The development of a 455 kHz IF-filter test and measurement setup
Over here the index page with links to lots of information about the long way to come to a hobby test setup to measure very accurately 455 kHz IF filters, up to -100 dB deep!!
|© PROJECT ENGINEER:
WALTER - PE1ABR.
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The long story (with lots of images) about the development history
The more clever Wandel & Goltermann adapter plug, CF1 mode to BNC
There is some screening and a switchable ground.
The spin-off: the 455 kHz IF-transformer setup
The page with lots of measuring results and manufacturer datasheets in PDF
An empty example XLS with all the graph engines and all modified Excel settings.
Direct open by clicking is useless.
Therefore, choose "Right mouse" and "Save target as" for a usefull local save.
The empty fill-in sheet in PDF to write down a complete measurement set of figures
(download from slow Homeserver)
The input and output terminating resistor table in PDF
(download from slow Homeserver)
|Here are some documentation links of Wandel & Goltermann equipment used by me. |
Copies of PDF files also available elsewhere on the web or versions edited and / or polished by me.
Scan of pencil scraps from a reverse engineering attempt of a very old SPM-2
This is a fairly limited device with missing (narrow) bandwidth and also limited sensitivity.
A tracking generator is not possible without your own mixer additions. On closer inspection (SPM-3 available) it also proved quite useless.
Scan of pencil scraps from a reverse engineering attempt of a very old SPM-3
This is still equipped with old Germanium transistors.
This was my first SPM that I could really work with. (double intermediate frequency for better and much more sensitive narrowband measurements). There were several faults in this device before I could use it. A.o. broken pot core threads. The input Z switch also remained defective, only 5kOhm-In works, that is no problem here.
The complete book belonging to the level meter SPM-3 with Silicon transistors
Please print the "large sheets" on A3. 41 MB!
The complete book belonging to the signal generator PS-3 with Silicon transistors
Please print the "large sheets" on A3. 50 MB!
I could buy a nice SPM-30 with an extra PSE-30 tracking oscillator module from a fellow amateur nearby for a low price. I am very happy with it.
After making an extra backlight option for use under limited light conditions it was found that the current limit in the power supply activated too early. High unstabilised Voltage changes with varying settings. The cause turned out to be very silly! A very low voltage zener was soldered the wrong way! So 0.7 V ref, instead of 1.5 V
(old version "C-series" circuit with D9 / D10, later versions with 2 standard Si-diodes. The service error made is understandable!)
In the PDF a manual from Jim's web, M0BMU. Recommended: Despite the naming, print ALL on A3.
A "datasheet folder" from the web about the SPM-30 and SPM-31 instruments. Stripped of annoying watermarks
Yet another SPM-30 description / manual. This one is without schematics.
Yet another SPM-30 description / manual. This one is the schematic appendix.
Yet another appendix. This is the schematic part for the SPM-31.
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Compilation by Walter - PE1ABR - 2021-02-12