WTB: GPSDO

So it seems the threat of replacement and a bunch of plugging and replugging into different computers has spurred my recalcitrant GPSDO back into life and it is now producing output again... This leaves me with the original problem of low sensitivity but at least I can solve that problem by using

Re: [time-nuts] WTB: GPSDO

On 3/20/17 2:26 PM, Mark Spencer wrote: Hi: Bob's comment about adjusting an oscillator from time to time aligns well with my limited experience in the time nuts hobby.Once I realized that in practice my better OCXO's were typically more than stable enough for my intended uses things

Re: [time-nuts] WTB: GPSDO

Hi A good OCXO run continuously should get down to < 0.1 ppb / week. Doing a tweak every Saturday is likely enough to keep it in that range. The *big* advantage is that you have the ADEV of the OCXO without any scruffy stuff from the control loop getting in the way. If your objective is to

Re: [time-nuts] WTB: GPSDO

Hi: Bob's comment about adjusting an oscillator from time to time aligns well with my limited experience in the time nuts hobby.Once I realized that in practice my better OCXO's were typically more than stable enough for my intended uses things became much simpler. I also realized that I

Re: [time-nuts] WTB: GPSDO

On Wed, Mar 15, 2017 at 1:09 AM, Attila Kinali wrote: > IMHO it's much easier to just > get a known-good GPSDO and a rubidium for verification. Yes, for sure it is easiest to buy something that already works. But the question was how to bootstrap from scratch? In other words,

Re: [time-nuts] WTB: GPSDO

On Tue, 14 Mar 2017 21:25:19 -0700 Chris Albertson wrote: > You can also verify the GPSDO is working correctly by looking at the > EFC voltage. That is the control signal the controller sends to that > $25 eBay crystal. You'd expect that the ESFC volts follows some

Re: [time-nuts] WTB: GPSDO

Yes, that is a problem. How to test a 10 MHz oscillator of any kind (GPSDO or not) if you only have one oscillator. I call it the "bootstrap problem" and I think it's worth some discussion. The easy way is to buy a few known good clocks before you set out to make a clock but that is the "easy

Re: [time-nuts] WTB: GPSDO

Hi > On Mar 14, 2017, at 6:33 PM, Tim Lister wrote: > > On Fri, Mar 10, 2017 at 2:35 PM, Chris Albertson > wrote: >> A GPSDO is not hard to make. All you need is some way to compare the >> phase of two signals, an XOR gate can do that. Then a

Re: [time-nuts] WTB: GPSDO

On Fri, Mar 10, 2017 at 2:35 PM, Chris Albertson wrote: > A GPSDO is not hard to make. All you need is some way to compare the > phase of two signals, an XOR gate can do that. Then a small $2 > process moves the control voltage on the crystal.I tried one to >

Re: [time-nuts] WTB: GPSDO

A GPSDO is not hard to make. All you need is some way to compare the phase of two signals, an XOR gate can do that. Then a small $2 process moves the control voltage on the crystal.I tried one to build the simplest GPSDO that could still work. Got the parts count down to about four or five

Re: [time-nuts] WTB: GPSDO

Jeff, I have been using a TrueTime XL-AK purchased on eBay a few years ago. It has worked flawlessly for the last five years. It seems to work well with most amplified antennas that I have tried. Supposedly accurate to better than 10 -12 but I have nothing to compare it to. It will supposedly

Re: [time-nuts] WTB: GPSDO

A few of us in the Twin Cities recently bought the current incarnation of the BG7TBL GPSDO - I can recommend this unit for value as well as the coverage it provides on simple Patch + LNA antennas versus the older egg or dome style units. The lower power consumption versus a Thunderbolt for example

Re: [time-nuts] WTB: GPSDO

Glad you didn't fare any worse in the event. Good luck and very 73, Jim wb4...@amsat.org On 3/9/2017 3:45 AM, Jeff AC0C wrote: We had a small tornado come through north of our house about 1/2 mile on Monday. Really did a number on the antennas. Only electronics impacted was my old

[time-nuts] WTB: GPSDO

We had a small tornado come through north of our house about 1/2 mile on Monday. Really did a number on the antennas. Only electronics impacted was my old Nortel GPSDO. It’s pretty much deaf now, as far as I can tell. The Nortel always had a hard enough time obtaining the initial lock in