Following up an earlier post:
It appears that the 11729's 640-MHz PA can drive the 7123
adequately, although the 12.16 GHz comb line is somewhat close to
the spec limit of -20 dBm. The 7113-110 is a better replacement
for the 33004A in the 11729C, since it would actually be
operating in
measurement
Subject: Re: [time-nuts] NLTL comb generators going away...
You need a really clean driver to be good enough to need a NLTL
instead of an SRD. Whatever the intrinsic noise of the NLTL is,
it is lower than any practical source so you can consider it zero.
Rick Karlquist N6RK
John Miles
measurement'
Subject: Re: [time-nuts] NLTL comb generators going away...
Over 20 years ago I was the lead guy in the development of the SCOTT
Milstar
satellite terminal at Magnavox. Our uplink frequency was from 43.5 to 45.5
GHz. The PN specifications were essentially almost impossible to meet
My 2 cents
At what freq offset are the measurments being made?
(NLTL vs. SRD)
Is it that the SRD has more flicker noise and thus
is worse than 20log(n) for close-in noise? Or does
the SRD have a wideband noise floor that is worse
than 20log(n)?
Their MWJ reprint talks about that:
measurement
Subject: Re: [time-nuts] NLTL comb generators going away...
My 2 cents
At what freq offset are the measurments being made?
(NLTL vs. SRD)
Is it that the SRD has more flicker noise and thus
is worse than 20log(n) for close-in noise? Or does
the SRD have a wideband noise floor
PROTECTED] On
Behalf Of John Miles
Sent: Friday, December 28, 2007 2:42 AM
To: time-nuts@febo.com
Subject: [time-nuts] NLTL comb generators going away...
FYI, I don't know how many others on the list are interested in microwave PN
measurement with gear like the HP 11729B/C or 70420/E5500 series
John Miles wrote:
Unfortunately, when I called Picosecond Pulse Labs to order my first choice
(the 7103 model), they told me they'd shut down their fab in Oregon and were
no longer producing NLTL multipliers. They have a few left in stock and are
selling them for $975 each regardless of the
-5960
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John Miles
Sent: Friday, December 28, 2007 2:42 AM
To: time-nuts@febo.com
Subject: [time-nuts] NLTL comb generators going away...
FYI, I don't know how many others on the list
I have a nice 3585B, 11729C (with all filters) and a nice working 8662A. I
assume the PN of the 640 output of the 8662A is still more than adequate.
Right; it doesn't make sense to swap out the 11729's SRD multiplier unless
you are also upgrading the 640-MHz drive source at the same time.
comb generators going away...
The SRD (step recovery diode) definitely degrades the phase
noise beyond 20 LOG N, according to Agilent engineers I have
talked to. They mentioned a number like -150 dBc/Hz or something.
Having said that, you also have to be very careful to design
the driver
).
-- john, KE5FX
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Richard (Rick) Karlquist
Sent: Friday, December 28, 2007 10:08 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NLTL comb generators going away...
The SRD
FYI, I don't know how many others on the list are interested in microwave PN
measurement with gear like the HP 11729B/C or 70420/E5500 series, but I'm in
the (slow) process of upgrading my own 11729C setup to lower its measurement
floor and thought I'd mention something I learned the other day in
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