Howdy. ?In my brief poking around inside he RF unit, I did not notice anything that looked like a YIG, but I wasn't looking for it. ?I doubt it's got the mod though. ?
What is the failure mode of the BWOs? ?Do they simply stop working, or drift, or have reduced sweep span? ?I noticed the warnings in the manual to keep the span at less than 100 MC/cm whenever possible. ? ?Anyway, it still works for now!
? Dan
________________________________
From: "d.seiter@..." <d.seiter@...>
To: hp agilent equipment <hp_agilent_equipment@...>
Sent: Saturday, December 29, 2012 12:11 AM
Subject: Re: [hp_agilent_equipment] HP 8551 Spectrum Analyzer FS or trade?
?
In theory, but I have yet to find one with the YIG mod. Or, to be more accurate, most people selling them only have the main unit, or it and a display, but none of the cables or filter- they don't even know if it works, let alone what it's internal config is. I honestly don't have the room for another set.
-Dave
----- Original Message -----
From: "Dave Brown" <tractorb@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Friday, December 28, 2012 1:18:20 PM
Subject: Re: [hp_agilent_equipment] HP 8551 Spectrum Analyzer FS or trade?
Once the BWO has been replaced with the YIG upgrade kit thats no longer an
issue- does this one have that upgrade applied?
73
Dave, ZL3FJ
Christchurch, NZ
----- Original Message -----
From: < d.seiter@... >
To: "hp agilent equipment" < hp_agilent_equipment@... >
Sent: Saturday, December 29, 2012 8:13 AM
Subject: Re: [hp_agilent_equipment] HP 8551 Spectrum Analyzer FS or trade?
Another problem with the 8551 (besides its' weight and therefore very high
shipping cost) it it's use of a BWO. They have a limited lifespan, and new
old stock are like hen's teeth. I got a nice one from the local estate
sale of a ham about three years ago, and it had multiple reminders on it
about not leaving it fully powered up for long periods of time. It also
can with three random BWOs and two HP sweepers that also use BWOs.
In talking with a few old timers I know from HP since then, the general
consensus was similar. They didn't worry about it at the time because they
could get new ones from Varian just down the road.
-Dave
----- Original Message -----
From: "Daniel Koller" < kaboomdk@... >
To: "hp agilent equipment" < hp_agilent_equipment@... >
Sent: Friday, December 28, 2012 6:44:17 AM
Subject: Re: [hp_agilent_equipment] HP 8551 Spectrum Analyzer FS or trade?
Hi folks,
Is there really ZERO interest in an HP 8551 spectrum analyzer? Given that
I didn't even get any comments from this usually vocal group, and having
found some replies to older posts that went into my spam folder, I figured
I'd just ask again (copied below). Perhaps a few more people are back from
the holidays as well.
Please do let me know if the group consensus is that this thing is really
just a useless boat anchor even by vintage instrument standards.
Thanks and have a happy new year!
Dan
________________________________
From: kaboomdk < kaboomdk@... >
To: hp_agilent_equipment@...
Sent: Saturday, December 22, 2012 12:48 PM
Subject: [hp_agilent_equipment] HP 8551 Spectrum Analyzer FS or trade?
Hello all,
I have an HP 8551 spectrum analyzer I would like to offer for sale or
trade. It works reasonably well, as I describe in more detail below, but I
am starting to upgrade my home shop with more "modern" equipment.
Cosmetically, the unit is clean, with some sticker residue on the display
units. It comes complete with all the necessary interconnecting cables and
the oval power cords. It weighs a TON. The RF unit alone is 90 lbs, so I
can't really ship it, even in parts. However, I live in Charlottesville,
VA, and I frequently travel up the north-east corridor, so if you live
anywhere between here and Burlington, VT, I am willing to deliver if you
can wait until March or so. Otherwise, perhaps we can make arrangements.
Some photos are posted here:
851_1.jpg A screen shot of the analyzer showing the FM band with a
dangling wire antenna and the input attenuator at 0 dB. Harmonic n=1. LO
signal on left.
851_2.jpg A 1 dBm, 2.4 GHz signal at the input with RF attenuation set to
30 dB. n=2.
851_3.jpg Same signal displayed on band 4, which uses the 200 MHz IF, n=1.
851_4.jpg The FM band again, displayed on the orange-screened 851B.
I would prefer not to part this instrument out, and to send all of it to a
good, loving home. Please make me an offer. I don't have a good feel for
price of this instrument particularly since shipping would normally be a
dominant part of the cost. Alternatively I am willing to trade for any of
the instruments below, in working or *repairable* condition. Of the
highest interest are any of the 141T SA plug-ins listed.
Any 8554/8555/8556 SA plug-ins for a 141T based spectrum analyzer,
preferably in grey paint.
182T mainframe
any 11664 A or B detectors
a 8755C swept amplitude analyzer
a sweeper covering ~MHz to ~2.5 GHz.
So, if interested, please contact me off-list and let's discuss. Thanks
and Happy Holidays!
Dan
851B/8551B Spectrum analyzer.
----------------------------
8551B: SN 625-00695 (RF unit)
851B: SN 526-00805 (Orange screen)
851B: SN 526-00339 (spare unit)
What works:
Mixer, at least at n=1, n=2 and n=3. I don't have sources to test higher
harmonics.
RF input attenuator
Stabilized fine tune - with some care
Trace centering is fine at or below 1 mc/cm, alowing one to quickly zoom
in on a signal.
Both 851B display units, with sharp and bright traces.
Fine and course tuning
Frequency vernier
What doesn't work:
Trace centering on the 3-300 MC/cm scales.
The signal jumps around when switching scales, though it can still be
tuned.
I can't follow the manual procedure in section 3-34 to set the spectrum
centering
adjustment on the front panel. The tracking meter does not respond as it
should.
As a result, LO scale pointer is ~100 MC off on scales at or below the 1
mc/cm sweep and
varies on the 3-300 mc/cm scales.
May need to reglue the scale drum at some point, but it's ok for now
The orange plastic filter in one of the 851s has cracks in it in the lower
left corner just off scale.
The tune knob had it's handle broken off, but I kept the original parts
and was able to
epoxy together a decent looking reconstruction, so it works now and looks
ok.
I can't figure out if the signal identifier works. It's supposed to shift
the signal by n cm at 100 KC/cm,
which it does, but when you press the "reference" knob, it should revert
to the n=1 state.
But instead the trace keeps moving off screen. I suspect this is related
to the issues at large spans.
What you get:
A functional piece of history - the first calibrated spectrum analyzer
from HP.
A basic, working spectrum analyzer
All interconnecting cables and oval power cords
One ORIGINAL PAPER MANUAL for the 851B display section
A spare 851B display unit (the orange one was originally paired with the
8551, judging from the stickers)
Satisfaction of working with a wonderful instrument
Herniated disks
What you don't get:
Any of the sources shown in the pictures
The instrument rack, though that can be negotiated separately
The 50 Ohm terminator on the back at the LO output. I only have a few of
these and I need them,
however it seems to work ok without it at the few frequencies I looked at.
Paper manuals for the 8551B section - but these are available on-line.
The right to return the instrument
Medical insurance
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Yahoo! Groups Links
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