I received the HP3400A today and I checked it out, all I could get out
of it was a large needle bounce between range changes.
After a little more testing, I found that the 1V scale does work and
looks accurate comparing it to my HP 400E.
The other 11 ranges are dead.
 I'm starting a return claim, but I have troubleshooting experience,
anyone looked inside, are these fairly easy to repair?
                         Mikek

In article <te3tas$34d0u$1@dont-email.me>, amdx <amdx@knology.net> wrote:
>I received the HP3400A today and I checked it out, all I could get out
>of it was a large needle bounce between range changes.
>After a little more testing, I found that the 1V scale does work and
>looks accurate comparing it to my HP 400E.
>The other 11 ranges are dead.
>  I'm starting a return claim, but I have troubleshooting experience,
>anyone looked inside, are these fairly easy to repair?

The manual is freely available on-line, and the design seems fairly
straightforward. I haven't had to do more to mine than clean the
switch contacts, fortunately.

If it's working properly on one band and seems to be accurate there,
that's a good indication that the essentials are all working - power
supply, thermistors, chopper circuit, "impedance converter" (the
buffer amplifier between the first and second switched attenuator
stages) and the video amplifier.

The only thing which changes when you go from one band to another, is
the setting of the two-stage attenuator - the two sections of switch
S301, and the signal routing via the cables to/from the switch
sections. The first attenuator stage looks like a two-range selection
(.001 through .3 volts, and 1 through 300 volts). The second stage is
a 6-way selector.

So, I'd check the switch itself for proper operation - maybe give it a
careful cleaning in case the contacts are gunked up. Then, check the
two attenuator-section boards for possible damage, open solder joints,
and so forth. If, for example, R302 on the A3 second-attenuator board
were open, it looks to me as if the .001 and 1 volt ranges would work,
but the others would all read zero. Broken wires in the A3-to-switch
cable could have a similar bad effect (you'd lose two bands per broken
wire).

If you have a 'scope it should be possible to follow a test signal
through the input chain (attenuators and impedance converter inputs
and outputs) pretty easily and see where you lose signal.

On 8/23/2022 9:18 PM, Dave Platt wrote:
> In article <te3tas$34d0u$1@dont-email.me>, amdx <amdx@knology.net> wrote:
>> I received the HP3400A today and I checked it out, all I could get out
>> of it was a large needle bounce between range changes.
>> After a little more testing, I found that the 1V scale does work and
>> looks accurate comparing it to my HP 400E.
>> The other 11 ranges are dead.
>>  I'm starting a return claim, but I have troubleshooting experience,
>> anyone looked inside, are these fairly easy to repair?
> The manual is freely available on-line, and the design seems fairly
> straightforward. I haven't had to do more to mine than clean the
> switch contacts, fortunately.
>
> If it's working properly on one band and seems to be accurate there,
> that's a good indication that the essentials are all working - power
> supply, thermistors, chopper circuit, "impedance converter" (the
> buffer amplifier between the first and second switched attenuator
> stages) and the video amplifier.
>
> The only thing which changes when you go from one band to another, is
> the setting of the two-stage attenuator - the two sections of switch
> S301, and the signal routing via the cables to/from the switch
> sections. The first attenuator stage looks like a two-range selection
> (.001 through .3 volts, and 1 through 300 volts). The second stage is
> a 6-way selector.
>
> So, I'd check the switch itself for proper operation - maybe give it a
> careful cleaning in case the contacts are gunked up. Then, check the
> two attenuator-section boards for possible damage, open solder joints,
> and so forth. If, for example, R302 on the A3 second-attenuator board
> were open, it looks to me as if the .001 and 1 volt ranges would work,
> but the others would all read zero. Broken wires in the A3-to-switch
> cable could have a similar bad effect (you'd lose two bands per broken
> wire).
Wow, thanks for that, I went back and checked and yes the .001 range is
working. So, as you say 1V and .001v range working,
could be R302, or wiring.
  I paid $129 with shipping, $100 for the meter. I offered to return it
of pay $30 and try to repair. we will see what the seller says.
Thanks, Mikek

>
> If you have a 'scope it should be possible to follow a test signal
> through the input chain (attenuators and impedance converter inputs
> and outputs) pretty easily and see where you lose signal.
>
>

On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
<amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:

>I received the HP3400A today and I checked it out, all I could get out
>of it was a large needle bounce between range changes.
>After a little more testing, I found that the 1V scale does work and
>looks accurate comparing it to my HP 400E.
>The other 11 ranges are dead.
>  I'm starting a return claim, but I have troubleshooting experience,
>anyone looked inside, are these fairly easy to repair?
>                          Mikek

Was this not originaly about measuring a RF signal up to 2 MHz??

Apart from checking if your digital voltmeters AC input goes that high
(300 mV AC range gives you mV resolution)
getting a decent _analog_ scope

WTF ??
IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
stage 1 high input impedance follower gain 1
stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
stage 3 precision recitfier (cost 1 diode)
optional stage 4 log amplifier

connect voltmetet / multimeter to the output.

Why waste those dollars? You gona need those for food when inflation takes off
crops fail, nukes fly and
OK

Any long + medum wave AM radio for that frequency make a spectrum analyzer.

On 8/24/2022 12:58 AM, Jan Panteltje wrote:
> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
> <amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:
>
>> I received the HP3400A today and I checked it out, all I could get out
>> of it was a large needle bounce between range changes.
>> After a little more testing, I found that the 1V scale does work and
>> looks accurate comparing it to my HP 400E.
>> The other 11 ranges are dead.
>>  I'm starting a return claim, but I have troubleshooting experience,
>> anyone looked inside, are these fairly easy to repair?
>>                          Mikek
> Was this not originaly about measuring a RF signal up to 2 MHz??
 That is a component.
>
> Apart from checking if your digital voltmeters AC input goes that high
> (300 mV AC range gives you mV resolution)
> getting a decent _analog_ scope
 My DVM=1000Hz
> WTF ??
> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
> stage 1 high input impedance follower gain 1
> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
> stage 3 precision recitfier (cost 1 diode)
> optional stage 4 log amplifier
 As I've said before, I was a fish monger, I have no design education.
I can build what I have a schematic for. I'm aware of
parasitics, and a can avoid them, probably capacitance better than
inductance. I have laid out pcbs with a program and
 have had them made, or made them myself. Never have quite under stood
log amplifiers, just seems like a non linear voltmeter.
> connect voltmetet / multimeter to the output.
>
> Why waste those dollars? You gona need those for food when inflation takes off
> crops fail, nukes fly and
> OK
  Last I checked I have 38 times my yearly spending. We will start SS
in 2.5 years and that will cover 78% of our spending,
reducing reducing my nest egg withdrawals to well under 1%. My problem
is learning to BTD, blow the dough after a
lifetime of frugality.
> Any long + medum wave AM radio for that frequency make a spectrum analyzer.
 Design me a down converter for the NanoVna, so I can see audio. I
think it goes down to 50kHz.
I admire your abilities, I don't have them.
                                                Mikek

On a sunny day (Wed, 24 Aug 2022 05:34:54 -0500) it happened amdx
<amdx@knology.net> wrote in <te4ush$39tv1$1@dont-email.me>:

>On 8/24/2022 12:58 AM, Jan Panteltje wrote:
>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
>> <amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:
>>
>>> I received the HP3400A today and I checked it out, all I could get out
>>> of it was a large needle bounce between range changes.
>>> After a little more testing, I found that the 1V scale does work and
>>> looks accurate comparing it to my HP 400E.
>>> The other 11 ranges are dead.
>>>  I'm starting a return claim, but I have troubleshooting experience,
>>> anyone looked inside, are these fairly easy to repair?
>>>                          Mikek
>> Was this not originaly about measuring a RF signal up to 2 MHz??
>  That is a component.
>>
>> Apart from checking if your digital voltmeters AC input goes that high
>> (300 mV AC range gives you mV resolution)
>> getting a decent _analog_ scope
>  My DVM=1000Hz
>> WTF ??
>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
>> stage 1 high input impedance follower gain 1
>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
>> stage 3 precision recitfier (cost 1 diode)
>> optional stage 4 log amplifier
>  As I've said before, I was a fish monger, I have no design education.
>I can build what I have a schematic for. I'm aware of
>parasitics, and a can avoid them, probably capacitance better than
>inductance. I have laid out pcbs with a program and
>  have had them made, or made them myself. Never have quite under stood
>log amplifiers, just seems like a non linear voltmeter.
>> connect voltmetet / multimeter to the output.
>>
>> Why waste those dollars? You gona need those for food when inflation takes off
>> crops fail, nukes fly and
>> OK
>   Last I checked I have 38 times my yearly spending. We will start SS
>in 2.5 years and that will cover 78% of our spending,
>reducing reducing my nest egg withdrawals to well under 1%. My problem
>is learning to BTD, blow the dough after a
>lifetime of frugality.
>> Any long + medum wave AM radio for that frequency make a spectrum analyzer.
>  Design me a down converter for the NanoVna, so I can see audio. I
>think it goes down to 50kHz.
>I admire your abilities, I don't have them.

Yea, this is a design group..
Anyways last thing first:
first link I find for nanoVNA says it runs from 10 kHz to 1.5 GHz
For 10kHz and lower (audio) you can use your PC soundcard
plenty of software applications for that.

One dual gate MOSFET as mixer and an oscillator of a few MHz and some software and you could use
RTL-SDR sticks.. LOTS of software for those on the web,

Dual gate MOSFETs make great mixers, signal on gate 1 and oscillator on gate 2, output from drain.
'tronix is not difficult, get a good book, always remember its about electrons moving.
Maybe one of those ham radio handbooks, helped me as a kid.
Or Winfield's or whatever his name was, is he still alive?
Many electronic magazines existed once, 'Elector'? had plenty of DIY circuits,
one a year a whole issue full IIRC.
Many datasheets about opamps also show rectifier and some log amp examples
else googling for '.. circuit' will show you many.
All costs cents...

I have no boat anchor at home...
Oh well, I do have an old analog 10 MHz scope though, all I need.
Analog scopes are better than those digital things, those lie,
usually not a problem if you know what you are doing.. but who ;-)

As to food, maybe I am eating too much chocolate.. but I have lived in the wild too.
Build a good radiation meter, :-) you may need it...
Just did read some mushrooms in Europe are still 'hot' with radiation for Tjernobyl.

Dollars? good printer?
With that much debt US cannot keep existing, even if they try to inflate debt away.
So learn Russian and Chinese, Maybe French and Spanish too...
;-0

On Wed, 24 Aug 2022 05:34:54 -0500, amdx <amdx@knology.net> wrote:

>On 8/24/2022 12:58 AM, Jan Panteltje wrote:
>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
>> <amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:
>>
>>> I received the HP3400A today and I checked it out, all I could get out
>>> of it was a large needle bounce between range changes.
>>> After a little more testing, I found that the 1V scale does work and
>>> looks accurate comparing it to my HP 400E.
>>> The other 11 ranges are dead.
>>>  I'm starting a return claim, but I have troubleshooting experience,
>>> anyone looked inside, are these fairly easy to repair?
>>>                          Mikek
>> Was this not originaly about measuring a RF signal up to 2 MHz??
>  That is a component.
>>
>> Apart from checking if your digital voltmeters AC input goes that high
>> (300 mV AC range gives you mV resolution)
>> getting a decent _analog_ scope

Analog scopes are unreliable antiques. A cheap 100 MHz color digital
scope has averaging, FFT, storage, variable persistance, all sorts of
cool stuff and you can lift it with one hand.

Lots of DVMs have crazy bad frequency response. Some die in the
mid-audio range.

Measure twice: DVM and scope.

>  My DVM=1000Hz
>> WTF ??
>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
>> stage 1 high input impedance follower gain 1
>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
>> stage 3 precision recitfier (cost 1 diode)
>> optional stage 4 log amplifier
>  As I've said before, I was a fish monger, I have no design education.

An EE degree is a PITA, but it forces people to learn the basic
physics and circuit theory and signals+systems. But you can do that
yourself, with simple experiments as the labs that reinforce
instincts.

>I can build what I have a schematic for. I'm aware of
>parasitics, and a can avoid them, probably capacitance better than
>inductance. I have laid out pcbs with a program and
>  have had them made, or made them myself. Never have quite under stood
>log amplifiers, just seems like a non linear voltmeter.

Log amps are rarely used.

>> connect voltmetet / multimeter to the output.
>>
>> Why waste those dollars? You gona need those for food when inflation takes off
>> crops fail, nukes fly and
>> OK
>   Last I checked I have 38 times my yearly spending. We will start SS
>in 2.5 years and that will cover 78% of our spending,
>reducing reducing my nest egg withdrawals to well under 1%. My problem
>is learning to BTD, blow the dough after a
>lifetime of frugality.

Electronic equipment is astoundingly cheap nowadays. You can learn a
lot with a simple signal generator, a cheap scope, a DVM, a battery,
and a couple of parts kits, under $400 total.

The Art of Electronics is a great book. Used ones are cheap.

On 8/24/2022 10:14 AM, jlarkin@highlandsniptechnology.com wrote:
> On Wed, 24 Aug 2022 05:34:54 -0500, amdx <amdx@knology.net> wrote:
>
>> On 8/24/2022 12:58 AM, Jan Panteltje wrote:
>>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
>>> <amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:
>>>
>>>> I received the HP3400A today and I checked it out, all I could get out
>>>> of it was a large needle bounce between range changes.
>>>> After a little more testing, I found that the 1V scale does work and
>>>> looks accurate comparing it to my HP 400E.
>>>> The other 11 ranges are dead.
>>>>  I'm starting a return claim, but I have troubleshooting experience,
>>>> anyone looked inside, are these fairly easy to repair?
>>>>                          Mikek
>>> Was this not originaly about measuring a RF signal up to 2 MHz??
>>  That is a component.
>>> Apart from checking if your digital voltmeters AC input goes that high
>>> (300 mV AC range gives you mV resolution)
>>> getting a decent _analog_ scope
> Analog scopes are unreliable antiques. A cheap 100 MHz color digital
> scope has averaging, FFT, storage, variable persistance, all sorts of
> cool stuff and you can lift it with one hand.
>
> Lots of DVMs have crazy bad frequency response. Some die in the
> mid-audio range.
>
> Measure twice: DVM and scope.
>
>
>>  My DVM=1000Hz
>>> WTF ??
>>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
>>> stage 1 high input impedance follower gain 1
>>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
>>> stage 3 precision recitfier (cost 1 diode)
>>> optional stage 4 log amplifier
>>  As I've said before, I was a fish monger, I have no design education.
> An EE degree is a PITA, but it forces people to learn the basic
> physics and circuit theory and signals+systems. But you can do that
> yourself, with simple experiments as the labs that reinforce
> instincts.
>
>> I can build what I have a schematic for. I'm aware of
>> parasitics, and a can avoid them, probably capacitance better than
>> inductance. I have laid out pcbs with a program and
>>  have had them made, or made them myself. Never have quite under stood
>> log amplifiers, just seems like a non linear voltmeter.
> Log amps are rarely used.
>
>>> connect voltmetet / multimeter to the output.
>>>
>>> Why waste those dollars? You gona need those for food when inflation takes off
>>> crops fail, nukes fly and
>>> OK
>>   Last I checked I have 38 times my yearly spending. We will start SS
>> in 2.5 years and that will cover 78% of our spending,
>> reducing reducing my nest egg withdrawals to well under 1%. My problem
>> is learning to BTD, blow the dough after a
>> lifetime of frugality.
> Electronic equipment is astoundingly cheap nowadays. You can learn a
> lot with a simple signal generator, a cheap scope, a DVM, a battery,
> and a couple of parts kits, under $400 total.
>
> The Art of Electronics is a great book. Used ones are cheap.
>
I have only recently (7 weeks) got out of a mental rut, after starting a
Carnivore diet and 3 day a week muscle building work out.
All the sudden I'm busy all day rather than slumbering on the computer.
So, ya, I have the equipment gathered over the years. Sig gen is an
HP8640B and HP651B, scope is a Tek 2464 CTS, DVM is
a Berman 235, batteries and several power supplies. Oh, and I have the
latest, Art of electronics.
All I need is to engage my brain, I find that works best, when I have a
project and have a need to know, then I learn.
                                               Thanks for all the help,
Mikek
PS, Thanks to everyone that has given input, even negative

j lurking wrote
>Analog scopes are unreliable antiques.

You really are an idiot

>Log amps are rarely used.

Any dB meter uses those

You know shit about audio
you know shit about RF
you know shit about digital
You cannot program

Maybe you can impress your also knowing shit customers
!

On Tuesday, August 23, 2022 at 9:02:28 PM UTC-4, amdx wrote:
> I received the HP3400A today and I checked it out, all I could get out
> of it was a large needle bounce between range changes.
> After a little more testing, I found that the 1V scale does work and
> looks accurate comparing it to my HP 400E.
> The other 11 ranges are dead.
> I'm starting a return claim, but I have troubleshooting experience,
> anyone looked inside, are these fairly easy to repair?
> Mikek

"One caution that should be observed is that the thermocoupling circuitry can be damaged by excessive overloads more easily than conventional meters so always start the meter at a higher voltage setting and then scale down to the range to be measured."

....which is probably what happened. You're not going to repair that, too much precision physics and packaging, and it probably costs a bunch of bucks to replace. Return it immediately.

jlarkin@highlandsniptechnology.com wrote:
> On Wed, 24 Aug 2022 05:34:54 -0500, amdx <amdx@knology.net> wrote:
>
>> On 8/24/2022 12:58 AM, Jan Panteltje wrote:
>>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
>>> <amdx@knology.net> wrote in <te3tas$34d0u$1@dont-email.me>:
>>>
>>>> I received the HP3400A today and I checked it out, all I could get out
>>>> of it was a large needle bounce between range changes.
>>>> After a little more testing, I found that the 1V scale does work and
>>>> looks accurate comparing it to my HP 400E.
>>>> The other 11 ranges are dead.
>>>>  I'm starting a return claim, but I have troubleshooting experience,
>>>> anyone looked inside, are these fairly easy to repair?
>>>>                          Mikek
>>> Was this not originaly about measuring a RF signal up to 2 MHz??
>>  That is a component.
>>>
>>> Apart from checking if your digital voltmeters AC input goes that high
>>> (300 mV AC range gives you mV resolution)
>>> getting a decent _analog_ scope
>
> Analog scopes are unreliable antiques. A cheap 100 MHz color digital
> scope has averaging, FFT, storage, variable persistance, all sorts of
> cool stuff and you can lift it with one hand.
>
> Lots of DVMs have crazy bad frequency response. Some die in the
> mid-audio range.
>
> Measure twice: DVM and scope.
>
>
>>  My DVM=1000Hz
>>> WTF ??
>>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
>>> stage 1 high input impedance follower gain 1
>>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
>>> stage 3 precision recitfier (cost 1 diode)
>>> optional stage 4 log amplifier
>>  As I've said before, I was a fish monger, I have no design education.
>
> An EE degree is a PITA, but it forces people to learn the basic
> physics and circuit theory and signals+systems. But you can do that
> yourself, with simple experiments as the labs that reinforce
> instincts.
>
>> I can build what I have a schematic for. I'm aware of
>> parasitics, and a can avoid them, probably capacitance better than
>> inductance. I have laid out pcbs with a program and
>>  have had them made, or made them myself. Never have quite under stood
>> log amplifiers, just seems like a non linear voltmeter.
>
> Log amps are rarely used.
>
>>> connect voltmetet / multimeter to the output.
>>>
>>> Why waste those dollars? You gona need those for food when inflation takes off
>>> crops fail, nukes fly and
>>> OK
>>   Last I checked I have 38 times my yearly spending. We will start SS
>> in 2.5 years and that will cover 78% of our spending,
>> reducing reducing my nest egg withdrawals to well under 1%. My problem
>> is learning to BTD, blow the dough after a
>> lifetime of frugality.
>
> Electronic equipment is astoundingly cheap nowadays. You can learn a
> lot with a simple signal generator, a cheap scope, a DVM, a battery,
> and a couple of parts kits, under $400 total.
>
> The Art of Electronics is a great book. Used ones are cheap.
>

It's worth having the second edition anyway, on account of the Bad
Circuits sections. A beginner can learn a lot figuring out why they
don't work.

Electronic Design seems to have discontinued their "Ideas for Design"
column, which used to be a good source of slightly more advanced Bad
Circuits. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Wednesday, August 24, 2022 at 2:41:32 PM UTC-4, Phil Hobbs wrote:
> jla...@highlandsniptechnology.com wrote:
> > On Wed, 24 Aug 2022 05:34:54 -0500, amdx <am...@knology.net> wrote:
> >
> >> On 8/24/2022 12:58 AM, Jan Panteltje wrote:
> >>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
> >>> <am...@knology.net> wrote in <te3tas$34d0u$1...@dont-email.me>:
> >>>
> >>>> I received the HP3400A today and I checked it out, all I could get out
> >>>> of it was a large needle bounce between range changes.
> >>>> After a little more testing, I found that the 1V scale does work and
> >>>> looks accurate comparing it to my HP 400E.
> >>>> The other 11 ranges are dead.
> >>>> Â I'm starting a return claim, but I have troubleshooting experience,
> >>>> anyone looked inside, are these fairly easy to repair?
> >>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Mikek
> >>> Was this not originaly about measuring a RF signal up to 2 MHz??
> >> That is a component.
> >>>
> >>> Apart from checking if your digital voltmeters AC input goes that high
> >>> (300 mV AC range gives you mV resolution)
> >>> getting a decent _analog_ scope
> >
> > Analog scopes are unreliable antiques. A cheap 100 MHz color digital
> > scope has averaging, FFT, storage, variable persistance, all sorts of
> > cool stuff and you can lift it with one hand.
> >
> > Lots of DVMs have crazy bad frequency response. Some die in the
> > mid-audio range.
> >
> > Measure twice: DVM and scope.
> >
> >
> >> My DVM=1000Hz
> >>> WTF ??
> >>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
> >>> stage 1 high input impedance follower gain 1
> >>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
> >>> stage 3 precision recitfier (cost 1 diode)
> >>> optional stage 4 log amplifier
> >> As I've said before, I was a fish monger, I have no design education.
> >
> > An EE degree is a PITA, but it forces people to learn the basic
> > physics and circuit theory and signals+systems. But you can do that
> > yourself, with simple experiments as the labs that reinforce
> > instincts.
> >
> >> I can build what I have a schematic for. I'm aware of
> >> parasitics, and a can avoid them, probably capacitance better than
> >> inductance. I have laid out pcbs with a program and
> >> have had them made, or made them myself. Never have quite under stood
> >> log amplifiers, just seems like a non linear voltmeter.
> >
> > Log amps are rarely used.
> >
> >>> connect voltmetet / multimeter to the output.
> >>>
> >>> Why waste those dollars? You gona need those for food when inflation takes off
> >>> crops fail, nukes fly and
> >>> OK
> >> Last I checked I have 38 times my yearly spending. We will start SS
> >> in 2.5 years and that will cover 78% of our spending,
> >> reducing reducing my nest egg withdrawals to well under 1%. My problem
> >> is learning to BTD, blow the dough after a
> >> lifetime of frugality.
> >
> > Electronic equipment is astoundingly cheap nowadays. You can learn a
> > lot with a simple signal generator, a cheap scope, a DVM, a battery,
> > and a couple of parts kits, under $400 total.
> >
> > The Art of Electronics is a great book. Used ones are cheap.
> >
> It's worth having the second edition anyway, on account of the Bad
> Circuits sections. A beginner can learn a lot figuring out why they
> don't work.
>
> Electronic Design seems to have discontinued their "Ideas for Design"
> column, which used to be a good source of slightly more advanced Bad
> Circuits. ;)

They were mostly circuits about what you can do with leftovers it seems.

Then this individual used to publish a lot of ideas there. They were parts intensive and complex but hardly bad design:
https://www.electronicdesign.com/home/contact/21809137/w-stephen-woodward

Then of course Williams wrote a design article or two for them:
https://www.electronicdesign.com/technologies/analog/article/21795335/jim-williams

Actually a lot of really accomplished electronics engineers wrote articles for them.

>
> Cheers
>
> Phil Hobbs
>
>
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510
>
> http://electrooptical.net
> http://hobbs-eo.com

Fred Bloggs wrote:
> On Wednesday, August 24, 2022 at 2:41:32 PM UTC-4, Phil Hobbs wrote:
>> jla...@highlandsniptechnology.com wrote:
>>> On Wed, 24 Aug 2022 05:34:54 -0500, amdx <am...@knology.net> wrote:
>>>
>>>> On 8/24/2022 12:58 AM, Jan Panteltje wrote:
>>>>> On a sunny day (Tue, 23 Aug 2022 20:02:18 -0500) it happened amdx
>>>>> <am...@knology.net> wrote in <te3tas$34d0u$1...@dont-email.me>:
>>>>>
>>>>>> I received the HP3400A today and I checked it out, all I could get out
>>>>>> of it was a large needle bounce between range changes.
>>>>>> After a little more testing, I found that the 1V scale does work and
>>>>>> looks accurate comparing it to my HP 400E.
>>>>>> The other 11 ranges are dead.
>>>>>> Â I'm starting a return claim, but I have troubleshooting experience,
>>>>>> anyone looked inside, are these fairly easy to repair?
>>>>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Mikek
>>>>> Was this not originaly about measuring a RF signal up to 2 MHz??
>>>> That is a component.
>>>>>
>>>>> Apart from checking if your digital voltmeters AC input goes that high
>>>>> (300 mV AC range gives you mV resolution)
>>>>> getting a decent _analog_ scope
>>>
>>> Analog scopes are unreliable antiques. A cheap 100 MHz color digital
>>> scope has averaging, FFT, storage, variable persistance, all sorts of
>>> cool stuff and you can lift it with one hand.
>>>
>>> Lots of DVMs have crazy bad frequency response. Some die in the
>>> mid-audio range.
>>>
>>> Measure twice: DVM and scope.
>>>
>>>
>>>> My DVM=1000Hz
>>>>> WTF ??
>>>>> IF YOU HAVE A DECENT (CMOS) QUAD OPAMP LAYING ABOUT
>>>>> stage 1 high input impedance follower gain 1
>>>>> stage 2 programmable gain, feeback 1k 10k 100k resistors on switch for gain 1 10 100 etc
>>>>> stage 3 precision recitfier (cost 1 diode)
>>>>> optional stage 4 log amplifier
>>>> As I've said before, I was a fish monger, I have no design education.
>>>
>>> An EE degree is a PITA, but it forces people to learn the basic
>>> physics and circuit theory and signals+systems. But you can do that
>>> yourself, with simple experiments as the labs that reinforce
>>> instincts.
>>>
>>>> I can build what I have a schematic for. I'm aware of
>>>> parasitics, and a can avoid them, probably capacitance better than
>>>> inductance. I have laid out pcbs with a program and
>>>> have had them made, or made them myself. Never have quite under stood
>>>> log amplifiers, just seems like a non linear voltmeter.
>>>
>>> Log amps are rarely used.
>>>
>>>>> connect voltmetet / multimeter to the output.
>>>>>
>>>>> Why waste those dollars? You gona need those for food when inflation takes off
>>>>> crops fail, nukes fly and
>>>>> OK
>>>> Last I checked I have 38 times my yearly spending. We will start SS
>>>> in 2.5 years and that will cover 78% of our spending,
>>>> reducing reducing my nest egg withdrawals to well under 1%. My problem
>>>> is learning to BTD, blow the dough after a
>>>> lifetime of frugality.
>>>
>>> Electronic equipment is astoundingly cheap nowadays. You can learn a
>>> lot with a simple signal generator, a cheap scope, a DVM, a battery,
>>> and a couple of parts kits, under $400 total.
>>>
>>> The Art of Electronics is a great book. Used ones are cheap.
>>>
>> It's worth having the second edition anyway, on account of the Bad
>> Circuits sections. A beginner can learn a lot figuring out why they
>> don't work.
>>
>> Electronic Design seems to have discontinued their "Ideas for Design"
>> column, which used to be a good source of slightly more advanced Bad
>> Circuits. ;)
>
> They were mostly circuits about what you can do with leftovers it seems.
>
> Then this individual used to publish a lot of ideas there. They were parts intensive and complex but hardly bad design:
> https://www.electronicdesign.com/home/contact/21809137/w-stephen-woodward
>
> Then of course Williams wrote a design article or two for them:
> https://www.electronicdesign.com/technologies/analog/article/21795335/jim-williams
>
> Actually a lot of really accomplished electronics engineers wrote articles for them.

Back in the long ago, sure. I learned a lot from ED, EDN, RF Design,
Microwaves, and Microwave Journal in the early 80s.

Pease and Williams both died in 2011, alas, along with Dennis Ritchie
and Tony Siegman (AES). Woodward is an interesting guy who published
some good stuff over the years, including a cool op amp feedforward
compensation trick that I've often thought about using, but which was
never quite the right fit to the problem.

Cheers

Phil Hobbs

On 8/23/2022 8:02 PM, amdx wrote:
> I received the HP3400A today and I checked it out, all I could get out
> of it was a large needle bounce between range changes.
> After a little more testing, I found that the 1V scale does work and
> looks accurate comparing it to my HP 400E.
> The other 11 ranges are dead.
>  I'm starting a return claim, but I have troubleshooting experience,
> anyone looked inside, are these fairly easy to repair?
>                          Mikek
>
OK, negotiated the $99 cost down to $30, so I stopped the return I started.
I opened it up and used DeOxit on the rotary switch. After a good
massage of the switch,
I retested it and every range now works! The ranges follow my HP651B sig
gen exactly,
so I walked it up, 1mv full scale, turn the range switch too 3mv and it
reads 1mv, increase the
sig gen until the meter reads full scale, turn the range switch to 10mv,
it reads 3mv, etc,etc.
 It all turned out good.
 It had a board flopping around, there are some plastic rectangular
holders that are way to big,
but I put it in there, so it couldn't short to anything. I think there
is some addition inserts
 or something for those holder, that I need to learn about. I'll pull
up a manual.
                          Mikek