Questions: HP 8640B signal generator . . .

Greetings all,
I picked up a used HP 8640B signal generator off of eBay. I have always
wanted one, and now I have one.
Mine seems to work okay, but the tuning cavity only requires use of the
clockwise most portion of its range. Much of the counter-clockwise range is
just not needed - even though the frequencies seem to be okay. Is this
normal? I have never used an HP 8640B before so I cannot say.
Also, I noticed that when I remove the top-most counter board (the board
that contains the digital readout segment displays), I see a smaller
compartment that contains the pre-scalar. Judging by the missing screws, and
the overall appearance, it looks like there could have been a lid on that
compartment. Was there in fact such a lid? Or, is this locations reserved
for an option? Also, after removing the top lid from the unit, I see two
strong "RF boxes" the smaller one, in the front, is the frequency counter
(with the 7-segment readout as described above), and the other box, the big
one in the middle right-most side (looking form the front), is presumably
the frequency multipliers. Now my question is, behind these two boxes, is
another (much smaller) open-lid box that contains a few plug-in cards. But
when looking closely at this box, I see that it too might have had a lid.
Can anyone say for sure if such lids were in fact present when the unit was
new? If so, can anyone provide such spare parts?
Oh, and while I'm at it, can anyone say if it is possible to add option-002
(the frequency doubler option)? Can such parts be obtained - perhaps from a
dead unit? Or am I better off just finding a unit that has the doubler
option already installed and parting with my current unit?
Thanks,
- Stan Shankman
K7SJB

Stan,

I can not answer your questions, but I would like to point out that there
are numerous Operator and Technical manuals on CD for that signal generator
available on EBay for only a couple dollars. You might consider buying
one.

Ed K7AAT

The following link will take you to Agilent's manuals webpage, where you
will find the operation/service manual for the 8640B as a free download:

ftp://ftp.agilent.com/pub/manuals/

This is the name of the file that you will be interested in:

08640-90017 8640B Operating & Service Jan74.pdf

Many people are selling HP manuals on eBay that are available as free
downloads from the Agilent site. This isn't only limited to HP
manuals...........many free manuals that are available on the BAMA website
and mods.dk are also being sold in this manner. Unfortunately, many folks
aren't aware of these websites.

Pete


"Ed" wrote in message
. 192.196...


Stan,

I can not answer your questions, but I would like to point out that there
are numerous Operator and Technical manuals on CD for that signal
generator
available on EBay for only a couple dollars. You might consider buying
one.

Ed K7AAT

Thanks for the suggestions guys, but I already have the Agilent manuals.
The problem is, the manuals are not detailed enough to answer my questions.
I was hoping to find an HP 8640B Guru.
I know there are guys out there that go nuts over these old signal
generators, and one day I would like to chat with such a person.
- Stan
K7SJB


"Stan Shankman" wrote in message
...
Questions: HP 8640B signal generator . . .

Greetings all,
I picked up a used HP 8640B signal generator off of eBay. I have always
wanted one, and now I have one.
Mine seems to work okay, but the tuning cavity only requires use of the
clockwise most portion of its range. Much of the counter-clockwise range
is just not needed - even though the frequencies seem to be okay. Is this
normal? I have never used an HP 8640B before so I cannot say.
Also, I noticed that when I remove the top-most counter board (the board
that contains the digital readout segment displays), I see a smaller
compartment that contains the pre-scalar. Judging by the missing screws,
and the overall appearance, it looks like there could have been a lid on
that compartment. Was there in fact such a lid? Or, is this locations
reserved for an option? Also, after removing the top lid from the unit, I
see two strong "RF boxes" the smaller one, in the front, is the frequency
counter (with the 7-segment readout as described above), and the other
box, the big one in the middle right-most side (looking form the front),
is presumably the frequency multipliers. Now my question is, behind these
two boxes, is another (much smaller) open-lid box that contains a few
plug-in cards. But when looking closely at this box, I see that it too
might have had a lid. Can anyone say for sure if such lids were in fact
present when the unit was new? If so, can anyone provide such spare parts?
Oh, and while I'm at it, can anyone say if it is possible to add
option-002 (the frequency doubler option)? Can such parts be obtained -
perhaps from a dead unit? Or am I better off just finding a unit that has
the doubler option already installed and parting with my current unit?
Thanks,
- Stan Shankman
K7SJB

In article ,
"Stan Shankman" wrote:

can anyone say if it is possible to add option-002
(the frequency doubler option)? Can such parts be obtained - perhaps from a
dead unit? Or am I better off just finding a unit that has the doubler
option already installed and parting with my current unit?

Stan-

I recall seeing that discussion some time back. Someone mentioned using
an external HP Frequency Doubler 11690A. This is a small device with
male and female BNC connectors.

I found the 11690A Operating And Service Manual somewhere, possibly at
the HP site. It contains a graph of conversion loss for different
frequencies vs input level. Internal construction details are shown.

At the time, I asked if anyone knew if you could use the internal parts
of the 11690A to add option-002 to the 8640B, but did not get a response.

Fred
K4DII

"Stan Shankman" wrote in
:

Questions: HP 8640B signal generator . . .

Greetings all,
I picked up a used HP 8640B signal generator off of eBay. I have
always wanted one, and now I have one.
Mine seems to work okay, but the tuning cavity only requires use of
the clockwise most portion of its range. Much of the counter-clockwise
range is just not needed - even though the frequencies seem to be
okay. Is this normal? I have never used an HP 8640B before so I cannot
say. Also, I noticed that when I remove the top-most counter board
(the board that contains the digital readout segment displays), I see
a smaller compartment that contains the pre-scalar. Judging by the
missing screws, and the overall appearance, it looks like there could
have been a lid on that compartment. Was there in fact such a lid? Or,
is this locations reserved for an option? Also, after removing the top
lid from the unit, I see two strong "RF boxes" the smaller one, in the
front, is the frequency counter (with the 7-segment readout as
described above), and the other box, the big one in the middle
right-most side (looking form the front), is presumably the frequency
multipliers. Now my question is, behind these two boxes, is another
(much smaller) open-lid box that contains a few plug-in cards. But
when looking closely at this box, I see that it too might have had a
lid. Can anyone say for sure if such lids were in fact present when
the unit was new? If so, can anyone provide such spare parts?
Oh, and while I'm at it, can anyone say if it is possible to add
option-002 (the frequency doubler option)? Can such parts be obtained
- perhaps from a dead unit? Or am I better off just finding a unit
that has the doubler option already installed and parting with my
current unit? Thanks,
- Stan Shankman
K7SJB


Rather than attempt to answer some of your questions with possibly
erroneous info, and since you have the manual on file, have you
studied the Service Sheets in Section 8, and especially page 8-73
closely? I might answer some of your questions regarding missing covers,
etc. I haven't dug through the thick manual for reference to your other
items... My manual does not cover any details on the Options, only the
main unit. I'm using HP manual, PN: 08640-90017

Ed K7AAT