[time-nuts] Any thoughts on best rubidium?

EWKehren at aol.com EWKehren at aol.com
Mon Sep 26 16:54:03 UTC 2011 

As I said before it is even by today's standards an excellent analyzer and  
I am sure there are people out there for that reason willing to pay the 
money  for a LCD display.
Bert Kehren
 
 
In a message dated 9/26/2011 10:56:30 A.M. Eastern Daylight Time,  
nerd at verizon.net writes:

The kit costs more than the analyzer.
If someone finds a good LCD panel and does the mechanical design  for
mounting I can begin work on an "open source" design for  the
electronics part.
That would expand the  market to far more of us.


On 09/26/11,  shalimr9 at gmail.com wrote:
There are aftermarket color LCD  replacement available for the HP 8566
and HP 8568 analyzers,  either as a do-it-yourself kit, or as a turn-key
service.
Didier KO4BB
Sent from my BlackBerry  Wireless thingy while I do other things...
-----Original  Message-----
From: [1]EWKehren at aol.com
Sender:  [2]time-nuts-bounces at febo.com
Date: Mon, 26 Sep 2011  07:01:36
To: <[3]time-nuts at febo.com>
Reply-To: Discussion of precise time and frequency measurement
<[4]time-nuts at febo.com>
Subject: Re: [time-nuts] Any  thoughts on best rubidium?
Roy,
for its time  it was the best because of the spectral purity of its Osc.
The
big problem with the unit today is its CRT. Limited life  and no
replacements. As rare as Cs tubes. If you can live with  1.3 GHz an
excellent choice,
the 22 GHz  version because of source does not have as good
specifications.Also repairable, many parts are readily  available.
Bert Kehren
In a message dated  9/26/2011 6:27:59 A.M. Eastern Daylight Time,
[5]phill.r1 at btinternet.com writes:
Bert
What's  your opinion of the "old" HP8568B with its max. frequency  range
of
1.3 Ghz and its weight of around 100  lbs. - are the more recent
instruments
that  much better ?
Roy
--------------------------------------------------
From:  <[6]EWKehren at aol.com>
Sent: Sunday, September 25, 2011  10:47 AM
To: <[7]time-nuts at febo.com>
Subject: Re: [time-nuts] Any thoughts on best rubidium?
>  If you want low noise in a spectrum analyzer it all comes down to  the
> signal quality into the first mixer. Every thing else  with today's
> technology
> is down  hill.
> Bert Kehren
>
>
> In a message dated 9/25/2011 5:32:31 A.M. Eastern  Daylight Time,
> [8]Robert at delien.nl  writes:
>
>> One other thing is that  some spectrum analyzers aren't really
designed
>> for low noise performance. Since the noise floor is often  pretty
high,
>> the design of the whole  RF chain (e.g. spur levels and such) might
have
>> assumed that lots of things would be hidden in  the grass.
>
> True, it's one of the  many selection criterions for selecting the
> instrument  that meets your needs.
> I've been looking a the luggable  HP series 859x and 856x, preferring
the
>  latter because they have a PLL YIG whereas the fist uses a
free-running
> oscillator. But these machines are old, 80's  and 90's, pricey, and
not
>  really
> THAT good. Add decent range (up to 9GHz to see  recent 5.8GHz devices)
and
>  a
> tracking generator and before you know it, you'll be  paying $6k or
more
> for
> a 20 year old instrument.
>
>>  If the
>> analyzer is of the recent "bring a band of RF  down to an IF, sample
and
>> FFT it for  fine resolution" architecture, such things as the number
of
>> bits in the ADC and the "cleanliness" of the  sampling clock might
have
>> been chosen  based upon doing 1024 point transforms being displayed
with
>> 100dB dynamic range (10dB/div and 10  divisions).
>
> Most modern instruments  do that, at least to some degree. My R&S goes
>  down
> to a RBW of 10Hz by just mixing. Additionally RBWs  of 5, 3, 2 and 1Hz
are
> achieve by  additional FFT. This instrument dates from 2001, but I
don't
> think more recent instruments can achieve a  mixing-only RBW of 5Hz or
> below.
>
>> (not to mention the spectrum analyzer actually  generating spurious
>> signals. I ran across that one  last year and thought I had an
>> interference source,  but, no, went back and checked the spec sheet
and
>> it said spurious are <-80dBc, and sure enough,  there it was at -82
dBc.
>> And stories  about the first LO coming back out through the input are
>> legion.)
>
> Gee, I wish I had  consulted this group BEFORE buying my instrument.
I'm
> happy with it and I don't regret anything, but you  could have added a
lot
> more arguments in  favor or againstA-c-AEURA|
>  _______________________________________________
> time-nuts  mailing list -- [9]time-nuts at febo.com
> To unsubscribe, go  to
>  [10]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>  _______________________________________________
> time-nuts  mailing list -- [11]time-nuts at febo.com
> To unsubscribe, go  to
>  [12]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
_______________________________________________
time-nuts  mailing list -- [13]time-nuts at febo.com
To unsubscribe, go  to
[14]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts  mailing list -- [15]time-nuts at febo.com
To unsubscribe, go  to
[16]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts  mailing list -- [17]time-nuts at febo.com
To unsubscribe, go  to
[18]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

References

1.  mailto:EWKehren at aol.com
2.  mailto:time-nuts-bounces at febo.com
3.  mailto:time-nuts at febo.com
4.  mailto:time-nuts at febo.com
5.  mailto:phill.r1 at btinternet.com
6.  mailto:EWKehren at aol.com
7.  mailto:time-nuts at febo.com
8.  mailto:Robert at delien.nl
9. mailto:time-nuts at febo.com
10. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
11.  mailto:time-nuts at febo.com
12.  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
13.  mailto:time-nuts at febo.com
14.  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
15.  mailto:time-nuts at febo.com
16.  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
17.  mailto:time-nuts at febo.com
18.  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com
To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.

More information about the time-nuts mailing list