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EIP 545B Frenquency counter
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HighPrecision:

--- Quote from: Guile on May 19, 2018, 11:43:43 am ---@HighPrecision: I owe you a beer!! If you're coming in Nice one day let me know I'll fulfill my promise then :)

Cheers

--- End quote ---

Hi Guile,
Good! I'm glad to know that it has completely solved the problems.
Ash:

--- Quote from: HighPrecision on May 19, 2018, 05:45:24 pm ---
--- Quote from: Ash on May 19, 2018, 08:09:28 am ---Do you know of any service documentation that better matches my model?

--- End quote ---

Hi Ash,
best available match is the 545A manual for CCN:2205, all cards, except A103 and A104, are pratically the same part number suffix (revision), I've uploaded here:

https://www.dropbox.com/s/hmu2vq9ew4fcaun/545A-548A_Manual_5580021-04_Apr83%20%28CCNs%202205%20and%202305%29_2nd%20Ed.pdf?dl=0

For A103 and A104 cards please refer to the available 57xB manual.

--- End quote ---

Awesome, thanks @HighPrecision! That helps a lot.

Now I've just got to find the time to do some playing around with it..  ::)

Ash.
Guile:
Hi guys,

I'm looking now on how to calibrate the power meter with the limited equipment that I have and then I've tried to read out the calibration data from files available online and also from 548B counter to see how I could interpolate the results over the entire range of the counter.

Thus I've attached the comparison results between 3 devices.
It looks like that a 2nd or 3rd order polynomial calculation could work well for the power level calibration at 2Ghz. However, the Frequency spread looks like more difficult to interpolate. At least I'll try once I'll have time and let you know how it goes.

By the way, at 2Ghz, with the data coming from the 548B counter I have 3dB of offset ; and as indicated by the Frequency chart spread, this offset varies over frequencies...

Cheers
Guile:
Hi Guys,

I'm providing some update regarding to the power meter calibration.
I've decided to use my signal generator with a 20dB attenuator to calibrate the first 150 power values at 2Ghz. Indeed, my power meter is reliable down to -20dBm and it looks like that I need to go down to -40dBm in order to calibrate nicely at 2Ghz. Hence, as my signal generator is able to deliver from +10 to -20dBm I'll use the 20dB attenuator for the lower part with my power meter to confirm that I'm running at the right level before attenuation.
However I'm not able to go above 8Ghz and after 3.8Ghz my power source is no more leveling the signal. Then I can set something around -15dBm with various attenuators, but I'll not be able to calibrate above 8Ghz. That's the reason why I tried first to find a polynomial model to interpolate the calibration values up to 20Ghz, but without a success.
Then I've moved to machine learning with Gradient boosting algorithm and it looks like to give reasonable estimation (I've attached the estimation with different parameters in yellow; the red curve is the prediction based on one EIP545A meter eeprom dump while the blue one is the prediction based on one EIP575A meter eeprom dump. The yellow curve is the prediction combining both). Hence once ready I'll explain more the theory I'll use. But I need first to fix my EIP again as I'm no more able to read a thing from GPIB while writting works partially. Maybe a bus driver is faulty on the A101 board ( |O )

Cheers

HighPrecision:

--- Quote from: Guile on June 02, 2018, 10:56:10 pm ---But I need first to fix my EIP again as I'm no more able to read a thing from GPIB while writting works partially. Maybe a bus driver is faulty on the A101 board ( |O )

--- End quote ---
Hi Guile,

if the interface don't respond at normal commands probably is a HW fault, BUT if you are not aware of these (E)EPROMs that have a limited number of WRITE cycles, apparently the Xicor type X2816A listed on 575B manual have approximately 500K/cycles estimated from new.
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