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Type 184


@0culus
 

It just needs to be better than the thing you’re calibrating...and it doesn’t take much to beat the accuracy of an analog scope timebase. I adjusted my 184’s crystal oven with the help of my GPSDO and HP 53310A. I was able to get 5 decimal places. Way overkill for calibrating scopes, but it’s cool that it can do that.

Sean


Stephen
 

On Fri, Jul 31, 2020 at 05:56 AM, Dave Seiter wrote:


I know how you feel! I still have two GPSDOs and a couple of Rb units sitting
around (just in case), but although having at least seven stable zeros is
nice, it doesn't make the scope you're working on any more accurate. 
Unsubscribing from Timenuts made my life easier...
-Dave
LOL


Stephen
 

On Fri, Jul 31, 2020 at 10:41 AM, Eric wrote:

Interleaved answers.


I have done a cal on the one that I have and it was a weird one. On mine
it did need some adjustment.
I think mine is just fine. 27Hz is really nothing, and way below specs. Given the tight tolerances And German built quality of this HAMEG counter, even if it’s 50Hz (which I highly doubt it is), I’m still good specs wise.
Mine probably needs some minor adjustments as well, I guess. I haven’t checked anything else yet beside the time base.

I love the build quality of the 184 and the ability to use double time marks + trigger.
Yep. It’s pretty amazing, I must say.

> Some scope cals call for trigger time with 2 different time marks. only thing i know that will do
that is the 184.
I’m no expert. This is the first and only Time Mark Generator that I’ve ever had, but I guess you’re right.



Zen

On 7/31/2020 12:55 PM, Dave Seiter wrote:
I know how you feel! I still have two GPSDOs and a couple of Rb units
sitting around (just in case), but although having at least seven stable zeros
is nice, it doesn't make the scope you're working on any more accurate. 
Unsubscribing from Timenuts made my life easier...
-Dave
On Friday, July 31, 2020, 09:43:19 AM PDT, Stephen
<stephen.nabet@...> wrote:

On Fri, Jul 31, 2020 at 05:36 AM, Tom Gardner wrote:

Ah. A perfectionist tweaker :)
Yes, I am.  I like precision.  Maybe I do have an OCD.  😂

A quick skim of the schematic makes me think I would expect to see offsets
on
the outputs.
Ok.

It is a time calibrator, not an amplitude calibrator. I'd be satisfied if
the
peak-peak amplitudes are acceptably large.
Honestly, I haven’t had the time to check everything yet, but for what
I’m using it for (mostly .1ms and 1ms time marks), it works like a charm.





Eric
 

I have done a cal on the one that I have and it was a weird one. On mine it did need some adjustment. I love the build quality of the 184 and the ability to use double time marks + trigger. Some scope cals call for trigger time with 2 different time marks. only thing i know that will do that is the 184


Zen

On 7/31/2020 12:55 PM, Dave Seiter wrote:
I know how you feel! I still have two GPSDOs and a couple of Rb units sitting around (just in case), but although having at least seven stable zeros is nice, it doesn't make the scope you're working on any more accurate.  Unsubscribing from Timenuts made my life easier...
-Dave
On Friday, July 31, 2020, 09:43:19 AM PDT, Stephen <stephen.nabet@...> wrote:
On Fri, Jul 31, 2020 at 05:36 AM, Tom Gardner wrote:

Ah. A perfectionist tweaker :)
Yes, I am.  I like precision.  Maybe I do have an OCD.  😂

A quick skim of the schematic makes me think I would expect to see offsets on
the outputs.
Ok.

It is a time calibrator, not an amplitude calibrator. I'd be satisfied if the
peak-peak amplitudes are acceptably large.
Honestly, I haven’t had the time to check everything yet, but for what I’m using it for (mostly .1ms and 1ms time marks), it works like a charm.




Dave Seiter
 

I know how you feel! I still have two GPSDOs and a couple of Rb units sitting around (just in case), but although having at least seven stable zeros is nice, it doesn't make the scope you're working on any more accurate.  Unsubscribing from Timenuts made my life easier...
-Dave

On Friday, July 31, 2020, 09:43:19 AM PDT, Stephen <stephen.nabet@...> wrote:

On Fri, Jul 31, 2020 at 05:36 AM, Tom Gardner wrote:

Ah. A perfectionist tweaker :)
Yes, I am.  I like precision.  Maybe I do have an OCD.  😂

A quick skim of the schematic makes me think I would expect to see offsets on
the outputs.
Ok.

It is a time calibrator, not an amplitude calibrator. I'd be satisfied if the
peak-peak amplitudes are acceptably large.
Honestly, I haven’t had the time to check everything yet, but for what I’m using it for (mostly .1ms and 1ms time marks), it works like a charm.


Stephen
 

So I guess that +27Hz / 10Mhz, after 40 years since it was last calibrated in 1982 says a lot about the build and design quality of this thing.


Stephen
 

On Fri, Jul 31, 2020 at 05:48 AM, Eric wrote:


Slight frequency oscillation is NORMAL and is called out in the
calibration document. It is because the temperature variation of the
ovenized crystal. the oscillation should coincide with the oven light
cycling on and off.
I didn’t pay attention to that.

If you are warming up the 187 to calibrate something
it needs a 2 hour warm up followed by the 30 minute ON warn up. The oven
needs 2 hours to thermal soak the crystal.
Yes, I usually let it on and forget about it for 4 or 5 hours before I use it.

Zen


Stephen
 

On Fri, Jul 31, 2020 at 05:40 AM, Roy Morgan wrote:


The error reading you get from your counter seems to be on the order of one
fifth of one thousandth of a percent.
Yes, I think so.

The spec on the 184 is one thousandth of one percent.

So, IF the counter is dead on, the 184 error is well within specification. I
offer two questions:

1) Is the counter dead on?
It’s probably not “dead on”, but should be very close to it. It was last calibrated in 2010.


2) Why worry about it? Do you really need or want time marks to be accurate
to one thousandth of one percent?
No, you are right.

(Another way to think about this is: how
wide is the trace on a scope you might > want to calibrate?)
Good point.

Roy Morgan
K1LKY Western Mass

On Jul 31, 2020, at 11:52 AM, Ken Eckert <eckertkp@...> wrote:

From the manual:

2. Check Crystal Oscillator Frequency
a. Requirement-Frequency 1 0 MHz ± 1 00 Hz at ambient
room temperature. Crystal oven stabil ized. (Two hours
warm-up time after power is appl ied before crystal oven is
stabilized.)

On Fri, Jul 31, 2020 at 8:41 AM Tom Gardner <tggzzz@...> wrote:

On 31/07/20 16:26, Stephen wrote:
I have this Type 184 that I acquired a few months back from EBay.
...


Eric
 

Slight frequency oscillation is NORMAL and is called out in the calibration document. It is because the temperature variation of the ovenized crystal. the oscillation should coincide with the oven light cycling on and off. If you are warming up the 187 to calibrate something it needs a 2 hour warm up followed by the 30 minute ON warn up. The oven needs 2 hours to thermal soak the crystal.

Zen

On 7/31/2020 12:23 PM, Stephen wrote:
On Fri, Jul 31, 2020 at 04:44 AM, Mlynch001 wrote:

On Fri, Jul 31, 2020 at 10:26 AM, Stephen wrote:

s it acceptable? It oscillates between 10000.024 to 10000.030 kHz

I don’t feel confident nor confortable touching it. Would you?
In my opinion, Your counter could just as easily have an error and be reading
slightly high. Without a verifiable standard to compare either instrument
with, it is impossible to determine, I would leave it as is until you can
find a reliable standard source.


--
Michael Lynch
Dardanelle, AR
That’s pretty much what I thought too. Hence my hesitation to touch it.
And now that Ken mentioned it, the manual does indeed specify +/-100Hz.
And I’m off by about 30Hz. The couter can loose +/-1-10-7 / month. So even if the counter is slightly off, I should still be with specs, I guess.

PS: Did you receive my last email yesterday?


Stephen
 

On Fri, Jul 31, 2020 at 05:36 AM, Tom Gardner wrote:

Ah. A perfectionist tweaker :)
Yes, I am. I like precision. Maybe I do have an OCD. 😂

A quick skim of the schematic makes me think I would expect to see offsets on
the outputs.
Ok.

It is a time calibrator, not an amplitude calibrator. I'd be satisfied if the
peak-peak amplitudes are acceptably large.
Honestly, I haven’t had the time to check everything yet, but for what I’m using it for (mostly .1ms and 1ms time marks), it works like a charm.


Roy Morgan
 

The error reading you get from your counter seems to be on the order of one fifth of one thousandth of a percent.

The spec on the 184 is one thousandth of one percent.

So, IF the counter is dead on, the 184 error is well within specification. I offer two questions:

1) Is the counter dead on?

2) Why worry about it? Do you really need or want time marks to be accurate to one thousandth of one percent? (Another way to think about this is: how wide is the trace on a scope you might want to calibrate?)

Roy Morgan
K1LKY Western Mass

On Jul 31, 2020, at 11:52 AM, Ken Eckert <eckertkp@...> wrote:

From the manual:

2. Check Crystal Oscillator Frequency
a. Requirement-Frequency 1 0 MHz ± 1 00 Hz at ambient
room temperature. Crystal oven stabil ized. (Two hours
warm-up time after power is appl ied before crystal oven is
stabilized.)

On Fri, Jul 31, 2020 at 8:41 AM Tom Gardner <tggzzz@...> wrote:

On 31/07/20 16:26, Stephen wrote:
I have this Type 184 that I acquired a few months back from EBay.
...


Tom Gardner
 

On 31/07/20 17:25, Stephen wrote:
On Fri, Jul 31, 2020 at 05:09 AM, Tom Gardner wrote:

On 31/07/20 17:05, Stephen wrote:
On Fri, Jul 31, 2020 at 04:40 AM, Tom Gardner wrote:

There are two possible answers:

* is it with the published specification?
* does it do what you need it to do?>
Yes and yes.
In that case the question becomes "what have I got to gain by fiddling with
it?". That can be balanced against what you might have to lose. The balance
seems easy :)

That presumes all the outputs work as expected, but that is very different to
the frequency accuracy.
Everything works. So you’re right. I have nothing to gain messing with it.

Although now that you mention it, I did notice some +DC offset when my scope is DC coupled...
Hmmmm...
Ah. A perfectionist tweaker :)

A quick skim of the schematic makes me think I would expect to see offsets on the outputs.

It is a time calibrator, not an amplitude calibrator. I'd be satisfied if the peak-peak amplitudes are acceptably large.


Stephen
 

That settles it, I guess. I’m not touching the calibration on it.


Stephen
 

On Fri, Jul 31, 2020 at 04:51 AM, Ken Eckert wrote:


From the manual:

2. Check Crystal Oscillator Frequency
a. Requirement-Frequency 1 0 MHz ± 1 00 Hz at ambient
room temperature. Crystal oven stabil ized. (Two hours
warm-up time after power is appl ied before crystal oven is
stabilized.)
You’re correct. I had forgotten about the +/-100Hz.


Stephen
 

On Fri, Jul 31, 2020 at 05:09 AM, Tom Gardner wrote:


On 31/07/20 17:05, Stephen wrote:
On Fri, Jul 31, 2020 at 04:40 AM, Tom Gardner wrote:

There are two possible answers:

* is it with the published specification?
* does it do what you need it to do?>
Yes and yes.
In that case the question becomes "what have I got to gain by fiddling with
it?". That can be balanced against what you might have to lose. The balance
seems easy :)

That presumes all the outputs work as expected, but that is very different to
the frequency accuracy.
Everything works. So you’re right. I have nothing to gain messing with it.

Although now that you mention it, I did notice some +DC offset when my scope is DC coupled...
Hmmmm...


Stephen
 

On Fri, Jul 31, 2020 at 04:44 AM, Mlynch001 wrote:


On Fri, Jul 31, 2020 at 10:26 AM, Stephen wrote:


s it acceptable? It oscillates between 10000.024 to 10000.030 kHz

I don’t feel confident nor confortable touching it. Would you?
In my opinion, Your counter could just as easily have an error and be reading
slightly high. Without a verifiable standard to compare either instrument
with, it is impossible to determine, I would leave it as is until you can
find a reliable standard source.


--
Michael Lynch
Dardanelle, AR
That’s pretty much what I thought too. Hence my hesitation to touch it.
And now that Ken mentioned it, the manual does indeed specify +/-100Hz.
And I’m off by about 30Hz. The couter can loose +/-1-10-7 / month. So even if the counter is slightly off, I should still be with specs, I guess.

PS: Did you receive my last email yesterday?


Stephen
 

On Fri, Jul 31, 2020 at 04:43 AM, n4buq wrote:


Is your Hameg counter in calibration and, if so, for what accuracy is is
spec'd?

Thanks,
Barry - N4BUQ
It should be, yes.

Translated from the manual:
Time lapse between 2 measures: >= 0.3s
Precision? +/- CMS +/- trigger error/N to the 3rd, + Time Base Error x Period.


Tom Gardner
 

On 31/07/20 17:05, Stephen wrote:
On Fri, Jul 31, 2020 at 04:40 AM, Tom Gardner wrote:

There are two possible answers:

* is it with the published specification?
* does it do what you need it to do?>
Yes and yes.
In that case the question becomes "what have I got to gain by fiddling with it?". That can be balanced against what you might have to lose. The balance seems easy :)

That presumes all the outputs work as expected, but that is very different to the frequency accuracy.


Stephen
 

On Fri, Jul 31, 2020 at 04:40 AM, Tom Gardner wrote:

There are two possible answers:

* is it with the published specification?
* does it do what you need it to do?>
Yes and yes.


Ken Eckert
 

From the manual:

2. Check Crystal Oscillator Frequency
a. Requirement-Frequency 1 0 MHz ± 1 00 Hz at ambient
room temperature. Crystal oven stabil ized. (Two hours
warm-up time after power is appl ied before crystal oven is
stabilized.)

On Fri, Jul 31, 2020 at 8:41 AM Tom Gardner <tggzzz@...> wrote:

On 31/07/20 16:26, Stephen wrote:
I have this Type 184 that I acquired a few months back from EBay.
After cleaning all the contacts and switches, it works fine. However,
the last calibration stickers dates from 1982. So I assume it hasn’t been
calibrated since.
Yesterday I checked the 10Mhz base frequency and found this:

https://groups.io/g/TekScopes/photo/251419/0?p=Created,,,20,2,0,0

Is it acceptable? It oscillates between 10000.024 to 10000.030 kHz
There are two possible answers:

* is it with the published specification?
* does it do what you need it to do?


I don’t feel confident nor confortable touching it. Would you?
Yes I would, but I'm not you.

I have been /very careful/ not to physically touch some of the internal
metalwork when plugged in, and only to bend some of the exposed wires
after it
has been /unplugged/ for at least a minute.

My attitude? If you are happy with it, then touching it can only make you
less
happy with it.