Siemens Shortwave Receiver rel 445 E311 d2 test teardown

[@priestblood]

The blue modules could be OP-amps ,that would be my guess..the blue ones on the relays will be diodes for feedback Protection,number 2 light on the ocxo seems to stay on might need to replace the temp controller. But what a great piece of equipment, I will be keeping a eye out for one .Thanks for sharing stay healthy

[@TeardownOZ2CPU]

i think they might be tiny selenium bridge rectifiers, they always have 5 pins, one fell apart, and it contain tiny washers and a spring, the ones in this unit with less than 5 pins, they just cut the others off

[@andytomm1]

There were no semiconductor opamps at the time this machines were designed. And in any case they wouldn't place them hanging from the relay pins. They are probably selenium rectifiers to quench the sparks generated by the back emf and prolong their life. The service manual is needed here.Agree the "2" oven thermostat need's repair or disconnection so as not to cook the nearby components. The coarse tune knob is there to allow the coarse tuning osc. to lock to multiples of 100KHZ and then interpolate with "fine tune" for more stability and better than 1KHZ frequency readout. They were very fine receivers fully workable today without the bells and whistles. Thank you.

[@Blackbird_Dynamics]

@@TeardownOZ2CPUit’s indeed a selenium rectifier

[@Blackbird_Dynamics]

The glass thing is a mercury thermometer / temperature switch. Controlling a relay that switches the heater on and off. Be careful not to break it. They can also break by overheating if the control relay fails.

[@radiomekaniker1234]

Tror ikke det er et krystal det store lange rør- tror det er en mekanisk oscillator-?

[@kentwolstrup4152]

Den manglende fatning og pære har siddet i serie med antennebøsningen for beskyttelse. Den anden fatning med pære er en reserve.

[@TeardownOZ2CPU]

god pointe, ja det lyder helt rigtigt, og forklare også deres vinkler

[@maxjakobsen5526]

Den ringelyd skyldes er rør der er blevet mikrofonisk. Det er nemt nok at finde, bare et lille dask på rørende med en skruetrækker.

[@kentwolstrup4152]

De små blå 5-benede er selen ensrettere 40V / 2mA

[@TeardownOZ2CPU]

super, ja det var også hvad jeg havde gættet på, nogen der har et datasheet ?

[@pznili]

but you destroy these radios?

[@TeardownOZ2CPU]

why ? would you do that ? if anyone would like to have it, collect it, trade it ? swap to new funny stuff to play with, I clean and fix and document 99% of all things you see in my videos.

[@pznili]

@@TeardownOZ2CPU ah sorry if you repair and refurbish them,. I would be more then happy to purchase some of them if they are for sale

[@jyrijyueseleev987]

Р-250 думаю лучше будет