HP 5061A Cesium Beam Std
Hello Time Nuts Friends,
I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube may be bad. The ion pump meter pins out and never comes down to a reasonable level. I don’t have an external HVPS to check the tube as suggested in the manual. I’m thinking the worst here… that the tube is probably bad. The seller listed it “For Parts” and the usual “I have no way of checking it.” Fortunately, he has a 14 day return policy. He’s offered me $400 to keep it. I have $725 in it.
My question to the group is… are there replacement tubes available? Any suggestions on what to do with it if I can’t get a replacement tube?
Thanks in advance,
Dave Smith / W6TE
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Dave,
The 'value' of the unit may be that of the 'parts'. Are there any options?
I have nine 5061A'a and B's and it has been my experience that if it has the 'High Performance Cs Tube', option 004, it likely has a dead tube.
If it has option 001, 002, or 003 (clock, battery backup, or both), there is likely some additional 'value' in the unit from the perspective of 'spare parts'. Absent option 004, the tube might be 'resurrectable' if you have the proper equipment, including a HV power supply capable of 4KV+ voltage with appropriate current. Even if so, the 'survival' after the 'resurrection' might be very limited.
I have a unit that I am able to resurrect with an external HV supply of about 5 KV over a couple of days but, eventually, it becomes 'non-op' as the ion pump 'pegs out'. Not completely sure that this is not a failure of the A18 assembly.
If there are 'spare' tubes available, I would love to hear about them.
Hope this helps.
Joe
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of David Smith
Sent: Thursday, February 09, 2017 7:22 PM
To: time-nuts@febo.com
Subject: [time-nuts] HP 5061A Cesium Beam Std
Hello Time Nuts Friends,
I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube may be bad. The ion pump meter pins out and never comes down to a reasonable level. I don’t have an external HVPS to check the tube as suggested in the manual. I’m thinking the worst here… that the tube is probably bad. The seller listed it “For Parts” and the usual “I have no way of checking it.” Fortunately, he has a 14 day return policy. He’s offered me $400 to keep it. I have $725 in it.
My question to the group is… are there replacement tubes available? Any suggestions on what to do with it if I can’t get a replacement tube?
Thanks in advance,
Dave Smith / W6TE
Sent from Mailhttps://go.microsoft.com/fwlink/?LinkId=550986 for Windows 10
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.
Search the list for what Paul and I did. There is a web page where someone
did the same forced pump down. If all the voltage s are good you have
nothing to loose. You are going to need a "real" high voltage source.
On Feb 9, 2017 6:01 PM, "David Smith" w6te@msn.com wrote:
Hello Time Nuts Friends,
I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube
may be bad. The ion pump meter pins out and never comes down to a
reasonable level. I don’t have an external HVPS to check the tube as
suggested in the manual. I’m thinking the worst here… that the tube is
probably bad. The seller listed it “For Parts” and the usual “I have no way
of checking it.” Fortunately, he has a 14 day return policy. He’s offered
me $400 to keep it. I have $725 in it.
My question to the group is… are there replacement tubes available? Any
suggestions on what to do with it if I can’t get a replacement tube?
Thanks in advance,
Dave Smith / W6TE
Sent from Mailhttps://go.microsoft.com/fwlink/?LinkId=550986 for
Windows 10
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.
For a tube which has not been powered up for a long time it can take days or weeks for the ion pump to bring the vacuum back to a normal state.
Replacement tubes are available but they are breathtakingly expensive on the order of 22k
It's a crapshoot with old Cs tubes but for $400 I'd be inclined to keep it and acquire over time the items needed to support it like HVPS etc
Content by Scott
Typos by Siri
On Feb 9, 2017, at 8:21 PM, David Smith w6te@msn.com wrote:
Hello Time Nuts Friends,
I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube may be bad. The ion pump meter pins out and never comes down to a reasonable level. I don’t have an external HVPS to check the tube as suggested in the manual. I’m thinking the worst here… that the tube is probably bad. The seller listed it “For Parts” and the usual “I have no way of checking it.” Fortunately, he has a 14 day return policy. He’s offered me $400 to keep it. I have $725 in it.
My question to the group is… are there replacement tubes available? Any suggestions on what to do with it if I can’t get a replacement tube?
Thanks in advance,
Dave Smith / W6TE
Sent from Mailhttps://go.microsoft.com/fwlink/?LinkId=550986 for Windows 10
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.
Search the list for what Paul and I did. There is a web page where someone
did the same forced pump down. If all the voltage s are good you have
nothing to loose. You are going to need a "real" high voltage source.
That may have been my page here: http://www.ke5fx.com/cs.htm
Bertan HV supplies are reasonably common on eBay for less than $50. Worth a try before giving up on the tube.
-- john, KE5FX
Miles Design LLC