[time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ?

[jack.davis]

You might try a 2N5060 scr.Sent from my Verizon, Samsung Galaxy smartphone by 
Morse code.
 Original message From: ed breya  Date: 
10/10/21  3:36 PM  (GMT-08:00) To: time-nuts@lists.febo.com Subject: 
[time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor 
"Continuous Operation" ? The CR13 can be almost any small SCR, like in a TO-92 
size. I happen to know of one offhand, because I just yesterday used it in the 
Z3801A project, for the same type of function - latching the state of the 
indicator. I have a bunch of these in the thyristor department, and looked up 
various ones until I found this particular part was about 
right.https://datasheetspdf.com/pdf-file/284595/UnisonicTechnologies/XL1225/1This
 is an oldie. Another classic one is the C103 SCR. There should be plenty of 
modern little SCRs that will do. If nothing seems right, you can always make 
your own equivalent from a PNP and NPN Q tacked together right - but two parts 
are needed, and possibly an extra resistor or two, so it would be kind of a 
kludge.For an SCR, the main 
 things are gate current sensitivity, trip (latching) anode current, and 
holding current.BTW in my Z3801A project, the SCR holds the "power on" state, 
but I drive the lamp the opposite way. It stays off in normal operation, and 
lights amber to warn that AC power has dropped out in the past - simply because 
I have plenty of a certain style amber lamps, but only one green (for lock). 
The reset button trips the SCR back on, and the light goes out.I found the 
circuit wouldn't latch at first - I had made the anode current only about 1 mA, 
well above the holding current, but the trick is you need the available trip 
current to be high enough to go, then it holds down to much lower amounts. 
Changing to a smaller resistor made it 
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[time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ?

[ed breya]

The CR13 can be almost any small SCR, like in a TO-92 size. I happen to 
know of one offhand, because I just yesterday used it in the Z3801A 
project, for the same type of function - latching the state of the 
indicator. I have a bunch of these in the thyristor department, and 
looked up various ones until I found this particular part was about right.


https://datasheetspdf.com/pdf-file/284595/UnisonicTechnologies/XL1225/1

This is an oldie. Another classic one is the C103 SCR. There should be 
plenty of modern little SCRs that will do. If nothing seems right, you 
can always make your own equivalent from a PNP and NPN Q tacked together 
right - but two parts are needed, and possibly an extra resistor or two, 
so it would be kind of a kludge.


For an SCR, the main things are gate current sensitivity, trip 
(latching) anode current, and holding current.


BTW in my Z3801A project, the SCR holds the "power on" state, but I 
drive the lamp the opposite way. It stays off in normal operation, and 
lights amber to warn that AC power has dropped out in the past - simply 
because I have plenty of a certain style amber lamps, but only one green 
(for lock). The reset button trips the SCR back on, and the light goes out.


I found the circuit wouldn't latch at first - I had made the anode 
current only about 1 mA, well above the holding current, but the trick 
is you need the available trip current to be high enough to go, then it 
holds down to much lower amounts. Changing to a smaller resistor made it 
work.


Ed
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[time-nuts] Re: HP Z3801A - Dead GPS Receiver - Oncore VP

[CFO]

On 10/10/2021 13.04, Gerhard Hoffmann wrote:


Am 08.10.21 um 15:26 schrieb CFO:

My Z3810 had begun to show Alarm on the GPS receiver.
On Coldstart it seems like it lives for 10min or so , and the enters 
alarm state.
I'm quite sure it's the GPS receiver that has gone to "heaven" , 
never got that "Coldstart" every 6 months incorporated in my routines


A span of 10 minutes from cold   points more towards the oven. Maybe 
it stays too far away


from the exact frequency so that a lock is impossible.

There would be no reason to complain as long as the oven is cold.



Gerhard

I had the unit running (it was in error state)  , and powered it off for 
a minute , then on.
Then it locked (i saw sats) , and went into error again after approx 10 
min , now i didn't see any sats.


I tried that 3..4 times , with the same result.

Will dig it out of storage, and try some more

CFO
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[time-nuts] 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ?

[Ulf Kylenfall via time-nuts]

Greetings,
Having experienced a repeated condition of unlock in spite of all DC levelsfrom 
the Rb Phase Lock circuitry being correct, I traced the problem to A14,the 
logic ass:y. I went about to replace almost all discrete transistorsthere after 
testing and discovering that some of them was leaky.No problems after that 
except that I did not find an easy wayto replace CR13, a 3N58 according to the 
parts list.
Any modern readily available type that will do?
All the best
Ulf KylenfallSM6GXV
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[time-nuts] Re: HP Z3801A info needed - 1PPS interface

[Magnus Danielson via time-nuts]

Hi,

Yes, you need to modify it to operate with RS232 levels. If one goes to 
the now more acient annals one find the instructions. Some of the 
resources may be on the brink of dropping of the web.


It would be good if the many scraps of material was supplied on a common 
place, such as a common Wiki where we could cover the many topics and 
update common resources.


I remember I had to modify up my Z3801A to get RS232 levels and then 
solder up a suitable cable. I now have one with a failed power-supply 
and have not attended to that. Maybe in due time.


Cheers,
Magnus

On 2021-10-10 18:08, paul swed wrote:

I believe it is as thats the alternate strap on the z3801. Its also the way
z3801s arrives as RS 422.
Regards
Paul

On Sun, Oct 10, 2021 at 11:14 AM Joseph Gwinn  wrote:


On Sun, 10 Oct 2021 03:30:24 -0400, time-nuts-requ...@lists.febo.com
wrote:
time-nuts Digest, Vol 210, Issue 7


Date: Sat, 9 Oct 2021 15:18:08 -0700
From: ed breya 
Subject: [time-nuts] Re: HP Z3801A info needed - 1PPS interface
To: time-nuts@lists.febo.com
Message-ID: <61621520.9050...@telight.com>
Content-Type: text/plain; charset=utf-8; format=flowed

I have the 1 PPS circuit working just fine. The pulse width is around 27
uSec, nice and flat and strong regardless of the termination. I can't
discern the rise time or prop delay yet.

I discovered an interesting thing about the 1 PPS signals from the DB-25
connector. They are (or rather, one of them is) rather odd in voltage -
not PECL, except under certain conditions.

I hooked up one of the 1 PPS outputs to the circuit, just with a pair of
wires. This gave me a chance to make some measurements out in the open.
The comparator circuit worked fine, and once I got a good view of the
result, I started looking into the details. The first thing I found is
that the quiescent "low" value of the "1 PPS_1-" (J3 P17) rests at about
2.5 VDC - not PECL at all. The high side "1 PPS_1+" (J3 P9) seemed about
right, near 3.9 V. Uh oh - I thought maybe the port is damaged. I double
and triple checked the connections (they were right), then tacked some
wires on the number two port, pins 8 and 21.

They behaved exactly the same, so probably normal - or both burned out
the same way. So, I figured there must be some logic to this big
asymmetry. It couldn't be terminations to ground, since the 2.5 V one
could only go lower, so differential is the only kind that makes sense.
I tried various values across the lines, and sure enough, the 2.5 V
level rose substantially with decreasing R, but did not reach a "proper"
PECL low level until the differential load was around 50 ohms. The high
side changed only a little, indicating it goes right to the output of an
ECL part - if it was reverse terminated it would have dropped much more
with the loading.

So, it looks like these lines are connected to the outputs of ECL parts
(run as PECL), or maybe a simulation from some other kind of circuit. If
you picture each line being the emitter output, the high one is on most
of the time, and of proper level, You'd think the low one should still
hold at PECL low, at some current into its load, but it doesn't. It
could be that its load is made heavier, and to ground, on purpose,
drawing it down more. If it were terminated into a proper terminator
supply, it should be 2 V below Vcc, or 3 V in this case, so it couldn't
go to 2.5 V. Anyway, I understand what it's doing, but don't see why it
was made this way.

Just in case, I checked these levels under different conditions - fresh
power-up, locked, and hold modes, to make sure the common-mode levels
aren't changed for external signalling of conditions. They were constant
in all conditions.

Then I checked the signals on all the lines with a scope, directly
through coax. I tried a few different termination Rs, as shown below,
with the results.

When the pulse goes active, the high side drops, and the low side rises,
to roughly the same as the DC levels, so only the terminator value and
end levels are needed to get the picture. Remember, these are
approximate, from eyeballing a scope trace flash once a second.

Open circuit 3.9/2.5
221 R 3.8/2.5
100 R 3.7/2.6
75 R 3.7/2.8
47 R 3.7/3.2

So, there's plenty of signal under all conditions, and I think it's just
a matter of picking a termination for whatever cable is used. I was
quite surprised by this oddity, but it seems to work fine with my
circuit no matter what.

BTW the two 10 MHz outputs there are also described as "pseudo-ECL," so
I'd imagine they have the same characteristics. I'll take a look when I
get a chance.

Ed

Can this be RS-422 from a 5-volt source?

.

Joe Gwinn
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[time-nuts] Re: HP Z3801A info needed - 1PPS interface

[paul swed]

I believe it is as thats the alternate strap on the z3801. Its also the way
z3801s arrives as RS 422.
Regards
Paul

On Sun, Oct 10, 2021 at 11:14 AM Joseph Gwinn  wrote:

> On Sun, 10 Oct 2021 03:30:24 -0400, time-nuts-requ...@lists.febo.com
> wrote:
> time-nuts Digest, Vol 210, Issue 7
>
> > Date: Sat, 9 Oct 2021 15:18:08 -0700
> > From: ed breya 
> > Subject: [time-nuts] Re: HP Z3801A info needed - 1PPS interface
> > To: time-nuts@lists.febo.com
> > Message-ID: <61621520.9050...@telight.com>
> > Content-Type: text/plain; charset=utf-8; format=flowed
> >
> > I have the 1 PPS circuit working just fine. The pulse width is around 27
> > uSec, nice and flat and strong regardless of the termination. I can't
> > discern the rise time or prop delay yet.
> >
> > I discovered an interesting thing about the 1 PPS signals from the DB-25
> > connector. They are (or rather, one of them is) rather odd in voltage -
> > not PECL, except under certain conditions.
> >
> > I hooked up one of the 1 PPS outputs to the circuit, just with a pair of
> > wires. This gave me a chance to make some measurements out in the open.
> > The comparator circuit worked fine, and once I got a good view of the
> > result, I started looking into the details. The first thing I found is
> > that the quiescent "low" value of the "1 PPS_1-" (J3 P17) rests at about
> > 2.5 VDC - not PECL at all. The high side "1 PPS_1+" (J3 P9) seemed about
> > right, near 3.9 V. Uh oh - I thought maybe the port is damaged. I double
> > and triple checked the connections (they were right), then tacked some
> > wires on the number two port, pins 8 and 21.
> >
> > They behaved exactly the same, so probably normal - or both burned out
> > the same way. So, I figured there must be some logic to this big
> > asymmetry. It couldn't be terminations to ground, since the 2.5 V one
> > could only go lower, so differential is the only kind that makes sense.
> > I tried various values across the lines, and sure enough, the 2.5 V
> > level rose substantially with decreasing R, but did not reach a "proper"
> > PECL low level until the differential load was around 50 ohms. The high
> > side changed only a little, indicating it goes right to the output of an
> > ECL part - if it was reverse terminated it would have dropped much more
> > with the loading.
> >
> > So, it looks like these lines are connected to the outputs of ECL parts
> > (run as PECL), or maybe a simulation from some other kind of circuit. If
> > you picture each line being the emitter output, the high one is on most
> > of the time, and of proper level, You'd think the low one should still
> > hold at PECL low, at some current into its load, but it doesn't. It
> > could be that its load is made heavier, and to ground, on purpose,
> > drawing it down more. If it were terminated into a proper terminator
> > supply, it should be 2 V below Vcc, or 3 V in this case, so it couldn't
> > go to 2.5 V. Anyway, I understand what it's doing, but don't see why it
> > was made this way.
> >
> > Just in case, I checked these levels under different conditions - fresh
> > power-up, locked, and hold modes, to make sure the common-mode levels
> > aren't changed for external signalling of conditions. They were constant
> > in all conditions.
> >
> > Then I checked the signals on all the lines with a scope, directly
> > through coax. I tried a few different termination Rs, as shown below,
> > with the results.
> >
> > When the pulse goes active, the high side drops, and the low side rises,
> > to roughly the same as the DC levels, so only the terminator value and
> > end levels are needed to get the picture. Remember, these are
> > approximate, from eyeballing a scope trace flash once a second.
> >
> > Open circuit 3.9/2.5
> > 221 R 3.8/2.5
> > 100 R 3.7/2.6
> > 75 R 3.7/2.8
> > 47 R 3.7/3.2
> >
> > So, there's plenty of signal under all conditions, and I think it's just
> > a matter of picking a termination for whatever cable is used. I was
> > quite surprised by this oddity, but it seems to work fine with my
> > circuit no matter what.
> >
> > BTW the two 10 MHz outputs there are also described as "pseudo-ECL," so
> > I'd imagine they have the same characteristics. I'll take a look when I
> > get a chance.
> >
> > Ed
>
> Can this be RS-422 from a 5-volt source?
>
> .
>
> Joe Gwinn
> ___
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> an email to time-nuts-le...@lists.febo.com
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>
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[time-nuts] Re: HP Z3801A info needed - 1PPS interface

[Joseph Gwinn]

On Sun, 10 Oct 2021 03:30:24 -0400, time-nuts-requ...@lists.febo.com 
wrote:
time-nuts Digest, Vol 210, Issue 7

> Date: Sat, 9 Oct 2021 15:18:08 -0700
> From: ed breya 
> Subject: [time-nuts] Re: HP Z3801A info needed - 1PPS interface
> To: time-nuts@lists.febo.com
> Message-ID: <61621520.9050...@telight.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> I have the 1 PPS circuit working just fine. The pulse width is around 27 
> uSec, nice and flat and strong regardless of the termination. I can't 
> discern the rise time or prop delay yet.
> 
> I discovered an interesting thing about the 1 PPS signals from the DB-25 
> connector. They are (or rather, one of them is) rather odd in voltage - 
> not PECL, except under certain conditions.
> 
> I hooked up one of the 1 PPS outputs to the circuit, just with a pair of 
> wires. This gave me a chance to make some measurements out in the open. 
> The comparator circuit worked fine, and once I got a good view of the 
> result, I started looking into the details. The first thing I found is 
> that the quiescent "low" value of the "1 PPS_1-" (J3 P17) rests at about 
> 2.5 VDC - not PECL at all. The high side "1 PPS_1+" (J3 P9) seemed about 
> right, near 3.9 V. Uh oh - I thought maybe the port is damaged. I double 
> and triple checked the connections (they were right), then tacked some 
> wires on the number two port, pins 8 and 21.
> 
> They behaved exactly the same, so probably normal - or both burned out 
> the same way. So, I figured there must be some logic to this big 
> asymmetry. It couldn't be terminations to ground, since the 2.5 V one 
> could only go lower, so differential is the only kind that makes sense. 
> I tried various values across the lines, and sure enough, the 2.5 V 
> level rose substantially with decreasing R, but did not reach a "proper" 
> PECL low level until the differential load was around 50 ohms. The high 
> side changed only a little, indicating it goes right to the output of an 
> ECL part - if it was reverse terminated it would have dropped much more 
> with the loading.
> 
> So, it looks like these lines are connected to the outputs of ECL parts 
> (run as PECL), or maybe a simulation from some other kind of circuit. If 
> you picture each line being the emitter output, the high one is on most 
> of the time, and of proper level, You'd think the low one should still 
> hold at PECL low, at some current into its load, but it doesn't. It 
> could be that its load is made heavier, and to ground, on purpose, 
> drawing it down more. If it were terminated into a proper terminator 
> supply, it should be 2 V below Vcc, or 3 V in this case, so it couldn't 
> go to 2.5 V. Anyway, I understand what it's doing, but don't see why it 
> was made this way.
> 
> Just in case, I checked these levels under different conditions - fresh 
> power-up, locked, and hold modes, to make sure the common-mode levels 
> aren't changed for external signalling of conditions. They were constant 
> in all conditions.
> 
> Then I checked the signals on all the lines with a scope, directly 
> through coax. I tried a few different termination Rs, as shown below, 
> with the results.
> 
> When the pulse goes active, the high side drops, and the low side rises, 
> to roughly the same as the DC levels, so only the terminator value and 
> end levels are needed to get the picture. Remember, these are 
> approximate, from eyeballing a scope trace flash once a second.
> 
> Open circuit 3.9/2.5
> 221 R 3.8/2.5
> 100 R 3.7/2.6
> 75 R 3.7/2.8
> 47 R 3.7/3.2
> 
> So, there's plenty of signal under all conditions, and I think it's just 
> a matter of picking a termination for whatever cable is used. I was 
> quite surprised by this oddity, but it seems to work fine with my 
> circuit no matter what.
> 
> BTW the two 10 MHz outputs there are also described as "pseudo-ECL," so 
> I'd imagine they have the same characteristics. I'll take a look when I 
> get a chance.
> 
> Ed

Can this be RS-422 from a 5-volt source?

.

Joe Gwinn
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[time-nuts] Re: HP Z3801A - Dead GPS Receiver - Oncore VP

[Gerhard Hoffmann]

Am 08.10.21 um 15:26 schrieb CFO:

My Z3810 had begun to show Alarm on the GPS receiver.
On Coldstart it seems like it lives for 10min or so , and the enters 
alarm state.
I'm quite sure it's the GPS receiver that has gone to "heaven" , never 
got that "Coldstart" every 6 months incorporated in my routines


A span of 10 minutes from cold   points more towards the oven. Maybe it 
stays too far away


from the exact frequency so that a lock is impossible.

There would be no reason to complain as long as the oven is cold.

cheers, Gerhard


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