mar. 28 août 2018

EIP 545B RF Frequency Counter - Part 6

Band 3 Sensitivity

I have been trying to figure out a bit more about the sensitivity problem described in part 3.

The main problem remains the first YIG sphere that has fall off the holding rod. I have tried to manipulate it with thin wood stick, under my cheap USB …

ven. 20 avril 2018

HP8662A Synthetized Signal Generator - Part 3

This is the part 3 on my series about my HP 8662A Signal Generator, and is about the third main problems I found with this unit, as evocated in part 2: Error 04 is lit and there are some very unpleasant spectrums at some frequencies.

Low Fequency Section

If the …

jeu. 12 avril 2018

HP8662A Synthetized Signal Generator - Part 2

This is the part 2 on my series about my HP 8662A Signal Generator. After fixing the PSU, several more problems needed to be addressed:

  • a few sloppy keys on the keypad,
  • the know did not work at all,
  • and more importantly, some very unpleasant spectrums at some frequencies (covered …

sam. 24 mars 2018

HP8662A Synthetized Signal Generator - Part 1

I recently pulled an HP 8662A I bought a while ago from my cellar. I don't remember exactly in what condition it was advertized when I purchased it, but it was most probably advertized as non working (otherwise it would have been cheap enough, more, what the fun in buying …

mar. 27 février 2018

EIP 545B RF Frequency Counter - Part 5

Thanks to HighPrecision, I've been able to get a copy of an old version of the EIP documentation "Additional Service Information for 5XX CW Counters". It's unfortunately unavailable online, still, it contains a lot of valuable information.

The part dedicated to verifying the Band 3 Microwave Converter (A203) is as …

jeu. 15 février 2018

EIP 545B RF Frequency Counter - Part 4

This part is about my attempt to modify the firmware to "fix" the problem of weird intial setup: a -160MHz offset and a resolution set to 5 digits.

In the previous part, we figured some probable spots in the firware where these default setup configurations might be set.

EPROM checksums …

ven. 26 janvier 2018

EIP 545B RF Frequency Counter - Part 3

Default settings

One of the annoying thing with this 'SPECIAL' edition of the firmware are the default settings:

  • Frequency Offset -160MHz
  • Resolution 5 digits

One of my goals while disassembling the formware was to 'fix' these defaults settings. I was wondering wether they where located in an undocumented part of …

sam. 20 janvier 2018

EIP 545B RF Frequency Counter - Part 2

I've started a discussion on the eevblog forum to gather a bit help for my project. And I did well since a few fellows did help me a lot on some aspects.

I have now been able to run the power meter at full resolution (even if it's very out …

mer. 20 décembre 2017

EIP 545B RF Frequency Counter

I recently purchased a broken EIP 545B microwave frequency counter on ebay. It was very inexpensive (around 150€ delivered), but obviously, non working.

The EIP 545B RF Counter

The device was described as "does not power up", an is clearly not in very good condition. Quite dirty, battered, with the band 2 BNC connector ruined …

ven. 22 septembre 2017

HP ZR24W PSU Repair

A friend of mine had a problem with his (a bit old) 24" HP monitor: the device was working properly, but only for a while (few minutes at most).

Looked like a good candidate for a quick repair, problem being most probably bad caps are so.

The first step was …

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