Re: [time-nuts] 5060A question
From: Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] 5060A question Date: Tue, 08 Jan 2008 20:56:14 +1300 Message-ID: [EMAIL PROTECTED] Dave Carlson wrote: Hello, Since the source of the noise is the vibration of the Hot Wire Ionizer ribbon inside the CBT it will require using something other than pressure on the outer container to snuff it out. The outer steel of the CBT is rigid. Dave Which is why it transmits the sound so well. Its not the pressure but the acoustic damping. However material which has high acoustic damping also tends to be a good thermal insulator, so care must be taken to avoid overheating components. Agree. The idea isnt so much to stop the ribbon vibrating but attenuate the transmission of the vibration to the surrounding structures and ultimately the air. Indeed, this was my point. A correctly sized and located acoustic resonator with appropriate internal damping can help by absorbing the sound caused by the vibration. The fixed frequency suits our purpose here. In the land of EMC there are there ways to reduce interference: 1) Make the transmitter less efficient 2) Make the transmission path less efficient 3) Make the receiver less efficient For this case, 3 is clearly out of the question, but there are certainly alot of options in rule 2 (which can be seens as rule 1 depending on where you draw the boarder between transmitter and transmission path). Cheers, Magnus ___ 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.
Re: [time-nuts] 5060A question
Thanks to everyone who gave me feedback about the 2KHz whine from my HP-5060A. It appears to be the nature of the design and I'm not quite willing to try and re-design the oven controller to convert it from 2KHz AC to DC. I guess my 5060A will continue live in the back room where it's not heard much. -Brian, WA1ZMS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Frequency Standards Services Sent: Wednesday, January 02, 2008 1:21 PM To: Time Nuts List Subject: Re: [time-nuts] 5060A question This was one of the reasons that HP eventually went to the DC oven controller. Even the early 5061A had this same problem. The 5060A and the early 5061As had an AC oven controller. When they changed to the DC controller, it probably saved a lot of people from insanity. some of the other reasons were the transformer taps that had to be changed when a new tube was installed, parts issues improved design, manufactureability, etc... Chuck 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 ___ 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.
Re: [time-nuts] 5060A question
From: [EMAIL PROTECTED] Subject: Re: [time-nuts] 5060A question Date: Mon, 7 Jan 2008 20:43:55 -0500 Message-ID: [EMAIL PROTECTED] Thanks to everyone who gave me feedback about the 2KHz whine from my HP-5060A. It appears to be the nature of the design and I'm not quite willing to try and re-design the oven controller to convert it from 2KHz AC to DC. I guess my 5060A will continue live in the back room where it's not heard much. Maybe set up a tuned box around it to cancel whine. MVH Magnus ___ 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.
Re: [time-nuts] 5060A question
Magnus Danielson wrote: From: [EMAIL PROTECTED] Subject: Re: [time-nuts] 5060A question Date: Mon, 7 Jan 2008 20:43:55 -0500 Message-ID: [EMAIL PROTECTED] Thanks to everyone who gave me feedback about the 2KHz whine from my HP-5060A. It appears to be the nature of the design and I'm not quite willing to try and re-design the oven controller to convert it from 2KHz AC to DC. I guess my 5060A will continue live in the back room where it's not heard much. Maybe set up a tuned box around it to cancel whine. MVH Magnus Hej Magnus Do you mean an active noise cancellation system?? Bruce ___ 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.
Re: [time-nuts] 5060A question
From: Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] 5060A question Date: Tue, 08 Jan 2008 15:31:17 +1300 Message-ID: [EMAIL PROTECTED] Hej Bruce, Maybe set up a tuned box around it to cancel whine. MVH Magnus Hej Magnus Do you mean an active noise cancellation system?? No, you could do that too, but I was basically refering to a simple box tuned in size to cancel at 2 kHz. Toss in a thick cloth for additional resistive damping. You could even go Helmholtz if you want. Simple passive cancelation. Classical acoustical approach. For 2 kHz it is in reasnoble sizes. Another thing is to put heavy lead-rubber on the metal faces to make them less of a resonator/radiator. That mod can be done inside the box. There are a whole bunch of other tricks. Pressing on the surfaces of the whining chamber will make it stiffer and provide a higher acoustical impedance. Pressing using rubber blocks, from say silicon rubber, is known to work. Cheers, Magnus ___ 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.
Re: [time-nuts] 5060A question
Magnus Danielson wrote: Hej Magnus Do you mean an active noise cancellation system?? No, you could do that too, but I was basically refering to a simple box tuned in size to cancel at 2 kHz. Toss in a thick cloth for additional resistive damping. You could even go Helmholtz if you want. Simple passive cancelation. Classical acoustical approach. For 2 kHz it is in reasnoble sizes. Another thing is to put heavy lead-rubber on the metal faces to make them less of a resonator/radiator. That mod can be done inside the box. There are a whole bunch of other tricks. Pressing on the surfaces of the whining chamber will make it stiffer and provide a higher acoustical impedance. Pressing using rubber blocks, from say silicon rubber, is known to work. Cheers, Magnus Hej Magnus Its a pity that the old rho-c impedance matched high dissipation rubber method only works under water. Bruce ___ 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.
Re: [time-nuts] 5060A question
Hello, Since the source of the noise is the vibration of the Hot Wire Ionizer ribbon inside the CBT it will require using something other than pressure on the outer container to snuff it out. The outer steel of the CBT is rigid. Dave - Original Message - From: Bruce Griffiths [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, January 07, 2008 9:58 PM Subject: Re: [time-nuts] 5060A question Magnus Danielson wrote: Hej Magnus Do you mean an active noise cancellation system?? No, you could do that too, but I was basically refering to a simple box tuned in size to cancel at 2 kHz. Toss in a thick cloth for additional resistive damping. You could even go Helmholtz if you want. Simple passive cancelation. Classical acoustical approach. For 2 kHz it is in reasnoble sizes. Another thing is to put heavy lead-rubber on the metal faces to make them less of a resonator/radiator. That mod can be done inside the box. There are a whole bunch of other tricks. Pressing on the surfaces of the whining chamber will make it stiffer and provide a higher acoustical impedance. Pressing using rubber blocks, from say silicon rubber, is known to work. Cheers, Magnus Hej Magnus Its a pity that the old rho-c impedance matched high dissipation rubber method only works under water. Bruce ___ 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.
Re: [time-nuts] 5060A question
Dave Carlson wrote: Hello, Since the source of the noise is the vibration of the Hot Wire Ionizer ribbon inside the CBT it will require using something other than pressure on the outer container to snuff it out. The outer steel of the CBT is rigid. Dave Which is why it transmits the sound so well. Its not the pressure but the acoustic damping. However material which has high acoustic damping also tends to be a good thermal insulator, so care must be taken to avoid overheating components. The idea isnt so much to stop the ribbon vibrating but attenuate the transmission of the vibration to the surrounding structures and ultimately the air. A correctly sized and located acoustic resonator with appropriate internal damping can help by absorbing the sound caused by the vibration. Bruce ___ 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.
Re: [time-nuts] 5060A question...
In message [EMAIL PROTECTED], [EMAIL PROTECTED] writes : Since I got it working several years ago, my HP-5060A has a rather loud ~2KHz audible whine coming from it. It seems to be a result of the switching power supply in the A20 oven controller module. My units did the same thing, and I traced the sound to one of the two high-voltage supplies and decided that it was probably not worth the trouble... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] 5060A question...
Hello, With reference the 2k noise, this indeed was coming from the circuitry in the A20 Oven Controller. We also had this in early 5061A from the original A11 Oven Controller. Actually this is the Hot Wire Ionizer ribbon inside the CBT being vibrated by the ac current flowing through it. It was resolved ultimately by designing the dc Oven Controller. Dave - Original Message - From: Sebastian Stolp [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, January 02, 2008 1:41 AM Subject: Re: [time-nuts] 5060A question... hi brian, maybe you can aply some tiny pieces of self adheshive lead band (golfer use on putters), or hotglue flat pieces of lead on the side of the modules metal case/ housing, or directly on whatever humms inside the device. this alters the mass that swings and produces the sound. just a thought, sebastian SEBASTIAN STOLP http://www.youtube.com/sebastianstolp -- Office: +41 (0) 56 534.56.26 Goetzhuserweg 165 Mobile: +41 (0) 76 200.00.80 CH-5245 Habsburg Email: [EMAIL PROTECTED] Schweiz/Suisse/Switzerland Google Earth: 47°28'04.15''N 8°10'06.10''E - This message is intended only for the use of the individual or entity to which it is addressed and may contain information that is non- public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication. Thank you. Am 02.01.2008 um 09:47 schrieb Poul-Henning Kamp: In message [EMAIL PROTECTED], [EMAIL PROTECTED] writes : Since I got it working several years ago, my HP-5060A has a rather loud ~2KHz audible whine coming from it. It seems to be a result of the switching power supply in the A20 oven controller module. My units did the same thing, and I traced the sound to one of the two high-voltage supplies and decided that it was probably not worth the trouble... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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. ___ 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] 5060A question...
Gentlemen- Since I got it working several years ago, my HP-5060A has a rather loud ~2KHz audible whine coming from it. It seems to be a result of the switching power supply in the A20 oven controller module. Is it worth my efforts to try and fix the problem or have others already found a solution? The unit lives in the back storage room to try and keep the whine from bothering myself and family, but after all these years it still bothers me. During my initial repairs to get the unit running nothing obvious appeared to be microphonic in the A20 module. The xfms are all potted in epoxy. Do other 5060 owners have the same symptoms? -Brian, WA1ZMS ___ 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.
