Re: [time-nuts] Cheap Rubidium (heatpipe cooling for)

At 12:00 PM + 12/27/09, time-nuts-requ...@febo.com wrote: Date: Sat, 26 Dec 2009 17:04:46 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com

[time-nuts] Fluke (Montronics) Model 207-5 WWVB Receiver/Comparator

Hello Group Members, I have a Fluke (Montronics) Model 207-5 WWVB Receiver/Comparator with various problems to many to mention on this list, if someone has any experience with this model and would like to help out please contact me off list salc...@rogers.comthank you for helping out.   Sal C.

Re: [time-nuts] Cheap Rubidium (heatpipe cooling for)

Hi The tip it and listen to it slam test is a standard way of checking out a triple point of water cell for basically the same reason (you check the vacuum. Of course since a TWP cell is thin glass and not a nice metal pipe, you *may* break the seal by testing it Bob On Dec 27, 2009,

Re: [time-nuts] Cheap Rubidium (TEC devices)

Hi Just in case anybody else is also looking for TEC's: The eplace has a number of Asian sellers with 100 to 150 W (power not Q) TEC's in the $3.xx to $5.xx range for 10 to 20 pieces delivered to the US. Assuming they are functional, that looks like better deal than scrapping out brand new

[time-nuts] Reminder -- MVUS Frequency Measuring Test begins 1500 UTC Monday

We're all set for the FMT beginning at 1500 UTC tomorrow. A couple of minor changes from the earlier announcement: * The 80M frequency will be around 3583 kHz, not 3577. * The 2M frequency (within 50 Hz) will be 144.2743 MHz. * We'll have a little more power on HF than we thought -- about 15

[time-nuts] Timenoob - Cheap and simple 10MHz reference

Hi all, just subscribed, I would like a quick advice on a 10MHz reference for calibrating my instruments and for fun. In particular, I would like to know if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, Thunderbolt and such. I would prefer a GPSDO (like the Thunderbolt),

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

Hi Your budget is going to make things tough. A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also needs a GPS antenna of some sort. The Rubidiums all need a supply and a heat sink. Some of them like the FRS-A need unusual connectors. They all need to be operated

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

And started down the dark path you have. You will not have to wait long before you completely succumb to the dark side. Jim Palfreyman 2009/12/28 Bob Camp li...@cq.nu: Hi Your budget is going to make things tough. A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also

Re: [time-nuts] chip scale atomic clock

On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or

[time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator

Interesting read on a low phase noise oscillator by Chris Bartram GW4DGU http://www.christopherbartramrfdesign.com/blaenffos/oscillator/VLNO.pdf ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

Thanks a lot to all for your quick answer. Rubinium should be good for my needs, but buying it surplus makes me think I could get something very used (and abused) and it does not have the self correcting thing thunderbolt has. GPSDO gives me also the time, maybe with a supercool LCD display.

Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator

Tom Clifton wrote: Interesting read on a low phase noise oscillator by Chris Bartram GW4DGU http://www.christopherbartramrfdesign.com/blaenffos/oscillator/VLNO.pdf There are several VHF crystal Oscillators designed by M Driscoll. The one shown is merely derived from one variant. It has

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

giuse...@marullo.it said: Do you know exactly the power requirement? On Ebay I read 15W then few mA on each branch (board only). Something is not clear to me. http://www.leapsecond.com/pages/tbolt/power.htm Lots more Thunderbolt info here: http://www.leapsecond.com/pages/tapr-tbolt/ --

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

Hi Giuseppe, I think you would be better served with the Thunderbolt as it is both a GPS and an oscillator, that is it is a GPSDO. Last I remember, an eBay user Flukel (the last character is a lower case L) was spoken of, on this list, as being a reliable Chinese vendor. He had oscillators,

Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator

Hi The feedback network in the Fig 7 schematic makes a lot more sense than the network in the first Fig 7 Bob On Dec 27, 2009, at 7:19 PM, Tom Clifton wrote: Interesting read on a low phase noise oscillator by Chris Bartram GW4DGU

Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference

Hi The simple answer on the supply is that there are a couple of answers. Very little current is pulled from the -12 supply. I can not imagine a supply that would not keep up with the -12 requirement. The +12 supply mainly runs the OCXO in the unit. Since it's running an oven, the power will

Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator

An inductor in series with the 220 ohm emitter resistor will improve the phase noise floor. The MMIC output amplifier has a wider bandwidth than necessary and doesn't have a particularly high reverse isolation. One could improve this by substituting a CB cascade or other discrete amplifier