Products > Test Equipment
EIP 545B Frenquency counter
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Guile:
Hi HighPrecision,

Thanks for your helps!
Right, the interface hardly respond to command and does not send back data when asked. That's weird as it was working great previously. I don't know how many times the EEPROM has been written but for my case I've written the 531 values only once, thus I don't think the EEPROM as suffered from this task (even if I still don't understand why it has wiped some of the YIG calibration data out).
I'll have a look at the A101 board as soon I have time.
Regarding to the calibration interpolation I'm planing to use, I'm more and more considering to calibrate the power level of the counter up to 3.8Ghz and use the interpolation up to 20Ghz. Then, I'll test the other frequencies up to 8Ghz (which is the maximum I can reach with my equipment) to have an idea of my interpolation function error... I'll be able to say if this idea is good or not :)

Cheers
Dave Cawley:
I think this is a relevant thread ?

I have an EIP 548A option 02, 06, counter that I have not used for about 15 years.

Today it would not do anything apart from some digits on the LED's.  Turned out the 12V line was a dead short on the +12V line on A107.  Fixed that (shorted tantalum by the edge connector) and it works at least up to 2.7Ghz (as far as I can generate right now).

However it is stuck on Band 3 and apart from the the offset button that sort of brings up the power meter, none of the other buttons seem to work, including test functions.  I would really like the power meter on/of  and the band buttons to work !  I seem to remember the band switching was always difficult.

I'm an analogue only engineer but have determined that the keypad is working with row and select going into the relevant chip, but then I'm stuck, any help greatly appreciated.

Thanks

Dave
wn1fju:
While it does sound more like a digital problem, you never know.  On my similar EIP 578 counter, there were 15 shorted tantalums!!!  Most of them
were the 10 uF jobs.  Carefully check ALL the power rails and check for any tantalums that are used for other purposes than filtering the voltages coming
on to the board from the power supply.  It shouldn't take much time and you might get lucky.
Dave Cawley:
All the power supply voltages are good.  I'll try all the other tants tomorrow, but see below :

I need to know what comes out where and especially what does the MC68B21 do and what should I see on its outputs ?

Thanks
Dave G4IUG
HighPrecision:
Hi,
the manual explains logic of keyboard scan, see A110 and A111 boards section, see also the troubleshooting chapter for keyboard problems.

If the 'Offset' button (Power-Meter Offset ?) is the only responsive button seems that the 'Keyboard Interrupt' circuit is locked by a low level from a single or more 'columns' lines... apparently your 'Offset' switch seems to be stuck closed or is leaking.
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