Hi

The regulator should be fixed, and the OCXO will work better with it repaired. That said, shifting the regulated voltage from 5.7 to 5.27 volts should not shift that oscillator 45 Hz.

Bob

On Jul 24, 2013, at 9:00 AM, paul swed paulswedb@gmail.com wrote:

I can hope
I will embed a k thermocouple also.

On Wed, Jul 24, 2013 at 7:45 PM, Bob Camp lists@rtty.us wrote:

Well learned quite a bit Q4 does have an issue. Further there is a reason
it has such high Beta. Its must deliver 30 ma to the oscillator and buffer.
I was quite surprised by this current level. I was  guessing the oscillator
was a few mils and the buffer maybe 8.
The 2n3904 simply does not cut it. Need to do some digging in the ole
transistors.
Regards
Paul.

On Wed, Jul 24, 2013 at 8:06 PM, paul swed paulswedb@gmail.com wrote:

Sorry mate, this isn't much help, I haven't heave of any of these, must be before my time?!

Mat

Struct

Pc

Ucb

Uce

Ueb

Ic

Tj

Ft

Cc, pF

Hfe

Caps

2N6429http://alltransistors.com/transistor.php?transistor=5816

Si

NPN

0.625

55

45

6

0.2

175

100

3

400

TO92

NTE2341http://alltransistors.com/transistor.php?transistor=44370

Si

NPN

1

100

80

7

1

2000

TO92

NTE46http://alltransistors.com/transistor.php?transistor=44457

Si

NPN

0.625

100

100

12

0.5

10000

TO92

NTE48http://alltransistors.com/transistor.php?transistor=44458

Si

NPN

1

60

50

12

1

25000

TO92

SM2285http://alltransistors.com/transistor.php?transistor=45948

Si

NPN

1

0

100

0

0.2

200

150

600

TO92

STL73Dhttp://alltransistors.com/transistor.php?transistor=50901

Si

NPN

0

700

400

0

1.5

0

TO92

STX112http://alltransistors.com/transistor.php?transistor=50927

Si

NPN

0

100

100

0

2

1000

TO92

STX616http://alltransistors.com/transistor.php?transistor=50930

Si

NPN

0

980

500

0

1.5

0

TO92

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of paul swed
Sent: Thursday, 25 July 2013 11:29 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP 10811 update

Well learned quite a bit Q4 does have an issue. Further there is a reason it has such high Beta. Its must deliver 30 ma to the oscillator and buffer.

I was quite surprised by this current level. I was  guessing the oscillator was a few mils and the buffer maybe 8.

The 2n3904 simply does not cut it. Need to do some digging in the ole transistors.

Regards

Paul.

On Wed, Jul 24, 2013 at 8:06 PM, paul swed <paulswedb@gmail.commailto:paulswedb@gmail.com> wrote:

time-nuts mailing list -- time-nuts@febo.commailto:time-nuts@febo.com

To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.

The 2N6429 crosses to an NTE123AP, in stock at Allied for $0.80.

http://www.alliedelec.com/search/productdetail.aspx?SKU=70214870&mkwid=szEc5
jMBI&pcrid=23468365337&pkw=nte123ap&pmt=e&pdv=c&gclid=CKyzu9_cybgCFWYV7AodJA
sAWQ

Good luck.

Joe

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of paul swed
Sent: Wednesday, July 24, 2013 8:29 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP 10811 update

Well learned quite a bit Q4 does have an issue. Further there is a reason it
has such high Beta. Its must deliver 30 ma to the oscillator and buffer.
I was quite surprised by this current level. I was  guessing the oscillator
was a few mils and the buffer maybe 8.
The 2n3904 simply does not cut it. Need to do some digging in the ole
transistors.
Regards
Paul.

On Wed, Jul 24, 2013 at 8:06 PM, paul swed paulswedb@gmail.com wrote:

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

I find it hard to believe that NTE spec the 123AP to replace a transistor
with min beta of 500...

This is quite entertaining:

http://www.vetco.net/catalog/product_info.php?products_id=1856

Look at the parts it's supposed to replace.

(Nothing against Vetco - they are a great source of NTE components and are
local to me.  They are just quoting what NTE claim.)

Orin.

On Wed, Jul 24, 2013 at 8:42 PM, J. L. Trantham jltran@att.net wrote:

I totally agree that a 123 will not replace it. A luck would have it I have
12 X 2n3390 xsistors Beta 400-1000. These are the older TO-98s and I will
try one tonight.
Regards
Paul
WB8TSL

On Thu, Jul 25, 2013 at 12:00 AM, Orin Eman orin.eman@gmail.com wrote:

FYI, The MPSA18RLRAG is a stock item at Digi-Key, min beta 500 at 1 & 10mA, 45V & 200mA rated, TO-92. $0.33 each.

http://www.digikey.com/product-detail/en/MPSA18RLRAG/MPSA18RLRAGOSCT-ND/1139919

Robert
I can't believe you found the transistor. When I pulled it out last night,
its actually a MPSA18!!! I had not had time to look it up but figured it
was a ebay leftover hunt. :-)
At that price I may order 20 of them. Like the gain.
Thanks.

On Thu, Jul 25, 2013 at 9:28 AM, Robert LaJeunesse <
rlajeunesse@sbcglobal.net> wrote:

Very interesting list.

I wonder if that is a way to identify a cross from a manufacturer's P/N
(Tek, HP, Fluke, etc.) to a 'real' part?

Either that or all you need is a collection of NTE parts and never anything
else :).

I have used NTE parts to cross to 'unobtanium' in the past and, so far, it's
worked.  However, my first choice is a 'new' item followed by 'NOS' followed
by 'used' then 'anything that will work'.

Joe

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Orin Eman
Sent: Wednesday, July 24, 2013 11:01 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP 10811 update

I find it hard to believe that NTE spec the 123AP to replace a transistor
with min beta of 500...

This is quite entertaining:

http://www.vetco.net/catalog/product_info.php?products_id=1856

Look at the parts it's supposed to replace.

(Nothing against Vetco - they are a great source of NTE components and are
local to me.  They are just quoting what NTE claim.)

Orin.

On Wed, Jul 24, 2013 at 8:42 PM, J. L. Trantham jltran@att.net wrote:

close.

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

NTE is actually a conglomeration of old parts cross reference stuff. Mostly
from the TV and radio days. They consolidated the consumer lines of
Motorola HEP, RCAs SK, and Sylvanias ECG lines to fill out the replacement
device business.

Thats when things could be repaired. So thats the reason the 123a can cover
a wide range. Its sort of  a cross of a cross sort of fits thing.
Don't get me at all wrong with these comments. Glad they are around. But it
is the reality.
Regards
Paul
WB8TSL

On Thu, Jul 25, 2013 at 9:50 AM, J. L. Trantham jltran@att.net wrote:

paul swed wrote:

Toshiba used to make a transistor with even higher gain, the
2SC3112/2SC3113/2SC3295/2SC4666 (same chip, different package). They
discontinued it recently, however.

Cheers
Stefan

Well lucks not so good do have the voltage closer but as Bob C said. That
ain't the issue.
Darn I hate when he is right. By the way the oscillator draws 26 ma approx
as a reference. Reassembled everything and let the oven heat up it settles
at 81C 15 min after start and within a respectable range of the temps
listed in the service manual. Measured with a K thermocouple. Freq is at
9.999955. or 45 Hz low
Tuning the variable cap has 20 Hz range and the cap was pretty much center
range. Have not played with the varicap but that should have a very small
effect.
I can easily adjust the temp setting R to raise the xtal temp. But that
seems like a jerry rig.
Could a xtal of this quality simply go bad over time?
Somewhat at a loss here.
I have a spare 10544 (Would not use the z3801 outer oven)and wonder if at
least I could use that with the Z3801. Anyone know if the efc would work?
Regards
Paul
WB8TSL

On Thu, Jul 25, 2013 at 10:28 AM, Stefan Heinzmann
stefan_heinzmann@gmx.dewrote:

On 7/25/2013 8:32 PM, paul swed wrote:

this may is a dumb question:

Lower than expected frequency means some extra capacitance in parallel
or not enough in series with the crystal... ?

Would that put suspicion on C4 (0.1uF between  crystal and Q1)?

Hi

Ok, since it's moved down  and it's about on temperature there are a couple of likely possibilities:

1. The crystal leaks and there's air in it
2. The trap coil(s) / capacitor(s) have changed value
3. The varicap is shorted / forward biased

Normal factory troubleshoot (after checking the varicap) would be to swap the crystal and see if the problem follows the crystal or the oscillator. Yes, I know, that's not very helpful in this case - sorry about that.

Bob

On Jul 25, 2013, at 9:32 PM, paul swed paulswedb@gmail.com wrote:

Good comments. Indeed I will order up a new xtal from digi-key. They should
be in stock any day now. I do agree with the comment on the cap in
parallel. I had not thought about the series cap dropping and there is a
.1uf as I recall. Need to look. The varicap seems to work very well so
don't believe thats an issue.
Will do some more hunting.
By the way as a heads up the top and bottom cover of the xtal compartment
are actually a pain to screw back together.
Anyone have a sense of the Hz change per degree C?
Thanks

On Fri, Jul 26, 2013 at 8:52 AM, Bob Camp lists@rtty.us wrote:

Hi

HP spec'd the crystals to be at a < 1x10^-8 / C slope at the marked temperature on the crystal. The center of the curve should be in the vicinity of 90C.

You are ~ -4.5 x 10^-6 low, so that would be > 10 C away from that point going cold and a bit further going hot. Since the oven is at ~80C, it's not to hot…

Bob

On Jul 26, 2013, at 10:09 AM, paul swed paulswedb@gmail.com wrote:

sounds like time to add a R across the temp set R. That will lower the R
and raise the temp. Its also easy to actually do.
Thanks

On Fri, Jul 26, 2013 at 12:08 PM, Bob Camp lists@rtty.us wrote:

Hi Paul,

Did you see this page that talks about tweaking the 10811 oven controller?

http://www.realhamradio.com/z3801a-turning-point.htm

Ed

On 7/26/2013 10:47 AM, paul swed wrote:

Ed Palmer wrote:

Although this article anecdotally claims success, it overlooks
a number of important issues.  First of all, a large proportion
of 10811 crystals DO NOT HAVE A TURNOVER.  They merely have a
very low TC around 82 degrees.  It is ALWAYS 82 degrees for these
crystals.  The crystals that do, technically, have a turnover,
still have very low TC even if the oven is slightly off the turnover.
Secondly, the tempco of the electronics, specifically
the selected 2N5179 oscillator transistor, is a significant player.
The thermal gain, if properly adjusted, is around 1000 at the
crystal, but is much less at the oscillator transistor.  It may
very well be the dominant factor in overall oscillator tempco.
Possibly, if you have a crystal with a turnover, you should
deliberately operate off the turnover at a point where the crystal
drift cancels the drift of the electronics.
If you want to tweak a 10811, you should also tweak the thermal
gain by custom adjustment of the heat balancing resistors for
the heater transistors.  This has to be done by converting the
oscillator to mode B and then converting it back to mode C
afterwards.

Rick Karlquist N6RK

Yes thanks ran across it. Skimmed it. Did not think I would be doing it. :-)

On Fri, Jul 26, 2013 at 1:15 PM, Ed Palmer ed_palmer@sasktel.net wrote:

Rick
Thanks. But I am far simpler than that. I am trying to get the 10811 back
to 10 Mhz its -45Hz. In the long thread above I go into the troubleshooting
details so far. Because a crystal simply can't go this bad. :-) I hope not
at least.
Regards
Paul.

On Fri, Jul 26, 2013 at 1:38 PM, Rick Karlquist richard@karlquist.comwrote:

Hi

Doing any real adjustment on these OCXO's pretty much requires you have a temperature chamber and a pretty good standard. A GPSDO will do for the standard, the chamber is a bit harder to come by.

Bob

On Jul 26, 2013, at 1:38 PM, Rick Karlquist richard@karlquist.com wrote:

So laying a sock over the insulated oven can doesn't count? Its a thick
sock.
Still not at the stage of needing a chamber I am 45 Hz off.

On Fri, Jul 26, 2013 at 2:36 PM, Bob Camp lists@rtty.us wrote:

Hi

Tossing a nice fluffy towel over it works pretty well. Just the thing if you are doing a bench turn hunt on an AT based OCXO. It's also a quick way to answer the age old question "is it broke or is it just all the people walking by while I'm trying to test it".

You need something that will let you go say 25C 5C 25C 45C 25C. Each time you make a change and re-test, you want to run the same temperatures. You need enough air circulation (and proper ducting) so that the device OCXO stabilizes quickly. 300 to 600 CFM is the range most chambers run in. Dead air = hard to know what temperature you are at / large delta T within the chamber. A dwell of maybe an hour at each one is about right. A Tenny Jr is a pretty good chamber for home use (no CO2). Keeping the refrigeration repaired can be a chore though…

Bob

On Jul 26, 2013, at 3:33 PM, paul swed paulswedb@gmail.com wrote:

Bob
I think the power bill exceeds the cost of a 10811. The chamber and CO2.
Going to pass.Though I am sure I can run down to work and throw a unit in
the various walk in units we have. Suspect they will not appreciate me
adjusting the temps though.
Back to work as they say.
Regards
Paul
WB8TSL

On Fri, Jul 26, 2013 at 3:53 PM, Bob Camp lists@rtty.us wrote:

Hi

Well if you get desperate to try it, I have CO2 and a chamber sitting in the garage. The biggest issue is that if we use too much CO2 for the chamber, the beer may go flat…

Bob

On Jul 26, 2013, at 4:09 PM, paul swed paulswedb@gmail.com wrote:

On 26/07/13 22:16, Bob Camp wrote:

Can't have that in the name of science, we need good beer after the
experiments, and you know that. :)

What would be good ovens for hobby usage / semi-pro BTW?

Cheers,
Magnus

Hi

On Jul 31, 2013, at 5:23 AM, Magnus Danielson magnus@rubidium.dyndns.org wrote:

It's just like at work - go with a refrigeration setup and get to know the service guy real well, or go with a CO2 chamber and become a regular at the gas store. The Delta chambers are pretty good for CO2. They show up at auction from time to time. Most of what's in them is pretty common stuff, so keeping them running isn't all that hard. You can convert them to a non-Delta controller without a lot of work if you have to.

Bob