I'm not talking about putting a diode where the thermocouple used to be, I'm talking generally about diode-based sensors on these meters. I'm quite aware of the internals, having studied them extensively and designed hardware for that interface.
-Dave
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On 5/19/22 13:22, Lothar baier wrote:
Yes there were diode based models ( 81D , 84A) but the electronics differed from the A/B/H series circuit boards , you can compare the schematics to see that there are differences , its also not just about "working" you can most certainly get something that will read power but duplicating the original specs in terms of linearity and accuracy is a different story
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire via groups.io
Sent: Thursday, May 19, 2022 12:14 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
I have a diode front end for this power meter interface working on the bench. It's certainly possible. And let's not forget that there were already diode-based sensors in that product line.
-Dave
On 5/19/22 12:52, Lothar baier wrote:
Long story short you cant fix the 8481 or replace them with a diode ,
the 848x series was based on a thermocouple that was designed by HP ,
the parts are not available from HP , one guy sells waffle packs of
them on ebay for like $7000 or so but even if you buy them replacing
the part requires a lot of skills and a steady hand , as far as diodes
concerns the output voltage of diodes and the characteristics are not
compatible with the electronics in the 848x
*From:* [email protected]
<[email protected]> *On Behalf Of
*visitslovenija via groups.io
*Sent:* Thursday, May 19, 2022 5:20 AM
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] A homemade diode power
sensor for HP meters
An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and
would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has
anyone successfully reworked one with busted thermocouples and
modified for a diode front end? I know it’s small and very fiddly, but
is that not easier than trying to build one from scratch?
--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA
Dave McGuire