K3 External Frequency Reference Questions

[dhhdeh]

Hi All,

I'm interested in possibly trying the K3EXREF in
my good ol'  K3 for no good reason other than its
something new and fun to try and can give some
bragging rights about frequency accuracy.  Can any
of you comment on your experiences in using the
K3EXREF? Elecraft provides very little background
info on how to get started with this accessory
after its installation.

I see that the once prolific Trimble Thunderbolt
units are now quite scarce on eBay and elsewhere
those that are available are now really pricey.  
What are any of you now using if you went the GPS
disciplined oscillator route?  Have any of you
used a rubidium standard as the alternative?

This may sound naive, but is a rubidium standard
device safe to have at home, i.e. is it
radioactive? I think I know the answer but I want
to ask anyway. With a toddler grandson around here
often I want to be very safe and very certain.

Any suggestions as to how to proceed, encountered
pitfalls and sourcing a reasonably priced
frequency standard would be greatly welcome.

I thank you all in advance.

73 de N1LQ-Dave
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[Roger de Valle]

Dave

I installed one about the time they were released, it was a pain free
exercise, plug an external 10Mhz in and it worked, unplug it and it falls
back to the internal reference. The whole exercise has proved invaluable for
external microwave transverters as well as the internal 2M module which is
now locked.

I built a 10Mhz reference based on the VE2ZAZ design (
http://ve2zaz.net/GPS_Std/GPS_Std.htm ) and used it to reference my test
equipment, frequency counter, signal generator as well as the K3, my shack
is basically GPS reference locked.. It is a GPS locked reference, a little
slow to lock, about 5 mins but rock solid when locked (I never turn it off).
Bert VE2ZAZ also had a design for a station clock based on the GPS receiver,
now this is one of the best things I have ever built.

I also have Rubidium standard but rarely use it for anything, it draws a lot
of current, particularly at start up. The only warning I have ever seen
about radiation was from spectratime (
http://www.spectratime.com/uploads/hazmat331.pdf ) and I doubt it is an
issue for anyone. The lamps lose efficiency as they age as well and some of
the older ones on EBay are getting to the age where they are marginal.

If you decide to build one I am sure there are lot of folks who have done
just that and can assist you, I would be happy to share my construction
experiences off list with you.

Regards.
Roger VK3ADE.

-----Original Message-----
Subject: [Elecraft] K3 External Frequency Reference Questions

Hi All,

I'm interested in possibly trying the K3EXREF in my good ol'  K3 for no good
reason other than its something new and fun to try and can give some
bragging rights about frequency accuracy.  Can any of you comment on your
experiences in using the K3EXREF? Elecraft provides very little background
info on how to get started with this accessory after its installation.

I see that the once prolific Trimble Thunderbolt units are now quite scarce
on eBay and elsewhere those that are available are now really pricey.  
What are any of you now using if you went the GPS disciplined oscillator
route?  Have any of you used a rubidium standard as the alternative?

This may sound naive, but is a rubidium standard device safe to have at
home, i.e. is it radioactive? I think I know the answer but I want to ask
anyway. With a toddler grandson around here often I want to be very safe and
very certain.

Any suggestions as to how to proceed, encountered pitfalls and sourcing a
reasonably priced frequency standard would be greatly welcome.

I thank you all in advance.

73 de N1LQ-Dave
______________________________________________________________


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[Elecraft mailing list]

I installed a K3EXREF and set up a Trimble Thunderbolt a few months
ago, and I've been very happy.

The K3EXREF was very easy to install - just remember that it's a very
good idea to use a static mat and wrist strap whenever you dive into
the inside of a K3. The instructions were quite clear, and since I'd built
my K3 from the kit, it was an easy procedure.

I don't have any experience with rubidium disciplined oscillators, but
I would suggest you take some time to read through the Time-Nuts
mailing list; the archive is at

time-nuts Info Page
 
             
time-nuts Info Page
time-nuts -- Discussion of precise time and frequency measurement   About time-nuts  
View on www.febo.com Preview by Yahoo  
 

I was able to get a lot of good information there, and although I didn't subscribe
and therefore don't know about any recent discussions, there is a treasure trove
of details about the use of various disciplined oscillators, including rubidiums.

In addition, I know that Down East Microwave has, among a lot of other things,
a distribution box for 10MHz signal sources so that you can feed the K3 from
one port and feed the LO for a transverter off of another, and they also have LO
modules that incorporate PLL/VCOs that can sync to external 10MHz references.

And, yes, it's a heady feeling to know that, at least on HF, your K3 displays
your frequency right down to the nearest Hz. There is a write-up in the K3EXREF
documentation that explains that it's a real good idea to jot down the frequency
of the master oscillator so that if your external reference fails, you can tell the K3
what you want it to set itself to, so that it doesn't jump to some arbitrary frequency.

73 de N1HO
 

________________________________
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[Matt Zilmer-3]

My experience was similar, using a Thunderbolt.  I won't duplicate
Bayard's narrative, except to emphaisze using ESD precautions when
working inside any transceiver.

73,
matt
W6NIA

On Thu, 18 Sep 2014 17:32:04 -0700, you wrote:

>I installed a K3EXREF and set up a Trimble Thunderbolt a few months
>ago, and I've been very happy.
>
>The K3EXREF was very easy to install - just remember that it's a very
>good idea to use a static mat and wrist strap whenever you dive into
>the inside of a K3. The instructions were quite clear, and since I'd built
>my K3 from the kit, it was an easy procedure.
>
>I don't have any experience with rubidium disciplined oscillators, but
>I would suggest you take some time to read through the Time-Nuts
>mailing list; the archive is at
>
>time-nuts Info Page
>  
>            
>time-nuts Info Page
>time-nuts -- Discussion of precise time and frequency measurement   About time-nuts  
>View on www.febo.com Preview by Yahoo  
>  
>
>I was able to get a lot of good information there, and although I didn't subscribe
>and therefore don't know about any recent discussions, there is a treasure trove
>of details about the use of various disciplined oscillators, including rubidiums.
>
>In addition, I know that Down East Microwave has, among a lot of other things,
>a distribution box for 10MHz signal sources so that you can feed the K3 from
>one port and feed the LO for a transverter off of another, and they also have LO
>modules that incorporate PLL/VCOs that can sync to external 10MHz references.
>
>And, yes, it's a heady feeling to know that, at least on HF, your K3 displays
>your frequency right down to the nearest Hz. There is a write-up in the K3EXREF
>documentation that explains that it's a real good idea to jot down the frequency
>of the master oscillator so that if your external reference fails, you can tell the K3
>what you want it to set itself to, so that it doesn't jump to some arbitrary frequency.
>
>73 de N1HO
>
>
>________________________________
>______________________________________________________________
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>
>This list hosted by: http://www.qsl.net
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>Message delivered to [hidden email]

Matt Zilmer, W6NIA
--
"Give me six hours to chop down a tree and I will
spend the first four sharpening the axe." -A. Lincoln
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[David Pratt]

In a recent message, David and Dianne on Comcast <[hidden email]>
writes
>I'm interested in possibly trying the K3EXREF in my good ol'  K3 for no
>good reason other than its something new and fun to try and can give
>some bragging rights about frequency accuracy.  Can any of you comment
>on your experiences in using the K3EXREF? Elecraft provides very little
>background info on how to get started with this accessory after its
>installation.

Go for it, Dave, it works very well.  I have used a Racal-Dana 9475
Rubidium standard (perfectly safe!) and also a GPS disciplined 10MHz
standard, but recently got a 10MHz MV89 double oven CXO which is
inexpensive and excellent. Mine is accurate to the nearest one-hundredth
of a Hertz at 10MHz, which is near enough for me ;-) Search eBay for
MV89 and MV89A. I built mine into a box with its own 12V, 2A regulated
linear PSU. After warm-up it draws just 9W from the supply mains.

73 de David G4DMP

--
 + - - - - - - - - - - - - - - - - +
 | David M Pratt, Kippax, Leeds.   |
 | Website: http://www.g4dmp.co.uk |
 + - - - - - - - - - - - - - - - - +

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[gm3sek]

A rubidium frequency source contains a few milligrams of natural
rubidium, some of which is weakly radioactive.

But there is about 5 times more radioactivity in a banana and about 1000
times more natural radioactivity in the human body itself (in both
cases, mostly due to natural potassium-40).

Guess which of those three requires the hazmat sheet?


73 from Ian GM3SEK


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[NK7Z]

The human body?
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net
for MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
for Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
for MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info


On Fri, 2014-09-19 at 20:15 +0100, Ian White wrote:

> A rubidium frequency source contains a few milligrams of natural
> rubidium, some of which is weakly radioactive.
>
> But there is about 5 times more radioactivity in a banana and about 1000
> times more natural radioactivity in the human body itself (in both
> cases, mostly due to natural potassium-40).
>
> Guess which of those three requires the hazmat sheet?
>
>
> 73 from Ian GM3SEK
>
>
> ______________________________________________________________
> Elecraft mailing list
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>
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[Sverre Holm (LA3ZA)]

I wonder what's the experience with the MV89A, does it need a lot of adjustment of the control voltage, or does it have this kind of accuracy out of the box?

David G4DMP wrote

but recently got a 10MHz MV89 double oven CXO which is inexpensive and excellent. Mine is accurate to the nearest one-hundredth of a Hertz at 10MHz, which is near enough for me ;-) Search eBay for MV89 and MV89A.

[NK7Z]

I too would like an overview of your setup as well...
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net
for MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
for Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
for MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info


On Fri, 2014-09-19 at 19:25 -0700, Sverre Holm (LA3ZA) wrote:

> I wonder what's the experience with the MV89A, does it need a lot of
> adjustment of the control voltage, or does it have this kind of accuracy out
> of the box?
>
>
> David G4DMP wrote
> > but recently got a 10MHz MV89 double oven CXO which is inexpensive and
> > excellent. Mine is accurate to the nearest one-hundredth of a Hertz at
> > 10MHz, which is near enough for me ;-) Search eBay for MV89 and MV89A.
>
>
>
>
>
> -----
> Sverre, LA3ZA
>
> K2 #2198, K3 #3391,
> LA3ZA Blog: http://la3za.blogspot.com,
> LA3ZA Unofficial Guide to K2 modifications: http://la3za.blogspot.com/p/la3za-unofficial-guide-to-elecraft-k2.html
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-External-Frequency-Reference-Questions-tp7593192p7593225.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
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[David Pratt]

In a recent message, "Sverre Holm (LA3ZA)" <[hidden email]> writes
>I wonder what's the experience with the MV89A, does it need a lot of
>adjustment of the control voltage, or does it have this kind of accuracy out
>of the box?

No, Sverre, I did not need an adjustable 5V control voltage as the MV89A
was spot on 10,000,000.00 Hz as measured on my Rubidium controlled
frequency counter. I merely applied a regulated 12V supply to it.
Obviously I cannot speak for all MV89A units but I guess they are all
very close.

73 de David G4DMP

--
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 | David M Pratt, Kippax, Leeds.   |
 | Website: http://www.g4dmp.co.uk |
 + - - - - - - - - - - - - - - - - +

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[Sverre Holm (LA3ZA)]

Thanks David,

David G4DMP wrote

No, Sverre, I did not need an adjustable 5V control voltage as the MV89A was spot on 10,000,000.00 Hz