Re: James Miller/Brooks Shera 10 MHz GPSDO
I found this helpful long ago...
http://www.realhamradio.com/GPS-oven-journey.htm
I think you would only need to go part way in to get to the adjustment
screw.
The double oven was used in some equipment spec'd for cold climate
operation. It helped speed warmup or some such issue. People have used
the outer oven to help stabilize the temperature, although from what I
understand that was not the original intention.
Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote:
Unfortunately the HP 10811's I have are in a completely enclosed can -
no holes to poke anything through. To get at any tuning capacitor would
probably entail taking the insides out of the can.
The oscillators like mine must have been fairly rare as I am unable to
find anything via Google. They have 2 main power leads coming out of
the can with 6 pin female connectors to connect to the power Power Board
which is out of an HP Z3801 GPSDO and 2 thin coaxes with SMB connectors
on the end - one marked as 10MHz and the other as EFC.
Regards, Merv
Dan,
As a last resort I would attempt to disassemble the osc. What concerns
me is the picture of the osc. shown in the article you gave is not my
version osc. so I'm pretty sure there would be no tuneable cap inside
mine?? Will keep the group posted on results.
Merv
On 30/08/2022 8:25 pm, Dan Kemppainen via time-nuts wrote:
I found this helpful long ago...
http://www.realhamradio.com/GPS-oven-journey.htm
I think you would only need to go part way in to get to the adjustment
screw.
The double oven was used in some equipment spec'd for cold climate
operation. It helped speed warmup or some such issue. People have used
the outer oven to help stabilize the temperature, although from what I
understand that was not the original intention.
Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote:
Unfortunately the HP 10811's I have are in a completely enclosed can
- no holes to poke anything through. To get at any tuning capacitor
would probably entail taking the insides out of the can.The oscillators like mine must have been fairly rare as I am unable
to find anything via Google. They have 2 main power leads coming out
of the can with 6 pin female connectors to connect to the power Power
Board which is out of an HP Z3801 GPSDO and 2 thin coaxes with SMB
connectors on the end - one marked as 10MHz and the other as EFC.Regards, Merv
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I have one of the double oven 10811s and there is no tuning hole in the
inner case. One would have to remove the flex-circuit outer oven
heating element and open the inner case to get to the tuning cap.
I do not find a schematic of the Brooks Shera board that uses an
AD1861. If there is one, perhaps we could rework the circuit to have
bipolar output.
David N1HAC
On 9/1/22 3:36 AM, Mervyn Thomas via time-nuts wrote:
Dan,
As a last resort I would attempt to disassemble the osc. What
concerns me is the picture of the osc. shown in the article you gave
is not my version osc. so I'm pretty sure there would be no tuneable
cap inside mine?? Will keep the group posted on results.
Merv
On 30/08/2022 8:25 pm, Dan Kemppainen via time-nuts wrote:
I think you would only need to go part way in to get to the
adjustment screw.
The double oven was used in some equipment spec'd for cold climate
operation. It helped speed warmup or some such issue. People have
used the outer oven to help stabilize the temperature, although from
what I understand that was not the original intention.
Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote:
Unfortunately the HP 10811's I have are in a completely enclosed can
- no holes to poke anything through. To get at any tuning capacitor
would probably entail taking the insides out of the can.
The oscillators like mine must have been fairly rare as I am unable
to find anything via Google. They have 2 main power leads coming
out of the can with 6 pin female connectors to connect to the power
Power Board which is out of an HP Z3801 GPSDO and 2 thin coaxes with
SMB connectors on the end - one marked as 10MHz and the other as EFC.
Regards, Merv
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
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The AD1861 is very similar to the PCM61. Both have plus and minus 3
volt output range. They may be effectively interchangeable.
Dave WA8YWQ
On 2022-09-01 14:52, David G. McGaw via time-nuts wrote:
I have one of the double oven 10811s and there is no tuning hole in the inner case. One would have to remove the flex-circuit outer oven heating element and open the inner case to get to the tuning cap.
I do not find a schematic of the Brooks Shera board that uses an AD1861. If there is one, perhaps we could rework the circuit to have bipolar output.
David N1HAC
On 9/1/22 3:36 AM, Mervyn Thomas via time-nuts wrote: Dan,
As a last resort I would attempt to disassemble the osc. What concerns me is the picture of the osc. shown in the article you gave is not my version osc. so I'm pretty sure there would be no tuneable cap inside mine?? Will keep the group posted on results.
Merv
On 30/08/2022 8:25 pm, Dan Kemppainen via time-nuts wrote: I found this helpful long ago...
https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.realhamradio.com%2FGPS-oven-journey.htm&data=05%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C4cec14fbc44e4985d4c608da8c548d5d%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637976592033788783%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=atgiKtTy8I1x3y5Lm71YavmLdGeQ84dBgfyi1%2FCXjwM%3D&reserved=0 I think you would only need to go part way in to get to the adjustment screw.
The double oven was used in some equipment spec'd for cold climate operation. It helped speed warmup or some such issue. People have used the outer oven to help stabilize the temperature, although from what I understand that was not the original intention.
Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote: Unfortunately the HP 10811's I have are in a completely enclosed can - no holes to poke anything through. To get at any tuning capacitor would probably entail taking the insides out of the can.
The oscillators like mine must have been fairly rare as I am unable to find anything via Google. They have 2 main power leads coming out of the can with 6 pin female connectors to connect to the power Power Board which is out of an HP Z3801 GPSDO and 2 thin coaxes with SMB connectors on the end - one marked as 10MHz and the other as EFC.
Regards, Merv _______________________________________________
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I'll see when my supply of PCM61P DAC's arrive if it makes any difference
Merv
On 2/09/2022 7:45 am, David via time-nuts wrote:
The AD1861 is very similar to the PCM61. Both have plus and minus 3
volt output range. They may be effectively interchangeable.
Dave WA8YWQ
On 2022-09-01 14:52, David G. McGaw via time-nuts wrote:
I have one of the double oven 10811s and there is no tuning hole in the inner case. One would have to remove the flex-circuit outer oven heating element and open the inner case to get to the tuning cap.
I do not find a schematic of the Brooks Shera board that uses an AD1861. If there is one, perhaps we could rework the circuit to have bipolar output.
David N1HAC
On 9/1/22 3:36 AM, Mervyn Thomas via time-nuts wrote: Dan,
As a last resort I would attempt to disassemble the osc. What concerns me is the picture of the osc. shown in the article you gave is not my version osc. so I'm pretty sure there would be no tuneable cap inside mine?? Will keep the group posted on results.
Merv
On 30/08/2022 8:25 pm, Dan Kemppainen via time-nuts wrote: I found this helpful long ago...
https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.realhamradio.com%2FGPS-oven-journey.htm&data=05%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C4cec14fbc44e4985d4c608da8c548d5d%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637976592033788783%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=atgiKtTy8I1x3y5Lm71YavmLdGeQ84dBgfyi1%2FCXjwM%3D&reserved=0 I think you would only need to go part way in to get to the adjustment screw.The double oven was used in some equipment spec'd for cold climate operation. It helped speed warmup or some such issue. People have used the outer oven to help stabilize the temperature, although from what I understand that was not the original intention.
Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote: Unfortunately the HP 10811's I have are in a completely enclosed can - no holes to poke anything through. To get at any tuning capacitor would probably entail taking the insides out of the can.
The oscillators like mine must have been fairly rare as I am unable to find anything via Google. They have 2 main power leads coming out of the can with 6 pin female connectors to connect to the power Power Board which is out of an HP Z3801 GPSDO and 2 thin coaxes with SMB connectors on the end - one marked as 10MHz and the other as EFC.
Regards, Merv _______________________________________________
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
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David,
Brooks Shera's only schematic for his GPSDO shows the DAC as a PCM61P
but when I purchased the partial kit back some 15+years ago he supplied
the AD1861. I've got some Burr Brown PCM61P's coming from an eBay
supplier and I will see if using one makes any difference. The general
consensus is that it will not.
Merv
On 2/09/2022 5:52 am, David G. McGaw via time-nuts wrote:
I have one of the double oven 10811s and there is no tuning hole in
the inner case. One would have to remove the flex-circuit outer oven
heating element and open the inner case to get to the tuning cap.
I do not find a schematic of the Brooks Shera board that uses an
AD1861. If there is one, perhaps we could rework the circuit to have
bipolar output.
David N1HAC
On 9/1/22 3:36 AM, Mervyn Thomas via time-nuts wrote:
Dan,
As a last resort I would attempt to disassemble the osc. What
concerns me is the picture of the osc. shown in the article you gave
is not my version osc. so I'm pretty sure there would be no tuneable
cap inside mine?? Will keep the group posted on results.Merv
On 30/08/2022 8:25 pm, Dan Kemppainen via time-nuts wrote:
I think you would only need to go part way in to get to the
adjustment screw.The double oven was used in some equipment spec'd for cold climate
operation. It helped speed warmup or some such issue. People have
used the outer oven to help stabilize the temperature, although from
what I understand that was not the original intention.Let us know what you find!
Dan
On 8/30/2022 3:31 AM, time-nuts-request@lists.febo.com wrote:
Unfortunately the HP 10811's I have are in a completely enclosed
can - no holes to poke anything through. To get at any tuning
capacitor would probably entail taking the insides out of the can.The oscillators like mine must have been fairly rare as I am unable
to find anything via Google. They have 2 main power leads coming
out of the can with 6 pin female connectors to connect to the power
Power Board which is out of an HP Z3801 GPSDO and 2 thin coaxes
with SMB connectors on the end - one marked as 10MHz and the other
as EFC.Regards, Merv
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com