Both of my hp82341A printers suffer from the same problem: The paper advance is not working properly anymore, as you can see from the picture.
When the paper is not advanced as it should be, the printer writes the lines ontop of eachother. I checked the printer before already, everything looks fine. Thus most likely the Rubber Wheels and the Roller Pinchs are worn out, not soft enough. A replacemenet of Roller and Wheels would be ideal, whoever the service manual doesn't tell any diameters or widths.
So first step is to disassable the printer.
Disassmbling the printer was almost no problem, thanks to the service manual. However, removing the flexible PCB from its connector was quite tricky. hp advices you to take a special tool but naturally this tool is not available. I built myself a tool, just a piece of stiff cardboard.
In August 2015, when I made first tests with my new Red Pitaya I wasn't very satisfied with the measurement results deliverd by the RP. The given maximum bandwidth for triangle and square wave forms wasn't really achievable because the signals measured on PC with the RP scope app as well as on my analog/digital storage scope Philips PM 3250 were seriously distorted.
A couple of month later I verified and modified the test setup:
- Coax cable: Shame on me, I used 75Ω instead of 50Ω cables. The cables are now swapped against new SMA cable.
- The 100Mbit/s switch connecting PC and RP probably was not boosting the performance of the data collection coming back from the RP. Thus I implemented a 1GBit/s switch variant. That was planned anyhow.
- Red Pitaya published an update of their scope/signal generator application, which I installed and used for my second test round.
With these improvements I retested the capability of the RP to produce square and triangle waves up to 10 MHz.
The result: Much, much better this time. The Red Dragonfruit made an excellent impression.
In this blog I describe how I refurbished my hp battery pack 82033A.
In order to run the Printer 82143A or the Cassette Drive 82161A it is mandatory to use this battery pack, that can provide higher currents, which cannot be provided with the standard hp AC power supply.
The 82033A battery pack originally consists of 4 NiCad rechargeable batteries, 1,2 V. Naturally, after more than 30 years in service those batteries are not working anymore. Even worse, some of them are leaking.
The procedure to change the batteries is relatively simple...
Jazzfire is the name of the big band in which I am playing trombone as you can see on the foto. Jazzfire is the "big" big band of the municipal musicschool of the City of Gladbeck. The band consists of about 18 musician and is conducted by Martin Greif, a well known saxophon player, composer and arranger.
We are playing modern big band arrangements of Minzer, Mingus, Herbolzheimer and Co. and of course all the good old swing-classics of Glenn Miller, etc.
"Dance Music" we play for special occasions like company parties, dancing nights and "second-school-final-examination" parties. A lot of more information can be found under www.Jazzfire.de
For a little appatizer you can listen to our music by turning on the music player below. Guess, what song it is...
My wife !! surprised me with a great birthday present - a Red Pitaya.
Red Pitaya is a linux based, open source powered development board. The hardware (14 bit ! ADC, FPGA and much more goodies), is designed to be able to act as a measurement instrument, - for example an oscilloscope, a function generator, a spectrum analyzer. Wow! And it has potential for many more use cases, since it can be programmed by the user. Read more about this project at the red pitaya homepage.
I will mainly use it as measurement tool for electronic designs, repairs, etc.
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