| Item of interest |
Information about this item and where used |
|
I have a strange habit of collecting old useless and empty rollerball and felttip pen's.
WHY???
You can make extremely handy, cheap and strong alignment tools out of them.
For every type of coil or IF transformer a special screwdriver made of PCB leftover's or scrap. Please: without the copper!
The ex-pen forms a luxury handgrip!
|
|
Current measurement trick for use in a battery compartment between batteries.
Uses a very thin double sided PCB clad shim.
|
|
A toroid winding help if you are going to use a large number of windings, so a large length of wire.
|
|
HF Aerial signal splitter to feed two radio's with the same signal without mutual interference.
Works from under 100 kHz to over 20 - 25 MHz. Principle like a TV-signal splitter.
Here is the UK splitter drawing in PDF.
Or drawing in a Dutch version in PDF.
Go to the page with more info about this item
|
|
Impedance corrector for old tube radios connected to 50 ohms coax.
UK drawing in PDF
Dutch version in PDF
Go to the page with more info about this item
|
|
Some ideas to make RF sniffers, connected to 50 ohms coax.
Go to the page with more info about this item
|
|
Hexadecial decade bank.
To obtain a low residual capacitance and in one setting a lot of values I do this with a mini hexadecimal (ABCD-)switch on a piece of experiment board. Sometimes with an extra on/off switch added. On it 4 (or 5) sets of C's in ascending values in the ratio 1-2-4-8(-16). You get rather easy 15 or 31-step linear incremental values (and step 16/32 = the value zero).
More info on the ferrite pages. See next items.....
|
|
A very accurate test setup to measure the AL value of toroids.
Go to the top of the Ferrite page and read the whole story over there.
|
|
A very quick (and dirty) setup to measure the AL value of toroids.
Very good method for a first and quick impression of the AL value.
F.i. on hobby fairs and markets!
It is a fast measurement method with a coil meter and a special set of windings.
It gives a direct read-out without (almost any) calculation of the approximate AL value.
Go to the top of the Ferrite page and read the whole story over there.
|
|
A current sucker device
A dynamic and adjustable heavy load for power supply torture.
YES, you read it well, can a power supply be killed, or is it really idiot-proof??
Test power supplies until they tend to oscillate (or not) or to see if the current limit is properly working! And how it behaves in current foldback mode. Also with a pulse input to make repetitive (dynamic) current pulses and to view the effects on a scope.
Here is the simple pencil-sketch of the "current sucker".
|
Sorry,
NO picture
|
An IC audio booster for use in a tube radio without speaker amplifier.
F.i. for use in a Racal RA-17 device.
It works on (doubled and rectfied) 6.3V AC heater voltage!
NO picture, the device has been sold! Click on PDF icon to see the design.
Or:
Go to the Radio-page with more info about this item
|
How to scan old datasheets or schematics to create a PDF.
A very short hands-on.
The WWW is overcrowded with badly scanned B&W documents,
it highly irritates me!
My printed scans are as sharp as the original, or even better!
And still very low in kilobytes.
|
Whenever you use the default settings of every scan_2_pdf program or scanner interface for Black&White (B&W), you probably get very moderate to bad results. Far too low resolution (f.i. default 200 DPI = WRONG!) and much to much kilobytes, due to too many colors or gray-stages. The only proper way is to reduce the color/gray stages to 2, only black and white. The resolution should be as high as possible (permitted by the "kilobytes"), the minimum is 300 and NORMAL is 600 DPI, YES 600!! To reduce the enormous size, lossless compression should be applied, as high as possible = G3 or preferably G4.
This means: NEVER save an intermediate result to JPG, NEVER! Because it is NOT lossless!
So, if you are going to edit to remove smears, save in TIFF-G4. And also NOT in LZW. Later you drag the TIFF in acrobat to make the PDF.
B&W-pictures?? Go to 1200 DPI with reduced flip-over point, NO gray stages for screenpixel (raster) prints! Gray doesn't exist in printed B&W-matter! You only have to scan the finest pixels in pure B&W.
If you scan directly to PDF (from within acrobat professional), take care that the scanner settings are 2-color black&white and 600 DPI, and the B&W flipping point somewhere halfway. Acrobat internally automatically also uses TIFF-G4 compression to obtain the lowest kilobytes at the highest resolution.
NEVER let it reduce to 300 or 200 DPI.
|
|
A very accurate 5x -10dB pad.
For 50 ohm use, totally made in SMD and extremely screened.
Has SMB click connectors.
Works excellent (from DC) to 500 MHz, usable over 800 MHz.
Go to the top of the 5x -10 dB PI-network page and read the whole story over there.
|
|
455 kHz IF filter measurement setup.
Go to the NRD-515 page where the IF-filter problems are described.
The NEW measurement setup page is over here.
Also publications by VERON to be announced (hopefully....).
|
|
IF transformer test setup. A spin-off from the previous item.
To identify the characteristics of an unknown (455 kHz) IF transformer.
Direct jump to the sub page.
|
|
Many TTL-PROM read-out adapters for an Eprom-reader socket.
Suitable for many, many types of TTL-PROMs.
Designed for reverse engineering purposes.
Go to the page with more info about this item.
The TTL PROM list, a special booklet with info and footprints about allmost all old TTL PROM's.
|
|
A 2708 read-only / read-out adapter for an eprom programmer that doesn't support this EPROM.
Designed for reverse engineering, but also upgrade (to 2732) purposes.
Go to the page with more info about this item.
|
|
Functional replacement of a MCM5101 or uPD5101 CMOS RAM.
For use as very low power battery back-up purposes.
Designed to replace blown memory RAM in a JRC NDH-518 unit.
Not blown by man, but by lightning!
Go to the special web page about this project.
|
