Selecting a used HP sweep/frequency generator
I have found on several occasions that you can read an "failing" EPROM in a
prommer, that will not operate in its application. Sometimes it is possible
to read. erase and reburn the same Eprom and get a working system again, but
it is always worth keeping an image.
Alan G3NYK
----- Original Message -----
From: "Poul-Henning Kamp" phk@phk.freebsd.dk
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Friday, April 15, 2011 1:49 PM
Subject: Re: [time-nuts] Selecting a used HP sweep/frequency generator
In message BANLkTimq6dnmrOUYYc=xjYHb7ajAs3gb_w@mail.gmail.com, paul swed
writ
es:
Please read the eproms. Mine are dead and they will absolutely die. The
mosteks are a known failure. If you can get me the images I will attempt
to
integrate them into a modern 27128 or something and do that install. I
have
had to do that on a couple of other types of HP gear.
I also put copies of eproms on Diddiers site for everyone.
It is sometimes possible to read otherwise "lost" eproms by manipulating
their temperature downwards.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.
and follow the instructions there.
In message 007901cbfb6e$0ffec400$4001a8c0@lark, "Alan Melia" writes:
I have found on several occasions that you can read an "failing" EPROM in a
prommer, that will not operate in its application. Sometimes it is possible
to read. erase and reburn the same Eprom and get a working system again, but
it is always worth keeping an image.
Yes, absolutely, I have made it routine to copy eproms when I have my
kit open these days, I can only recommend everybody else do the same.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On 4/14/11 9:46 PM, bownes wrote:
Thanks for the input folks. Based on what you all have said, my needs and the availability from a list member, I'm going to go with a 3325.
I spent some time reading the manual this evening, which states that the 3325 will output up to 20,999,999.99 hz on the front connector and up to about 60Mhz on the aux rear connector. That might just be a very useful feature.
As a side note, the need here is for a sweeper that can be used in conjunction with a network analyzer at the lower frequencies. The function generation of things other than sine is just a bonus.
Thanks again for all the advice. Another question follows in a new post, so as not to hijack this one. ;)
We've got tons of 3325A and 3325B's at work
Some oddities:
you can't get non-sine at as high a frequency on the front panel. I
think square waves go up to 10 MHz or so..
The backpanel waveform is always a sine, but not necessarily a very high
quality one.
You can sync multiple 3325s together, which is nice for testing I/Q
modulators and the like.
Jim wrote:
Some oddities [of 3325A and 3325B's]:
you can't get non-sine at as high a frequency on the front panel. I
think square waves go up to 10 MHz or so..
The backpanel waveform is always a sine, but not necessarily a very
high quality one.
The triangle and ramp signals only go up to 11 kHz.
The logarithmic sweep on a 3225A or B is accomplished by piecewise
linear approximation -- 10 segments/decade in single-sweep mode, and
only 2 segments per decade in continuous mode -- so its utility as a
continuous, wide-range logarithmic sweep generator (for example, as
one would generally want for audio testing) is limited. The markers
do not work in log sweep mode, either.
As a radio generator, not so bad. But be aware that 1 mV p-p (~ -56
dBm) is the minimum output, so you need good external attenuators for
it to be fully useful in that role.
The 3324A is, in my view, the sleeper of the bunch. First, it powers
up the way you left it rather than set to the factory defaults
(unless you set it to emulate a 3225). Second, IME the output
attenuator assembly is more reliable than either the 3325A or B. And
finally, they are usually much cheaper. Of course, if you need
frequencies down to uHz rather than just mHz, you need a 3325.
Best regards,
Charles