Whoever named it a boat-anchor was right on--the whole line of HP generators
from that era fit the description--particularly the upper
microwave-range ones.
Was it the 620 that weighed about 100 pounds?
--doug
Missed this. Pretty heavy but not 100 lbs. I used to work on 620, 616, 614 generators and could manhandle them without too much trouble. These and the 608, 612, etc, were built like steam locomotives. -- Richard Knoppow Los Angeles WB6KBL dickburk@...
|
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Show quoted text
----- Original Message ----- From: "Doug" <dmcgarrett@...> To: <hp_agilent_equipment@...> Cc: "Merchison Burke" <merchison@...> Sent: Friday, December 21, 2012 10:16 PM Subject: Re: [hp_agilent_equipment] HP-608A Repair Wonder if anyone here can post a schematic of the attenuator on some
accessible site. (I wonder, for instance, about "53" ohm resistors, since
that is not a standard value, and about the value of the capacitor and
what it is
used for, unless it's just a coupling cap to the output.) I might just
take a look
and see how complicated it might be to fix the thing.
The spring-finger stock doesn't surprise me, and it might very well take
more
than paper to squeeze the fingers back down to go into the tube--I'm
thinking
maybe .010" brass strip or similar--maybe a strip of aluminum cut from a
beer can might work.
Whoever named it a boat-anchor was right on--the whole line of HP generators
from that era fit the description--particularly the upper
microwave-range ones.
Was it the 620 that weighed about 100 pounds?
--doug There are pretty complete instructions for repairing the attenuator probe in the 608D manual. They take a gentle touch but anyone familiar with modern circuit boards should have no trouble. I repaired many of these probes at -hp-. Of course, I had all the right parts. My memory is that the probe can be put into the tube with a little body English. A couple of the fingers are slightly bent to make it easier. If you repair it you should check its impedance with an RF bridge or network analyzer. You can also check the VSWR. There is a tuning slug for trimming the impedance. The most common problem was burned out resistors from someone having connected a transmitter to the output. I also vaguely remember replacing some shorted caps but I think that was pretty rare. I wish I could remember more specifically but its been something like forty years since I worked on one. Its helpful to have a Yankee or electric screwdriver. I wound up looking like Popeye from using a plain one. -- Richard Knoppow Los Angeles WB6KBL dickburk@...
|
On 12/22/2012 12:09 AM, Merchison Burke wrote:
If I recall correctly, I believe that the sliding portion of the
attenuator can be removed from the fixed portion to effect repairs on
the resistors and capacitor but it is ringed with spring fingers (to
provide grounding) and they must be carefully squeezed together in order
to insert the sliding portion back into the fixed portion. You may have
to use a piece of paper wrapped around the finger to squeeze them
together. I would not suggest using anything sticky, like tape to
squeeze and hold the fingers together. That would cause another problem.
Merchison in Toronto
On 2012-12-21 1:22 PM, Max Robinson wrote:
The sliding part of the attenuator has a couple of 53 ohm resistors and a
variable capacitor in it. It may or may not be possible to get the thing
apart to replace them. In any case it would be a lot of work.
Regards.
Max. K 4 O DS.
Email: max@... <mailto:max%40maxsmusicplace.com>
Wonder if anyone here can post a schematic of the attenuator on some accessible site. (I wonder, for instance, about "53" ohm resistors, since that is not a standard value, and about the value of the capacitor and what it is used for, unless it's just a coupling cap to the output.) I might just take a look and see how complicated it might be to fix the thing. The spring-finger stock doesn't surprise me, and it might very well take more than paper to squeeze the fingers back down to go into the tube--I'm thinking maybe .010" brass strip or similar--maybe a strip of aluminum cut from a beer can might work. Whoever named it a boat-anchor was right on--the whole line of HP generators from that era fit the description--particularly the upper microwave-range ones. Was it the 620 that weighed about 100 pounds? --doug
|
Are you aware the very cheap DMMs are often only 1 Meg input resistance
instead of the 10 meg in better meters. They can still be very useful as
long as you realize they can load a high impedance circuit.
Don Black.
toggle quoted message
Show quoted text
On 22-Dec-12 3:21 AM, Ed Breya wrote:
The nice big old lab/bench type DMMs will usually be a good deal in
terms of performance v. price, since most people are looking for more
modern, smaller types. Unless you plan to become a volt-nut, you
likely won't need to go beyond six digits of resolution, so DMMs in
the HP3456A class are just right for the top-end of a home lab, and
can be used as the standard to calibrate all lesser equipment.
I have a 3456A, but I prefer the 3455A - I recently added a second,
fixed with a simple repair. I've collected these over several years,
and some Fluke 8400A five digit models, and a couple of Dana five
digit ones. As I recall, I paid around USD30 to USD75 for the HPs in
unknown working condition (they were OK or needed only minor repairs),
and about USD5 to USD15 for the others.
The HPs usually sit on the shelf, to be brought out only for high
precision work. The Flukes are the workhorses, used all the time for
bench stuff. The most used, however, are those $3 handheld, disposable
ones from Harbor Freight - good enough for routine work, and when in
doubt, double checked with a Fluke.
So, portability is important, but it's nice to have at least one
really high performance lab/bench unit available.
If you read entirely message #48085 from a couple of weeks back, you
will see some more detailed discussion of DMM issues. Note that this
thread was about the HP34(65)A - a crappy 4.5 digit model - not to be
confused with the HP34(56)A, the nice 6 digit one presently discussed.
Ed
--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>, Jeff Machesky
<jeff@...> wrote:
So what's a fair price for the 3456A without a known state of
calibration? I'm still looking at the 3478A's as well or maybe even the
3468A. Something really intriguing about the 3456A however. I did order
one of the fluke 8050A's just because. Found one that was powered on
and
appeared very clean. Doubt I'll have it before x-mas however. Can one
really have too many meters ?
Thanks,
Jeff
On 12/20/2012 9:42 PM, David C. Partridge wrote:
Normal behaviour. They have VERY high input impedance on the low
voltage ranges, so any stray charge can cause a reading.
Dave
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
<mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of
Michael Hong
Sent: 20 December 2012 23:23
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] 3456A Voltmeter
Hi everyone,
I just bought two 3456As from the same dealer off eBay.
Both of them have the same problem. When they are turned on, the
number drift from low mV number and goes up to -8.nnnnn for one meter
and the other meter to -6.nnnn. And then float around there. When I
short the leads at Ohm or Volt setting, they show the near zero and
when disconnected, go to their the number again.
I expect they stay at very low mV or zero without any input. What
seems be the problem?
Thank you.
------------------------------------
Yahoo! Groups Links
|
Re: FS: Percent Modulation meter for HP 608 (?) signal generators
That helps. Thank you. Finding the modulation meter would be nice but if I found the RF meter I could shunt it and change the scale. If someone could tell me where to find a negative resistor I could use the 608 modulation meter and shunt it to make a 50 uA meter. That's a joke yall.
Regards.
Max. K 4 O DS.
Email: max@...
Transistor site
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----- Original Message ----- From: "David" <dgminala@...> To: <hp_agilent_equipment@...> Sent: Friday, December 21, 2012 7:20 PM Subject: [hp_agilent_equipment] Re: FS: Percent Modulation meter for HP 608 (?) signal generators
--- In hp_agilent_equipment@..., "Max Robinson" <max@...> wrote:
Oops? I looked up the meters in the 608D manual and I find that the two are
not identical. The RF level is 50 uA while the modulation is 1 mA.
Unfortunately I need the RF level for the 608. In the case of the 606 the
PDF of the manual I have is not very clear and I couldn't find the meter
listing. I think they are both 200 uA meter movements. I had to shunt the
100 uA meter I kluged in to be able to calibrate it.
Regards.
Max. K 4 O DS.
Max,
About the meters for the HP 606... I have the manual for the 606B, which lists the meters in the parts list. M1 (Percent Modulation) is a 200uA movement, part number 1120-0075 (the parts list identifies it as a 200ma movement).
M2 (RF Output) is as a 100uA, part number 1120-0074 (listed as a 100ma movement).
Cheers,
Dave M
------------------------------------
Yahoo! Groups Links
|
I have an old HP catalog which does not show a year but the picture on the front and back looks like an aerial view of the ocean with many things superimposed. They include a rocket, an Atlas Centaur I think, several test instruments, a disembodied scope screen and an HP knob with calibrations on its skirt. The back has the moon, a radar scope, and a spectrum display. In this catalog are an HP 260A and an HP 250A. The pictures have exactly the same control layout as the original Boonton instruments. The University where I used to teach had an RX meter which upon reflection had an HP 4 digit model number. I don't remember what it was.
Regards.
Max. K 4 O DS.
Email: max@...
Transistor site
Vacuum tube site:
Woodworking site
Music site:
To subscribe to the fun with transistors group send an email to.
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To subscribe to the fun with tubes group send an email to,
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----- Original Message ----- From: "Dave Daniel" <kc0wjn@...> To: <hp_agilent_equipment@...> Sent: Friday, December 21, 2012 6:47 PM Subject: Re: [hp_agilent_equipment] HP Oldies. Really? I thought I've seen Boonton instruments younger than that. Did
HP keep the Boonton name for a while after the acquisition?
Dave
On 12/21/2012 2:12 PM, w0eom@... wrote:
1959. the instruments are shown in the HP 1963 catalog.
In a message dated 12/21/2012 12:22:30 P.M. Pacific Standard Time,
kc0wjn@... <mailto:kc0wjn%40gmail.com> writes:
Wow. I didn't know HP bought Boonton. I always liked Boonton
instruments, probably because I was born in Boonton. When did HP buy them?
Dave
On 12/21/2012 12:59 PM, Max Robinson wrote:
I am looking for a couple of HP oldies. The 260A Q meter and the 250A RX
meter. I can't find any on eBay. These two instruments were carried over
from Boonton when HP bought them out.
Regards.
Max. K 4 O DS.
Email: _max@... <mailto:_max%40maxsmusicplace.com>_
(mailto:max@... <mailto:max%40maxsmusicplace.com>)
<mailto:max%40maxsmusicplace.com>
Transistor site _
()
Vacuum tube site: _ ()
Woodworking site
_
()
Music site: _ ()
To subscribe to the fun with transistors group send an email to.
_funwithtransistors-subscribe@...
<mailto:_funwithtransistors-subscribe%40yahoogroups.com>_
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To subscribe to the fun with tubes group send an email to,
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If I recall correctly, I believe that the sliding portion of the attenuator can be removed from the fixed portion to effect repairs on the resistors and capacitor but it is ringed with spring fingers (to provide grounding) and they must be carefully squeezed together in order to insert the sliding portion back into the fixed portion. You may have to use a piece of paper wrapped around the finger to squeeze them together. I would not suggest using anything sticky, like tape to squeeze and hold the fingers together. That would cause another problem.
Merchison in Toronto
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Show quoted text
On 2012-12-21 1:22 PM, Max Robinson wrote: The sliding part of the attenuator has a couple of 53 ohm resistors and a
variable capacitor in it. It may or may not be possible to get the thing
apart to replace them. In any case it would be a lot of work.
Regards.
Max. K 4 O DS.
Email: max@...
|
toggle quoted message
Show quoted text
----- Original Message ----- From: "Dave Daniel" <kc0wjn@...> To: <hp_agilent_equipment@...> Sent: Friday, December 21, 2012 4:47 PM Subject: Re: [hp_agilent_equipment] HP Oldies. Really? I thought I've seen Boonton instruments younger than that. Did
HP keep the Boonton name for a while after the acquisition?
Dave
Boonton radio started in 1934 as Radio Frequency Laboratories and reformed as Boonton Radio Corporation a short time later. Its first product was the Q-Meter. -hp- kept the Boonton name for a couple of years anyway. I don't know if any Q-Meters or RX-Meters were made with the -hp- trade mark on them but the name is on the label on the back. -- Richard Knoppow Los Angeles WB6KBL dickburk@...
|
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----- Original Message ----- From: "David DiGiacomo" <daviddigiacomo@...> To: <hp_agilent_equipment@...> Sent: Friday, December 21, 2012 3:49 PM Subject: Re: [hp_agilent_equipment] HP Oldies. On Fri, Dec 21, 2012 at 1:22 PM, Dave Daniel <kc0wjn@...> wrote:
Wow. I didn't know HP bought Boonton. I always liked Boonton
instruments, probably because I was born in Boonton. When did HP buy them?
Dave This is confusing (at least to me), because there was Boonton
Electronics, Boonton Measurements (usually just called Measurements),
and Boonton Radio. HP bought Boonton Radio, but not the other two.
Most of the familiar Boonton instruments are from Boonton Electronics.
Boonton Electronics made sensitive electronic voltmeters and some other equipment. Measurements Corp made voltmeters and signal generators. I have a frequency calibrator/marker made by Measurements Corp. Boonton Radio Corp made the Q-Meter, which they originated, the RX-Meter, which is a consolidation of an RF bridge, signal generator, and detector in one box, and a variety of signal generators, mainly FM, and test sets for air navigation equipment. There was also Aircraft Radio Corporation or ARC, which was a pioneer in airborne radio equipment. There were a couple of other companies too but my memory is not very reliable about them. -hp- bought only Boonton Radio Corporation. I don't know what they wanted. They continued to build the Q-Meter and RX-Meter for a time and a small VHF signal generator, originally sold under the Boonton name and later as an -hp- product. At the time -hp- bought Boonton they were buying a lot of small companies. -- Richard Knoppow Los Angeles WB6KBL dickburk@...
|
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----- Original Message ----- From: "Brad Thompson" <brad.thompson@...> To: <hp_agilent_equipment@...> Cc: "J. Forster" <jfor@...> Sent: Friday, December 21, 2012 3:27 PM Subject: Re: [hp_agilent_equipment] HP Oldies. On 12/21/2012 5:39 PM, J. Forster wrote:
-John
Hello--
There's also...
...And...
...And even Wikipedia gets into the act...
73--
Brad AA1IP
The first is a mailing list dedicated to Boonton equipment. Originally it was just Boonton radio but also covers other stuff like the meters made by Boonton Electronics. The other sites above are good for manuals and information but I think this fellow wants to correspond with other users of Boonton gear and find some parts. -- Richard Knoppow Los Angeles WB6KBL dickburk@...
|
Re: FS: Percent Modulation meter for HP 608 (?) signal generators
--- In hp_agilent_equipment@..., "Max Robinson" <max@...> wrote:
Oops? I looked up the meters in the 608D manual and I find that the two are
not identical. The RF level is 50 uA while the modulation is 1 mA.
Unfortunately I need the RF level for the 608. In the case of the 606 the
PDF of the manual I have is not very clear and I couldn't find the meter
listing. I think they are both 200 uA meter movements. I had to shunt the
100 uA meter I kluged in to be able to calibrate it.
Regards.
Max. K 4 O DS.
Max, About the meters for the HP 606... I have the manual for the 606B, which lists the meters in the parts list. M1 (Percent Modulation) is a 200uA movement, part number 1120-0075 (the parts list identifies it as a 200ma movement). M2 (RF Output) is as a 100uA, part number 1120-0074 (listed as a 100ma movement). Cheers, Dave M
|
I have a Boonton 42BD Microwattmeter with a digital display and use it often. Im guessing a mid 70's product?
toggle quoted message
Show quoted text
----- Original Message -----
From: Dave Daniel
To: hp_agilent_equipment@...
Sent: Friday, December 21, 2012 7:47 PM
Subject: Re: [hp_agilent_equipment] HP Oldies.
Really? I thought I've seen Boonton instruments younger than that. Did
HP keep the Boonton name for a while after the acquisition?
Dave
On 12/21/2012 2:12 PM, w0eom@... wrote:
>
> 1959. the instruments are shown in the HP 1963 catalog.
>
>
> In a message dated 12/21/2012 12:22:30 P.M. Pacific Standard Time,
> kc0wjn@... <mailto:kc0wjn%40gmail.com> writes:
>
> Wow. I didn't know HP bought Boonton. I always liked Boonton
> instruments, probably because I was born in Boonton. When did HP buy them?
>
> Dave
>
> On 12/21/2012 12:59 PM, Max Robinson wrote:
> >
> > I am looking for a couple of HP oldies. The 260A Q meter and the 250A RX
> > meter. I can't find any on eBay. These two instruments were carried over
> > from Boonton when HP bought them out.
> >
> > Regards.
> >
> > Max. K 4 O DS.
> >
> > Email: _max@... <mailto:_max%40maxsmusicplace.com>_
> (mailto:max@... <mailto:max%40maxsmusicplace.com>)
> <mailto:max%40maxsmusicplace.com>
> >
> > Transistor site _
> ()
> > Vacuum tube site: _
> ()
> > Woodworking site
> >
> _
>
> ()
>
> > Music site: _
> ()
> >
> > To subscribe to the fun with transistors group send an email to.
> > _funwithtransistors-subscribe@...
> <mailto:_funwithtransistors-subscribe%40yahoogroups.com>_
> (mailto:funwithtransistors-subscribe@...
> <mailto:funwithtransistors-subscribe%40yahoogroups.com>)
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> >
> > To subscribe to the fun with tubes group send an email to,
> > _funwithtubes-subscribe@...
> <mailto:_funwithtubes-subscribe%40yahoogroups.com>_
> (mailto:funwithtubes-subscribe@...
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> >
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> >
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>
> [Non-text portions of this message have been removed]
>
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>
>
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Really? I thought I've seen Boonton instruments younger than that. Did HP keep the Boonton name for a while after the acquisition? Dave On 12/21/2012 2:12 PM, w0eom@... wrote:
1959. the instruments are shown in the HP 1963 catalog.
In a message dated 12/21/2012 12:22:30 P.M. Pacific Standard Time,
kc0wjn@... <mailto:kc0wjn%40gmail.com> writes:
Wow. I didn't know HP bought Boonton. I always liked Boonton
instruments, probably because I was born in Boonton. When did HP buy them?
Dave
On 12/21/2012 12:59 PM, Max Robinson wrote:
I am looking for a couple of HP oldies. The 260A Q meter and the 250A RX
meter. I can't find any on eBay. These two instruments were carried over
from Boonton when HP bought them out.
Regards.
Max. K 4 O DS.
Email: _max@... <mailto:_max%40maxsmusicplace.com>_
(mailto:max@... <mailto:max%40maxsmusicplace.com>)
<mailto:max%40maxsmusicplace.com>
Transistor site _
()
Vacuum tube site: _ ()
Woodworking site
_
()
Music site: _ ()
To subscribe to the fun with transistors group send an email to.
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Re: Parts to repair an HP 6434B 40V 25A power supply
If the handle is what I think it is, it is malleable steel.
A hammer would be fine, but use some wood between the hammer
and the handle to avoid scarring it. Or, depending on how
it is bent, a vise and a pipe.
Life would be simpler if folks would learn how to pack.
-Chuck Harris
James Newton wrote:
toggle quoted message
Show quoted text
Thanks for the advice Chuck,
I'm trying some epoxy on the bezel as we speak.
Not sure what I have that would bend that handle... it's a monster. How do you
think beating it a bit with a hammer would work? It isn't bent much... just enough
to jam the bolt in it and cause it to be misaligned with the case.
Picked up the banana post today, I'll try soldering that on once I have the meter
back in and then fire it up and hope it doesn't smoke.
-- James.
|
Re: Parts to repair an HP 6434B 40V 25A power supply
Thanks for the advice Chuck,
I'm trying some epoxy on the bezel as we speak.
Not sure what I have that would bend that handle... it's a monster. How do you think beating it a bit with a hammer would work? It isn't bent much... just enough to jam the bolt in it and cause it to be misaligned with the case.
Picked up the banana post today, I'll try soldering that on once I have the meter back in and then fire it up and hope it doesn't smoke.
--
James.
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., Chuck Harris <cfharris@...> wrote:
Take the bezel apart, and glue it back together. If you
are careful, it should even look ok. Bakelite glues ok
with cyanoacrylates, and most every other plastic does
ok with a thin solvent glue, like testors.
As to the handle, You can sometimes bend them back if you
go in small steps, and let the aluminum relax before the
next bend. The bolts that remain won't need drilling, as
once the tension is off, they should turn easily.
-Chuck Harris
James Newton wrote:
Just purchased this thing from eBay and the seller shipped it without ANY padding
on the bottom of the box. I know they are pretty well built, but that's just
crazy... He refunded the purchase price, so I got what's left for the shipping.
Right handle sheared off the case, the ends are bent so I doubt I can drill out
the bolts and re-mount it. HP Part # 5020-5512
And the left (voltage) meter was pushed back into the case after the handle
wiggled over to that side and got pushed up against the box. The meter /may/ be
ok, but the little black plastic bezel that holds the meter in is cracked. HP part
# 4040-0296.
And the (-) binder clip is sheared off. No problem repairing that.
I can probably live without the handle. Any ideas where I can get a new bezel or
mount that meter? Very strange mounting system. Hope someone here has seen it and
knows what I'm talking about.
By way of introduction: I've been in firmware most of my life, I ran the MIT
PIClist mailing list for years and still archive it at PICList.com. I make and
sell some open source stepper drivers now and so I'm getting more into
electronics. I have a 1662C 'scope and a 1653B analyzer that I love. Can't beat
the old stuff.
------------------------------------
Yahoo! Groups Links
|
On Fri, Dec 21, 2012 at 1:22 PM, Dave Daniel <kc0wjn@...> wrote: Wow. I didn't know HP bought Boonton. I always liked Boonton
instruments, probably because I was born in Boonton. When did HP buy them?
Dave This is confusing (at least to me), because there was Boonton Electronics, Boonton Measurements (usually just called Measurements), and Boonton Radio. HP bought Boonton Radio, but not the other two. Most of the familiar Boonton instruments are from Boonton Electronics.
|
On 12/21/2012 5:39 PM, J. Forster wrote:
-John
Hello-- There's also... ...And... ...And even Wikipedia gets into the act... 73-- Brad AA1IP
|
Re: 70902A spectrum analyzer IF module RESOLUTION BANDWIDTH problems
I think the IF filter architecture of the 70902A may be roughly the same as in the 8566. If so, those crystal filters are all 3.0 MHz center frequency, with the bandwidth set by controlling the load impedance, hence Q, by virtue of the RF resistance of PIN diodes. It should be a cascade of similar stages, all with varying PIN currents according to the selected IFBW. So, all of the sections should be active, but the BW is controlled by logical steps supplying PIN currents set by precision series resistors. The higher the PIN currents, the narrower the BW. There should be other PINs to route the IF around the crystal section at the wider bandwidths, and also some to provide gain compensation to match the gain for all the BW settings.
In the 8566, the 21.4 MHz IF is mixed down to 3 MHz, processed through the filters, then converted back up and sent on its way. I don't recall if the LC filters also process at 3 MHz, or at 21.4 MHz - either way is possible.
Those indicator lights may be the key to solving the problem, but not for the reason you suggested. It's possible that those are overload or other status indicators - not necessarily logical on/off. Maybe some of the logic states or levels are wrong, causing some filter BW settings to do the wrong thing. You would have to find the individual BW selection logic lines and see what they're doing. They may be high voltage logic - directly driving the PIN current setting resistors with up to +/- 20 V or so. Just remember, when the crystal section is needed, all the stages should be on, while the logically-controlled PIN currents set the BW.
Since these PIN signal routing and "tuning" lines actually can be considered to be analog control, a loose line out of control can allow for various wrong currents to flow between stages, causing interesting results - that is what I think may have happened. A wrongly tuned or stuck filter stage, or a partially turned on switch that should be on or off, could make quite a mess.
You may want to look at the down/up conversion process too, to make sure it's actually on the right frequency - there should be a crystal oscillator nearby running at 18.4 or 24.4 MHz. The filter crystals should say 3 MHz, or whatever they run at. If they are 21.4 MHz, then no down/up conversion is needed. If you can ID these you'll have a pretty good idea of what's going on.
It sounds like you don't have a schematic or manual, but maybe similar systems like the 8566 would at least provide some info you can use, presuming it's actually similar. I don't recall there being indicators on the filters, but I've never needed to look closely at the IF/display section yet.
The breakpoints around 10 kHz or 3 kHz make sense - the crystal filters are only used at the narrowest bandwidths, while the LC ones do the upper, and may also be in-line when the crystal section is used. I believe the LC filters are fixed BW, set only by the L and C adjustments - not by PIN loading - although there would be associated PIN switches for signal routing.
Ed
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--- In hp_agilent_equipment@..., "roberto.barrios" <rbarrioss@...> wrote:
Hello,
I am trying to fix a 71100A spectrum analyzer and I'm stuck. It passes the "analyzer test" built into the firmware but does not pass calibration of the resolution bandwidth for some of the bandwidth filters (in the 70902A IF module).
The problen is easily seen in the shape of the curve from the calibrator, which for three of the filters does not look like it should. If you take a look at
you will see that:
* 10 Hz: Looks like if it was composed of two filters in series not aligned to the same center frequency. Peak amplitude 8 dB down.
* 30 Hz: Almost right but again not 100% symmetric. Peak amplitude OK.
* 100 Hz: Seems nice to me.
* 300 Hz: Just A bit asymmetric
* 1.00 kHz: Ugly, centered but no simmetry. Peak amplitude OK.
* 3.00 kHz: Ugliest, a complete mess. Peak amplitude 13dB up.
* 30.0 kHz: Looks nice.
* 100 kHz: Strange shape, convex skirts instead of concave (??)
* 300 kHz: Strange shape, convex skirts instead of concave (??)
The first error ( 2023 , Illegal Cal Signal ) appears when the 3.0 kHz test is done. The last one ( 6011 , RBW hardware error ) appears after the last one, which is the 10Hz test.
I have the Component Level Information Package (from ARTEKMANUALS) for the module, and it shows there are (among other), 9 filter stages:
LC1 > LC2 > XTAL1 > XTAL2 > XTAL3 > XTAL4 > XTAL5 > LC3 > LC4
Most of the stages have a bandwidth and center control pot/cap, some also a symmetry control. I tweaked them and could not see any significant difference in the ones that don't look nice so I carefully left them all where they were.
There are also "SHORT" LEDs on each filter stage, I believe to signal which stages are being bypassed. What I do not understand is why the LC1, LC2, LC3 and LC4 LEDs are never ON and the XTAL1, XTAL2, XTAL3, XTAL4 and XTAL5 are either ON
of OFF, all at the same time. From 10K up they are all ON and from 3K and down they are all OFF. I was expecting some kind of weighted switching to get the desired filter bandwidth, so I could find and repair the stage that was failing, but it does not seem to be that easy. Since it is possible to have continuos bandwidth control, some of the stages are probably not as simple as I thought.
Appart from some of the trim caps being stuck, there was no physical damage that I could find.
Does anyone know how the filter stages work? Suggestions to try?
Thank you and Merry xmas to you all.
Roberto EB4EQA
|
-John
===============
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I didn't know there was a Boonton group. I'll check it out.
Regards.
Max. K 4 O DS.
Email: max@...
Transistor site
Vacuum tube site:
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Music site:
To subscribe to the fun with transistors group send an email to.
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----- Original Message -----
From: "J. Forster" <jfor@...>
To: <hp_agilent_equipment@...>
Sent: Friday, December 21, 2012 2:04 PM
Subject: Re: [hp_agilent_equipment] HP Oldies.
Also ask on the Boonton Group.
-John
==========
I am looking for a couple of HP oldies. The 260A Q meter and the 250A
RX
meter. I can't find any on eBay. These two instruments were carried
over
from Boonton when HP bought them out.
Regards.
Max. K 4 O DS.
Email: max@...
Transistor site
Vacuum tube site:
Woodworking site
Music site:
To subscribe to the fun with transistors group send an email to.
funwithtransistors-subscribe@...
To subscribe to the fun with tubes group send an email to,
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Re: 70902A spectrum analyzer IF module RESOLUTION BANDWIDTH problems
Hi Roberto,
Check your e-mail.
Vladan
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--- In hp_agilent_equipment@..., "roberto.barrios" <rbarrioss@...> wrote:
Hello,
I am trying to fix a 71100A spectrum analyzer and I'm stuck. It passes the "analyzer test" built into the firmware but does not pass calibration of the resolution bandwidth for some of the bandwidth filters (in the 70902A IF module).
The problen is easily seen in the shape of the curve from the calibrator, which for three of the filters does not look like it should. If you take a look at
you will see that:
* 10 Hz: Looks like if it was composed of two filters in series not aligned to the same center frequency. Peak amplitude 8 dB down.
* 30 Hz: Almost right but again not 100% symmetric. Peak amplitude OK.
* 100 Hz: Seems nice to me.
* 300 Hz: Just A bit asymmetric
* 1.00 kHz: Ugly, centered but no simmetry. Peak amplitude OK.
* 3.00 kHz: Ugliest, a complete mess. Peak amplitude 13dB up.
* 30.0 kHz: Looks nice.
* 100 kHz: Strange shape, convex skirts instead of concave (??)
* 300 kHz: Strange shape, convex skirts instead of concave (??)
The first error ( 2023 , Illegal Cal Signal ) appears when the 3.0 kHz test is done. The last one ( 6011 , RBW hardware error ) appears after the last one, which is the 10Hz test.
I have the Component Level Information Package (from ARTEKMANUALS) for the module, and it shows there are (among other), 9 filter stages:
LC1 > LC2 > XTAL1 > XTAL2 > XTAL3 > XTAL4 > XTAL5 > LC3 > LC4
Most of the stages have a bandwidth and center control pot/cap, some also a symmetry control. I tweaked them and could not see any significant difference in the ones that don't look nice so I carefully left them all where they were.
There are also "SHORT" LEDs on each filter stage, I believe to signal which stages are being bypassed. What I do not understand is why the LC1, LC2, LC3 and LC4 LEDs are never ON and the XTAL1, XTAL2, XTAL3, XTAL4 and XTAL5 are either ON
of OFF, all at the same time. From 10K up they are all ON and from 3K and down they are all OFF. I was expecting some kind of weighted switching to get the desired filter bandwidth, so I could find and repair the stage that was failing, but it does not seem to be that easy. Since it is possible to have continuos bandwidth control, some of the stages are probably not as simple as I thought.
Appart from some of the trim caps being stuck, there was no physical damage that I could find.
Does anyone know how the filter stages work? Suggestions to try?
Thank you and Merry xmas to you all.
Roberto EB4EQA
|
