[time-nuts] FRS

[EWKehren]

On one of my older FRS I tightened the cover to much blowing in the process 
 the TIP 31 and the 2N4021. Any idea where to get a 2N4021 or what would be 
a  substitute.
Thanks   Bert Kehren
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Re: [time-nuts] FRS

[paul swed]

Bert
Who knows what these2n4021s cost but they have a 800 number and 3 in stock
http://chipstech.com/NATIONAL-SEMICONDUCTOR/2N4021/prod_2649.html
regards
Paul

On Sun, Mar 13, 2011 at 7:30 PM,  wrote:

> On one of my older FRS I tightened the cover to much blowing in the process
>  the TIP 31 and the 2N4021. Any idea where to get a 2N4021 or what would be
> a  substitute.
> Thanks   Bert Kehren
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Re: [time-nuts] FRS

[Mike S]

At 07:30 PM 3/13/2011, ewkeh...@aol.com wrote...
On one of my older FRS I tightened the cover to much blowing in the 
process
 the TIP 31 and the 2N4021. Any idea where to get a 2N4021 or what 
would be

a  substitute.


I think it's a 2n4091, from the parts list and schematic. 2N4021 is a 
PNP bipolar, 2N4091 is a N-Channel JFET.


2n4091 is available here: 
http://store.americanmicrosemiconductor.com/2n4091.html


I'd think a 2n4392 would work, Mouser has 'em, along with the TIP31B.



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Re: [time-nuts] FRS

[EWKehren]

Thank you, yes it is a 2N4091, my fingers are getting bad. I think I am  
going to try a TIP122, I have plenty of TIP31C's,  to much trouble and  money 
for a single 2N4091 when you take into consideration the age of the unit  
and lamp voltage shows 6 volt.
Bert Kehren
 
 
In a message dated 3/13/2011 9:02:21 P.M. Eastern Daylight Time,  
mi...@flatsurface.com writes:

At 07:30  PM 3/13/2011, ewkeh...@aol.com wrote...
>On one of my older FRS I  tightened the cover to much blowing in the 
>process
>  the  TIP 31 and the 2N4021. Any idea where to get a 2N4021 or what 
> would  be
>a  substitute.

I think it's a 2n4091, from the parts  list and schematic. 2N4021 is a 
PNP bipolar, 2N4091 is a N-Channel  JFET.

2n4091 is available here:  
http://store.americanmicrosemiconductor.com/2n4091.html

I'd think a  2n4392 would work, Mouser has 'em, along with the  TIP31B.



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[time-nuts] FRS-C

[Fred King]

Hi all.

I have one of the above - one like it can be seen at 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130005941358&ssPageName=ADME:B:EF:US:11

I need info on the two boards.

Board 1:
55761ASSY101874-002 Rev B
55761-101886-001 Rev A
Pc 1 94V-0 

Board 2:
55761ASSY101720-002 Rev T
55761-101719-001 Rev E

SERNO 7375

Thanks!

Fred


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[time-nuts] FRS-C spec

[chuck]

Is anyone familiar with the Efratom model FRS-C rubidium? I am trying to
find out if there is a published spec for jitter on it.
If it isn't available, does anyone have one of these units and knows
what it typically runs on theirs?
Thanks, Chuck Norton


Frequency Standards & Services
2727 E. Palmer Park Blvd. Ste. 100
Colorado Springs, CO. 80909-5068
719-228-0540   Voice
719-228-9009   Fax 



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Re: [time-nuts] FRS-C

[Had]

Fred,

There is some info on my Web site  www.to-way.com  that might help.

Hadley


At 07:09 AM 7/22/2006, you wrote:
>Hi all.
>
>I have one of the above - one like it can be seen at 
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130005941358&ssPageName=ADME:B:EF:US:11
>
>I need info on the two boards.
>
>Board 1:
>55761ASSY101874-002 Rev B
>55761-101886-001 Rev A
>Pc 1 94V-0
>
>Board 2:
>55761ASSY101720-002 Rev T
>55761-101719-001 Rev E
>
>SERNO 7375
>
>Thanks!
>
>Fred
>
>
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A well regulated Militia, being necessary to the security of a free
State, the right of the people to keep and bear Arms, shall not be
infringed.



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Re: [time-nuts] FRS-C

[Rex]

On Sat, 22 Jul 2006 12:12:08 -0700, Had <[EMAIL PROTECTED]> wrote:

>Fred,
>
>There is some info on my Web site  www.to-way.com  that might help.
>
>Hadley
>

I see the FRS manual, is there something more that applies to the
external boards?


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[time-nuts] frs-c rubidium osc.

[george]

Anybody have experience with ball efratom frs-c oscillators?

Are these any good?  I purchased one on ebay and have been waiting for
about a week to see good stability.. AT 10k samples against gps 1pps
indicate 5-11th  accuracy.. which is exactly at spec.. I was hoping for
something close to 3-12th.

To be more specific with my line of questions;
This standard is adjusted with precision 20 turn pot supplied from in
internal 17 volt requlator which I think isn't that stable of a voltage
source because the manual shows and alternate customer provides variable
5 volt source for the adjustment (these adjustments vary the C-field).
The internal adjustment pot has voltage divider resisters that bring the
semi-stable 17 volt source down to around 5 volts to the adjustment pot.

I've been monitoring the wiper voltage day by day I see .05 volt
difference and think that this variation is effecting my stability.
Its only changing day by day not hour to hour.

This wouldn't be a big deal to provide my own stable 5 volt supply to an
external adjustment pot.. but further investigation of the schematics
indicate internal temperature compensation circuitry is varying the
C-field as well.. along with another 17 volt source to the C-field via
Select In Test Resistor (the manual calls fixed C-field).

Is it customary for Atomic standards to vary the C-field to obtain
compensate for internal temperature variation?

Cant the closed loop servo handle these temperature/frequency errors
alone.  Without the need of additional circuitry trying to compensate
via the C-field ?

Or is the Closed loop servo a low resolution adjustment and maybe the
C-field a better resolution adjustment?
Or maybe efratoms just have low resolution servo loops and require
messing with C-field.. How can I set the C-field manually if the
internals are playing with the c-field to..

What would you do?
A. Disable internal c-field temperature compensation.

B. Run external stable 5 volt sourced C-field trim pot.

C. Wire spare pin on interface to provide external 17 volt supply that
feeds C-field trim pot and fixed C-field supply?
D. All the above..

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Re: [time-nuts] FRS-C spec

[Brian Kirby]

No jitter spec, but the manual shows it should have a short term 
stability of less than 1x10-10 for 1 second to 100 second Allan variances.


[EMAIL PROTECTED] wrote:


Is anyone familiar with the Efratom model FRS-C rubidium? I am trying to
find out if there is a published spec for jitter on it.
If it isn't available, does anyone have one of these units and knows
what it typically runs on theirs?
Thanks, Chuck Norton


Frequency Standards & Services
2727 E. Palmer Park Blvd. Ste. 100
Colorado Springs, CO. 80909-5068
719-228-0540   Voice
719-228-9009   Fax 




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Re: [time-nuts] FRS-C spec

[John Ackermann N8UR]

[EMAIL PROTECTED] wrote:

Is anyone familiar with the Efratom model FRS-C rubidium? I am trying to
find out if there is a published spec for jitter on it.
If it isn't available, does anyone have one of these units and knows
what it typically runs on theirs?
Thanks, Chuck Norton


Hi Chuck --

I have an FRS-C and the book for it.

The short term  stability is 1x10e-10 for 1 second, 3.16x10e-11 for 10 
seconds, and 1x10e-11 for 100 seconds.  "1 day stability" is 
1x10e-10/day, and long term drift is <5x10e-11/month.  Phase noise is 
-70dBc at 1Hz, improving to -130dBc at 1kHz.


There's also an FRS-N version ("C" is communications, "N" is navigation, 
I think).  It's about half an order of magnitude better in short term 
stability, but the same in phase noise and long term drift.


Hope this helps.

John



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Re: [time-nuts] FRS-C spec

[Brian Kirby]

I forgot the measurements I made a few months ago

for 100 second modified Allan variance 1.17x10-12 (FRK-L timebase),
second test 2.48x10-12 (Z3801A timebase), third test 2.16x10-11
(Motorola M12+ GPS RX comparison)

for 1,000 second modified Allan variance 2.07x10-12 (Z3801A Timebase),
second test 1.17x10-12 (M12+ RX Comparison), 6.72x10-13 (FRK-L timebase)

for 10,000 second modified Allan variance 7.71x10-13 (Z3801A timebase),
7.16x10-13 (M12+ RX comparison), 8.84x10-13 (FRK-L timebase)

Brian - N4FMN

[EMAIL PROTECTED] wrote:


Is anyone familiar with the Efratom model FRS-C rubidium? I am trying to
find out if there is a published spec for jitter on it.
If it isn't available, does anyone have one of these units and knows
what it typically runs on theirs?
Thanks, Chuck Norton


Frequency Standards & Services
2727 E. Palmer Park Blvd. Ste. 100
Colorado Springs, CO. 80909-5068
719-228-0540   Voice
719-228-9009   Fax 




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[time-nuts] FRS-C Rb Oscillator questions

[Robert Darlington]

Hi guys,

Today I received a shiny new (to me anyway) FRS-C Rb from one of the usual
sellers in China.  It locked after roughly 2 minutes.  Comparing it to my
Thunderbolt I saw that it was running at a very slightly different rate.  I
adjusted the c-field pot and made it slightly better but I ran out of range
on the pot!  It's fully counter-clockwise and one trace is moving past the
other very slowly.   I can speed it up by turning it all the way to the
right but it never stops or changes direction.

Is there anything I can do that isn't too difficult to remedy the
situation?  Should I let it warm up overnight before messing with this? (my
other unit does not have this problem -at least it didn't before I killed
it).

Thank you for any suggestions,
Bob

(ps, the thunderbolt has been on for over a year so I don't think that's the
issue but I really don't have any way to verify it.  Lady Heather thinks
it's okay.
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Re: [time-nuts] frs-c rubidium osc.

[Brian Kirby]

I know Rex and myself have them.  I also have a FRK-L and a mutate FEI5680A.
When I got my FRS-C, back in December, I put it together in a permanent 
package and I let it run for a month before I ran any test on it.  
Efratom did not warrant any specs until the unit is burned in.  Looking 
at yesterdays raw data and my unit was tweaked on frequency 4 days ago, 
it had a drift of  311 nanoseconds for 24 hours.

My unit is frequency controlled by an external 1 kilo-ohm 10 turn pot.  
When an external pot is hooked up to the unit, it overrides the internal 
frequency control.  The top of the pot is connected to pin 8, the bottom 
of the pot to pin 3 (ground) and the wiper to pin 2 of the FRS-C 
connector.  In this method I see 6.9138 volts on the top of the pot from 
the rubidium and its solid, no variation (using a Fluke 45 voltmeter).  
A month ago I did a check and at 6.9 volts the rubidiums frequency was 
+2.709x10-9, and at zero volts is was -1.052x10-9 in respect to UTC.  
Currently its on frequency at 2.1048 volts.

Is your meter stable enough to monitor the EFC ?  Is your power tightly 
regulated to the unit ?  Is your ambient temperature stable ?  Does the 
unit have an adequate heat sink ?

-
I am also working on using this unit with Brooks Shera's GPS controller 
- I had to build a stable amplifier and voltage reference to interface 
with his controller.   My circuit uses a LM399 voltage reference and 
OP07 op amps and this regulator is more stable than the circuitry in the 
FRS-C.  It may be overkill.  The FRS-C unit (mine) has a 1 volt 
sensitivity of 5x10-10, so 100 mV would be 5x10-11, 10 mV 5x10-12, and 
maybe 1 mV 5x10-13.

Also, I have read that the FRS-C is not as stable as the older FRK-L and 
it has to do with the way the rubidium cells are manufactured - the new 
process is considerably more cheaper.

Brian - N4FMN
george wrote:
Anybody have experience with ball efratom frs-c oscillators?
Are these any good?  I purchased one on ebay and have been waiting for
about a week to see good stability.. AT 10k samples against gps 1pps
indicate 5-11th  accuracy.. which is exactly at spec.. I was hoping for
something close to 3-12th.
To be more specific with my line of questions;
This standard is adjusted with precision 20 turn pot supplied from in
internal 17 volt requlator which I think isn't that stable of a voltage
source because the manual shows and alternate customer provides variable
5 volt source for the adjustment (these adjustments vary the C-field).
The internal adjustment pot has voltage divider resisters that bring the
semi-stable 17 volt source down to around 5 volts to the adjustment pot.
I've been monitoring the wiper voltage day by day I see .05 volt
difference and think that this variation is effecting my stability.
Its only changing day by day not hour to hour.
This wouldn't be a big deal to provide my own stable 5 volt supply to an
external adjustment pot.. but further investigation of the schematics
indicate internal temperature compensation circuitry is varying the
C-field as well.. along with another 17 volt source to the C-field via
Select In Test Resistor (the manual calls fixed C-field).
Is it customary for Atomic standards to vary the C-field to obtain
compensate for internal temperature variation?
Cant the closed loop servo handle these temperature/frequency errors
alone.  Without the need of additional circuitry trying to compensate
via the C-field ?
Or is the Closed loop servo a low resolution adjustment and maybe the
C-field a better resolution adjustment?
Or maybe efratoms just have low resolution servo loops and require
messing with C-field.. How can I set the C-field manually if the
internals are playing with the c-field to..
What would you do?
A. Disable internal c-field temperature compensation.
B. Run external stable 5 volt sourced C-field trim pot.
C. Wire spare pin on interface to provide external 17 volt supply that
feeds C-field trim pot and fixed C-field supply?
D. All the above..
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Re: [time-nuts] frs-c rubidium osc.

[george]

Thank you Brian Your information is very helpfull.
You mentioned getting your unit back in december was it at the factory
having work done?
Its heat sink is appromimately 6 square inches larger than the osc.
itself the fins are only about 3/8" tall I keep a computer case fan
directed at the sink which keeps it between 80 and 92 F.  But no to your
other question my ambient temperature varies 73 to 85 F. 

I've been thinking of putting it in an electricly cooled Ice chest for
stability.

Could you describe your heat sink and ambient environment?

Brian Kirby wrote:
> 
> I know Rex and myself have them.  I also have a FRK-L and a mutate FEI5680A.
> 
> When I got my FRS-C, back in December, I put it together in a permanent
> package and I let it run for a month before I ran any test on it.
> Efratom did not warrant any specs until the unit is burned in.  Looking
> at yesterdays raw data and my unit was tweaked on frequency 4 days ago,
> it had a drift of  311 nanoseconds for 24 hours.
> 
> My unit is frequency controlled by an external 1 kilo-ohm 10 turn pot.
> When an external pot is hooked up to the unit, it overrides the internal
> frequency control.  The top of the pot is connected to pin 8, the bottom
> of the pot to pin 3 (ground) and the wiper to pin 2 of the FRS-C
> connector.  In this method I see 6.9138 volts on the top of the pot from
> the rubidium and its solid, no variation (using a Fluke 45 voltmeter).
> A month ago I did a check and at 6.9 volts the rubidiums frequency was
> +2.709x10-9, and at zero volts is was -1.052x10-9 in respect to UTC.
> Currently its on frequency at 2.1048 volts.
> 
> Is your meter stable enough to monitor the EFC ?  Is your power tightly
> regulated to the unit ?  Is your ambient temperature stable ?  Does the
> unit have an adequate heat sink ?
> 
> -
> 
> I am also working on using this unit with Brooks Shera's GPS controller
> - I had to build a stable amplifier and voltage reference to interface
> with his controller.   My circuit uses a LM399 voltage reference and
> OP07 op amps and this regulator is more stable than the circuitry in the
> FRS-C.  It may be overkill.  The FRS-C unit (mine) has a 1 volt
> sensitivity of 5x10-10, so 100 mV would be 5x10-11, 10 mV 5x10-12, and
> maybe 1 mV 5x10-13.
> 
> Also, I have read that the FRS-C is not as stable as the older FRK-L and
> it has to do with the way the rubidium cells are manufactured - the new
> process is considerably more cheaper.
> 
> Brian - N4FMN
> 
> george wrote:
> 
> >Anybody have experience with ball efratom frs-c oscillators?
> >
> >Are these any good?  I purchased one on ebay and have been waiting for
> >about a week to see good stability.. AT 10k samples against gps 1pps
> >indicate 5-11th  accuracy.. which is exactly at spec.. I was hoping for
> >something close to 3-12th.
> >
> >To be more specific with my line of questions;
> >This standard is adjusted with precision 20 turn pot supplied from in
> >internal 17 volt requlator which I think isn't that stable of a voltage
> >source because the manual shows and alternate customer provides variable
> >5 volt source for the adjustment (these adjustments vary the C-field).
> >The internal adjustment pot has voltage divider resisters that bring the
> >semi-stable 17 volt source down to around 5 volts to the adjustment pot.
> >
> >I've been monitoring the wiper voltage day by day I see .05 volt
> >difference and think that this variation is effecting my stability.
> >Its only changing day by day not hour to hour.
> >
> >This wouldn't be a big deal to provide my own stable 5 volt supply to an
> >external adjustment pot.. but further investigation of the schematics
> >indicate internal temperature compensation circuitry is varying the
> >C-field as well.. along with another 17 volt source to the C-field via
> >Select In Test Resistor (the manual calls fixed C-field).
> >
> >Is it customary for Atomic standards to vary the C-field to obtain
> >compensate for internal temperature variation?
> >
> >Cant the closed loop servo handle these temperature/frequency errors
> >alone.  Without the need of additional circuitry trying to compensate
> >via the C-field ?
> >
> >Or is the Closed loop servo a low resolution adjustment and maybe the
> >C-field a better resolution adjustment?
> >Or maybe efratoms just have low resolution servo loops and require
> >messing with C-field.. How can I set the C-field manually if the
> >internals are playing with the c-field to..
> >
> >What would you do?
> >A. Disable internal c-field temperature compensation.
> >
> >B. Run external stable 5 volt sourced C-field trim pot.
> >
> >C. Wire spare pin on interface to provide external 17 volt supply that
> >feeds C-field trim pot and fixed C-field supply?
> >D. All the above..
> >
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> >
> >
> >

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Re: [time-nuts] frs-c rubidium osc.

[george]

Oops I have I little more info Yes external power is pure and stable.
I've monitored my efc with analogue vtvm at 8 volts the manual states
normal efc range to be 4 to 8 volts I'm wondering if the quartz osc has
aged near the limit of normal efc range. However upon power up I see the
efc slew from 12 down to 1 volt then back to 12 and lock on the second
sweep at 8 volts every time which almost seems premature. Unit always
locks at about 2 minutes.
My external frequency adjust wiper is at .675 volts.
I think my unit has minor problems other than ambient temp allthough at
around or above 91.9 f it becomes very stable +/- 50 nanoseconds over
several hours..

Brian Kirby wrote:
> 
> I know Rex and myself have them.  I also have a FRK-L and a mutate FEI5680A.
> 
> When I got my FRS-C, back in December, I put it together in a permanent
> package and I let it run for a month before I ran any test on it.
> Efratom did not warrant any specs until the unit is burned in.  Looking
> at yesterdays raw data and my unit was tweaked on frequency 4 days ago,
> it had a drift of  311 nanoseconds for 24 hours.
> 
> My unit is frequency controlled by an external 1 kilo-ohm 10 turn pot.
> When an external pot is hooked up to the unit, it overrides the internal
> frequency control.  The top of the pot is connected to pin 8, the bottom
> of the pot to pin 3 (ground) and the wiper to pin 2 of the FRS-C
> connector.  In this method I see 6.9138 volts on the top of the pot from
> the rubidium and its solid, no variation (using a Fluke 45 voltmeter).
> A month ago I did a check and at 6.9 volts the rubidiums frequency was
> +2.709x10-9, and at zero volts is was -1.052x10-9 in respect to UTC.
> Currently its on frequency at 2.1048 volts.
> 
> Is your meter stable enough to monitor the EFC ?  Is your power tightly
> regulated to the unit ?  Is your ambient temperature stable ?  Does the
> unit have an adequate heat sink ?
> 
> -
> 
> I am also working on using this unit with Brooks Shera's GPS controller
> - I had to build a stable amplifier and voltage reference to interface
> with his controller.   My circuit uses a LM399 voltage reference and
> OP07 op amps and this regulator is more stable than the circuitry in the
> FRS-C.  It may be overkill.  The FRS-C unit (mine) has a 1 volt
> sensitivity of 5x10-10, so 100 mV would be 5x10-11, 10 mV 5x10-12, and
> maybe 1 mV 5x10-13.
> 
> Also, I have read that the FRS-C is not as stable as the older FRK-L and
> it has to do with the way the rubidium cells are manufactured - the new
> process is considerably more cheaper.
> 
> Brian - N4FMN
> 
> george wrote:
> 
> >Anybody have experience with ball efratom frs-c oscillators?
> >
> >Are these any good?  I purchased one on ebay and have been waiting for
> >about a week to see good stability.. AT 10k samples against gps 1pps
> >indicate 5-11th  accuracy.. which is exactly at spec.. I was hoping for
> >something close to 3-12th.
> >
> >To be more specific with my line of questions;
> >This standard is adjusted with precision 20 turn pot supplied from in
> >internal 17 volt requlator which I think isn't that stable of a voltage
> >source because the manual shows and alternate customer provides variable
> >5 volt source for the adjustment (these adjustments vary the C-field).
> >The internal adjustment pot has voltage divider resisters that bring the
> >semi-stable 17 volt source down to around 5 volts to the adjustment pot.
> >
> >I've been monitoring the wiper voltage day by day I see .05 volt
> >difference and think that this variation is effecting my stability.
> >Its only changing day by day not hour to hour.
> >
> >This wouldn't be a big deal to provide my own stable 5 volt supply to an
> >external adjustment pot.. but further investigation of the schematics
> >indicate internal temperature compensation circuitry is varying the
> >C-field as well.. along with another 17 volt source to the C-field via
> >Select In Test Resistor (the manual calls fixed C-field).
> >
> >Is it customary for Atomic standards to vary the C-field to obtain
> >compensate for internal temperature variation?
> >
> >Cant the closed loop servo handle these temperature/frequency errors
> >alone.  Without the need of additional circuitry trying to compensate
> >via the C-field ?
> >
> >Or is the Closed loop servo a low resolution adjustment and maybe the
> >C-field a better resolution adjustment?
> >Or maybe efratoms just have low resolution servo loops and require
> >messing with C-field.. How can I set the C-field manually if the
> >internals are playing with the c-field to..
> >
> >What would you do?
> >A. Disable internal c-field temperature compensation.
> >
> >B. Run external stable 5 volt sourced C-field trim pot.
> >
> >C. Wire spare pin on interface to provide external 17 volt supply that
> >feeds C-field trim pot and fixed C-field supply?
> >D. All the above..
> >
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> >time-nuts@febo.

[time-nuts] FRS-C TTL / sine outboard filter question

[Leigh L. Klotz, Jr WA5ZNU]

At the local flea market, I picked up what appears to be an Efratom 
FRS-C.  It is marked "TTL" internally.  It has the passive connector 
board, but not the active board with the 15 MHz synthesizer on it.


Mine is marked "TTL" internally.  The service manual has a chart showing 
the differences between the sine and TTL options, and I converted it to 
the sine version by changing a jumper to a resistor and populating an LC 
filter with 10uH and 100pF (~5 MHz).  I also terminated the RF 
connection on the connector board with a 47 ohm resistor to ground.


The output now doesn't have the tremendous overshoot it used to have, 
but it's also not very sinusoidal.  That's not surprising given the 
simplicity of the on-board filter.


Instead of a multi-stage LC filter, I wondered about a crystal ladder 
filter: since the output frequency is fixed, the high Q and low cost of 
the crystal filter might be an advantage, but I wasn't sure about how 
effective xtal ladder filters are at suppressing harmonics, as each 
individual crystals would have odd overtone responses, so it might not 
be a good plan.


Does anyone have practical experience with a filter topology for 
cleaning up the output of the FRS-C at 10 MHz?


Leigh.

P.S. Just so that I can be topical, note that the FRS-C has a C-field 
adjustment 0-5V input, so I could use it as the reference oscillator for 
a TPLL.



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[David Smith]

Leigh, I have the same FRS-C TTL unit. I do not have a manual.

Would you be so kind as to send the conversation info to me?

Thanks,

Dave W6TE
  - Original Message - 
  From: Leigh L. Klotz, Jr WA5ZNU<mailto:le...@wa5znu.org> 
  To: time nuts<mailto:time-nuts@febo.com> 
  Sent: Tuesday, June 22, 2010 9:54 PM
  Subject: [time-nuts] FRS-C TTL / sine outboard filter question


  At the local flea market, I picked up what appears to be an Efratom 
  FRS-C.  It is marked "TTL" internally.  It has the passive connector 
  board, but not the active board with the 15 MHz synthesizer on it.

  Mine is marked "TTL" internally.  The service manual has a chart showing 
  the differences between the sine and TTL options, and I converted it to 
  the sine version by changing a jumper to a resistor and populating an LC 
  filter with 10uH and 100pF (~5 MHz).  I also terminated the RF 
  connection on the connector board with a 47 ohm resistor to ground.

  The output now doesn't have the tremendous overshoot it used to have, 
  but it's also not very sinusoidal.  That's not surprising given the 
  simplicity of the on-board filter.

  Instead of a multi-stage LC filter, I wondered about a crystal ladder 
  filter: since the output frequency is fixed, the high Q and low cost of 
  the crystal filter might be an advantage, but I wasn't sure about how 
  effective xtal ladder filters are at suppressing harmonics, as each 
  individual crystals would have odd overtone responses, so it might not 
  be a good plan.

  Does anyone have practical experience with a filter topology for 
  cleaning up the output of the FRS-C at 10 MHz?

  Leigh.

  P.S. Just so that I can be topical, note that the FRS-C has a C-field 
  adjustment 0-5V input, so I could use it as the reference oscillator for 
  a TPLL.


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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Steve Rooke]

What load do you have it running into? It maybe that you need to load
it into 50 ohms.

Steve

On 23 June 2010 16:54, Leigh L. Klotz, Jr WA5ZNU  wrote:
> At the local flea market, I picked up what appears to be an Efratom FRS-C.
>  It is marked "TTL" internally.  It has the passive connector board, but not
> the active board with the 15 MHz synthesizer on it.
>
> Mine is marked "TTL" internally.  The service manual has a chart showing the
> differences between the sine and TTL options, and I converted it to the sine
> version by changing a jumper to a resistor and populating an LC filter with
> 10uH and 100pF (~5 MHz).  I also terminated the RF connection on the
> connector board with a 47 ohm resistor to ground.
>
> The output now doesn't have the tremendous overshoot it used to have, but
> it's also not very sinusoidal.  That's not surprising given the simplicity
> of the on-board filter.
>
> Instead of a multi-stage LC filter, I wondered about a crystal ladder
> filter: since the output frequency is fixed, the high Q and low cost of the
> crystal filter might be an advantage, but I wasn't sure about how effective
> xtal ladder filters are at suppressing harmonics, as each individual
> crystals would have odd overtone responses, so it might not be a good plan.
>
> Does anyone have practical experience with a filter topology for cleaning up
> the output of the FRS-C at 10 MHz?
>
> Leigh.
>
> P.S. Just so that I can be topical, note that the FRS-C has a C-field
> adjustment 0-5V input, so I could use it as the reference oscillator for a
> TPLL.
>
>
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> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
The only reason for time is so that everything doesn't happen at once.
- Einstein

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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Robert Atkinson]

Hi Leigh,
I can't comment on the crystal filter option., but I've found that the packaged 
filters and filter/balun modules from old 10Mb/s Ethernet cards work well. See 
this excellent little page by Dave G4HUP 
http://g4hup.com/DA/Filters%20Transformers%20and%20DC%20Converters.pdf
 
Robert G8RPI.

--- On Wed, 23/6/10, Leigh L. Klotz, Jr WA5ZNU  wrote:


From: Leigh L. Klotz, Jr WA5ZNU 
Subject: [time-nuts] FRS-C TTL / sine outboard filter question
To: "time nuts" 
Date: Wednesday, 23 June, 2010, 5:54


At the local flea market, I picked up what appears to be an Efratom FRS-C.  It 
is marked "TTL" internally.  It has the passive connector board, but not the 
active board with the 15 MHz synthesizer on it.

Mine is marked "TTL" internally.  The service manual has a chart showing the 
differences between the sine and TTL options, and I converted it to the sine 
version by changing a jumper to a resistor and populating an LC filter with 
10uH and 100pF (~5 MHz).  I also terminated the RF connection on the connector 
board with a 47 ohm resistor to ground.

The output now doesn't have the tremendous overshoot it used to have, but it's 
also not very sinusoidal.  That's not surprising given the simplicity of the 
on-board filter.

Instead of a multi-stage LC filter, I wondered about a crystal ladder filter: 
since the output frequency is fixed, the high Q and low cost of the crystal 
filter might be an advantage, but I wasn't sure about how effective xtal ladder 
filters are at suppressing harmonics, as each individual crystals would have 
odd overtone responses, so it might not be a good plan.

Does anyone have practical experience with a filter topology for cleaning up 
the output of the FRS-C at 10 MHz?

Leigh.

P.S. Just so that I can be topical, note that the FRS-C has a C-field 
adjustment 0-5V input, so I could use it as the reference oscillator for a TPLL.


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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Mike Feher]

On a military satcom program in the mid 80's that I worked on, we used a 10
MHz crystal filter with about a 100 Hz BW to reduce phase noise of our Rb
source. Regards - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ 07731
732-886-5960 



-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Leigh L. Klotz, Jr WA5ZNU
Sent: Wednesday, June 23, 2010 12:54 AM
To: time nuts
Subject: [time-nuts] FRS-C TTL / sine outboard filter question

At the local flea market, I picked up what appears to be an Efratom 
FRS-C.  It is marked "TTL" internally.  It has the passive connector 
board, but not the active board with the 15 MHz synthesizer on it.

Mine is marked "TTL" internally.  The service manual has a chart showing 
the differences between the sine and TTL options, and I converted it to 
the sine version by changing a jumper to a resistor and populating an LC 
filter with 10uH and 100pF (~5 MHz).  I also terminated the RF 
connection on the connector board with a 47 ohm resistor to ground.

The output now doesn't have the tremendous overshoot it used to have, 
but it's also not very sinusoidal.  That's not surprising given the 
simplicity of the on-board filter.

Instead of a multi-stage LC filter, I wondered about a crystal ladder 
filter: since the output frequency is fixed, the high Q and low cost of 
the crystal filter might be an advantage, but I wasn't sure about how 
effective xtal ladder filters are at suppressing harmonics, as each 
individual crystals would have odd overtone responses, so it might not 
be a good plan.

Does anyone have practical experience with a filter topology for 
cleaning up the output of the FRS-C at 10 MHz?

Leigh.

P.S. Just so that I can be topical, note that the FRS-C has a C-field 
adjustment 0-5V input, so I could use it as the reference oscillator for 
a TPLL.


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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Didier Juges]

If your concern is to clean up the harmonics, a crystal ladder filter is 
probably not the best choice, a low pass filter would be easier to design, 
would probably require no adjustment and be cheaper in parts with less effect 
on the fundamental signal you are interested in.

If your concern is cleanliness and close-in phase noise (as Mike referred to), 
then a narrow crystal filter would indeed be a better choice. Keep in mind that 
ladder filters have an assymetric frequency response. That may or may not help 
you.

On the other end, if you are going to drive any kind of digital circuitry, a 
square wave (even distorted) is probably better than a sine wave.

Didier

 Sent from my BlackBerry Wireless thingy while I do 
other things... 

-Original Message-
From: "Leigh L. Klotz, Jr WA5ZNU" 
Sender: time-nuts-boun...@febo.com
Date: Tue, 22 Jun 2010 21:54:01 
To: time nuts
Reply-To: Discussion of precise time and frequency measurement

Subject: [time-nuts] FRS-C TTL / sine outboard filter question

At the local flea market, I picked up what appears to be an Efratom 
FRS-C.  It is marked "TTL" internally.  It has the passive connector 
board, but not the active board with the 15 MHz synthesizer on it.

Mine is marked "TTL" internally.  The service manual has a chart showing 
the differences between the sine and TTL options, and I converted it to 
the sine version by changing a jumper to a resistor and populating an LC 
filter with 10uH and 100pF (~5 MHz).  I also terminated the RF 
connection on the connector board with a 47 ohm resistor to ground.

The output now doesn't have the tremendous overshoot it used to have, 
but it's also not very sinusoidal.  That's not surprising given the 
simplicity of the on-board filter.

Instead of a multi-stage LC filter, I wondered about a crystal ladder 
filter: since the output frequency is fixed, the high Q and low cost of 
the crystal filter might be an advantage, but I wasn't sure about how 
effective xtal ladder filters are at suppressing harmonics, as each 
individual crystals would have odd overtone responses, so it might not 
be a good plan.

Does anyone have practical experience with a filter topology for 
cleaning up the output of the FRS-C at 10 MHz?

Leigh.

P.S. Just so that I can be topical, note that the FRS-C has a C-field 
adjustment 0-5V input, so I could use it as the reference oscillator for 
a TPLL.


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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Mike S]

At 12:54 AM 6/23/2010, Leigh L. Klotz, Jr WA5ZNU wrote...
At the local flea market, I picked up what appears to be an Efratom 
FRS-C.  It is marked "TTL" internally.  It has the passive connector 
board, but not the active board with the 15 MHz synthesizer on it.


Connector board? No such beast described in the manual. Do you mean the 
A3 power supply board, which has the i/o connector on it?


Active board? Ditto. Do you mean the A4 oscillator board, which has a 
20 MHz VCXO on it? There's no 15 MHz anywhere in an FRS-C.


Here's a manual: http://www.to-way.com/tf/frs.pdf

Mine is marked "TTL" internally.  The service manual has a chart 
showing the differences between the sine and TTL options, and I 
converted it to the sine version by changing a jumper to a resistor 
and populating an LC filter with 10uH and 100pF (~5 MHz).  I also 
terminated the RF connection on the connector board with a 47 ohm 
resistor to ground.


It sounds like you made the changes to the A4 oscillator board, but not 
the ones to the A3 power supply board (several inductors, resistors and 
caps). I found that using a 1 uF for C16, instead of the documented 0.1 
uF, gives a better signal. See the top of page A-15 in the manual. 



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[GandalfG8]

 
In a message dated 23/06/2010 14:12:00 GMT Daylight Time,  
mi...@flatsurface.com writes:

>At  the local flea market, I picked up what appears to be an Efratom  
>FRS-C.  It is marked "TTL" internally.  It has the passive  connector 
>board, but not the active board with the 15 MHz synthesizer  on it.

Connector board? No such beast described in the manual. Do you  mean the 
A3 power supply board, which has the i/o connector on  it?

Active board? Ditto. Do you mean the A4 oscillator board, which has  a 
20 MHz VCXO on it? There's no 15 MHz anywhere in an  FRS-C.



--
The connector board and missing 15MHz board are external parts from the  
Lucent unit that originally contained them, not internal to the FRS  module.
 
The 15MHz board, "active" in that it contains electronics circuitry, isn't  
of much use to most folks anyway but the connector board carries the 
special D  type connector with coax insert that interfaces to the FRS so that's 
extremely  useful.
 
regards
 
Nigel
GM8PZR
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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Adrian]

...


Mine is marked "TTL" internally.  The service manual has a chart 
showing the differences between the sine and TTL options, and I 
converted it to the sine version by changing a jumper to a resistor 
and populating an LC filter with 10uH and 100pF (~5 MHz).  I also 
terminated the RF connection on the connector board with a 47 ohm 
resistor to ground.


It sounds like you made the changes to the A4 oscillator board, but 
not the ones to the A3 power supply board (several inductors, 
resistors and caps). I found that using a 1 uF for C16, instead of the 
documented 0.1 uF, gives a better signal. See the top of page A-15 in 
the manual.




Exactly that's probably the culprit.
If you need a sine wave output but don't want to change anything inside, 
just add a lowpass filter.
A 5th order LPF (three inductors/ 2 caps or vice versa) should give you 
a clean sine wave output.

Just add a coupling cap to remove the DC component.

Adrian

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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Leigh L. Klotz, Jr. WA5ZNU]

Mike S wrote:

> It sounds like you made the changes to the A4 oscillator board, but not
> the ones to the A3 power supply board (several inductors, resistors
> and caps). I found that using a 1 uF for C16, instead of the
> documented 0.1 uF, gives a better signal.
> See the top of page A-15 in the manual.

Thank you.  This is just what I needed to hear.  I had clearly overlooked
that page.

I've made an attempt at reading page A-15 for the 10 MHz sine option, and
consulted the schematic and parts list on the succeeding pages.  I still
don't have legible values for L1, L2, and R16.

If you have these values we can document the rest of this process in one
place.

10 MHz sine TTL
L1   ?.? uH L1 OMIT
L2   1? uH  Replace with R23 130 OHM 1 WATT
R16  ?10 OHM NOM100 OHM NOM
R17  1.0K   274 OHM NOM 1/4W
R18  1.0K   OMIT
C8   47pF NOM   JUMPER
C9   6800pf NOM 0.47 uF NOM
C16  0.1uF [1uF: see above] JUMPER
C17  240pF NOM NP0  OMIT
INSTALL JUMPER A-0

Leigh.




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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Leigh L. Klotz, Jr. WA5ZNU]

> ...
>> [snip]
> If you need a sine wave output but don't want to change anything inside,
> just add a lowpass filter.
> A 5th order LPF (three inductors/ 2 caps or vice versa) should give you
> a clean sine wave output.
> Just add a coupling cap to remove the DC component.
>
> Adrian
>
> _

Thank you, Adrian.  I'll pursue both options, internal fixes and external
filter.  A multi-pole LPF is easily understood, and I don't believe I care
about passband ripple, though I wonder a little about the effect of the
coupling on phase changes (i.e., does this have any unfortunate effect on
adev?).

I still don't know if a crystal ladder filter will suppress the harmonics,
but I did get the answers that make me not need to ask anymore (1. fix the
internal filter, 2. use the high Q xtal filter for optional removal of
close-in noise)

Given time I would do all of these things, but I may not get to them all!

Leigh.



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Mike S]

At 04:19 PM 6/23/2010, Leigh L. Klotz, Jr. WA5ZNU wrote...

If you have these values we can document the rest of this process in 
one

place.

10 MHz sine TTL
L1   ?.? uH L1 OMIT
L2   1? uH  Replace with R23 130 OHM 1 WATT
R16  ?10 OHM NOM100 OHM NOM
R17  1.0K   274 OHM NOM 1/4W
R18  1.0K   OMIT
C8   47pF NOM   JUMPER
C9   6800pf NOM 0.47 uF NOM
C16  0.1uF [1uF: see above] JUMPER
C17  240pF NOM NP0  OMIT
INSTALL JUMPER A-0



Here are the values I used.

L1 6.8 uH
L2 15 uH
R16 910 Ohm nom
R17 1.0K nom
R18 1.0K
C8 47 pF nom
C9 6800 pF nom
C16 0.1 uF (but 1.0 uF provides much cleaner signal)
C17 240 pF NPO nom 



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Didier Juges]

Leigh,

A narrow filter around 10MHz is likely to show phase ripple in its passband, 
and that will most certainly vary over temperature, not a good thing for ADEV, 
that's why a LPF is preferred.

Also, most crystal filters may not be happy with the output level of a typical 
OCXO, so you would have to attenuate the signal before the filter and amplify 
it after, an unnecessary complexity that will not help ADEV.

Crystal filters are not usually used for harmonic suppression because away from 
the resonance, crystals are good capacitors, so you will probably not find much 
data, and if you find data, it will probably suck :) In most applications, they 
are preceded and followed by L-C filters to normalize the out-of-band response.

Didier

 Sent from my BlackBerry Wireless thingy while I do 
other things... 

-Original Message-
From: "Leigh L. Klotz, Jr. WA5ZNU" 
Sender: time-nuts-boun...@febo.com
Date: Wed, 23 Jun 2010 13:44:37 
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] FRS-C TTL / sine outboard filter question

> ...
>> [snip]
> If you need a sine wave output but don't want to change anything inside,
> just add a lowpass filter.
> A 5th order LPF (three inductors/ 2 caps or vice versa) should give you
> a clean sine wave output.
> Just add a coupling cap to remove the DC component.
>
> Adrian
>
> _

Thank you, Adrian.  I'll pursue both options, internal fixes and external
filter.  A multi-pole LPF is easily understood, and I don't believe I care
about passband ripple, though I wonder a little about the effect of the
coupling on phase changes (i.e., does this have any unfortunate effect on
adev?).

I still don't know if a crystal ladder filter will suppress the harmonics,
but I did get the answers that make me not need to ask anymore (1. fix the
internal filter, 2. use the high Q xtal filter for optional removal of
close-in noise)

Given time I would do all of these things, but I may not get to them all!

Leigh.



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Leigh L. Klotz, Jr. WA5ZNU]

Thank you, Didier.

That pretty much sums it up. I was aware of the signal level issue but
didn't consider that passband ripple would be temperature sensitive.  It's
fun learning to think in the long time domain.

In the meantime I've found a 10 mbit ethernet ISA card in my office and
will follow Robert G8RPI's suggestion to use G4HUP's document to obtain a
ready-made 10 MHz filter from it.  Plus as a bonus the box had a BNC T
connector in it.

Leigh/WA5ZNU



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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Mike Feher]

I do not understand why the passband ripple would be of any consequence in
the big (or small as we typically talk about) picture. During any
measurement interval, it will be a constant, for all practical purposes,
including ours. A measurement at a different time, at a different
temperature that may adversely affect where the ripple is, it will certainly
create a slightly different amplitude and phase delay, however, again, a
constant through the measurement process, not affecting the result. When we
were designing the system I mentioned previously, both Dave and Fred of NIST
were in assistance, as well as the staff of the relevant departments of
MIT's LL, and no one saw any issues. Regards - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ 07731
732-886-5960 

 

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Leigh L. Klotz, Jr. WA5ZNU
Sent: Wednesday, June 23, 2010 6:15 PM
To: did...@cox.net; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FRS-C TTL / sine outboard filter question

Thank you, Didier.

That pretty much sums it up. I was aware of the signal level issue but
didn't consider that passband ripple would be temperature sensitive.  It's
fun learning to think in the long time domain.

In the meantime I've found a 10 mbit ethernet ISA card in my office and
will follow Robert G8RPI's suggestion to use G4HUP's document to obtain a
ready-made 10 MHz filter from it.  Plus as a bonus the box had a BNC T
connector in it.

Leigh/WA5ZNU



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and follow the instructions there.


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Re: [time-nuts] FRS-C TTL / sine outboard filter question

[Didier Juges]

Mike,

I agree with you that for SatCom application, long term stability is not as 
much of a concern, phase noise typically is the main issue.

But I suspect that for a time nuts looking at stability over periods of hours 
or days, temperature effects cannot be ignored. Passband ripple usually goes 
with group delay ripple, and that delay will change with temperature. For 
instance, on the Tek 494P I have, the 30Hz crystal filter is thermostatically 
regulated. When the instrument is cold, there is no signal at all...

Didier


--Original Message--
From: Mike Feher
To: Time-Nuts
To: Didier Juges via Cox
Subject: RE: [time-nuts] FRS-C TTL / sine outboard filter question
Sent: Jun 23, 2010 8:41 PM

I do not understand why the passband ripple would be of any consequence in
the big (or small as we typically talk about) picture. During any
measurement interval, it will be a constant, for all practical purposes,
including ours. A measurement at a different time, at a different
temperature that may adversely affect where the ripple is, it will certainly
create a slightly different amplitude and phase delay, however, again, a
constant through the measurement process, not affecting the result. When we
were designing the system I mentioned previously, both Dave and Fred of NIST
were in assistance, as well as the staff of the relevant departments of
MIT's LL, and no one saw any issues. Regards - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ 07731
732-886-5960 

 

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Leigh L. Klotz, Jr. WA5ZNU
Sent: Wednesday, June 23, 2010 6:15 PM
To: did...@cox.net; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FRS-C TTL / sine outboard filter question

Thank you, Didier.

That pretty much sums it up. I was aware of the signal level issue but
didn't consider that passband ripple would be temperature sensitive.  It's
fun learning to think in the long time domain.

In the meantime I've found a 10 mbit ethernet ISA card in my office and
will follow Robert G8RPI's suggestion to use G4HUP's document to obtain a
ready-made 10 MHz filter from it.  Plus as a bonus the box had a BNC T
connector in it.

Leigh/WA5ZNU



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 Sent from my BlackBerry Wireless thingy while I do 
other things... 
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[time-nuts] FRS-C schematic/manual information request from a timenuts newbie

[mike c]

Hi,

I didn't know how to send this message just to Brian K. or George M, so
pardon me if you are all getting this.  After searching the archives, they
may be most able to help me

I'm Mike C at YSU physics.  I would like to  find  information on the
pinout (or schematic, if possible) for the physics package of an old 
Efratom
FRS-C. In particular, the connector consists of a coax to the microwave
diode and row of 10 pins. Thanks so much for your trouble...it will save my
student much time and agravation studying the tiny PC boards...-mike


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Re: [time-nuts] FRS-C schematic/manual information request from a timenuts newbie

[Javier]

I'm sending you the manual with schematics in a separate e-mail.

Regards,

Javier, EA1CRB

mike c wrote:

>Hi,
>
>I didn't know how to send this message just to Brian K. or George M, so
>pardon me if you are all getting this.  After searching the archives, they
>may be most able to help me
>
>I'm Mike C at YSU physics.  I would like to  find  information on the
>pinout (or schematic, if possible) for the physics package of an old 
>Efratom
>FRS-C. In particular, the connector consists of a coax to the microwave
>diode and row of 10 pins. Thanks so much for your trouble...it will save my
>student much time and agravation studying the tiny PC boards...-mike
>
>
>___
>time-nuts mailing list
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>
>
>  
>


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Re: [time-nuts] FRS-C schematic/manual information request from a timenuts newbie

[Had]

Mike,

You can download the FRS-C manual at myWeb site  www.to-way.com   it 
should elp a lot.

Had


At 06:36 AM 6/9/2006, you wrote:

>Hi,
>
> I didn't know how to send this message just to Brian K. or George M, so
>pardon me if you are all getting this.  After searching the archives, they
>may be most able to help me
>
> I'm Mike C at YSU physics.  I would like to  find  information on the
>pinout (or schematic, if possible) for the physics package of an old
>Efratom
>FRS-C. In particular, the connector consists of a coax to the microwave
>diode and row of 10 pins. Thanks so much for your trouble...it will save my
>student much time and agravation studying the tiny PC boards...-mike
>
>
>___
>time-nuts mailing list
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A well regulated Militia, being necessary to the security of a free
State, the right of the people to keep and bear Arms, shall not be
infringed.



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Re: [time-nuts] FRS-C schematic/manual information request from a timenuts newbie

[Brian Kirby]

Since a couple of folks posted/hosted...the manuals...that should do it.

If you need anything else...let us know

Brian

mike c wrote:
> Hi,
>
> I didn't know how to send this message just to Brian K. or George M, so
> pardon me if you are all getting this.  After searching the archives, they
> may be most able to help me
>
> I'm Mike C at YSU physics.  I would like to  find  information on the
> pinout (or schematic, if possible) for the physics package of an old 
> Efratom
> FRS-C. In particular, the connector consists of a coax to the microwave
> diode and row of 10 pins. Thanks so much for your trouble...it will save my
> student much time and agravation studying the tiny PC boards...-mike
>
>
> ___
> time-nuts mailing list
> time-nuts@febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>   

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Re: [time-nuts] FRS-C schematic/manual information request from a timenuts newbie

[mike c]

Your colleagues took good care of me...thanks for the follow up anyways. 
peace, -mike

Brian Kirby wrote:

>Since a couple of folks posted/hosted...the manuals...that should do it.
>
>If you need anything else...let us know
>
>Brian
>
>mike c wrote:
>  
>
>>Hi,
>>
>>I didn't know how to send this message just to Brian K. or George M, so
>>pardon me if you are all getting this.  After searching the archives, they
>>may be most able to help me
>>
>>I'm Mike C at YSU physics.  I would like to  find  information on the
>>pinout (or schematic, if possible) for the physics package of an old 
>>Efratom
>>FRS-C. In particular, the connector consists of a coax to the microwave
>>diode and row of 10 pins. Thanks so much for your trouble...it will save my
>>student much time and agravation studying the tiny PC boards...-mike
>>
>>
>>___
>>time-nuts mailing list
>>time-nuts@febo.com
>>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>
>>  
>>
>>
>
>___
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>  
>


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Re: [time-nuts] FRS-C manual this is available from ebay seller ID "accelium"

[philipadavies2004]

Hello There

RE: FRS-C manual, 

This is available from Ebay seller ID "accelium"
Who sells lots of High End Frequency and Time Equipment.
And their service is good 

Best Regards

Philip Davies

--

Today's Topics:

   1. Re: FRS-C schematic/manual information request from a
  timenuts newbie (mike c)


--

Message: 1
Date: Mon, 12 Jun 2006 07:56:58 -0400
From: mike c <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] FRS-C schematic/manual information request
from a timenuts newbie
To: Discussion of precise time and frequency measurement

Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=us-ascii; format=flowed


Your colleagues took good care of me...thanks for the follow up anyways. 
peace, -mike

Brian Kirby wrote:

>Since a couple of folks posted/hosted...the manuals...that should do it.
>
>If you need anything else...let us know
>
>Brian
>
>mike c wrote:
>  
>
>>Hi,
>>
>>I didn't know how to send this message just to Brian K. or George M,
so
>>pardon me if you are all getting this.  After searching the archives, they
>>may be most able to help me
>>
>>I'm Mike C at YSU physics.  I would like to  find  information on the
>>pinout (or schematic, if possible) for the physics package of an old 
>>Efratom
>>FRS-C. In particular, the connector consists of a coax to the microwave
>>diode and row of 10 pins. Thanks so much for your trouble...it will save
my
>>student much time and agravation studying the tiny PC boards...-mike
>>
>>
>>___
>>time-nuts mailing list
>>time-nuts@febo.com
>>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>
>>  
>>
>>
>
>___
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>time-nuts@febo.com
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>  
>




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End of time-nuts Digest, Vol 23, Issue 6



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Re: [time-nuts] FRS-C manual this is available from ebay seller ID "accelium"

[bg]

On Mon, June 12, 2006 19:00, [EMAIL PROTECTED] said:
> Hello There
>
> RE: FRS-C manual,
>
> This is available from Ebay seller ID "accelium"
> Who sells lots of High End Frequency and Time Equipment.
> And their service is good
>

At one time he announced special prices for readers of this mailinglist...
;-)

But why buy the manual, when its available from list members. Buy and scan
manuals when they are not available here.

--

   Björn


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Re: [time-nuts] FRS-C manual this is available from ebay seller ID "accelium"

[bg]

Sorry about the "High priority" flag.

--

Björn

On Mon, June 12, 2006 20:06, [EMAIL PROTECTED] said:
> On Mon, June 12, 2006 19:00, [EMAIL PROTECTED] said:
>> Hello There
>>
>> RE: FRS-C manual,
>>
>> This is available from Ebay seller ID "accelium"
>> Who sells lots of High End Frequency and Time Equipment.
>> And their service is good
>>
>
> At one time he announced special prices for readers of this mailinglist...
> ;-)
>
> But why buy the manual, when its available from list members. Buy and scan
> manuals when they are not available here.
>
> --
>
>Björn
>
>
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