Zerhacker vibrator-replacement module

endeavour

 

Page initiated 11 October 2024

Current status: 20 October 2024

 

Chapter 1    (since 13 October 2024)

Chapter 2    (since 20 October 2024)   

 

AOB: All went today differently then was scheduled for;

the design of this dedicated webpage is engendered from a more or less enfolding confusion,

as we discovered that the available electronic vibrator substitute does not directly

match onto the requirements discovered on our side.

 

It is evident - that when we have been supplied with a modified suitable substitute, in due course,

that we shall start with a dedicated new web-page.

However, this does not imply that what you will encounter on this current page isn't worth to be noticed.

 

 

Quite confusing - when we started was to get a touch what the various schematics had in common

What mainly bothered us, was to understand the newly designed electronic vibrator (Zerhacker) of  "The Crypto Museum" newly designed miniature mother-boards.

At the same time, reconstructing what actually were the principles of the current power-supply schematics.

On the left-hand side of the table, we notice our quite new Foundation board-member Eric Reits.

 

After all we concluded that one of the applications in conjunction with a Feldfunk set was truly conflicting (the true option was not foreseen)

Quite some pain striking deliberations had to be accomplished before we really understood what the various schematics had in common and what was truly conflicting

Our second impression concerns our lively technical deliberations

We discovered some curious unexpected technical aspects which might necessitate some minor circuit alterations.

 

                                                                                Copyright Cryptomuseum.com

This principle was expected by Marc of the Cryptomuseum; though it doesn't match to what is shown in the next schematic

 

It is evident that here the vibrator (Zerhacker) is functioning differently, compared to the foregoing showed principle schematic circuitry

 

 

Now viewing its essential detail within the red circle

When the centre vibrator tongue is touching the left-hand side contact of line 7 than the electrolytic capacitor '32' is being charged with a + voltage polarity

Next we notice the opposite situation

 

Considering now the circuitry inside the green/blue ellipsoid

Again considering what occurs inside the green/blue ellipsoid

The right-hand side vibrator (Zerhacker) tongue (Kontaktzunge) is touching the contact of line '47' and that is minus contact of the electrolytic capacitor C 33 which is being connected onto '0' (after its current passed through choke (Drossel) D 5; which is in most German schematics equalling chassis or ground. But now transformer line 44 is charging capacitor C 33.

The circuitry is thus doubling its output voltage consisting of the charge within C 32 + C 33; C 34 is then smoothing these two voltages to a usable (sound) HT voltage of ca. 90 - 100 V (I suppose).

For the electronic circuit designer might be a bit complicating the fact the line '47' is via resistor W 10 is causing a negative grid voltage of valve Rö 1 (line '4')

 

Ambro is heavily involved in our endeavours too

We luckily possess an additional vibrator pack as well as a complete Feldfunk apparatus, albeit without case, which is a versatile  sample to designate various components.

 

Ambro is considering the schematics of Marc's (Cryptomuseum) electronic substitute

The small electronic dual PCB is actually constituting Marc's newly designed vibrator unit.

What is striking and can't be found by most other designs: is, that it operates reliably from 1.5 V supply voltage onwards; up to ca. 15 V battery supply voltage.

The Al cylinder is the a WGl. 2,4 unit maintained in most German field applications 

This link provides the full Cryptomuseum.com documentation:

https://www.cryptomuseum.com/pub/cm/zerhacker/

 

Later Ambro took a detailed view of what the Feldfunk set is about.

Then I remembered the 1000 µF electrolytic capacitor; which proved, in our set under consideration to possess a capacitance of 1500 µF.

 

Our first approach was straight away testing the capacitance of the 1500 µF electrolytic capacitor

We tested it and measured > 1100 µF how is that possible after 80 years?

Thereafter we made an ohmic measurement and gave curious results.

Finally, we measured the pure current consumption inside the Feldfunk set under consideration.

Fist we measured with a far too high current flow, but after we disconnected a small EW (Iron-hydrogen resistor) (glass-bulb) the current consumption dropped considerably.

It went from a ca. 50 mA to about 300 µA after, say, one hour test.

We cannot say definitely where our measurement session will be conclusive, but the tendency with which the current consumption reduces, that we might measure that this electrolytic capacitor is still operating well after, say, 80 years of age.

How is this possible?

At least from what I remembered from a set I once considered about 1975, thus say about 50 years ago, that my foregoing sample was hermetically sealed-off from environment.

The phenomena we noticed yesterday may be due to the so-called (Dutch language) 'formeren' (restoring?) is that the flowing current is re-processing the Al oxide-skin. A process well known from older electrolytic capacitors.

I noticed the current-flow status when we switched off the power sully (2.4 V).

It might take some time to recover the electrolytic capacitor under test, but we still hope it will do reasonably.

 

   

That the meter pointer of our 'General Radio' RLC bridge is pointing far to the right-hand side is only due to the fact that one bridge section is 'open'; I should have turned off the on-off switch!

As to measure accurately, we used our digital Fluke meter.

The current consumption being measured for simplicity across the filament wiring, but all valves had been removed as we did with the EW (the quite small iron-hydrogen current stabiliser device).

 

 

                                                                                    Photo taken by Eric Reitz with his telephone

The Al tubular device (down on the left-hand side of the Feldfunk chassis/frame) constitutes the 1500 µF electrolytic capacitor; which is hermetically sealed-off from environmentEric

 

                                                                                                                                                        Photo taken by Eric Reitz with his telephone

(all shielding plates removed)

Eric took two nice photographs of the same set, containing much interesting information

Please notice on the left-hand side photo the cylindrical Al device where we just read (quoting): Kapazität 1500 µF ...  Spitzenspannung 5 V Temperatur - 30°C

It truly constitutes a compact module design.

Please notice on the left-hand photo just up the valve-base on the far right-hand side the tubular EW (Iron-hydrogen filled glass envelope device)

Just visible is a label carrying the Dutch Call-sign: PA 0 GAD. Google provides: Gerard Achterberg, Driebergen. He did pass away in 1987.

He or someone must have donated this device, which now is so useful to us.

 

                                                                                                                                        Photo taken by Eric Reitz with his telephone

Finally today I would like to show a photo compilation Eric Reits took of three of our Feldfunk sets on display

The set on the far right-hand side is the set operating in the 10 m spectrum (when I remember well)

Albeit, that the system concepts - in all cases - being about equally.

 

(2 (since 20 October 2024)

 

On 18 October 2024 we continued our survey around our electronic Zerhacker - Vibrator Survey.

 

   Ambro's first approach was to understand fully the implications which we encounter in the electronic Zerhacker-vibrator replacement

As apparently some crucial aspects of the application in conjunction with the Feldfunk b .. c ... f derivates, is forcing at least some thoughts about an optimal adaptation with the existing electronic circuitry.  

 

The Fluke meter indicates an unloaded output of 103.5 volt

Which seemingly might be good, but this output voltage is not yet being loaded.

 

We got Marc's Zerhacker/vibrator prototype device with an attached 2 x AAA type battery-holder supplying thus ca. 3 V

Therefore Ambro decided to consider a variable power-supply.

Which did not yet solved the loaded output voltage problems.

 

At a certain moment Ambro decided to prepare the genuine electronic Zerhacker/vibrator circuitry - with the real transformer of a Feldfunk - b power supply unit, as to measure what actually is happening

 

The blue coloured PVC transformer bobbin is the output transformer

What is essential, is that we prevent insulation errors in the, say, 80 years old capacitors.

The natural (dielectric) wax is very hygroscopic and was already during - or shortly after - the war causing serious capacitor insulation problems.

 

The primary transformer windings connections '41' and '42' being inter-connected with the electronic circuitry end secondary lines '43' and '44' being kept open the electrolytic capacitors C 32 and C 33 (which 100% being defect) do not yet concern in Ambo's current test series

 

Let us consider this photograph constituting an impression only

The green coloured PCB constitutes Marc's electronic Zerhacker/vibrator substitute  

 

Already over-due for quite many years was to get the mounting base for a Lo 6K or L being secured fixed

This most rare mounting frame I did obtain some years ago, but what I did not was aware of was that the 4 table mountings were lacking.

The previous owner did substitute 4 heavy rubber tubes instead.

But the frame was to allow pulling the heavy Lo 6 receiver frames toward outside for, say 25 to 30 cm and considering the receiver weighting about 50 Kg the chassis frame likely will become instable; we prevented this by the implementation of two heavy screws of M 8.

Anton is fixing the special case sockets.

 

  

On the left-hand we notice the fixed mounting frame

Please notice the black tubular sockets

In front we notice the actual receiver module

Separating the receiver case from the receiver eased the actual fixing of the case on top of the mounting frame. 

 

On the left-hand side we notice the Lo6K39 and right of it we notice our Lo6L39 (long-wave) receiver

Why are these mounting frames so most rare?

As always concerning German wartime gear: - the gear being easily removed, but mountings and frame like devices demanded time and often special tools, which most people do not carry around usually; and - in the post-war days the electronic gear was valuable and mountings and that like weren't.

 

Viewing it from a different perspective

 

To be continued in due course  

 

By Arthur O. Bauer

Start