David,
I looked in a few tube books I had and didn't see the tubes. I'll look in a few
more to see what I find. I'd about bet they're the same, just a newer version
tube. I'll let you know what I find.
Best,
Will
*********** REPLY SEPARATOR ***********
On 5/16/06 at 1:51 PM David C. Hallam wrote:
>Will,
>
>These tubes are the one used in the tip of the AC probe. HP used the EA53
>or 2-01C diode in the probe for the 410B. They had different filament
>voltages and the meter had an adjustment to change the voltage as required.
>The 410C used the EA53 with no filament voltage adjustment. The USM-116
>used the EA52 which has the same filament voltage as the EA53.
>
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
>Behalf Of Will Matney
>Sent: Tuesday, May 16, 2006 1:18 PM
>To: amps@contesting.com
>Subject: Re: [Amps] VTVM Diodes
>
>
>Being a rectifer, it will most likely work since the pin out is the same
>along with the heater voltage. The tube you have to worry about is the ones
>used in the probes. It will throw it off, and could to a good amount. I'm
>thinking that this model used the acorn tube probes. The rectifier could
>some if the voltage out is raised going to the meter circuits. I'd do the
>tests before and after changing them out.
>
>Best,
>
>Will
>
>*********** REPLY SEPARATOR ***********
>
>On 5/16/06 at 1:08 PM David C. Hallam wrote:
>
>>Will,
>>
>>I am not too worried about the calibration. I am not doing anything that
>>requires traceability to any standard. It is just for my own use. I can
>>calibrate the meter myself close enough for my use.
>>
>>I just was trying to find out if there are any significant differences
>>between the EA52 and EA53 that would kill the idea.
>>
>>David
>>
>>-----Original Message-----
>>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
>>Behalf Of Will Matney
>>Sent: Tuesday, May 16, 2006 12:33 PM
>>To: amps@contesting.com
>>Subject: Re: [Amps] VTVM Diodes
>>
>>
>>David,
>>
>>The tube type differences could be the gain, or voltages, I'm not sure.
>The
>>probes could possibly work, but those are the ones that used an acorn tube
>>in the tip aren't they? Here's the biggest problem. If you change the
>>tube(s), the meter will about sure be out of calibration. What happenes is
>>that as the meter was used from when it was new, the tubes gradually got
>>weaker while the meter was sent out once a year for calibration. Each time
>>it was re-calibrated, it was to the weaker tube signals. When you put a
>new
>>tube in that is 100%, it throws off the calibration. Solid state meters
>>don't do this to that extent. The yearly calibration for solid state I
>>don't
>>think is needed. Maybe every three years, and that's if they're really
>used
>>a lot. However, if a solid state is repaired, it needs to be checked for
>>calibration then unless the part was out of the same batch as the
>original.
>>Even then, there's a possibility it could be off because of the gain
>>difference. The tube meters
>> though really need the calibration over shorter spans over the tubes
>gain
>>dropping over use. How much a new tube could throw it off, I'm not sure.
>>
>>What you could do is measure some standards if you have them, and write
>>down
>>the measured values. Really they don't have to be standards, just save the
>>original parts you used to test back for the last test. Compare these
>>measurements to the ones you get after you replace the tube, and adjust
>for
>>them.
>>
>>Best,
>>
>>Will
>>
>>*********** REPLY SEPARATOR ***********
>>
>>On 5/15/06 at 4:36 PM David C. Hallam wrote:
>>
>>>I am trying to find an AC probe for my HP-410C. I have a probe from a
>USM
>>>116 VTVM. The 410C uses an EA53 diode in the probe and the 116 uses an
>>>EA52. From what I have found on the internet, these two tubes seem to be
>>>similar, base connection, heater voltage, frequency range, etc. Does any
>>>one know if I could use the probe from the USM 116 on the 410C?
>>>
>>>David
>>>KC2JD
>>>
>>>
>>>
>>>
>>>
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>>>http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>>
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>
>
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