How good were German a/c radios?

[Glasses]

I don't know about German radios but I do know that many programs in the History channel and or Military channel have gotten many things wrong. Partly due to the fact those channels are made to entertain while trying to teach stuff of what happened, like Mcdonald's or KFC of history. Sure you'll be full but that doesn't mean it's healthy. The analogy would be sure you're being put aware of the things that happend but that doesn't neccesarily mean that what you're watching is the most informative and accurate. But it has one good point,in the fact it raises awarness of those things. They're always fun to watch but in short doses.

PS Sorry for the Hijack carry PWN!  

[Cobra412]

So Bruno where exactly did your info come from since you seem to feel the need to get up Anguss arse?

If folks present information related to a topic then at least they could do is provide some source or a direction as to where the information came from so those who are interested in the topic can go 'check for themselves'.

I don't see any references in this statement.

Not only that that but it's not even correct. German, RAF and AMI radios are very comparable to each other.

Or does your advice only work for others?

[Bruno]

So Bruno where exactly did your info come from since you seem to feel the need to get up Anguss arse?

Read Harry's reply, he posted specs for the FuG 10, there was/is no need for me to repeat it. I guess I can post them for the FuG 7 or 16 but what's the difference, Angus 'heard' they sucked...

Or does your advice only work for others?

My advice was specific to one person who consistently posts 'I think' and 'I heard', just do a search.

Aren't you the guy that faked his death a while back? Stick to what you know...

[Angus]

Ahh, Bruno
"Unfortunately your 'If I recalls' and 'I thinks' and 'I heards' rarely prove to be factual"

No, they have a habit of sticking. Read the last summary of the infamous slats thread to see how sticky they can be

That said, I'm digging on the radios. I was wrong about the BoB raid though, - it was more of a communication problem than the radios.
Rall mentions that they didn't get a proper radio before they had the 262.
Than one sticks, but there is an explanation to that one as well. Would you want to guess what it is?

[Bruno]

Of course LW radio equipment was improved upon through out the war but that's different the blanket statement 'they sucked'. If you ever find a source to support that please post it...

[Angus]

I have two little coins into your slot Bruno.
From books.
1. Not all LW 109's during the BoB had a radio for it was regarded as "not the most needed gadget, and 109's in Spain flew without Wireless with good results"
2. Rall refers to the radio equipment as very good - in a 262. Finally clear of the disturbances caused by the magnettos in the 109.
"Endlich ein Funkgerat, das nicht durch die Zundanlage des triebwerks gestört wird"

Now it is your turn to tell me it's rubbish

[MiloMorai]

Did bombers and fighters have the same radios.

[Angus]

I rather think they didn't. Weight you see.
Oh, and my referrence to the BoB was about radios after all. Apparently there were wrong christals installed, - the effect being bombers flying off while not knowing that the operation was cancelled.
Fink was there. (LW)

[Crumpp]

The allied radios used quartz.  This makes them not only more precise for frequency tuning (no problems with frrequency shift) but allows the radio to generate more power.

As the name implies they are made from quartz, a naturally occurring form of silicon, although most of that used for electronics applications is manufactured synthetically these days. The components rely on the remarkable properties of quartz for their operation. When placed into an electronic circuit a crystal acts as a tuned circuit. However it has an exceptionally high Q. Ordinary LC tuned circuits may exhibit values of a few hundred if carefully designed and constructed, but quartz crystals exhibit values of up to 100 000. Apart from their Q, crystals also have a number of other advantages. Their stability is remarkably good with respect to temperature and time. In fact most crystals will have these figures specified and they might typically be ±5 ppm (parts per million) per year for the ageing and ±30 ppm over a temperature range of 0 to 60 degrees Celsius.

http://www.radio-electronics.com/info/data/crystals/xtals.php

This means for the same voltage input, the allied radios gave more RF output.

Sirs: In proportion to size these little glass like quartz wafers are perhaps the most remarkable of all the tools science has given to war. When the story of the almost incredible progress in research and manufacture of radio crystals can be told, it will prove to be a tale of one of the war's greatest achievements. No less significant will be the fruit of these advancements to a new world at peace where crystals will be the vibrating hearts of most telecommunication equipment. Gerald James Holton, Harvard University, Cambridge, Mass.

One piece of equipment which they ordered was a VHF transmitter-receiver for aircraft use employing 4 crystal units in the transmitter and 4 in the receiver. The equipment was made by the Bendix Corp. and the crystal units were the DC-11 and the DC-12 types. Thisset, with a few modifications became the SCR-522, the most important airborne set in the U.S. Air Force and its crystal unit became the CR-1.

 

The problem of ageing was especially severe in the CR-1unit used by the Air Force because these units operated at higher frequencies and required closer tolerances. As a temporary measure orders were issued by Wright Field that all quartz plates must be able to withstand the test of scrubbing with soap and water and a toothbrush. Soon each Signal Corps Inspector and each crystal finisher was equipped with a toothbrush and a dish of soapy water. The directive was a boon to the toothbrush industry but contributed little to the solution of the ageing problem.

By the end of 1943 it had been shown that quartz blanks which had been etched to frequency exhibited very small changes of frequency and activity even when subjected to tropical conditions. However considerable opposition existed to the idea of etching and much valuable time was lost in investigating other approaches before the decision was made to require etching. This was due to a reluctance to specify a manufacturing process which might require rewriting of the specifications and renegotiating of contracts and to a wise policy of specifying test results instead of manufacturing procedures. Yet it was impossible to depend upon inspection procedures to insure that crystal units would remain useable and a vast amount of work had failed to reveal any other manufacturing procedure which would do so.

Consequently a Conference of all Crystal Manufacturers was called on July 11-12, 1944 in the old Stevens Hotel in Chicago. The problem was explained in detail and the proposed remedy was presented. There was no time to rewrite the specifications or to renegotiate contracts so the manufacturers were asked to convert their production processes from hand lapping to etching. It was expected that units made by the etching process might be more expensive. Again the industry rose to meet a challenge. The manufacturers went back to their plants and converted to the new process with such success that they produced satisfactory units at a lower cost. As one example, Ken Ross, who had converted his coil winding plant in Chicago to a facility for making FT-243 crystal units, designed and built a continuous etching system which, with four operators, turned out as many finished crystal units as 20 operators finishing by hand lapping. The Ross system was soon widely copied throughout the industry.

http://www.ieee-uffc.org/fc_history/bottom.html


German radios relied upon vaccum tubes with require more energy per output, generate more heat, and are subject to frequency shift.

Additionally the LW fighter were smaller dimensionally.  They simply could not carry a vacuum tube radio large enough to give them the range needed to co-ordinate their entire effort in the air.

All the best,

Crumpp

[Angus]

Bloody hell Crumpp, magnificent summary.!!
Although, I am confused about the size problem. The radios were usually located aft, so in theory one had the whole fuselage to play with. Well, on the RAF fighters normally.

[Crumpp]

The radios were usually located aft,

The radios are larger than you think and the spaces smaller in the LW fighters.

The allied fighters were dimensionally larger, especially the huge fighters the US liked to build.

All the best,

Crumpp

[Bruno]

Originally posted by MiloMorai
Did bombers and fighters have the same radios.

bombers and Recce used FuG 10, fighters used FuG 7 then FuG 16

Site with some relevant info.:

Collection of German W.W.II. Radios

FuG 10

FuG 10
American Manufacturers have exhibited considerable interest in captured Axis equipment, wherever it has been shown. The following detailed description of the German FUG-10 panel used in bomber and reconnaissance aircraft should, therefore, prove useful.

The German FUG-10 panel, or rack, contains two transmitters and two receivers. One transmitter and its companion receiver operate in the 300-600 kc hand. The other transmitter and its associated receiver operate in the 3000-6000 kc band. Both units employ CW and MCW operation. No voice communication is used. In addition, the following units are mounted on the panel: A remote-controlled direction-finder operating in the 100-1100 kc band, a blind-landing device operating in the 28-32 Mc band, and an inter-phone system which serves to supply communication to the aircraft crew as well as to interrupt the CW transmission for purposes of ground homing.

Equipment is non-crystal controlled and relies on capacitance compensation for frequency satiability. Facilities are available for tuning a predetermined spot on a dial to a master-signal station which is undoubtedly maintained on frequency by crystal control.

Transmitter Units SL and SK
These instruments each contain 3 type RLI2P 35 valves, which are indirectly-heated pentodes of 35 watts anode dissipation. One valve as master oscillator drives an output stage using two tubes in parallel. Master-oscillator and output circuit primary tuning is by iron cored variometer driven through backlash-compensated gearing from a single tuning control.

Electrically the high-frequency and medium-frequency transmitter units differ in detail only. Looking at a circuit diagram of the high-frequency unit SK, and it will be seen that the master oscillator is of the Colpitts type. Certain of the fixed condensers are of the high-negative coefficient ceramic type giving a considerable degree of temperature compensation. A small neutralising condenser is provided. The normal use of the transmitter is for c.w. communication, keying being carried out in he master oscillator and power-amplifier grid circuits. Special uses are radiotelephone transmission on the 5K unit with grid modulation, and impulse transmission on the SL unit.

The radio-telephony facility when provided requires an additional switch unit accessible to the wireless operator and a press-to-talk button for the pilot. The switch unit sets the output-stage grid bias to the correct value and provides modulating signals via the intercommunication amplifier. The pilot's radio-telephone requirements are catered for in later installations by a separate transmitter-receiver.

The impulse modulation feature was used to provide ground stations with a signal suitable for the taking of direction-finding bearings free from night error, but has been discontinued in the latest installations. The repetition frequency of this type of modulation is 300 impulses/sec and the impulse duration 500 micro sec. The generating oscillator and shaping output stage are incorporated in the intercommunication amplifier unit, the output being applied to transmitter power-amplifier grid circuit under the control of the main system switch. Power output is between 40 and 69 watts throughout both frequency bands on c.w.

The mechanical construction of the transmitter units is of light-alloy die castings are used for the several sub units, which are bolted together to form the complete transmitter. Plug-and-socket interconnections are used between the sub-units, and the captive fixing screws are identified by red paint. In both transmitter and receiver units the large-diameter dial revolves on a stub-axle and is calibrated in frequency, the scale subtending some 300 degrees. The hub of the dial carries four notched discs for the rapid selection of pre-set spot frequencies. Locking and unlocking of any one disc is accomplished by turning through 90 degrees the appropriate one of four coin slotted screws, visible on the front face of the dial hub. The spring-loaded stop-levers are interesting in that they are pivoted on an eccentric spindle which can be rotated through 180 degrees.

Receiver Units EL and EK
The receivers are of the super heterodyne type with one signal frequency amplifying stage. The EL unit, covering 300 to 600 kc/s, has an intermediate frequency of 140 kc/s with a total band width of 1 - 0 kc/s at 6 dB attenuation. The EK unit, covering 30 to 60 Mc/s, has an intermediate frequency of 14 Mc/s and a band width of 8 kc/s at 6 dB attenuation. The signal / noise ratio in each case approaches the theoretical limit determined by first tube and circuit noise. One micro volt (C.W.) applied through 50 ohms gives signal to noise ratios of 20 dB and 17 dB respectively, and the total gain at this input is such that the telephones receive 50 mw and 2.5 mw respectively. The second channel attenuation figures are 78 dB and 70 dB.

One type of tube, the Telefunken RV.12P 2000, is used throughout these receivers and also in the intercommunication amplifier and miscellaneous tube circuits. It is a small indirectly-heated pentode with a side-contact base and ring seal. The overall length is 5 cm, and the bulb diameter 2 cm. The moulded valve holder carries integral contact springs to make the top-cap grid connection and to earth via the metal frame. Input and output capacitance's are both approximately 4mmfd The mutual conductance is 2 -4 mA/volt, and the heater current 0.07A at 13 volts. The FuG 10 equipment uses a total of 25 tubes of this type.

A circuit diagram of the medium-frequency receiver EL 5. shows there is no automatic gain control, and the manual gain control operates on r.f. and 1st i.f. stages only. Radiotelephony reception is not provided. A separate local oscillator is used with a pentode frequency changer and anode - bend detector. The i.f. transformers have separately screened adjustable, iron-cored coils with fixed tubular ceramic condensers. Coupling is by capacitance connected between appropriate tapings to enable a standard type of variable trimmer to be used.

In the EK receiver the heterodyne oscillator is controlled by an on-off switch. The EL receiver differs in having the oscillator permanently on, and using a 3- position switch associated with two small ceramic condensers to give zero - beat or heterodynes 1000 c/s below or above intermediate frequency. This facilitates accurate inter-tuning of the transmitter to the receiver and ground station, and provides a means of eliminating interference from an adjacent channel. Mechanical design is on the same lines as the transmitter units with dimensions slightly smaller. Click-stop details are identical.

Two Aerial-Matching Units are used, one for the trailing aerial and one for the fixed, mounted as near to the fair lead and deck insulator as possible. Each unit contains two tapped variometer for tuning on h.f. and m.f. ranges, and iron-cored auto - transformers for matching aerial resistance to the 50-ohm feeders.

Most LW radios were built by Lorenz, originally a subsidy of American company (I T & T IIRC). As with all things produced in Germany during the war quality suffered as the war progressed due to the lack of materials and declining production standards.

Range wasn't an issue with the radios on board aircraft and in air control was maintained on the Gruppe/squadron level. Master signal stations (Ground) used crystal / quartz sets and had plenty of range / and powerful receivers to maintain control of the air.

Angus,

In every discussion about the LW you only ever source Rall (I don't how times I have seen you site p.214 of Mein Flugbuch). There were more pilots in the LW then Rall. The problem that Rall describes could easily be addressed with proper insulation and grounding.

As for for your BoB reference, on board LW radio sets didn't use crystals as Crumpp said. In Spain radio technology was still rather raw and during that time not many nations produced reliable on board radios so I don't why bring that up. The Commies were using hand signals...

LW raiders sometimes shut their radios off. Not only did radios work for communication but for navigation RDF, IFF etc... With out more information about those LW bombers failing to get the 'call off' message there could 1000 reasons. That alone doesn't support you claim that LW radio equipment 'sucked'.

Ami bombers ran into the same problems where the target was switched to a secondary target or a raid called off due to weather. A section of the stream failing to turn back or switch target.

[Angus]

Very nice

[Crumpp]

Equipment is non-crystal controlled and relies on capacitance compensation for frequency satiability.

Range wasn't an issue with the radios on board aircraft

It most certainly was an issue.

air control was maintained on the Gruppe/squadron level.

Exactly as they could not coordinate large interception efforts.  The Luftwaffe had to push actual control down to lower levels which meant:

Master signal stations (Ground) used crystal / quartz sets and had plenty of range

Is also true.  However they did not control anything.  Mostly they broadcast a "running comentary" on the location of the bomber stream.

The Reichsjaegerwelle could not reach the length and breadth of the Operational area in order to communicate with all the fighters in the air over Germany, France, Holland, etc...

"Y" control was also very fickle with only roughly 50 percent of the S.E. fighters being equipped with it in the first place.

and powerful receivers to maintain control of the air.

No such thing.  The best you can do to recieve is built a good antenna.  However it is subject to the law of reciprocity.

The operation of antennas, and telescopes in general, are governed by electromagnetic theory and diffraction theory plays an important role. In order to understand this, one first needs to know the reciprocity theorem. This theorem states that the telescope operates the same way whether it is receiving or transmitting radiation.

http://web.haystack.mit.edu/urei/tut6.html

So it will work only as good as the poorest antenna in the system.  So while you may be blowing his socks off transmitting with a high dB gain antenna and the poor antenna will hear a poorer signal but most likely readable in the case of the Luftwaffe.  When the poor antenna transmits, the high dB gain antenna will hear nothing or very little.

An amplifier could help but the absence of signal means nothing to amplify.  An unreadable transmission really loud is still an unreadable transmission.  It is just louder static.

Additionally these radios used the VHF spectrum.  This spectrum properties mean it primarily uses ground wave propogation and is a "Line of Sight" radio.

http://members.aol.com/svennord/radio.htm

So you are dealing with the curvature of the earth, antenna, power output, and the height of the aircraft to determine range.

All the best,

Crumpp

[Bruno]

Exactly as they could not coordinate large interception efforts. The Luftwaffe had to push actual control down to lower levels which meant:

Sure they could and they did. Gefechtsverband were made of multiple Gruppen or even mixed Geschwadern. These formations were large consisting of  bomber killers, close escort and top cover. Range wasn't issue as they formation wasn't spread out over hundreds of miles like the Ami bomber streams and escort. Communiction between the sections was not overly difficult. You wouldn't need or want every one using the R/T and chatting betwen each other. Only those leading the section.

Is also true. However they did not control anything. Mostly they broadcast a "running comentary" on the location of the bomber stream.

The Reichsjaegerwelle could not reach the length and breadth of the Operational area in order to communicate with all the fighters in the air over Germany, France, Holland, etc...

"Y" control was also very fickle with only roughly 50 percent of the S.E. fighters being equipped with it in the first place.

More nonsense. The LW command and control from the ground was very sophisticated and they could easily maintain control and direct the Gefechtsverband to sections of the bomber stream the were least protected by escort even very late in the war. This information came from recce, ground observers and various stations through out WETO. All relayed through the command and control structure and relayed to the pilots even in flight.

Here's a link to SES's site that goes into LW command and control:

GYGES

In February 1942 the Y-Linien system was introduced, and it was in widespread use in early 1943.  The Y-Linien Stellungen tracked the fighter formation, reported to the Jafü, and the Jlo could now direct up to 5 fighter formations at the same time.  (Y-Verfahren (Jagd).  After the BIG reorganization this process was performed from the GefStd of the JD.

No such thing. The best you can do to recieve is built a good antenna. However it is subject to the law of reciprocity.

Nonsense, search signal amplifier, you can definitely boost the signal. Search for pic of LW communication antenna. They were plenty big enough

The rest of your post is just clutter and no reply is needed.