[Amps] Cal Lab

[Dr. David Kirkby]

Will Matney wrote:
> All,
> 

Hi,
I tried mailing you off-list, but the message bounced with :

Remote host said: 550 Email from your Email Service Provider is 
currently blocked by Verizon Online's anti-spam system.

So it seems your ISP does not like my ISP!

> I wanted to let everyone know I recently finished buying almost everything to set up a calibration lab for hams and others. The price of calibration is too high for anyone to stand,

It's also debatable how many need acurately calibrated test equipment 
for amateur use. With the exception of frequency, I'm not sure what else 
  needs to be accurately calibrated. Frequency is the one thing that is 
quite easy & cheap to do at home anyway.

> so I decided to start this and offer prices that well all could afford. Right now, I will have the following equipment available to use by the end of next month;
> 
> Fluke 760A volt/amp/ohm calibrator which was just calibrated by the military metcal lab.
> 
> Calibration Standards DC-110BR precision voltage calibrator that shows the difference between the meter under test and the standard (differential test) allowing you to set the meter dead on with the standard.


> ESI 230B Guarded Resistance Bridge which will be converted to a precision resistance standard of 1 Ohm - 12 Giga Ohm at 0.01% tolerance.
> 
> A custom frequency standard which is under construction using a HP 10544A high stability oven oscillator that was just checked for aging and calibrated with a cesium frequency standard. I will be building a custom rubidium standard within the next 2-3 months to go with it. Also, I am working on another OCXO standard using a Stanford Research Systems, low phase noise, 10 MHz oven oscillator.

I don't feel a free-running OCXO is much of a frequency "standard" in 
this day and age. You would really need to lock that to a GPS or similar 
to consider it a worthwhile frequency standard in my opinion.

There's quite a bit of data on oscillators like that (particularly HP 
10811A) on leapsecond.com. As you will see, they differ a lot even on 
the same model.

It is not too hard to lock an OCXO to a GPS receiver. Either use 
something like the 'Brook Shera' design (originally in QST I think), or 
buy something like a Stanford PRS-10 rubidium and lock the rubidium to 
the GPS.

And what do you mean by "just checked for aging"? Note aging rate 
changes if the oscillator is switched on/off, so people into frequency 
standards run them 24/7 with battery backup in case of mains failure.

> L and C standards are all I haven't started to purchase yet as there's not too many who have LCR meters to calibrate. I will eventually have these in the future. I am also looking at making some standards for L, C, and R to sell which will be a lot cheaper than the ones available. I have the supplies to buy the components from, it's just a matter of starting them.

0.01% resistors are pretty cheap. I use them in projects some times when 
I want accuracy. Converting from pounds to USD, I reckon they are about 
$7. Not exactly expensive and quite within the range of a ham to own a 
few. Hence I somewhat doubt there is much point selling resistance 
standards.

> If any are interested, please contact me off the list.
> 
> Best,
> 
> Will

Good luck, but I somehow think you will have a hard time convincing 
others to pay for calibration, even if it quite cheap.