Empathy List Archives

JO

John or Susan

Fri, Jan 19, 2024 8:02 PM

The thermal fuse in my 10811B oscillator has opened. Troubleshooting
results say that the oven is ok, but I do need to replace the fuse and
cannot find any information about it. The manual says the Mfg. number
was 2110-0617, and the HP part number was 10811-80008. I am guessing
something on the order of either 1/2 A slow-blow or 1 A regular fuse.
Can anyone provide any guidance as to the proper fuse? Also any thoughts
as to why it failed would be appreciated. It is part of a home-brew
GPSDO, mounted in a case right next to ventilation slots.

John W2TX

The thermal fuse in my 10811B oscillator has opened. Troubleshooting results say that the oven is ok, but I do need to replace the fuse and cannot find any information about it. The manual says the Mfg. number was 2110-0617, and the HP part number was 10811-80008. I am guessing something on the order of either 1/2 A slow-blow or 1 A regular fuse. Can anyone provide any guidance as to the proper fuse? Also any thoughts as to why it failed would be appreciated. It is part of a home-brew GPSDO, mounted in a case right next to ventilation slots. John W2TX

RV

Rsec Van der leij

Sat, Jan 20, 2024 8:41 AM

On 20 Jan 2024, at 07:19, John or Susan via time-nuts time-nuts@lists.febo.com wrote:

I am guessing something on the order of either 1/2 A slow-blow or 1 A regular fuse.

Some googling tells me it's a combination of a thermal fuse (115ºC) and a 1A slow-blow current limitter. Over time the wax in the fuse moves and eventually the fuse fails, after many thermal cycles.

If you are the belt and suspender type, you could use a 1A fuse in combination with a thermal cutout.

Somebody suggests a Tamura E7F with a normal 5x20 glass fuse will fit, but you might have trouble finding them..

https://web.archive.org/web/20151127140920/http://www.tamurathermaldevice.co.jp/e/product_thermal-cutoff/e-f.html

--
Ruben

> On 20 Jan 2024, at 07:19, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote: > > I am guessing something on the order of either 1/2 A slow-blow or 1 A regular fuse. Some googling tells me it's a combination of a thermal fuse (115ºC) and a 1A slow-blow current limitter. Over time the wax in the fuse moves and eventually the fuse fails, after many thermal cycles. If you are the belt and suspender type, you could use a 1A fuse in combination with a thermal cutout. Somebody suggests a Tamura E7F with a normal 5x20 glass fuse will fit, but you might have trouble finding them.. https://web.archive.org/web/20151127140920/http://www.tamurathermaldevice.co.jp/e/product_thermal-cutoff/e-f.html -- Ruben

TK

Taka Kamiya

Sat, Jan 20, 2024 10:29 AM

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)

(Mr.) Taka Kamiya

On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote:

The thermal fuse in my 10811B oscillator has opened. Troubleshooting
results say that the oven is ok, but I do need to replace the fuse and
cannot find any information about it. The manual says the Mfg. number
was 2110-0617, and the HP part number was 10811-80008. I am guessing
something on the order of either 1/2 A slow-blow or 1 A regular fuse.
Can anyone provide any guidance as to the proper fuse? Also any thoughts
as to why it failed would be appreciated. It is part of a home-brew
GPSDO, mounted in a case right next to ventilation slots.

John W2TX

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now) --------------------------------------- (Mr.) Taka Kamiya On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote: The thermal fuse in my 10811B oscillator has opened. Troubleshooting results say that the oven is ok, but I do need to replace the fuse and cannot find any information about it. The manual says the Mfg. number was 2110-0617, and the HP part number was 10811-80008. I am guessing something on the order of either 1/2 A slow-blow or 1 A regular fuse. Can anyone provide any guidance as to the proper fuse? Also any thoughts as to why it failed would be appreciated. It is part of a home-brew GPSDO, mounted in a case right next to ventilation slots. John W2TX _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com

DR

Dan Rae

Sat, Jan 20, 2024 2:59 PM

On 1/19/2024 12:02 PM, John or Susan via time-nuts wrote:

The thermal fuse in my 10811B oscillator has opened. Troubleshooting
results say that the oven is ok, but I do need to replace the fuse and
cannot find any information about it. The manual says the Mfg. number
was 2110-0617, and the HP part number was 10811-80008. I am guessing
something on the order of either 1/2 A slow-blow or 1 A regular fuse.

John, it is a /Thermal/ Fuse, i.e. it fails open when it gets above a
certain temperature, in this case I think about 105°C. I bought a bunch
of 20 of the Panasonic ones when they were still available from Digikey;
I could stick one in an envelope and mail it to you.

Personally I think it's a really bad idea to link it out, and would be
surprised if -hp- recommended this.

Anyway I'll go look for the packet :^)

73 - Dan

ac6ao / g3ncr

On 1/19/2024 12:02 PM, John or Susan via time-nuts wrote: > The thermal fuse in my 10811B oscillator has opened. Troubleshooting > results say that the oven is ok, but I do need to replace the fuse and > cannot find any information about it. The manual says the Mfg. number > was 2110-0617, and the HP part number was 10811-80008. I am guessing > something on the order of either 1/2 A slow-blow or 1 A regular fuse. John, it is a /Thermal/ Fuse, i.e. it fails open when it gets above a certain temperature, in this case I think about 105°C. I bought a bunch of 20 of the Panasonic ones when they were still available from Digikey; I could stick one in an envelope and mail it to you. Personally I think it's a really bad idea to link it out, and would be surprised if -hp- recommended this. Anyway I'll go look for the packet :^) 73 - Dan ac6ao / g3ncr

DG

David G. McGaw

Sat, Jan 20, 2024 3:28 PM

Here is a discussion about this:
https://www.febo.com/pipermail/time-nuts/2017-May/105193.html

73,

David N1HAC

On 1/20/24 5:29 AM, Taka Kamiya via time-nuts wrote:

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)

(Mr.) Taka Kamiya

  On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote:

The thermal fuse in my 10811B oscillator has opened. Troubleshooting
results say that the oven is ok, but I do need to replace the fuse and
cannot find any information about it. The manual says the Mfg. number
was 2110-0617, and the HP part number was 10811-80008. I am guessing
something on the order of either 1/2 A slow-blow or 1 A regular fuse.
Can anyone provide any guidance as to the proper fuse? Also any thoughts
as to why it failed would be appreciated. It is part of a home-brew
GPSDO, mounted in a case right next to ventilation slots.

John W2TX

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com

Here is a discussion about this: https://www.febo.com/pipermail/time-nuts/2017-May/105193.html 73, David N1HAC On 1/20/24 5:29 AM, Taka Kamiya via time-nuts wrote: > I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now) > --------------------------------------- > (Mr.) Taka Kamiya > > > > On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote: > > The thermal fuse in my 10811B oscillator has opened. Troubleshooting > results say that the oven is ok, but I do need to replace the fuse and > cannot find any information about it. The manual says the Mfg. number > was 2110-0617, and the HP part number was 10811-80008. I am guessing > something on the order of either 1/2 A slow-blow or 1 A regular fuse. > Can anyone provide any guidance as to the proper fuse? Also any thoughts > as to why it failed would be appreciated. It is part of a home-brew > GPSDO, mounted in a case right next to ventilation slots. > > John W2TX > _______________________________________________ > 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

BC

Bob Camp

Sat, Jan 20, 2024 6:29 PM

Hi

Yup

That’s how everybody else does it ….

The MTBF of the fuse is horrible compared to the rest of the OCXO. The price of the fuse is non-trivial compared to what an entire OCXO costs on eBay. Even if HP didn’t suggest it, there still are very good reasons to go that way.

Bob

On Jan 20, 2024, at 5:29 AM, Taka Kamiya via time-nuts time-nuts@lists.febo.com wrote:

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)

(Mr.) Taka Kamiya

On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote:

The thermal fuse in my 10811B oscillator has opened. Troubleshooting
results say that the oven is ok, but I do need to replace the fuse and
cannot find any information about it. The manual says the Mfg. number
was 2110-0617, and the HP part number was 10811-80008. I am guessing
something on the order of either 1/2 A slow-blow or 1 A regular fuse.
Can anyone provide any guidance as to the proper fuse? Also any thoughts
as to why it failed would be appreciated. It is part of a home-brew
GPSDO, mounted in a case right next to ventilation slots.

John W2TX

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi Yup That’s how everybody else does it …. The MTBF of the fuse is horrible compared to the rest of the OCXO. The price of the fuse is non-trivial compared to what an entire OCXO costs on eBay. Even if HP didn’t suggest it, there still are very good reasons to go that way. Bob > On Jan 20, 2024, at 5:29 AM, Taka Kamiya via time-nuts <time-nuts@lists.febo.com> wrote: > > I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now) > --------------------------------------- > (Mr.) Taka Kamiya > > > > On Saturday, January 20, 2024 at 01:19:58 AM EST, John or Susan via time-nuts <time-nuts@lists.febo.com> wrote: > > The thermal fuse in my 10811B oscillator has opened. Troubleshooting > results say that the oven is ok, but I do need to replace the fuse and > cannot find any information about it. The manual says the Mfg. number > was 2110-0617, and the HP part number was 10811-80008. I am guessing > something on the order of either 1/2 A slow-blow or 1 A regular fuse. > Can anyone provide any guidance as to the proper fuse? Also any thoughts > as to why it failed would be appreciated. It is part of a home-brew > GPSDO, mounted in a case right next to ventilation slots. > > John W2TX > _______________________________________________ > 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

time-nuts@lists.febo.com

HP-10811B thermal fuse

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)

I seem to recall HP's official recommendation is to remove the fuse and substitute it with a simple jumper. I think there is a bulletin for this. (which I cannot find now)