F Knobs vs F Buttons on Signal Generators

[Michael A. Terrell]

I wouldn't even touch a frequency generator that hasn't a rotary knob
to set the frequency.

After using a HP/Agilent 3325B and a HP 8660 for a years, you can
have ALL of sig/function/sweep generators with knobs.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[D from BC]

After using a HP/Agilent 3325B and a HP 8660 for a years, you can
have ALL of sig/function/sweep generators with knobs.

I'm not familiar with those generators.
Do those have many knobs?
Or, with some button pressing, a single 'master knob' is assigned for
say f,offset or amplitude adjustment?


D from BC
British Columbia
Canada.

 

[Michael A. Terrell]

I'm not familiar with those generators.
Do those have many knobs?
Or, with some button pressing, a single 'master knob' is assigned for
say f,offset or amplitude adjustment?

<http://www.testequipmentdepot.com/usedequipment/hewlettpackard/signalgenerators/3325b.htm>
<http://www.testelectronics.com/used/hp8660c-86631b-86603a.htm>



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[D from BC]

<http://www.testequipmentdepot.com/usedequipment/hewlettpackard/signalgenerators/3325b.htm>
<http://www.testelectronics.com/used/hp8660c-86631b-86603a.htm>

The 3325B has all buttons.
I see a knob on the HP8660.

I'm interested in who rules for the 2 classes of generator users.

Test Equipment
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+----- +-----+
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Button Knob
Pressers Turners


However, I'll probably buy any cheapo generator. Knobs or not.


D from BC
British Columbia
Canada.

 

[Michael A. Terrell]

The 3325B has all buttons.
I see a knob on the HP8660.

There are a couple, but it depends on the plug ins

I'm interested in who rules for the 2 classes of generator users.

Test Equipment
|
+----- +-----+
| |
Button Knob
Pressers Turners

However, I'll probably buy any cheapo generator. Knobs or not.

Both have computer interface to use for SATE or ATE applications.
The 8660 was a '70s product, full of TTL. You could program it, then
use the tuning knob to move in discrete steps.

I used the 3325B to test and align video boards, and to find the
integration time of the AGC systems.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[[email protected]]

The best homebrew compromise to buying an expensive optical encoder is
to tear up an old mouse and use one of its optical encoders. I think
there are also high-res encoders in VCR heads, which come with nice metal
"knobs". ;-)

There's a quite nice optical encoder on the motor in the original
(boxy rectangular) HP deskjet, but it's been supplanted by a strip
encoder in the newer models. The part number of the reader is odd,
but the pinout is the same as the standard HEDS modules (see US
Digital website).

If you get one of the old ones, don't try to take it off the motor,
just use the motor as a spindle bearing and mount a knob over the gear
somehow. Forget the resolution, but it should be sufficient when run
with quadrature decoding for most purposes.

 

[[email protected]]

I'm interested in who rules for the 2 classes of generator users.

Test Equipment
|
+----- +-----+
| |
Button Knob
Pressers Turners

I think one of the issues actually is that for navigating menus you
need a coarse encoder with detents, but for tuning frequency (on an HF
band for example) you really want a wheel with some mass, fine
resolution, and no detents.

 

[Spehro Pefhany]

I think one of the issues actually is that for navigating menus you
need a coarse encoder with detents, but for tuning frequency (on an HF
band for example) you really want a wheel with some mass, fine
resolution, and no detents.

Well, there's no law against having more than one encoder. The second
type costs a LOT more money, so adding a few cheap ones isn't very
significant cost-wise. CNC machine tools have some of the finest
encoders I've used.

Best regards,
Spehro Pefhany

 

[D from BC]

Well, there's no law against having more than one encoder. The second
type costs a LOT more money, so adding a few cheap ones isn't very
significant cost-wise. CNC machine tools have some of the finest
encoders I've used.

Best regards,
Spehro Pefhany

Which reminds of....
I have digital calipers that go down to 1/1000".
I wonder how that works.


D from BC
British Columbia
Canada.

 

[Nico Coesel]

Do you mean using the entire stepper motor?
Yes.

One detects and decodes the pulses from the drive coils?

Indeed. Just run a few mA throught the windings and you'll have a
simple-to-detect-signal.

 

[Rich Grise]

I wouldn't even touch a frequency generator that hasn't a rotary knob
to set the frequency.

I was once working at some outfit where one of their products was
very much like a scanning electron microscope (SEM). It had buttons
for magnification and focus and stuff, and it was frustrating as hell,
because you'd hold the button down and watch the image come into focus,
and when you released the button, it would "coast", as if there were
a flywheel on a knob. This is ludicrous, of course, because it was
digital. Obviously, the programmer was incompetent, as most high-
buck programmers are.

But the point is, one day my engineer was sitting at the console
of one of these things, dicking around with the focus buttons and
so on, and summed it up very concisely:

"I'd rather have a knob."

Cheers!
Rich

 

[Rich Grise]

Well, there's no law against having more than one encoder. The second
type costs a LOT more money, so adding a few cheap ones isn't very
significant cost-wise. CNC machine tools have some of the finest
encoders I've used.

Which reminds of....
I have digital calipers that go down to 1/1000".
I wonder how that works.[/QUOTE]

Something like two scales like a vernier, and read the interference
patterns?

Cheers!
Rich

 

[john jardine]

I was once working at some outfit where one of their products was
very much like a scanning electron microscope (SEM). It had buttons
for magnification and focus and stuff, and it was frustrating as hell,
because you'd hold the button down and watch the image come into focus,
and when you released the button, it would "coast", as if there were
a flywheel on a knob. This is ludicrous, of course, because it was
digital. Obviously, the programmer was incompetent, as most high-
buck programmers are.

But the point is, one day my engineer was sitting at the console
of one of these things, dicking around with the focus buttons and
so on, and summed it up very concisely:

"I'd rather have a knob."

Cheers!
Rich

That same programmer did my Fuji E510 cam. It's normal electronic
"autofocus" is ever so slightly out, (hence the cam is f****** useless) and
it's "manual focus" mode involves pushing buttons to try hunt the motorised
lens back and forth while peering at a pixely screen.
Methinks this prolific offender needs searching out and punishing in some
rather cruel and unusual manner.
As aside ... was talking to a young guy today who'd just got a degree in
Computer Aided Engineering. Seems much of his course time was spent on
'business practice' and 'case law'.
Seems like our so called educators deserve to shoulder much of the blame for
the crap products out there.