Ferrophon
FERROPHON by LOEWE OPTA - What is a Ferrophon ?
FERROPHON is are audio tape recorders for recordings of very high quality. In order to reach the very highest level of attainable playback quality in every case it is imperative to familiarize oneself with the design features of this instrument. Therefore, it is suggested to the first time user of a FERROPHON to read the following pages carefully.
What are the main design features of a FERROPHON?
The Ferrophon III (the current model) is a dual-drive (two brushless motors) type. One motor, the so-called ‘Audio Motor', carries on its shaft the (exchangeable) ‘Audio Pulley'- drive pulley. This motor alone – no other feature - is responsible for tape speed. Since its Rpms are directly controlled by the main's frequency, variations on the power grid would be the reason for possible variations in tape speed.
This motor also drives the pick-up platter.
The second motor has only one function, the rewinding of the tapes. Its electrical characteristics together with a mechanical Rewind Control provide for a very smooth and fast rewind that is gentle on tapes. Tapes can be spooled back as fast as 1000m in 2 minutes.
This ‘Rewind Motor' is not used to provide drag to the source tape when the system is in the Forward mode. It totally disengages itself from the shaft of the reel platter. The necessary tension on the tape – as explained later – is created in a different manner. This is one of the features of the FERROPHON that is responsible for the smooth and consistent operation of the mechanical part of the recorder. This is true even during the last few meters of tape. The much dreaded ‘howl' towards the end of the tape does not exist; even when reels as small as 7cm of diameter are used.
Reels of maximum 28cm diameter can be used, that is up to 1000m of single layer tapes. Any type of tape may be used.
One of the most significant design details of the Ferrophon are the pick-up clutches as well as the brake of the tape platters.
Tape recordings require a particularly constant and optimized tape tension at the tape heads. The relatively large difference in diameter (about 1:4) between an empty and a full reel offers the greatest challenge towards meeting that goal. This problem has been solved here by using the weight of the reel as it relates to the amount of tape that the reel carries at any given time. Below each reel platter is attached a ‘friction bell' made of steel. The polished inner surface of this bell fits accurately over a carbon cone. The pressure and with it the friction force between bell and cone are relative to the weight of platter and reel. The cone on the right side is motor-driven. It turns the reel platter by friction. During FWD mode the left carbon cone is at rest. Thus it provides the only drag on the supply (left side) reel. This works so well that the variations from the mean tape tension (100g) are not more than 15%.
The actual drive of the tape differs from most other known systems by the. The required friction at the drive pulley is created by a substantial wrap of the tape – nearly 180 degrees – instead of by the use a pressure roller. This eliminates the crawling of the tape on the roller and the ensuing stretching of the tape edges.
The incomparably gentle treatment of tapes and the possibility to play even old and brittle tapes without the danger of breaking them will delight the FERROPHON user ever again
Here is the Ferrophon built for Loewe Opta by Max Ihle, this is only the recording device.
The Audio Motor also drives the pick-up platter. A special drive belt is used. The employed seamless flat-belt sticks so well to the surfaces of the belt pulleys that only very low belt tension is needed. This provides for minimal bearing wear. Tension adjustments if ever required are easily done. In general, parts of the FERROPHON that may be subject to some wear are easily accessible and without any tools. Thus small repairs – should they become necessary – can be done quickly by the user.
Yet another one of the notable mechanical design details is the Quick-Start and Quick-Stop feature. This relates to the platters. In the Forward mode it allows a Start-up and Stop in a fraction of a second – with the motors running. With the way this is arranged threading of the tape is made easy. During Play-back this provides for finding particular spots of the tape easily with previously unknown precision. Worth mentioning at this point is ( please note the time at which this was issued originally. the translator ) the fact that mechanical Starts and Stops eliminate loading of the mains, especially when inverters are in use. Thus voltage and frequency are not affected.
Ferrophon uses tried and proven special heads which make the occasional adjustment of the electronics (due to wear) unnecessary. Separate heads are used for recording and play-back. This allowed for monitoring during the recording process thus providing the increased chance towards a perfect tape.
During RECORDING a small lamp in the heads cover is lighted by the ERASE heads HF current. It warns of unintentional Erasing and also gives an indication of the correct level of erasing current. The latter feature is subjective but effective.
The electrical part of the FERROPHON is made up (in addition to the motor circuits and the spark quenching at the contacts) of a Play-back/ Recording amplifier as well as a HF (high frequency) generator. For recording a maximum of 70V (1000Hz) at high impedance is required. This voltage was chosen since most amplifiers and radio sets can efficiently work with it at their output stages. This suggests an LC or ‘100V Standard' output section. This will result in minimum distortion and low ripple voltage. There are frequency sensitive circuit elements located between the input jacks and the recording head. They pre-emphasize the trebles to compensate for the customary recording losses. The HF (high-frequency) is picked up at the Erase generator. The HF magnetizing bias current is, like the equalizing parameters, is adjustable at the equalizer circuit chassis. Both are preset at the factory.
The replay equalizer is two-phased. Use of a high-impedance replay head combined with the selected circuitry provides a minimum of amplifier-tube noise. Hence there is no audible noise during tape standby. Due to the selected circuit there is only a minimum of vibration interference. Special improvement at the HF circuitry provides the absolute noise minimum on a recorded tape. The usual output voltage when using standard tapes is, at full peak and 1000 Hz, above 0.5 V ( high resistance connection) which is about the same voltage of a sensitive turntable pick up. Due to the relatively low output impedance it is possible to connect longer shielded cables to the outputs.
The Ferrophon can be used with any untuned amplifier for recording and replay without the need for matching-circuits.
The carefully manufactured case should as well be mentioned. For the standard version it is made of massive, aged hardwood which is very stable, even in difficult environments. The Ferrophon chassis can be withdrawn from its case as a complete unit. It can be set down on its aluminum frame, by its shock absorbers.
This is the Ferrophon III c / 3
The device carries the Loewe Opta logo.
A radio reporter in 1951 had to be a strong guy to carry the Ferrophon around. This semi-professional tape recorder of Loewe Opta Radio AG Type Ferrophon III c / 3 was hardly affordable for the non-commercial user. The replay quality is excellent (max. tape speed of 76 cm / sec.) and likewise the used components (a lot of copper parts) which was rare in the early past war years.
Including a match box in the picture helps to visualize the physical size of this recorder combination.
With friendly permission of Technikmuseum - Main - Taunus
How to operate the Ferrophon?
The following manual refers only to the Ferrophon. It does not include references to the recommended amplifiers ZV I or ZV I (L). They are described in their relevant manuals.
Before use check the mains voltage. A voltage of 220V / 50Hz is required. To provide tolerance free use it is necessary to keep a constant voltage and constant frequency, especially if generators are used. The specified tolerance free operating characteristics of the Ferrophon can only be achieved in a stable environment ! Grounding of the set is not necessary but recommended and may only be done using the "Erde" (ground) connector. You have to avoid an 'ground' loop via the NF input feed which may result in unwanted hum. All needed plug sockets are clearly labeled on the connector board. The output voltage is sufficient for each radio set or amplifier with pick-up input. On the Input side it is necessary to gauge the NF peaks since an excess of the 70V maximum may result in signal distortion. Matching auxiliary components are available for use of the additional amplifiers. When the recorder is used for the first time and once the power cord and the amplifiers are connected, the recorder's mechanical functions should be checked out.
The main switch which is located on the left side of the front plate of the set is switched to ON and the function switch on the right side to V (Vorlauf = forward). At this point the right reel platter will start to turn, and on the left side only the small shiny shat cap will turn in a counter-clockwise direction. Now switch the function switch past the H (Halt=Stop) position to R (Ruecklauf=Reverse). Now the left platter will turn clockwise. Its RPM are governed by the position of the knob designated Rücklaufregler (Reverse control). Provided that both tests were successful, return the function switch to H . By pushing the Aufname button verify that HF generator is operational which is indicated at that moment by the red indicator lamp in the cover of the heads. Once this test also has been completed successfully the tape recorder is ready. To make a recording place a blank or recorded tape (on a standard reel) on the platter in such a way that the pickup pins freely pass through the holes in the reel. (For placing the tape on the recorder refer to the following sketches)
According to the sketch the tape is threaded into the machine and one or two loose turns of the tape are placed around the core of the right reel. If at this time a sound signal of 70V is applied (input impedance 60k) to the input jacks and simultaneously the red button is pushed and the function switch is turned to V, recording starts. Any previous recordings on the tape are erased.
When recording off the radio it may happen that harmonics of the HF generator of the recorder interfere with the received station. In order to eliminate the resulting whistle tone one moves the switch designated Frequenzweiche (selective bypass filter) to its alternate position and the whistle tone will disappear.
At this point mention is to be made of placing the tape into the recorder with the correct side. The coated (matt) side always has to be in contact with the tape heads. However, F and C type tapes are shipped from the manufacturer in such a way that the coated side would be away from the heads. A 180 degree twist in the tape between the reel and the left guide roller corrects this without adversely affecting the proper functioning of the set. Generally, but not always, C and F type tapes wrap more tightly with the coating on the outside. In order to simplify working with tapes one should try to store them with the recorded (matt) side towards the centre of the reel. With short tapes this works all the time. LG and LGN tapes must be spooled matt side in. With L and E type tapes (one-layer type) it works either way. However, with L and E it is important that once they have been recorded they are placed on the recorder in the same way as when they were recorded. Otherwise level and treble losses as well difficulties in erasing may happen.
Great care in the choice of tapes is advisable. The user of Ferrophon should be aware of the fact that this device makes possible recordings of such high quality that any potential flaw can only be attributed to the chosen tape material. For best results chose only quality tapes especially do not use tapes of unknown origin. Possible pitfalls are: deposits of tape material on heads and rollers, hissing and background noise in recordings, periodic flaws in the tape which cannot be removed by erasing or recording, poor replay of trebles (piano sounds like the were sand in the keys), tapes do not rest flat against the heads due to aging, tapes cannot be erased, tapes 'copy' but very strong signals across their layers. The latter causes echoes ahead and
After completing a recording the tape may be rewound and played back right away. When 'Cutting' (editing) the tape, repeated gluing of the ends will be necessary. Only the glue provided by the manufacturer for the particular tape is to be used. Incorrect glue will either not stick at all, dry or set too slowly, stick to the neighbouring turns of the tape or in time may promote brittleness of the glue join. Get into the habit of cutting the tape at an angle since this minimizes the possibility of 'hearing' the glue join during playback.
Part of the maintenance of the recording system is the occasional 'demagnetizing' of the heads with the 'demagnetizing coil'. Despite certain design features of the system it is not always possible avoid remaining 'rest magnetism' especially of the recording head. This becomes apparent by the presence of background hiss in a recording. If that happens plug the demagnetizing coil into the mains and slowly pass its magnet back and forth several times in close proximity to the heads' poles. Should that not eliminate the hiss other factors are the cause (usually tapes of poor quality).
Magnetizing the heads can be prevented by setting the recording level with recording system at rest and by adjusting the level to zero or switching off the set before switching between input sources.
Generally adequate air circulation is to be assured during continuous usage. Therefore during extended times of operation complete closure of the covers is to be avoided.
One additional advise in closing: The mechanical STOP is only to be used for the 'Forward' run of the tape. It is not to be used for 'Reverse' since this will put undue stress on the tape.
For the special edition of Ferrophon IIIc, a double-track recorder, special operating instructions are not necessary. In general 'Reverse' is not used. Once the tape has been used on 'one side', the take-up reel is taken off the right platter, flipped over and placed on the left platter. By this process the 'other' tape edge will be placed on the top. This edge which had remained unrecorded on the first pass can now be used. One recognizes which tape edge is in use by the fact that now the wrong side of the reel is visible (on top).
How to look after your Ferrophon?
Ferrophon recorders require very little maintenance. In order to guarantee trouble free functioning for a long time a few preventive inspections should be done especially in the beginning. It is well known that in highly bred mechanical devices small problems may appear during the startup period, which could not be found by the final inspection. It is therefore advisable just as it is during the first few kilometers of a new automobile, to do the following small service items after the first 50 hours of operation. A long time of trouble free service will be the reward.
Service starts already with the unpacking of the set prior to the first startup. Especially transport and incorrect storage can be the cause of minor troubles that are not apparent first-time user. If the outer packaging does not show any obvious damage one can assume that that set has not sustained any damage during transport. The packaging guarantees to a large degree trouble free shipping. The astute reader of the description of the set will remember that the carbon friction couplings (clutches) are an important mechanical element of the Ferrophon. For reasons that are obvious to the novice as well special finishes cannot be applied to the inner machined surfaces of the friction bells. It is therefore conceivable that after extended periods of storage in moist air light deposits of rust may appear. If not removed this may hamper the proper functioning of the clutches during the first hours of operation. If in doubt inspection of the surfaces of the friction bells should be done by unscrewing them. Minor rust deposits should be carefully removed without scratching the polished surfaces. For this purpose use petroleum or very fine but used sandpaper. Lubricant must not be allowed to contact the friction surfaces under any circumstances. Should that happen a sticky paste would form that interefers the correct functioning of the clutches. Some sets especially for overseas are shipped with lightly lubricated bells. Before startup the grease has to be carefully washed off with gasoline. Should some grease have transferred to the carbon cones, they also have to be removed for cleaning with gasoline. In especially bad cases the grease may be burned off using a flame of low heat. Correct functioning of the clutches may be tested touching the running tape. One should not feel any jerks in the running tape.
Before leaving the factory all bearings of the set have been properly lubricated. (See lub plan)
Lubricate per table
Oil all A type locations every 800 hours
Oil all B type locations as required
For this reason new sets do not need lubrication. As much as lubrications for long term use is necessary too much lubrication is detrimental. If with a new set oil has leaked from a bearing it must be removed. Especially the rubber coating of the Tone Rollen is to be kept clean since oil will cause them to swell. This in turn causes uneven run of the Tone Rollen. Greasy fingers will cause the same problem in time. Skin oils on the guide rollers will transfer via the tape to the Tone Rolle.
After some time of operation an initial inspection of clutches, Tone Rolle and head may be in order. The clutches have to function as evenly as on the first day. There should not be any deposits on the friction bells. Dirt buildup on the heads is an indication of poor quality tapes. They must be replaced, otherwise poor treble replay is to be expected. Soiled heads are to be cleaned with a strong brush (under no circumstances are metal screw drivers to be used). The surface of the Tone Rolle is to be cleaned with the motor running by firmly holding a clean rag against it. Tensioning of the drive belt should hardly ever be required. Should it become necessary the tensioning mechanism becomes easily accessible by removing the metal cover under the right tape platter.
Trouble-Shooting Tips:
In order to help the user of the Ferrophon correct minor difficulties without the need of invoking the warranty issue here is a list of trouble shooting tips. Naturally, this is meant as guide only. It is to be used for minor items that will not require opening and/or dismantling of the unit since this would void the warranty.
During Playback:
1) Frequency Variations: if they happen with a perfect tape they may be caused by a sticking or dragging clutch. This causes varying tension of the tape during playback. As indicated earlier in this user guide this may be due to lubricant that found its way onto the surfaces of the 'friction bell'. The reason may be grease leaking from the bell's bearing due to higher than normal ambient temperatures. After removing access grease from the outside of the bearing both parts of the friction bells have to be degreased as explained earlier.
2) Chirping : In all cases this is caused by a 'out-of-round' Tone Rolle (Audio Pulley). It must be replaced.
3) Rewinding of full reels is too slow. Assuming that the supply voltage from the mains is correct this problem may be caused by the type of tape that is used. Deposits on the tape heads may increase friction in spite of otherwise normal tape tension. The remedy is cleaning of the heads and the use of a different quality of tapes. Also refer to item 1) in this section.
4) Poor spooling of the tape during Rewind of an undamaged (not stretched, without scalloped edges) tape. This is caused in mostly by the use of 'out-of-round' tape reels. This out-round-condition sets up vibrations during the high rpms of the rewind operation. The remedy is to use good tape reels.
5) Recordings are distorted in sections of high volume. The signal level was too high and got clipped. Lower the recording level.
6) Not enough volume. Possible cause may be that the tape was recorded on the 'wrong side'. For guidance please refer to the section ' How to use the Ferrophon?'
During Recording:
1) New recordings produce more hiss than old ones. This is an indication of residual magnetism being present. The use of the Demagnetizing coil corrects this condition.
2) Previous recordings are not erased. The RED recording light is not ON since it may be burned out. This interrupts the ERASE circuit. Replace the indicator light bulb.
3) Tapes do not erase completely. With one-layer tapes this may be remedied by running the tape through one more time but with the wrong side towards the heads. With some tapes - even though otherwise they are of excellent quality - this may happen after prolonged storage especially with recordings of very high signal levels. The only way to avoid this is by working with lower recording levels as well as by removing of recordings that are no longer needed.
4) Recordings off the Radio: they often have a whistle tone 'attached' to them. This tone cannot be heard when listening to the radio directly. It is caused by interference - see earlier in this manual - and can be avoided during recordings by moving the switch marked 'Frequenzweiche' to the corresponding alternate position.
Should other difficulties arise other than the ones mentioned here it is strongly suggested to follow the advise of a specialist or to contact the LOEWE OPTA . In any case, opening of the recorder is to be avoided if one does not fully understand the function of each one of its parts.
We, the manufacturers of the Ferrophon, believe that the users of our equipment will have very few difficulties if the above suggestions for operation and maintenance have been followed.
The equipment, which has been detailed here has been built for LOEWE OPTA by the manufacturer Max Ihle . It was equipped with - for the time - excellent heads made by LOEWE OPTA.
here you found amy info from the Catalog
Ferrophon IIIc-3 aus Katalog 1954-55
Stromart: Wechselstrom Netzspannungen: 220 V Leistungsaufnahme: 120 W
Antrieb: Papstmotor Jandgeschwindigkeiten: wahlweise 76, 38, 19 cm/s bzw. 38, 19, 9,5 cm/s
Einfachspur-/Doppelspur- verfahren: "beide Verfahren je nach Bestellung Spieldauer: je nach Bandlänge und Bandgeschwindigkeit
20 Minuten ... 3 Std.
Aussteuerungskontrolle: durch Aussteuerungsinstrument Frequenzbereich:
bei 76 cm = 30...10000 Hz
bei 38 cm = 50...12000 Hz
bei 19 cm = 50...10000 Hz
bei 9,5 cm = 100... 6000 Hz
Spannungsbedarf für Vollaussteuerung: 60 V erforderliche Aufsprechspannung: 20...40 V
Ausgangsspannung bei Wiedergabe: 2,5 V
Mikrofoneingang: bei Gerätetyp IIIc-3 ZV II/L 200 Ohm
Besonderheiten: 3 Bandgeschwindigkeiten. Typ IIIc-3 ZV III/L 2 Kanalsystem, Mischpult, Endstufe 10 W, Lautsprecher im Kofferdeckel
Gehäuse: Koffer Abmessungen: 6S0 x 450 x 230 mm Gewicht: 33 kg
Röhren: EF40 EF40 EL 41 AZ41
Ferrophon IIIc-3 normal Preis DM 2505,—
Ferrophon IIIc-8 ZV III/L Preis DM 3840,—
The following is the schematic for the recorder.
Many thanks to the translator Dieter Reeh a good friend from Canada
