GNSSs - and the capability to add others w/o major surgery, and add a rubidium clock as a bonus. Very compact modules are currently available to do all of this. GPS-only represents
a glaring single-point-of-failure in a world where geopolitical tensions suggest diversifying one's information sources.
The day the current GPS system totally fails will probably be a bad day, I'm probably going to be to busy ducking, and swerving to worry about the accuracy of the VFO's or about the nanosecond accuracy of a clock, for a few days when that happens.
Beyond a few days, lets hope I don't survive. DX is likely to be all thats available after that. Band noise might or might not be a factor.
I plan on installing alternate modules if/when they become available.
I can't depend on not surviving, to err is human.
Jay - NO5J
BEIDOU, GALILEO ... (see: http://www.spectraprecision.com/products/gnss-surveying/sp80-43987.kjsp), and I suspect a) either a common format exists or will evolve, and/or b) the modules will be field-loadable with new info. So I'd like to see Flex offer that Flex-ibility! The rubidium clocks are wonderfully small modules now; I really don't see a problem here with board real estate. I have badgered Flex about vertical card cage architecture from day zero - which would make upgrades trivial - but have been assured by the clairvoyant multitudes (!) that that ain't likely going to happen.
I suspect Flex will come out with a GNSSDO for the 7000 series.
Yes ... let's hope it doesn't become a critical resource!
and I built a atomic clock controlled 10MHz source, but I use it only for measurements, as almost all my TRX are stable enough. Exception is the elecraft KX3, which runs a bit when getting hot.
which I have built and which is working very well.
73, Alex DH2ID
systems (e.g. GLONASS, GALILEO, BEIDU (sp?), etc.) rather than just "GPS". One sees the beginnings of this in high-end surveying equipment. The chipsets are out there. No other arcana intended - at this time.
Really uncertain where a multi-system upgrade takes us?
Usually when you have to "marry" multi-system inputs a device has to prioritize and internally "vote" on a relationship that it then uses as primary anyways.
Given the present usage-limitations of much of what the present GPSDO could be providing for data time-stamping, and the dissipating/diminishing returns as other calculated limitations limit the achievable accuracy of the core equipment, would the expenditure to do multi-system be worthwhile?
Will an radio amateur be willing to invest many thousands of dollars to "be ready for a post-GPS multi-system possible potential need" rather than wait to swap out the optional GSPDO for some other GNSSDO module in the future? Remember the Spectra Precision location receiver mentioned is on its own a $12,500 unit, and carries a $3,000 premium over the equivalent GPS-Only unit.
So would a $3,700-plus GNSSDO module be worth it to a ham over the present $700 module?
And that $3,000 increment is extrapolated, as it could well be two-three times more of an increase.
With the present usage, rather unlikely.
About 8 years ago I built a Rb-frequency reference for my Flex-5000A https://k9zw.wordpress.com/2010/04/28/getting-exactly-in-step-adding-a-rubidium-frequency-reference/ and found it useful. Surplus cell-tower unit interfaced to the transceiver. Worked awesome after it was on & stabilized, but wasn't anything special for a few minutes when first turned on.
When my Flex-6700 (#11 BTW) delivered I discovered the Flex-6700 with the GPS "Off" was on par with the externally reference Flex-5000A. Lacking either the equipment or training to dig deeply into the ultimate performance I've soldiered on with the Flex-6700 with the GPS enabled and the Rb-Reference sits in a box as the Flex-5000A ended up in a cousin's ham shack.
I mention this as I did notice the Rb-Reference had a heat signature - which could be a difficultly putting "under the hood" in a radio not intended to have another heat source added to its cooling load. I'd have to dig it out to investigate where and why the Rb-Reference gave off heat.
What does one do with the frequency accuracy and the time-stamping the available GPSDO offers?
Additional frequency accuracy is always a plus, but only to the limits of the resolution effectively used in amateur pursuits.
The time-stamping is largely underused/unused but offers future upside potential for signal combining. Five-six years ago I outlined my thoughts on what the timestamp might do: https://k9zw.wordpress.com/2012/09/05/flex-6700-fantasies-dreaming-what-might-be-series-diversity-re...
Now I doubt an radio manufacturer is going to install a used reference on their add-in module, so I doubt the $200-250 price point of my homebrew unit relates to an all new unit (I know the module I used was about $1500 or so new).
In summary, while technologically appealing the migration from GPSDO to GNSSDO has low Return-on-Investment, potentially at costs exceeding the host radio's base costs, and brings complexity to where a simple solution is more than adequate.
(We also haven't even touched on the sensor antenna differences and other technological differences BTW).
The move to GNSSDO may be theoretically elegant but offers rather little as a practical benefit for the investment.
Internalizing a Reference Source has potential, but loses the commonality of a shared time reference for future SmartSDR signal combining or wide-space diversity with multiple antenna/transceiver set-ups. It also may have a heating issues to be engineered around as a side issue.
The Internal Rb-Reference offers only a subset what the present GSPDO has for capabilities, and has side issues to deal with, while only offering perhaps a cost savings - and maybe not even that.
YYMV of course and a very interesting discussion!
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