Terry,
I beg to differ. I did extensive comparisons of the UBLOX units with my
Rb. There is also an article by an LA ham concluded the same.
Yes there is jitter, however it's peak amount is fraction of the 1 Hz
step the XREF corrects for.
If you're interested I'll send you a plot of deviations.
73 de Brian/K3KO
On 3/10/2016 5:04 AM, [email protected] wrote:
The Ublox GPS units (like the Neo-6 and NEO-7) are not great for this
application. Their master oscillators are an oddball frequency (as far
as freq standards go, IIRC 48MHz?). That doesn't divide evenly to
10MHz, so there is some jitter component at 10MHz output. Not what you
want for a reference signal.
I've used a used commercial-grade GPSDO that I found used, and an
HP3801A from ebay, both less than $100.
I've also purchased rubidium-based units, Efratom LPRO-101 from ebay for
about $75 each.
There are several other GPS-based thingies that aren't "disciplined" for
pretty good prices. The older Trimble units are usually good. Hams
Summers of QRPLabs.com sells a QLG1 for about $23 that seems to be
usable - I think. I've got one for my QRP Labs beacon. You might want
to look at the specs for the SKM1 GPS module on his board.
There are many designs for GPS disciplined oscillators, and many
inexpensive GPS receivers out there. Make sure their 10MHz output is
stable. However, if you want "portability", or your shack can't easily
see the sky, you might want to check out the various rubidium
oscillators instead. I'm sure you can find a TON more info on the
timenuts forum.
Also be careful with the 10MHz reference signal distribution, it can
play havoc with the 30 Meters band (and 10MHz WWV), especially it it's a
ratty square wave.
73, Terry, N4TLF
-----Original Message----- From: Kevin Cozens
Sent: Wednesday, March 09, 2016 5:51 PM
To: [email protected]
Subject: Re: [Elecraft] 10 MHz external reference
Am 09.03.2016 um 18:37 schrieb Gary Smith:
What external 10-MHz reference signal source might I find get that is
not terribly expensive that will do the proper job and allow me to
get this working?
You can look for a GPS disciplined oscillator (GPSDO), an FE-5680 Rubidium
based oscillator, or look for some of the lesser expensive GPS receiver
modules that have 10MHz outputs.
A GPSDO can be expensive but there are some more affordable ones if you
look
around. FE-5680's used to be available around $100US (or less if you got
lucky). Lately the prices seem to have gone up for these devices, and they
tend to be power hungry. There are some GPS receiver modules that have GPS
receiver blocks on them made by companies such as Ublox. Take a look for
GPS
receiver devices that are meant to be used as part of a flight control
system for radio controlled aircraft (or what some people call drones).
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