Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[William H. Fite]

Guys, remember what it said under Brian's picture in his senior yearbook:
 "Pick a side and I'll argue with you."





On Tue, Feb 19, 2013 at 7:41 PM, Brian Lloyd  wrote:

> On Tue, Feb 19, 2013 at 11:59 AM, Jerry Flanders  >wrote:
>
> > I think the most important thing to remember in the Rb vs GPSDO debate is
> > that without some other standard like a GPSDO or better to compare to or
> > calibrate against, you never know that your Rb oscillator is actually
> > on-freq.
>
>
> Sure you do. Double check it against WWV. If it is within 1/2 Hz, the Rb is
> locked and all is well. If it is unlocked it is very obvious because the
> output frequency sweeps up and down by almost 1kHz. Tune in WWV and you
> will KNOW it is unlocked. Once it locks and WWV is clear, it is working and
> nothing it going to move it off 10MHz.
>
>
> > The LPRO-101 has an adjustment to vary its freq. How would I know that
> > adjustment pot didn't get jostled during shipment?
>
>
> OMG, it could be .015 Hz off if it got turned all the way to the stops! Yes
> the tuning limit is +/- 15 MILLIHERTZ. Remember, the frequency
> determination is fixed by an electron transition in a shell of the Rubidium
> atom. Unlike a crystal oscillator, it can't be very far off. If it locks up
> at all, it will be within 1/2 Hz at 10MHz and quickly get better than that.
>
>
> > Lastly, since we know the early Rb units were subject to failure due to
> > aging of the Rb tube, how would I know the one I was considering has much
> > life remaining ?
> >
>
> Measure the lamp voltage. It is a pin on the connector. More than 7.5V and
> it still has lots of life left.
>
> >
> > Bottom line - I would HAVE to be able to check/calibrate it, but against
> > what primary reference?
> >
>
> And that is the point. You don't. Sure if you want to get it within 1 mHz
> you could tweak it but even without any calibration max it could be off
> after warmup is less that 1/100 of a Hz.
>
> Without a GPSDO to compare the Rb to, I think buying a Rb one would be a
> > crap-shoot.  After thinking it through, I skipped the Rb step and went
> > straight to the GPSDO.
> >
>
> But the GPSDO can be farther off during periods of poor GPS constellation
> geometry.
>
> Bottom line: it pays to understand the technology.
>
> --
> Brian Lloyd, WB6RQN/J79BPL
> 3191 Western Dr.
> Cameron Park, CA 95682
> br...@lloyd.com
> +1.767.617.1365 (Dominica)
> +1.916.877.5067 (USA)
> ___
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> Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
> Knowledge Base: http://kc.flexradio.com/  Homepage:
> http://www.flexradio.com/
>



-- 
I can explain it for you, but I can't comprehend it for you.
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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[Brian Lloyd]

On Tue, Feb 19, 2013 at 11:59 AM, Jerry Flanders wrote:

> I think the most important thing to remember in the Rb vs GPSDO debate is
> that without some other standard like a GPSDO or better to compare to or
> calibrate against, you never know that your Rb oscillator is actually
> on-freq.


Sure you do. Double check it against WWV. If it is within 1/2 Hz, the Rb is
locked and all is well. If it is unlocked it is very obvious because the
output frequency sweeps up and down by almost 1kHz. Tune in WWV and you
will KNOW it is unlocked. Once it locks and WWV is clear, it is working and
nothing it going to move it off 10MHz.


> The LPRO-101 has an adjustment to vary its freq. How would I know that
> adjustment pot didn't get jostled during shipment?


OMG, it could be .015 Hz off if it got turned all the way to the stops! Yes
the tuning limit is +/- 15 MILLIHERTZ. Remember, the frequency
determination is fixed by an electron transition in a shell of the Rubidium
atom. Unlike a crystal oscillator, it can't be very far off. If it locks up
at all, it will be within 1/2 Hz at 10MHz and quickly get better than that.


> Lastly, since we know the early Rb units were subject to failure due to
> aging of the Rb tube, how would I know the one I was considering has much
> life remaining ?
>

Measure the lamp voltage. It is a pin on the connector. More than 7.5V and
it still has lots of life left.

>
> Bottom line - I would HAVE to be able to check/calibrate it, but against
> what primary reference?
>

And that is the point. You don't. Sure if you want to get it within 1 mHz
you could tweak it but even without any calibration max it could be off
after warmup is less that 1/100 of a Hz.

Without a GPSDO to compare the Rb to, I think buying a Rb one would be a
> crap-shoot.  After thinking it through, I skipped the Rb step and went
> straight to the GPSDO.
>

But the GPSDO can be farther off during periods of poor GPS constellation
geometry.

Bottom line: it pays to understand the technology.

-- 
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
br...@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[Richard Solomon]

My apologies, old age got me again ... it was Lucent not Agilent.

73, Dick, W1KSZ


On 2/19/2013 3:44 PM, kq...@verizon.net wrote:

I agree with Patrick.

Just type in "rubidium" and you'll get more hits than you wanted.

73, Jim  KQ6EA
On 02/19/13, Richard Solomon wrote:
A while back, over on the "evil empire", they were selling both the
GPSDO and
RbO that were scrapped out of Agilent systems. The didn't have the inter-
connect cables, but they were easy to make.

I bought one just to experiment with, but quickly decided that for my
needs, the
GPSDO was all I needed.

Alas, they seem to have dried up.

73, Dick, W1KSZ


On 2/19/2013 12:59 PM, Jerry Flanders wrote:
> I think the most important thing to remember in the Rb vs GPSDO debate
> is that without some other standard like a GPSDO or better to compare
> to or calibrate against, you never know that your Rb oscillator is
> actually on-freq. The LPRO-101 has an adjustment to vary its freq. How
> would I know that adjustment pot didn't get jostled during shipment?
> Lastly, since we know the early Rb units were subject to failure due
> to aging of the Rb tube, how would I know the one I was considering
> has much life remaining ?
>
> Bottom line - I would HAVE to be able to check/calibrate it, but
> against what primary reference?
>
> Without a GPSDO to compare the Rb to, I think buying a Rb one would be
> a crap-shoot. After thinking it through, I skipped the Rb step and
> went straight to the GPSDO.
>
> Jerry W4UK
>
> At 11:47 PM 2/18/2013, Brian Lloyd wrote:
>> On Mon, Feb 18, 2013 at 7:35 PM, Richard Solomon
>> mailto:w1...@earthlink.net>>wrote:
>>
>> > I also have both (two RbO's and 4 GPSDO's). I'll take the GPSDO any
>> day.
>> >
>>
>> This is not a, "which one is better," question. It is a question of
>> what is
>> the job you are trying to do.
>>
>> It is useful to understand the differences. Certainly the long-term
>> stability of the GPSDO is better because the reference oscillator is
>> always
>> being corrected back to the correct time, i.e. long term number of
>> cycles.
>> But in the short term, variations in the GPS satellite geometry can
>> cause
>> the GPSDO to exhibit short-term frequency errors. Of course, long-term
>> these are corrected back out but if one was comparing one would notice
>> small short-term variations in the frequency of the GPSDO while the RbO
>> showed more stability. So the question is, which is more important?
>>
>> Of course, could could have a GPS-disciplined Rb reference. Now you
>> get the
>> best of both worlds, i.e. dead-nuts accurate long term stability with
>> outstanding short-term stability.
>>
>> And the other thing that many people seem to forget about is the phase
>> noise of the disciplined reference oscillator. That may have 
substantial

>> effect on the performance of the receiver over and above the frequency
>> accuracy.
>>
>> So, when it comes to the question of, "which is better, an Rb reference
>> oscillator or a GPS disciplined oscillator," the answer is a 
resounding,

>> "it depends."
>>
>> I still hold that, for most people looking to increase the frequency
>> stability and accuracy of their Flex 1500 or 5000, an Rb reference
>> like the
>> LPRO-101 is simpler for the following reasons:
>>
>> 1. No outside GPS antenna needed.
>> 2. The LPRO-101 runs on a single 19V supply (I use an old laptop
>> power
>> supply) while the Thunderbolt needs +5V, +12V, and -14V. I use a
>> cheap
>> laptop DC supply to run my LPRO-101 from the shack 12V supply.
>> 3. The output of the LPRO-101 may be fed to the external reference
>> input
>> with no attenuation.
>> 4. The LPRO-101 has relatively low phase noise.
>>
>> Like I said, I have both but find the LPRO-101 Rb reference easier to
>> use
>> and its accuracy still exceeds the tuning accuracy of the radio.
>>
>> --
>> Brian Lloyd, WB6RQN/J79BPL
>> 3191 Western Dr.
>> Cameron Park, CA 95682
>> br...@lloyd.com 
>> +1.767.617.1365 (Dominica)
>> +1.916.877.5067 (USA)
>> ___
>> FlexRadio Systems Mailing List
>> FlexRadio@flex-radio.biz 
>> http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
>> Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
>> Knowledge Base: http://kc.flexradio.com/ Homepage:
>> http://www.flexradio.com/
>
>
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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[Patrick Greenlee]

Not dried up.  $75 or so on evilBay now.

-Original Message- 
From: Richard Solomon

Sent: Tuesday, February 19, 2013 3:59 PM
To: flexradio@flex-radio.biz
Subject: Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" 
orreally close


A while back, over on the "evil empire", they were selling both the
GPSDO and
RbO that were scrapped out of Agilent systems. The didn't have the inter-
connect cables, but they were easy to make.

I bought one just to experiment with, but quickly decided that for my
needs, the
GPSDO was all I needed.

Alas, they seem to have dried up.

73, Dick, W1KSZ


On 2/19/2013 12:59 PM, Jerry Flanders wrote:
I think the most important thing to remember in the Rb vs GPSDO debate is 
that without some other standard like a GPSDO or better to compare to or 
calibrate against, you never know that your Rb oscillator is actually 
on-freq. The LPRO-101 has an adjustment to vary its freq. How would I know 
that adjustment pot didn't get jostled during shipment?  Lastly, since we 
know the early Rb units were subject to failure due to aging of the Rb 
tube, how would I know the one I was considering has much life remaining ?


Bottom line - I would HAVE to be able to check/calibrate it, but against 
what primary reference?


Without a GPSDO to compare the Rb to, I think buying a Rb one would be a 
crap-shoot.  After thinking it through, I skipped the Rb step and went 
straight to the GPSDO.


Jerry W4UK

At 11:47 PM 2/18/2013, Brian Lloyd wrote:
On Mon, Feb 18, 2013 at 7:35 PM, Richard Solomon 
wrote:


> I also have both (two RbO's and 4 GPSDO's). I'll take the GPSDO any
day.
>

This is not a, "which one is better," question. It is a question of what 
is

the job you are trying to do.

It is useful to understand the differences. Certainly the long-term
stability of the GPSDO is better because the reference oscillator is 
always
being corrected back to the correct time, i.e. long term number of 
cycles.

But in the short term, variations in the GPS satellite geometry can cause
the GPSDO to exhibit short-term frequency errors. Of course, long-term
these are corrected back out but if one was comparing one would notice
small short-term variations in the frequency of the GPSDO while the RbO
showed more stability. So the question is, which is more important?

Of course, could could have a GPS-disciplined Rb reference. Now you get 
the

best of both worlds, i.e. dead-nuts accurate long term stability with
outstanding short-term stability.

And the other thing that many people seem to forget about is the phase
noise of the disciplined reference oscillator. That may have substantial
effect on the performance of the receiver over and above the frequency
accuracy.

So, when it comes to the question of, "which is better, an Rb reference
oscillator or a GPS disciplined oscillator," the answer is a resounding,
"it depends."

I still hold that, for most people looking to increase the frequency
stability and accuracy of their Flex 1500 or 5000, an Rb reference like 
the

LPRO-101 is simpler for the following reasons:

   1. No outside GPS antenna needed.
   2. The LPRO-101 runs on a single 19V supply (I use an old laptop power
   supply) while the Thunderbolt needs +5V, +12V, and -14V. I use a cheap
   laptop DC supply to run my LPRO-101 from the shack 12V supply.
   3. The output of the LPRO-101 may be fed to the external reference 
input

   with no attenuation.
   4. The LPRO-101 has relatively low phase noise.

Like I said, I have both but find the LPRO-101 Rb reference easier to use
and its accuracy still exceeds the tuning accuracy of the radio.

--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
br...@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[Richard Solomon]

A while back, over on the "evil empire", they were selling both the 
GPSDO and

RbO that were scrapped out of Agilent systems. The didn't have the inter-
connect cables, but they were easy to make.

I bought one just to experiment with, but quickly decided that for my 
needs, the

GPSDO was all I needed.

Alas, they seem to have dried up.

73, Dick, W1KSZ


On 2/19/2013 12:59 PM, Jerry Flanders wrote:
I think the most important thing to remember in the Rb vs GPSDO debate 
is that without some other standard like a GPSDO or better to compare 
to or calibrate against, you never know that your Rb oscillator is 
actually on-freq. The LPRO-101 has an adjustment to vary its freq. How 
would I know that adjustment pot didn't get jostled during shipment?  
Lastly, since we know the early Rb units were subject to failure due 
to aging of the Rb tube, how would I know the one I was considering 
has much life remaining ?


Bottom line - I would HAVE to be able to check/calibrate it, but 
against what primary reference?


Without a GPSDO to compare the Rb to, I think buying a Rb one would be 
a crap-shoot.  After thinking it through, I skipped the Rb step and 
went straight to the GPSDO.


Jerry W4UK

At 11:47 PM 2/18/2013, Brian Lloyd wrote:
On Mon, Feb 18, 2013 at 7:35 PM, Richard Solomon 
wrote:


> I also have both (two RbO's and 4 GPSDO's). I'll take the GPSDO any 
day.

>

This is not a, "which one is better," question. It is a question of 
what is

the job you are trying to do.

It is useful to understand the differences. Certainly the long-term
stability of the GPSDO is better because the reference oscillator is 
always
being corrected back to the correct time, i.e. long term number of 
cycles.
But in the short term, variations in the GPS satellite geometry can 
cause

the GPSDO to exhibit short-term frequency errors. Of course, long-term
these are corrected back out but if one was comparing one would notice
small short-term variations in the frequency of the GPSDO while the RbO
showed more stability. So the question is, which is more important?

Of course, could could have a GPS-disciplined Rb reference. Now you 
get the

best of both worlds, i.e. dead-nuts accurate long term stability with
outstanding short-term stability.

And the other thing that many people seem to forget about is the phase
noise of the disciplined reference oscillator. That may have substantial
effect on the performance of the receiver over and above the frequency
accuracy.

So, when it comes to the question of, "which is better, an Rb reference
oscillator or a GPS disciplined oscillator," the answer is a resounding,
"it depends."

I still hold that, for most people looking to increase the frequency
stability and accuracy of their Flex 1500 or 5000, an Rb reference 
like the

LPRO-101 is simpler for the following reasons:

   1. No outside GPS antenna needed.
   2. The LPRO-101 runs on a single 19V supply (I use an old laptop 
power
   supply) while the Thunderbolt needs +5V, +12V, and -14V. I use a 
cheap

   laptop DC supply to run my LPRO-101 from the shack 12V supply.
   3. The output of the LPRO-101 may be fed to the external reference 
input

   with no attenuation.
   4. The LPRO-101 has relatively low phase noise.

Like I said, I have both but find the LPRO-101 Rb reference easier to 
use

and its accuracy still exceeds the tuning accuracy of the radio.

--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
br...@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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[Flexradio] Question about NB1 and NB2, not working as I expect it to

[Mark Lunday]

I don't normally use these.because of what happens.  

I have local conditions that are quiet (-130 dBm,  But I do have a few RFI
sources (still to be located) which generate a 20 kHz wide "hilltop" of
noise up to -115 dBm.  The noise looks like a camel hump on the panadapter,
and is usually on the CW portion of the 15 meter band down low, and the 12
meter CW portion as well.

When I turn on NB1 to curb that "camel hump" because I want to hear weak
signals that are affected in that 20 kHz segment, the entire noise floor
drops including that "hump", but so do the signals to the point of being
unreadable.  And if there is a strong signal above -115 dBm anywhere in the
band, the noise floor pulses to that signal.especially if it is CW.  Which
renders the NB1 effect useless. 

I see a similar but less pronounced behavior when using NB2.the "hump" drops
a bit but the noise floor and signals do not drop (good, but not as good in
eliminating the noise with NB1).but the entire band pulses if any CW signals
above -115 dBm are present (obviously not good).

Pre-amp has no impact.  Resetting database has no impact.

Using Flex 3000, SDR 2.5.3.  I have noticed this in earlier versions of SDR,
which is why I did not use the features.  But it has me wondering about
it.and I would like to use it.

Mark Lunday, WD4ELG
Greensboro, NC  FM06be
wd4...@arrl.net
http://wd4elg.blogspot.com


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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" or really close

[John Stuart]

I'm with you Jerry.  I have 4 Rb oscillators and only one still runs.  I
also have 4 GPSDOs and they all have always worked.

 

Also, with ThunderBolt GPSDOs, you get to play with Lady Heather, and that's
a real learning experience!

 

John Stuart, KM6QX

FMT Nut with a Flex-1500 

 

 

-Original Message-
From: FlexRadio [mailto:flexradio-boun...@flex-radio.biz] On Behalf Of Jerry
Flanders
Sent: Tuesday, February 19, 2013 12:00 PM
To: Brian Lloyd
Cc: FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON"
orreally close

 

I think the most important thing to remember in the Rb vs GPSDO 

debate is that without some other standard like a GPSDO or better to 

compare to or calibrate against, you never know that your Rb 

oscillator is actually on-freq. The LPRO-101 has an adjustment to 

vary its freq. How would I know that adjustment pot didn't get 

jostled during shipment?  Lastly, since we know the early Rb units 

were subject to failure due to aging of the Rb tube, how would I know 

the one I was considering has much life remaining ?

 

Bottom line - I would HAVE to be able to check/calibrate it, but 

against what primary reference?

 

Without a GPSDO to compare the Rb to, I think buying a Rb one would 

be a crap-shoot.  After thinking it through, I skipped the Rb step 

and went straight to the GPSDO.

 

Jerry W4UK

 

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Re: [Flexradio] DIY 10 MHz sources for putting Flex 5000A "DEAD ON" orreally close

[Jerry Flanders]

I think the most important thing to remember in the Rb vs GPSDO 
debate is that without some other standard like a GPSDO or better to 
compare to or calibrate against, you never know that your Rb 
oscillator is actually on-freq. The LPRO-101 has an adjustment to 
vary its freq. How would I know that adjustment pot didn't get 
jostled during shipment?  Lastly, since we know the early Rb units 
were subject to failure due to aging of the Rb tube, how would I know 
the one I was considering has much life remaining ?


Bottom line - I would HAVE to be able to check/calibrate it, but 
against what primary reference?


Without a GPSDO to compare the Rb to, I think buying a Rb one would 
be a crap-shoot.  After thinking it through, I skipped the Rb step 
and went straight to the GPSDO.


Jerry W4UK

At 11:47 PM 2/18/2013, Brian Lloyd wrote:

On Mon, Feb 18, 2013 at 7:35 PM, Richard Solomon wrote:

> I also have both (two RbO's and 4 GPSDO's). I'll take the GPSDO any day.
>

This is not a, "which one is better," question. It is a question of what is
the job you are trying to do.

It is useful to understand the differences. Certainly the long-term
stability of the GPSDO is better because the reference oscillator is always
being corrected back to the correct time, i.e. long term number of cycles.
But in the short term, variations in the GPS satellite geometry can cause
the GPSDO to exhibit short-term frequency errors. Of course, long-term
these are corrected back out but if one was comparing one would notice
small short-term variations in the frequency of the GPSDO while the RbO
showed more stability. So the question is, which is more important?

Of course, could could have a GPS-disciplined Rb reference. Now you get the
best of both worlds, i.e. dead-nuts accurate long term stability with
outstanding short-term stability.

And the other thing that many people seem to forget about is the phase
noise of the disciplined reference oscillator. That may have substantial
effect on the performance of the receiver over and above the frequency
accuracy.

So, when it comes to the question of, "which is better, an Rb reference
oscillator or a GPS disciplined oscillator," the answer is a resounding,
"it depends."

I still hold that, for most people looking to increase the frequency
stability and accuracy of their Flex 1500 or 5000, an Rb reference like the
LPRO-101 is simpler for the following reasons:

   1. No outside GPS antenna needed.
   2. The LPRO-101 runs on a single 19V supply (I use an old laptop power
   supply) while the Thunderbolt needs +5V, +12V, and -14V. I use a cheap
   laptop DC supply to run my LPRO-101 from the shack 12V supply.
   3. The output of the LPRO-101 may be fed to the external reference input
   with no attenuation.
   4. The LPRO-101 has relatively low phase noise.

Like I said, I have both but find the LPRO-101 Rb reference easier to use
and its accuracy still exceeds the tuning accuracy of the radio.

--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
br...@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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Re: [Flexradio] [FlexEdge] VAC _ ver.4.12

[Ernest Garcia]

Thank you one and all Flexers, I received many email regarding the use of VAC  
version 4.12,  And I will use that version. 73, Ernest - W4EG - San Diego   
   
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Re: [Flexradio] Ah stumble upon

[Koos du Plessis]

Good one Dave,

Thanks.  I was wondering about this since making my 5K available on
RemoteHams.
The Guys have been working 9U4U on split.

73 de Koos
ZS6BFD 

-Original Message-
From: FlexRadio [mailto:flexradio-boun...@flex-radio.biz] On Behalf Of David
Walker
Sent: 19 February 2013 01:09 PM
To: flexradio@flex-radio.biz
Subject: [Flexradio] Ah stumble upon

Hi,

Found just what I was looking for -> Settings -> General -> Options ->
Disable split on band change = tick.  No more accidential tuning up the
AL-80B on 6m!

Tnx.  Features.


73


Dave.

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[Flexradio] Ah stumble upon

[David Walker]

Hi,

Found just what I was looking for -> Settings -> General -> Options -> 
Disable split on band change = tick.  No more accidential tuning up the 
AL-80B on 6m!


Tnx.  Features.


73


Dave.

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