Re: [time-nuts] strange hp 5345A option C19

[GandalfG8]

Hi Luca
 
I'm sorry to hear that, there's not much satisfaction in being right when  
it comes with such news attached:-(
 
The mod I devised was just a simple single link, totally reversible, that  
allowed testing, and use if required, of the counters without the internal  
reference.
It's been a while but if I remember rightly the link just routed  the 
external reference to feed both the internal and external inputs to the PLL  
which kept it locked and happy, but, of course, knowing that isn't really  of 
much help in this instance.
 
I may be able to help with some spares but will write to you directly about 
 that later, probably after the weekend, as I'm fiercely chasing my tail as 
 always and need to go out shortly anyway.
Time, or at least a very severe lack of it, is definitely driving me  even 
more nuts these days!
 
Regards
 
Nigel
GM8PZR
 
 
 
 
 
In a message dated 24/08/2013 10:29:10 GMT Daylight Time, iw2...@gmail.com  
writes:

Hi  Nigel,
You are right.
A previous user, made a very  very bad fix
There are some traks modified in the PLL board related to  the external
reference.
Now I have to start with a complete restoration  process.
I have dismounted the counter and extracted the boards.  Fortunately
no other horrible items appeared.
Thank you  again.
Regards
Luca




Il giorno giovedì 22 agosto 2013,  ha scritto:

> Hi Luca
>
> The earlier 5345As were fitted  with the 10544A oscillator, I've seen 
units
> with both that and the  later 10811, so it could indeed be the original
> oscillator.
> If  your 10544A has the PCB edge connector and  is installed in the  usual
> place then without seeing what's actually been  done I'm a  bit lost as to
> why
> it would have been modified. If there was  a  problem perhaps with the
> original int/ext reference switching,  or with the phose  locking to an
> external
> source, that  might be a reason, but for that it sounds  like quite a
>  drastic
> fix:-)
>
> Regards
>
> Nigel
>  GM8PZR
>
>
> In a message dated 22/08/2013 10:31:06 GMT  Daylight Time, 
iw2...@gmail.com
>  writes:
>
> Thank  you Nigel for your comment.
> Now I  understand the reason why it may be  useful to have this
>  additional external link.
> In the counter is fitted  an oscillator  model 10544A (instead of a more
> known 10811), but I  think   that it is the original one because the
> date code of the serial   number is a bit old (year 1981). At that date,
> the 10544 was still in  use.  Observing carefully the way  in which the
> internal  connections to the  Ref In and Out are made, I notice that
> wires,  insulating material and  sockets are different from the original
>  HP's. So it seems actually to be a  user made modification not  related
> to option C19.
> Good  bye
>  Luca
>
>
>
>
> 2013/8/21:
> > Hi Luca
> >
> >  There are other  items of HP equipment fitted with Ref Out  and Ref  In
> > terminals  joined by an external link, with the intention  that  the 
link
> is
> >  removed to connect an  external standard to the Ref In terminal,  but 
in
> a   "normal"
> > 5345A the external reference is used to phase  lock  the  internal
> oscillator
> > which means that the unit  can't work from an   external reference if 
the
> > internal  10MHz oscillator has been   removed.
> >
> >  However, I found some time ago that it is possible,  just by fitting  a
> > single link internally, to drive the counter via an   external reference
> even if
> > the internal standard has been  removed so  I'm guessing that the 
internal
> > standard on this  one might have been  removed at some time and a 
previous
> >  owner has fitted a non original  internal standard with a similar
>  provision  to
> > bypass the normal  arrangement.
>  >
> > It should be fairly easy to check just by looking  to  see if the
>  original
> > HP oscillator is still fitted  or whether  a different one has been
>  added.
>  >
> > Whether or not this  relates to the Option C19 I don't  know.
> >
> >  Regards
> >
> >  Nigel
> > GM8PZR
> >
> >
> > In a   message dated 21/08/2013 17:00:21 GMT Daylight Time,
>  iw2...@gmail.com
> >  writes:
> >
> >  Dear  all,
> >
> > I have bought an HP  5345A.  It’s ok and I’m  very glad. On the rear
> > panel it is  wrote  "OPTION C19" (a little bit  strange!) and there are
>  > two  additional BNC installed on the little panel  normally  used to
> >  place the HPIB connector when present.
>  >
> > These 2 BNCs  are  named REF OUT and REF IN and  there is a jumper cable
> > that connects  the  output to  the input.
> >
> > It seems to be a modification  made  by some user  (very strange: I can’
t
> > understand why to  place  an extra auxiliary bypass  for the 10 MHz
> >   reference).
> >
> > Do you have an idea about this  strange   modification and about the
> > strange option  C19? Could it be a custom  option?  Could the option C19
>  > and the 2 BNC for the reference  be  related?
>  >
> > Thanks
> >
> > Bye
> >
>  >  Luca – IW2LJE – Milano –  Italy
> >   

Re: [time-nuts] strange hp 5345A option C19

[Luca Dal Passo]

Hi Nigel,
 You are right.
A previous user, made a very very bad fix
There are some traks modified in the PLL board related to the external
reference.
Now I have to start with a complete restoration process.
I have dismounted the counter and extracted the boards. Fortunately
no other horrible items appeared.
Thank you again.
Regards
Luca




Il giorno giovedì 22 agosto 2013, ha scritto:

> Hi Luca
>
> The earlier 5345As were fitted with the 10544A oscillator, I've seen units
> with both that and the later 10811, so it could indeed be the original
> oscillator.
> If your 10544A has the PCB edge connector and  is installed in the usual
> place then without seeing what's actually been  done I'm a bit lost as to
> why
> it would have been modified. If there was a  problem perhaps with the
> original int/ext reference switching, or with the phose  locking to an
> external
> source, that might be a reason, but for that it sounds  like quite a
> drastic
> fix:-)
>
> Regards
>
> Nigel
> GM8PZR
>
>
> In a message dated 22/08/2013 10:31:06 GMT Daylight Time, 
> iw2...@gmail.com
> writes:
>
> Thank  you Nigel for your comment.
> Now I understand the reason why it may be  useful to have this
> additional external link.
> In the counter is fitted  an oscillator model 10544A (instead of a more
> known 10811), but I  think  that it is the original one because the
> date code of the serial  number is a bit old (year 1981). At that date,
> the 10544 was still in use.  Observing carefully the way  in which the
> internal connections to the  Ref In and Out are made, I notice that
> wires, insulating material and  sockets are different from the original
> HP's. So it seems actually to be a  user made modification not related
> to option C19.
> Good  bye
> Luca
>
>
>
>
> 2013/8/21   :
> > Hi Luca
> >
> > There are other  items of HP equipment fitted with Ref Out  and Ref In
> > terminals  joined by an external link, with the intention that  the link
> is
> >  removed to connect an external standard to the Ref In terminal,  but in
> a  "normal"
> > 5345A the external reference is used to phase  lock the  internal
> oscillator
> > which means that the unit can't work from an   external reference if the
> > internal 10MHz oscillator has been   removed.
> >
> > However, I found some time ago that it is possible,  just by fitting a
> > single link internally, to drive the counter via an  external reference
> even if
> > the internal standard has been removed so  I'm guessing that the internal
> > standard on this one might have been  removed at some time and a previous
> > owner has fitted a non original  internal standard with a similar
> provision  to
> > bypass the normal  arrangement.
> >
> > It should be fairly easy to check just by looking  to see if the
>  original
> > HP oscillator is still fitted or whether  a different one has been
>  added.
> >
> > Whether or not this  relates to the Option C19 I don't know.
> >
> >  Regards
> >
> > Nigel
> > GM8PZR
> >
> >
> > In a  message dated 21/08/2013 17:00:21 GMT Daylight Time,
> iw2...@gmail.com
> >  writes:
> >
> > Dear  all,
> >
> > I have bought an HP  5345A. It’s ok and I’m  very glad. On the rear
> > panel it is wrote  "OPTION C19" (a little bit  strange!) and there are
> > two  additional BNC installed on the little panel  normally used to
> >  place the HPIB connector when present.
> >
> > These 2 BNCs  are  named REF OUT and REF IN and there is a jumper cable
> > that connects  the  output to the input.
> >
> > It seems to be a modification  made by some user  (very strange: I can’t
> > understand why to place  an extra auxiliary bypass  for the 10 MHz
> >  reference).
> >
> > Do you have an idea about this strange   modification and about the
> > strange option C19? Could it be a custom  option?  Could the option C19
> > and the 2 BNC for the reference  be  related?
> >
> > Thanks
> >
> > Bye
> >
> >  Luca – IW2LJE – Milano –  Italy
> >  ___
> > 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.
> >  ___
> > 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.
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Re: [time-nuts] strange hp 5345A option C19

[GandalfG8]

Hi Luca
 
The earlier 5345As were fitted with the 10544A oscillator, I've seen units  
with both that and the later 10811, so it could indeed be the original  
oscillator.
If your 10544A has the PCB edge connector and  is installed in the usual 
place then without seeing what's actually been  done I'm a bit lost as to why 
it would have been modified. If there was a  problem perhaps with the 
original int/ext reference switching, or with the phose  locking to an external 
source, that might be a reason, but for that it sounds  like quite a drastic 
fix:-)
 
Regards
 
Nigel
GM8PZR
 
 
In a message dated 22/08/2013 10:31:06 GMT Daylight Time, iw2...@gmail.com  
writes:

Thank  you Nigel for your comment.
Now I understand the reason why it may be  useful to have this
additional external link.
In the counter is fitted  an oscillator model 10544A (instead of a more
known 10811), but I  think  that it is the original one because the
date code of the serial  number is a bit old (year 1981). At that date,
the 10544 was still in use.  Observing carefully the way  in which the
internal connections to the  Ref In and Out are made, I notice that
wires, insulating material and  sockets are different from the original
HP's. So it seems actually to be a  user made modification not related
to option C19.
Good  bye
Luca




2013/8/21   :
> Hi Luca
>
> There are other  items of HP equipment fitted with Ref Out  and Ref In
> terminals  joined by an external link, with the intention that  the link 
is
>  removed to connect an external standard to the Ref In terminal,  but in 
a  "normal"
> 5345A the external reference is used to phase  lock the  internal 
oscillator
> which means that the unit can't work from an   external reference if the
> internal 10MHz oscillator has been   removed.
>
> However, I found some time ago that it is possible,  just by fitting a
> single link internally, to drive the counter via an  external reference 
even if
> the internal standard has been removed so  I'm guessing that the internal
> standard on this one might have been  removed at some time and a previous
> owner has fitted a non original  internal standard with a similar 
provision  to
> bypass the normal  arrangement.
>
> It should be fairly easy to check just by looking  to see if the  original
> HP oscillator is still fitted or whether  a different one has been  added.
>
> Whether or not this  relates to the Option C19 I don't know.
>
>  Regards
>
> Nigel
> GM8PZR
>
>
> In a  message dated 21/08/2013 17:00:21 GMT Daylight Time, 
iw2...@gmail.com
>  writes:
>
> Dear  all,
>
> I have bought an HP  5345A. It’s ok and I’m  very glad. On the rear
> panel it is wrote  "OPTION C19" (a little bit  strange!) and there are
> two  additional BNC installed on the little panel  normally used to
>  place the HPIB connector when present.
>
> These 2 BNCs  are  named REF OUT and REF IN and there is a jumper cable
> that connects  the  output to the input.
>
> It seems to be a modification  made by some user  (very strange: I can’t
> understand why to place  an extra auxiliary bypass  for the 10 MHz
>  reference).
>
> Do you have an idea about this strange   modification and about the
> strange option C19? Could it be a custom  option?  Could the option C19
> and the 2 BNC for the reference  be  related?
>
> Thanks
>
> Bye
>
>  Luca – IW2LJE – Milano –  Italy
>  ___
> 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.
>  ___
> 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.
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and follow the instructions there.

Re: [time-nuts] strange hp 5345A option C19

[Luca Dal Passo]

Thank you Nigel for your comment.
Now I understand the reason why it may be useful to have this
additional external link.
In the counter is fitted an oscillator model 10544A (instead of a more
known 10811), but I think  that it is the original one because the
date code of the serial number is a bit old (year 1981). At that date,
the 10544 was still in use. Observing carefully the way  in which the
internal connections to the Ref In and Out are made, I notice that
wires, insulating material and sockets are different from the original
HP's. So it seems actually to be a user made modification not related
to option C19.
Good bye
Luca




2013/8/21  :
> Hi Luca
>
> There are other items of HP equipment fitted with Ref Out  and Ref In
> terminals joined by an external link, with the intention that  the link is
> removed to connect an external standard to the Ref In terminal,  but in a 
> "normal"
> 5345A the external reference is used to phase  lock the internal oscillator
> which means that the unit can't work from an  external reference if the
> internal 10MHz oscillator has been  removed.
>
> However, I found some time ago that it is possible, just by fitting a
> single link internally, to drive the counter via an external reference even if
> the internal standard has been removed so I'm guessing that the internal
> standard on this one might have been removed at some time and a previous
> owner has fitted a non original internal standard with a similar provision  to
> bypass the normal arrangement.
>
> It should be fairly easy to check just by looking to see if the  original
> HP oscillator is still fitted or whether a different one has been  added.
>
> Whether or not this relates to the Option C19 I don't know.
>
> Regards
>
> Nigel
> GM8PZR
>
>
> In a message dated 21/08/2013 17:00:21 GMT Daylight Time, iw2...@gmail.com
> writes:
>
> Dear  all,
>
> I have bought an HP 5345A. It’s ok and I’m  very glad. On the rear
> panel it is wrote "OPTION C19" (a little bit  strange!) and there are
> two additional BNC installed on the little panel  normally used to
> place the HPIB connector when present.
>
> These 2 BNCs  are named REF OUT and REF IN and there is a jumper cable
> that connects the  output to the input.
>
> It seems to be a modification made by some user  (very strange: I can’t
> understand why to place an extra auxiliary bypass  for the 10 MHz
> reference).
>
> Do you have an idea about this strange  modification and about the
> strange option C19? Could it be a custom option?  Could the option C19
> and the 2 BNC for the reference be  related?
>
> Thanks
>
> Bye
>
> Luca – IW2LJE – Milano –  Italy
> ___
> 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.
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> and follow the instructions there.
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and follow the instructions there.

Re: [time-nuts] strange hp 5345A option C19

[GandalfG8]

Hi Luca
 
There are other items of HP equipment fitted with Ref Out  and Ref In 
terminals joined by an external link, with the intention that  the link is 
removed to connect an external standard to the Ref In terminal,  but in a 
"normal" 
5345A the external reference is used to phase  lock the internal oscillator 
which means that the unit can't work from an  external reference if the 
internal 10MHz oscillator has been  removed.
 
However, I found some time ago that it is possible, just by fitting a  
single link internally, to drive the counter via an external reference even if  
the internal standard has been removed so I'm guessing that the internal  
standard on this one might have been removed at some time and a previous  
owner has fitted a non original internal standard with a similar provision  to 
bypass the normal arrangement.
 
It should be fairly easy to check just by looking to see if the  original 
HP oscillator is still fitted or whether a different one has been  added.
 
Whether or not this relates to the Option C19 I don't know.
 
Regards
 
Nigel
GM8PZR
 
 
In a message dated 21/08/2013 17:00:21 GMT Daylight Time, iw2...@gmail.com  
writes:

Dear  all,

I have bought an HP 5345A. It’s ok and I’m  very glad. On the rear
panel it is wrote "OPTION C19" (a little bit  strange!) and there are
two additional BNC installed on the little panel  normally used to
place the HPIB connector when present.

These 2 BNCs  are named REF OUT and REF IN and there is a jumper cable
that connects the  output to the input.

It seems to be a modification made by some user  (very strange: I can’t
understand why to place an extra auxiliary bypass  for the 10 MHz
reference).

Do you have an idea about this strange  modification and about the
strange option C19? Could it be a custom option?  Could the option C19
and the 2 BNC for the reference be  related?

Thanks

Bye

Luca – IW2LJE – Milano –  Italy
___
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[time-nuts] strange hp 5345A option C19

[Luca Dal Passo]

Dear all,

 I have bought an HP 5345A. It’s ok and I’m very glad. On the rear
panel it is wrote "OPTION C19" (a little bit strange!) and there are
two additional BNC installed on the little panel normally used to
place the HPIB connector when present.

These 2 BNCs are named REF OUT and REF IN and there is a jumper cable
that connects the output to the input.

It seems to be a modification made by some user (very strange: I can’t
understand why to place an extra auxiliary bypass for the 10 MHz
reference).

Do you have an idea about this strange modification and about the
strange option C19? Could it be a custom option? Could the option C19
and the 2 BNC for the reference be related?

Thanks

Bye

Luca – IW2LJE – Milano – Italy
___
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