[time-nuts] hp5061a/b no I beam current

[wa1zms]

I used the LF coil to test for beam I when I found a used tube. I was  
able to confirm it had "Cs emission".

-Brian, WA1ZMS

On Oct 19, 2009, at 10:28 PM, service at frequencystandards.com wrote:

>
>>   3. hp5061a/b no I beam current (paul swed)
>> Message: 3
>> Date: Sun, 18 Oct 2009 12:25:30 -0400
>> From: paul swed <paulswedb at gmail.com>
>> Subject: [time-nuts] hp5061a/b no I beam current
>> To: time-nuts at febo.com
>> Message-ID:
>>    <ac803ca80910180925y78cf028ai31e6560554264d62 at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Lets see if this works.
>> I am new to the time-nuts user group
>> Just obtained a HP 5061a CS standard. Pumps down very well to 0  
>> (Hard to
>> believe) But it did.
>> CS oven comes up to temp. But in operation no I beam current.
>> Noticed that the tube states -2083V multiplier. But its regulating to
>> -1606V
>> can adjust to 2083.
>> Still no current. Also no 2nd harmonic but with No I that's what I  
>> expect.
>> Its an interesting unit from the naval observatory.
>> I have the traditional 5061 a service manual. Its halfway between a  
>> A and
>> a
>> B unit.
>> As example A15 power reg is using ICs and I found a website with that
>> schematic.
>> The CS control board A11 also is using ICs at least 3 switching  
>> supplies
>> us
>> SG3524s
>> I would like to see a schematic of this if anyone has it. Though I  
>> suspect
>> that the CS board is fine.
>> I want to check several of the voltages though.
>> Any help would be appreciated.
>> Thanks
>
> Paul, there are several different versions of the A15 board. To get  
> the
> correct schematic, you will need the part number which is etched on  
> the
> board. It will be something like 05061-6199. The series number will  
> also
> help. It may be on a sticker lable or etched, depending on the age  
> of the
> board.
> The A11 module also has more than 1 version. 05061-06144 is the last  
> one
> if my memory serves right. Hopefully you don't have one with several  
> round
> epoxied transformers on it with lots of taps. If you do, that means  
> you
> have the old AC controller. You can probably tell that just by  
> listening
> for the whistle of it. The DC ones don't whistle. Since you said the  
> Cs
> oven comes up to a normal meter reading, you are probably safe in  
> saying
> that A11 is OK.
> The first key though is to make sure that the 5Mhz oscillator is on
> frequency. If it is very far off, you will not get 2nd harmonic or  
> beam
> current. If you are off even 1/2 hz, it is too much. I usually try  
> to get
> them within 3 millihertz before look8ing for beam current. Be careful
> turning the coarse frequency adjust, it only takes a small fraction  
> of a
> rotation to make a very large frequency change. You can twist them  
> off if
> you try to turn too hard and are at the end of the adjustment range.
> There are several sites hosted by Time nuts members that have  
> manuals for
> the 5061 scanned in. I dont believe any of them charge you to  
> download a
> copy. Don't remember off the top of my head which sites they are.  
> Try to
> find one as close to the series of your unit as possible. If not  
> exact, go
> for the next series up as they contain backdating info in all of  
> them. If
> you aren't familiar with finding the series, it is the first 4  
> digits of
> the serial numbers on the back of the unit. This does not mean all the
> modules in the unit are this series, it is just the series of that  
> unit.
> Let us know how you make out.
> Chuck Norton
>
>
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