DIY Storno Type C32 A radio test station 1968 teardown
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- čas přidán 11. 09. 2024
- i think it is from 1968-1978, please correct me if you know better,
it was made by Danish company Storno most likely internal test system or repair station for VHF mobile radios.
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#diyelectronics
#teardown
#repair
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I use auto generated subs, i am sorry there are a few spelling errors,
maybe one day they can do it better..
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(Thanks to all my Sponsors / Traders / Swappers / Sellers / Buyers, without your support and constant flow of cool items in/out, none of this would be possible)
I ws contacted by a REAL expert in this unit, here are the comments I got, thanks a lot Sven.
I was employed in Storno's instrument department from 1980, from approx. 1983 as head of the department...
C32 is a test box for the CQF/M600 series. It was used both in the factory and in service workshops. You connect the CQM/F to the multi-socket on the right side, to that power supply, measurement transmitter, wattmeter, etc. year approx. 1962 and a decade ahead.
In the video we see:
0:30 frame is floating in a CQM, and therefore it can be used in cars with both plus and minus for frame. If there is a wrong connection from e.g. plus to frame, then one of the lamps lights up. It could happen that the radio got plus on frame in a minus on frame car, and then all the power that the car's battery could supply ran through the screen of the antenna cable to the antenna on the roof, and the screen glowed up in an instant and burned the interior. Hence this test.
0:45 switches for the two voltmeters, including the HF probe, which you don't have. It is available in two versions, either the 'dog whistle' or a square block, both in DC and AC versions. The pointer instruments are stuck, but you've probably seen that.
1:55 It is definitely not a DIY project, but a top professional measuring instrument…
4:08 The cement resistors of 0.20 ohms are measurement shunts for current consumption measurement - and the number identification are internal Storno numbers from the instrument department. The prints are laid out by hand by my old draftsman/documentation man Preben Haunstrup Beyer.
7:18 Excellent coax relay, up to 500 MHz. I have a few lying around.
9:36 The small extra board is the LF speaker amplifier from the CQM600. If you turn the print a little more and look at the heat sink from the other side, they will see why the heat sink is called the 'fox terrier'!
10:00 The three tone generators use an NTC resistor as a stabilizing element, as you also say. It is an STC R53 NTC thermistor, which is excellent for that task and which is now unavailable. Watch out for them! They can also be used for HF power measurement in a bolometer bridge.
12:15 No, it's not a receiver, but two MF generators at 455 kHz and 10.7 MHz for tuning the intermediate frequency and discriminator. You will probably correct this yourself a little later, when you pull the 10.7 MHz crystal out of the socket.
Capacitors have a date code of batch 1k of year 1, so week 19 of 1971 as manufacture. The transistors look like 1965, and the Motorola transistors in the power supply look to be around that era, so the likely date is early 1970's, probably no later than 1975, as the stock of 1965 2N3055's would have been long gone by then. Yes built from products off the line, the 2 IF units in the can are selected, probably using PIN diodes, and you select which IF you are going to use to drive the audio amplifier, with a single RF input of that from the separate receiver, or from unit under service or alignment, and this then fed out as audio via an unscreened wire to the repurposed amplifier. Going to guess the cooked board was an IF out buffer, and somebody selected to use it as RF in, or transmitted via a set connected there by accident (many wires, and easy to make a mistake when only thing is a small identifier on the end) and the 10W of RF cooked it.
then set aside for repair, and then somebody needed a fuse, and this one was open, so grabbed a fuse from it, and then somebody else needed the power supply, so it vanished, and so it landed in the basement. One of those many "I will got to it as soon as...." projects, interrupted by a silent key.