[Test-Equipment] [Mw] Question and help with a HP-8671B Sig.Gen.

[John Miles]

Hi, Ed --

The 8671B was a reduced-cost 8672A for users who didn't need AM/FM
modulation, so most service info that applies to the 8672A will also apply
to it.  It would be reasonable to troubleshoot an 8671B with an 8672A
manual, and the latter might be easier to find.  www.artekmedia.com sells
the 8672A .pdf, for instance.

Those option codes sound like they're customer-specific, which you may not
be able to find in the HP catalogs or manuals.  One possibility is that they
were meant to help implement chapter 11 of AN 283-3 ("Low Phase Noise
Applications of the 8662A...Signal Generator", in which an 8662A or similar
generator is substituted for the M/N synthesizer loop in the 8672A.

If you don't use an external M/N synth, then you would connect the coax
jumpers as needed to use the original one.  Check out AN 283-3 at
agilent.com, and those extra jacks may make more sense.

Re: your specific problem, YTO loop failures in 8671/8672/8566-family
instruments are very common and usually trivial to fix.  Do a visual
inspection for leakage from all of the axial electrolytics on the boards
underneath the hinged plastic cover by the fan, and check their ESR.  You
probably have either one or more open electrolytics in that area, or the YTO
pretune DAC calibration has drifted over time.

Finally, if your 8671 still has NiCd backup batteries, get 'em out, now,
before they leak.  A 3-cell NiCd cordless phone battery is OK to replace
them, or you could buy three NiCd AAs and a holder from Radio Shack.

-- john, KE5FX



> -----Original Message-----
> From: microwave-bounces at lists.eclectechs.com
> [mailto:microwave-bounces at lists.eclectechs.com]On Behalf Of Ed White
> WA3BZT
> Sent: Monday, February 08, 2010 6:21 PM
> To: Discussion of Electronic Test Equipment; Test Equip Trader
> Cc: Microwave Lists
> Subject: Re: [Mw] [Test-Equipment] Question and help with a HP-8671B
> Sig.Gen.
>
>
> Sorry:
> More info on the TNC connector Reverse Power should be IN, OUT M/N
>
>
> On 2/8/2010 9:06 PM, Ed White WA3BZT wrote:
> > Hi Gang:
> > I have a HP-8671B 2 to 18 GHz frequency generator that I am working
> > on.that has some problems and have fixes most of them with out a manual
> > but would like to get the manual with all the mods that I have. Anybody
> > have one?
> >
> > Here is what I know about the HP-8671B S/N 2644A00262
> > Has options C01, H04, H24
> > H04 is two BNC connectors that are IN, OUT 20-30 MHz with a tag H04
> > these connectors need a BNC jumper to work correctly
> > there is also a INT, EXT Standard that are BNC and they need a BNC
> > jumper to get it to work with the internal standard also the switch set
> > to internal.
> > The unit also has the following  connectors on the back panel
> > BNC 100 MHz out
> > BNC 10 MHz out
> > N connector  RF OUT (no RF out on front panel)
> > BNC  INT, EXT Standard
> > BNC  IN , OUT 20-30 MHz H04
> > TNC  IN,OUT M/N
> >
> > Question does the TNC IN, OUT M/N need a jumper for this option? What
> > is this option?
> > A service manual would be great do you have one? I think this unit has a
> > binder type Operational, service, programming or what ever?
> > The generator will lock up on 3 GHz but when I start tuning for other
> > frequency's it lites up "Not Phased Locked" and the lite inside "YTO
> > loop" lite goes out.
> >
> > Any help will be of great use for me to get this unit working
> > Again thank you for the help so far.
> > I would hate to scrap the unit. I could use the unit for several testing
> > things Noise extension, and general signal gen.
> >
> > Ed
> > WA3BZT
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