elektronik

Lötstation ZD-917

Spurtikus
Einfache Löt- und Entlötstation. Gekauft vor ungefähr 10 Jahren. Funktioniert sehr gut. 03/2022 wurde der Lötkolben nicht mehr warm. Vermutlich Heizelement defekt. Das Gerät zeigt direkt nach dem Einschalten kurz “u01” an, evtl. eine Firmwarenummer. Am Lötkolben-Stecker sind 4 Kontakte, zwei für den Thermofühler (rund 2,4MOhm bei 25°C) und zwei für das Heizelement. Ich messe am defekten Kolben 2,2 Ohm. Meine Vermutung ist, dass das Element einen inneren Kurzschluß hat. Es handelt sich um einen 24 Volt / 60 Watt Lötkolben.

Teardown of a Multimedia Color Monitor TM-7003A 7 Inch

Spurtikus
This monitor is from automotive area. On the case, we find the name Multimedia Color Monitor TM-7003A. I saw that this display was sold under many different names and brands. Panel: Hannstar 721q310c35-a0, 7 Zoll, 480x234, mit Touchscreen 26 pin. Not a parallel RGB input display. This display has three pins for R,G,B analogue input and several inputs for horizontal and vertical syncronization. I would say this is something like old VGA data.

Teardown of a 9 Inch automotive monitor with Toshiba TFT panel

Spurtikus
This monitor is from automotive area. Panel: Toshiba LTA090B400F 9 Zoll, 800x480, 6 Bit RGB (parallel RGB) 40 pin, 0,5mm pitch connector Front. I already had opened it and all the switches fell out. Back Back cover removed. We see at the left the custom controller for the monitor, at the right the HV section fort backlight. At the bottom a small PCB can be seen for switches and A/V connectors.

Teardown of a Navilock 8 Inch touchscreen panel

Spurtikus
This monitor is from automotive area. It has a touchscreen, and a low resolution of 640x480, I suppose it is an older one, maybe more than 10 years old. Panel: Sharp LQ080V30DG01 8 Inch, 640x480, 6 Bit RGB (parallel RGB) 32 pin 0,5mm pitch connector Front Back Back cover removed Panel connector Monitor PCB removed. We see the pure panel with its controller. Panel controller. Touchscreen controller removed from main PCB

Converting a DEC Keyboard LK401 to an USB Keyboard

Spurtikus
DEC Keyboard LK401 has serial interface, 4800 Baud, 8N1. See more information on the keyboard hardware here. The keyboard is solid and heavy, has superb tactile keys and is of the old 80ies quality. That you simply cannot order on Amazon or so. For a long time, the keyboard was supported by the Linux kernel, but this time is gone. My idea: connect the keyboard to a microcontroller that can connect to a PC via USB.

DEC LK401 Keyboard

Spurtikus
This keyboard came in as part of a Digital DEV VT402 terminal. I have some information on that terminal here . After some time, I found that the keyboard of that terminal is also an interesting kind of thing. DEC LK401 Hardware DEC Keyboard has a serial interface. The connector to plug into a DEC VT420 terminal looks like an old telephone connector, with 4 pins, called RJ10. An Intel 80C51 microcontroller handles most of the keyboard functions We can see also the Beeper and a 7.

Experimenting with an old FM tuner

Spurtikus
I tried to buy a variable capacitor via ebay. What I got was the variable capacitor together with a small metal box. The box contains a FM tuner. It contains two germanium transistors AF121/AF125 and it seems it is from the 1960ies. (click to view larger version) This picture shows the variable capacitor, forming the base for the FM tuner. Metal box has been removed. I was not able to move the shaft/axis of the capacitor.

Modulation and Demodulation - HF-Probe

Spurtikus
When searching for a scheme for a HF probe, I found a good working solution at https://elektronikbasteln.pl7.de/signalverfolger-fuer-nf-und-hf-selbst-gebaut . The scheme uses two germanium rectifiers and looks like this: (click to view larger version) My hand drawing, a better image can be found on https://elektronikbasteln.pl7.de/signalverfolger-fuer-nf-und-hf-selbst-gebaut I tried that HP probe schema with good results. The original uses 2 diodes AA118, I have used AA143. In the next images, we can see a 25 MHz signal, AM-modulated with a 1 KHz signal.

Tube Meter Heathkit IM-18D

Spurtikus
Since the 1950ies, Heathkit produced tube voltmeters. The Heathkit IM-18D is one of these, more from the 60ies, but I do not know the exact production year of my device. Heathkit sold these devices as kits. So you got all parts and soldered it all together. Also calibration was left to the buyer. You can compare this tube meter with my Heathkit V-7A, which is about 10 years older but very close…

Tube Meter Heathkit V-7A

Spurtikus
When buying my Heathkit IM18D (see here), I got this meter for a few more bucks. It was very dirty and was sold as not working. Also, someone has poured some silver paint over the poor device… Heathkit V-7A after some cleaning (knobs were in dishwasher when I took that photo) Some strange kind of line connector was found (this is a DIN connector, and I suppose someone had a cable that was used to put 230 volts in here…)