f 

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ASA REVIEW - January-.Febr1QIF-L9if) :~t-250 

The War in the Ether : 

uRote Kapelle" Case 

(QeM'iieftt!Ml) 

Translated from orislnal German materials By 

Dr. Ray W. Pettensill 

(*Kapelle means on the one band a chapel, on the other an aggregation of muaiciana - a band, orchestra or choir; therefore here a group that plays together.} 

Let ua state at the start that this case 

has nothing to do with a church chapel. 

Neither was such a chapel used to set up 

an agent' a transmitter, nor were clergy 

involved. The designation resulted from 

a whim of German officials in Belgium who 

labeled every case of radio agents with 

the general term "Ka.pelle" and gave each 

individual case a particula.r designation; 

thus, there arose in the course of time a 

"Scbrammel-Ka.pelle, 0 a "Zither-Ka.pelle," a 11Blas-Kapeile," and "Ardennen-Kapelle, 11 a 

"Ka.pelle Etterbeck," and one day a "Rote 

Ka:pelle 11 where the color referred to Bolshevism, since this "Case" bad been controlled by M:>scow and worked in turn for 

!&:>scow. The whole story was as follows: 

Even before the outbreak of the Germa.nRussian War in the summer of 1941, the 

Russians had set up a network of agents 

which had ex-pa.nded over all of Central and 

Western Euro"Pe· It was intended for espionage and was to become effective in a 

la.rge way only in the event of an armed 

conflict. When the war with Russia broke 

out, this radio agent net waa by no means 

completely developed and thoroughly organized. Only individual portions were so 

well organized that they were fully capable of functioning. 

Spy Center in Brussels 

Among others, the Russians had set up 

such a center for radio agents in Brussels. 

The head of this spy center had become 

a partner in a large Be l.gian Commercial enterprise and thus had provided 

the opportunity of making extensive jourJ1nu1ry • Febru1ry 1952 

nays again and again without attracting 

attention, and so of establishing contact 

with a great many leading personalities. 

In this way he could gain insight into a 

number of things and gather information; 

at first he aent this to :t.t>scow through 

Russian diplomatic and commercial representatives. This route, which bad previously led via Berlin, ceased to function 

shortly before the beginning of the war 

between Germany and Russia. They now resorted to the radio to send the results of 

their spying to !&:>scow. 

The radio traffic as such waa soon intercepted by German monitoring stations, 

for the first time on 26 June, 1. e., a few 

days after the beginning of the war. However, it was not possible to solve the 

cryptographic system employed and to read 

the contents ao as to gain an insight into 

the activity of the organization behind 

the radio station. Furthermore, it was a 

long time before the German direction 

finding service was able to fix the location of the station. 

Not until November 1941 was it determined that the station was surely in Brussels. 

Now began the close range search. On 12 

December the transmitter was fixed uniquely, so that steps could be taken for 

picking it up. On 13 December 1941 it was 

captured by organs of the German Counter 

Intelligence Service in Brussels. 

This was the first transmitter of its 

type that had been located in Western 

Europe • The v1 lla in which it had been 

set up and from which it had operated had 

been rented in the summer of 1941 by the 

Russian Espionage Service and was cared 

9 

Declassified and approved for release by NSA on 01-30-2014 pursuantto E.O. 1352a 
REF ID:A59250 

f'or b'1 a 'Belsie.n houeekee}ler. The building served not only as the location of the 

radio station but also as shelter for members of the agent group and as calling 

point for agents and informers. 

Chief Agent Escapes 

On the occasion of the raid, six 'Persons 

were arrested in all, among them an operator who came in on the following day, two 

Russian Officers, and a Polish woman who 

had come from Paris and served as ci}lher 

clerk. However, this was merely the crew 

of the radio station; the chief and actual 

head of the agents was not caught. 

Among the materials found were some 500 

enciphered radiograms which this transmitter had forwarded; hence,there was no 

doubt that the encipherment and decipherment had been done in the house and that 

the cipher keys must be somewhere in the 

house. Otherwise nothing could be done 

for the moment with the materials found. 

It was only possible to ascertain that a 

grille system was involved which was obviously reenciphered with a so-called book 

key. For a book key, any book may be used 

which is agreed upon by the sender and recipient; the text is taken serially for 

encipherment, replacing each letter of the 

alphabet by a number after the manner of 

the "Caesar": the resulting series of digits is then added to or subtracted from 

the series of digits resulting from the 

basic grille. Since this "additive sequence" is practically endless and repetitions do not occur, solution was not posible without knowing the book used. 

With the characteristic egoism and interest in its own affairs which marks official agencies, the :Brussels counterintelligence office declined "for security 

reasons" any further cooperation with organs of "radio counterintelligence" after 

the transmitter had been picked up. The 

villa which had been confiscated for the 

moment was released after a short time and 

after six weeks "radio counterintelligence" 

received a final report from which it appeared that those arrested had stubbornly 

refused to make any statements except the 

housekeeper and that she knew nothing of 

consequence regarding the organization 

which had operated here. Attached to the 

report were photographic copies of the material as found and a statement that an attempt by the cipher section of OKW to de10 

~ cipher the radiograms had not }lroved successful. 

Scrap of Pa}ler Reveals Key 

Now the "Photographs were subjected to a 

careful check at the central office of 

"radio counterintelligence"; in doing this 

it was discovered that one of the scra}lsof 

paper photographed contained a so-called 

Caesar Key, such as is employed in Russian 

Systems for enciphering plain text. This 

scrap of paper showed several rows of the 

enci}lherment of a radiogram; this proved 

that encipherment had been carried on in 

the house. Consequently, the books used 

for encipherment must also be present tb:ire. 

Some notes in secret ink, as well as 

some of the letters discovered, contained 

hints that the organization had branches 

in France and Holland. 

By making a frequency count of the digit 

groups of the book cipher text on the 

scraps of paper, it was possible to ascertain that the book employed could only 

have been in the French language. For the 

moment this did not help much since only 

a knowledge of the entire content of the 

book would afford a possibility of current 

decipherment. 

By ca.refUl questioning of the Belguim 

Lady who had run the house it was possible 

to learn little by little the titles of 

eight or nine books which might have been 

involved in the encipherment and decipherment work of the Russian agents. 

Now it was a question of getting these 

nine books; there was only one way and 

that was by purchasing them on the market 

since the villa had meanwhile changed owr•-

ers and the entire library had disappeared.. 

Even though the titles of the books were 

now known, there was no guarantee that the 

proper edition would be found in a bookstore, i.e., that edition which corres-

}londed with the books used in "PBSination, 

and thus in text. 

Meanwhile, the cry-ptanalytic section of 

the central office of "radio counterintelligence", which had become acquainted 

with all cipher systems hitherto known to 

be used by radio agents in the east, attempted to solve this cryptographic system 

by analytic means. The half-destroyed 

ASA Review 
REF ID:A59250 

fragment of a sheet, on which an enc1~herment had been pre-pared, was the critical 

factor. 

After about six weeks 

lea.med how the additive 

encipherment was made up. 

of work it was 

sequence for the 

Character in Novel Named 

Taking into account the matter of composition for transmittal by radio of agent 

traffic previously observed in the east, 

it was finally possible to resolve the 

additive sequence into letters; the short 

sentence thus obtained contained the significant name "Proctor." After the novels 

sought had been procured, this name was 

found in one of the novels. In this way 

the keybook was discovered and the system 

was broken. 

Now part of the captured radiograms could 

be deciphered, whereby the addresses of a 

number of important agents were disclosed 

and the -preliminary conditions created for 

penetrating a widely ramified Russian 

agent network which extended over the 

western territory and, in particular, over 

Germany itself. The deciphered messages 

proved that one had here gotten on the 

trail of an especially clever man who must 

have connections with the highest German 

command, since he transmitted, for example, in November 1941 the intentions of 

_the German Command to carry out an attack 

on the Caucasus in the spring of 1942. 

Furthermore, it was possible to deduce 

from exact reports on the gasoline consumption of the Army and of the Air Force, 

as well as on existing stocks of fuel, on 

the stock of planes, and on losses in the 

east, that he must have some sort of a 

connection with the Air Ministry or with 

the Supreme Command of the Air Force. He 

even transmitted to Moscow the prediction 

ma.de by German astronomers and weather experts of an impending exceedingly cold 

winter. He even gave a very clear calculation of the time when German fuel reserves would be exhausted. 

Another Name Enters Case 

This principle agent in Brussels, who 

was always ref erred to in the radiograms 

by the cover name "KENT," was on the road 

a great deal of the time. Using the deciphered messages it was possible to follow hie Journeys to Czechoslovakia and 

J1nu1ry-f ebruary 1952 

throughout all of Germany. KENT received 

hie principal information from a confidential agent designated in the messages by a 

cover name "CORO." It was a question of 

getting on the trail of this source. The 

following chance happening provided a 

possibility. 

The war with Russia broke out at a time 

when the Russian intelligence service had 

not yet completed the building up of its 

foreign organization. Radio connections 

from Germany were not functioning. The 

call signs in the traffic schedules had 

not been fixed definitely by days but were 

to be changed from one transmission to the 

next; in this way the transmitters got out 

of step and could not get adjusted again. 

To this accident was due a radiogram in 

which the name and address of three collaborators in Berlin were sent to the Belgium group with instructions to tell them 

to establish radio connections with the 

central office in Moscow. Such a step, of 

itself, groesl.v contravened the most elemental principles of conspiracy and can be 

explained only from the necessities of the 

situation. 

KENT came to Berlin to reestablish the 

contact, which had bogged down, of the 

"Coro" group with Moscow. This was the 

end of October or the beginnine; of November 1941. However, the contact remained 

inadequate and Coro continued to send most 

of his material by way of KENT. 

Air Force Lieutenant Involved 

The radiogram had mentioned three groups 

in Berlin. At first nothing could be done 

with one of the Berlin addresses; more 

than half of a year had gone by and the 

dwelling had changed hands. Only after a 

long search did they get on the right 

track, but this proved of secondary importance. There was more success with 

the second address. Here investigations 

led to a first lieutenant of the air force 

who was employed in the newspaper and information section of the Air Ministry, 

later in the attache group of this ministry. In civilian life he had been a teacher at the University of Berlin and before 

1933 had taken an active part in politics; 

he had good relations with the Foreign 

Office and contacts with a large circle of 

acquaintances and men of similar political 

beliefs. He was a man of outstanding intelligence, blUff'ly opposed to National 

11 
REF ID:A59250 •• 

Socialism, and sympathizing with the ideals of Communism and with the Soviet 

Union. Through his activity in the Air 

Ministry he came into contact with most of 

the higher offices of the department as 

well as with many other high officials and 

with industrial plants. This ma.n - a certain Schulze-Boysen - was a relative of 

the Tirpitz family. Using masterful disguise he had become the head of a widely 

ramified German resistance organization 

which was trying to overthrow National 

Socialism at any cost. 

In contrast to other German resistance 

groups, whose activities were exhausted in 

preparing plans or in waiting, the group 

headed by Schulze-Boysen was geared both 

within and without the country. 

"Coro", or Schulze-Boysen,was now watched unostentatiouely by the German Gestapo, 

likewise hie acquaintances and bis whole 

intellectual circle. Among other things, 

it was established that at definite times 

he met Superior Government Councilor Dr. 

Ha.ma.ck who turned out later to be oneof 

Cora's most important collaborators. He 

had a'PPea.red at all times in the messagee 

under the name of "Arwid," and this was 

actually one of his given names. 

In tracing down Schulze-Boysen's circle 

of acquaintances and in checking all relations and connections, there developed 

a long sequency of surprises of which each 

one "had something to it." 

Operations In Radar Industry 

For instance, with the Berlin radio firm 

Loewe there was a head construction man in 

a special de'partment; his name does not 

matter and we call him Z. This Z. had for 

a long time been a convinced communist and 

had formerly been in contact with Moscow. 

However, he had succeeded in cleverly 

camouflaging his attitude. He was a very 

clever technician. He was the head of the 

section which was engaged in the development of television apparatus, radar apparatus, and the like at the behest of the 

Air Ministry. 

In, and of itself, the principle of the 

electric Echolot, i.e., of space scanning 

(radar) , had long been known. Only thus 

far little had been done to adapt the invention for military purposes. During the 

war this question had become prominent. 

1! 

Electric space scanning devices were proving important in fixing a'PProa.ching enemy 

aircraft. 

Solution of this problem was of great 

importance at the moment in Germany, for 

bomber warfare was Just being developed 

and recognition of attacking planes at 

night and in fog had become indispensable 

in properly combatting them. The Loewe 

firm was supposed to assist in developing 

and building· the apparatus. 

For everyone who knows German cond1 ticns, 

it is clear that, at the very moment in 

which German authorities began to occupy 

themselves with these matters, there began 

a very busy air of secrecy. Instead of 

intrusting as many people as possible with 

development of this a'PParatus which was so 

important to the Air Force, and thus finally achieving a highly developed apparatus in this battle of minds, the whole 

project was surrounded with an utterly 

superfluous veil of secrecy. Cover names, 

etc., were issued. The circle of participants was kept as small as possible. No 

one was allowed to talk with anyone else 

concerning the question as a whole, etc. 

The consequence was that only a very small 

circle of engineers was occupied with the 

work. Director of this section at the 

Loewe plant And,therefore,practically in 

control of progress on the work was, as 

stated, that construction chief Z. In his 

hands rested the fate of this invention. 

Z. had good fellow workmen. Whenever 

one of these men bad ma.de any progress on 

the device, Z. saw to it that this was reported to the Air Ministry; but he also 

saw to it that the engineer disappeared 

from the plant. Either he had his deferment cancelled so that the man went to the 

front, or he intrusted him with "more important" tasks, or he had him transferred. 

In his place he put a man who, he was certain, was more or less a stranger to this 

field of work. Thus,for almost two years 

he was successful in sabotaging this important work so that England and America 

gained a corresponding head start. The 

principle of the invention had long since 

been known over there; now they had time 

to go about the technical execution calml;y. 

Thia led to the creation of those radar 

instruments by the aid of which the German 

submarine was soon driven :from the seas. 

ASA Review 
ASA REVIEW - November-Dec~F l~n;ii,: 1l§i 9-2-§..QI 

The War in the Ether : 

The Russian Radio Agent Service in 1942 

(Co1111aent±al) 

Translated from original German materials By 

Dr. Ray W. Pettensill 

Frequent mention has been ma.de of the 

employment of Russian radio agent~, and 

their work has been adequately described. 

We shall now sum up this chapter, and show 

the extent which this work assumed during 

the Second World War. 

Bolshevist Russia was the first country 

to tackle the principle of radiocontrolled 

espionage and to put it into effect on a 

large scale. The beginnings go back to 

approximately the year 1931, that is, to 

the t:!me when it became clear that National 

Socialism was beginning to gain ground in 

Germany, and thus a collision with the Soviet Union entered the realm of possibility. This might havs resulted sooner or 

later but it was unavoidable if National 

Socialism seized power. The utmost watchfulness was necessary. Therefore the Soviet Union began setting up a widespread 

shortwave radio net with the control station in Moscow and a full dozen su.bordina te stations distributed all over Europe. 

At that time the German intercept service 

did not succeed in gaining aEy insight into the content of the messages exchanged; 

it was assumed in Germany that this was 

merely a control net created by the Communist Internationale which served to guide 

Communist propaganda and agitaticn throughout the world. How mistaken they were 

appeared only during the course of the Second World War when the German radio defense was able to get extensive insight 

into the work of the Russian intelligence service. 

After the outbreak of the war between 

Germany and the Soviet Union it turned out 

that the famed "Comintern Net" - which was 

really a net of the Russian intelligence 

service - constituted only a very small 

portion of the Russian spy net. Much 

greater was the net of agent radio stations 

which had been set up all over Europe long 

Novem1>er-December 1951 

before the war but had r.emained silent until the war began. .This now appeared in 

an all the more dangerous form. Already 

in 1940 the number of Russian agent stations in Europe had increased sharply. In 

May 1941 there were already some 25 radio 

stations. 

In June 1941 the radio traffic on the 

Russian WNA Net-as the Germans called it 

after the call sign of the control station 

in Moscow - grew to 78 radio circuits. 

Shortly before the outbreak of the GermanBussian War the exchange of teleg-cams in 

this net increased enormously. In August 

1941 the German intercept service copied 

not less than 600 radiograms on this net. 

The aims of the Russian secret service 

were: 

1. Seeking information in all fields 

connected with the armed forces and 

armed strength of all European countries, 9f the U.S.A., of Japan, and 

of a few other states. 

2. Seeking information in all fields of 

industry and economics in these 

countries. 

3. Seeking information on all political 

occurrences in these countries which 

might have any reaction on the political life of the Soviet Union. 

4. Infiltration into the centers of the 

secret service of those countries, 

and gathering information ~egarding 

any measures planned against the soviet Union. 

By using its diploma.tic and commercial 

representatives or by employing special 

radio agents the Soviet Union organized an 

11 
REF ID:A59250 

intelligence net which worked splendidly. 

In the various branches of this net agents 

of all branches of the Russian secret service had been injected: officers of the 

General Staff, agents of the Peoples Com- missaria~ for Internal Affairs (NKVD), 

Party functionaries, diplomats, etc. The 

procurement of' information on themilitary, 

political, and economic developments in 

foreign countries was carried out on a 

grani scale and by all possible means. The 

central offices set up abroad, the branch 

offices, and individual agents were equipped with special shortwave sets and were 

in direct co~tact with ~.oacow. 

THE "ROTE DREI" 

In the course of the Second World War 

there was a goodly number of ver-y dangerous 

groups of agents. IvRny groups the Germans 

were able to render innocuous, many they 

could not. But I think it was the moat 

dangerous group of all which they did not 

succeed in rendering harmless. Thia group 

could only be cleared up in small measure, 

and that m1.lch too late . 

Since June 1941 the German intercept 

service observed three radio circuits running from Switzerland to Moscow. In 

&.ritzerla.nd in tile vicinity of Lake Geneva, 

were located three radio stations which 

stood in cot!lClunication with M..oscow. It 

was acxn recognized that these were agents' 

stations, and that they belonged to the 

Russian mill tary espionage system. Beyond that no essential information was 

possible, especially since the cryptographic systems employed were not broken. 

Month by month the Germans watched this 

traffic, took down the messages, and tried 

to break the cryptographic system. They 

gave this agents' net the name "Die Rote 

Drei." This "Rote Drei" caused many a 

headache to a great many people, - also in 

Switzerland, but the more they worried 

about it the less clever they became. 

It was not until December 1942 after the ( 11 l n arrest of the agent Kent Rote Kapel e 

case) that the Germans got any clue for 11 i n breaking into the net of Rote Dre • 

Kent had eta ted that in the summer 1940 he 

brought a cryptographic system to Geneva, 

and delivered it in Bue de Lausanne. Now 

the Swiss Central Office of the Comintern 

was located in the Rue de Lausanne • The 

transmitter's position had been fixed as 

12 

close to the French border. Through Con) 

fidential agents in Switzerland and the 

German counterintelligence af'flce in Dijon, 

France, an attempt was made to get at this 

organization, above all to get some clue 

which would make it possible to break into 

the cryptographic system so as to be able 

to read the tremendous volume of traffic 

over this network. 

Not until the summer of 1944 was Germany 

able to read those messages which had been 

goir.g out for a long time. What they now 

saw was enough to take many a person's 

breath away. 

During the whole period of the eastern 

campaign, during the first German offensive in 1941, in the preliminary stages of 

the campaign of 1942, in the most critical 

period on the eastern front, at the time 

of the battles around Stalingrad and in 

the Caucasus, and then later in the sprirg, 

summer, and autumn of 1943, in those decisive days when the German armies in the 

southern and central sectors of the eastern front were being swept back, in those 

days when one expected that somewhere, 

perhaps on the Dnieper, they would be able 

to make a stand, check the onrushing tide 

of the Russian armies, and build a new 

firm front, precisely in those days, weeks 

and months the most secret information regarding the German military situation on 

the eastern front, regarding troop units, 

strength, assembly areas, intentions, etc., 

was passing currently through Switzerland 

to Moscow. These were exclusively matters 

which must have come from the highest 

level of German military com:na.nd. 

The sender always signed "Dora"; the 

sources were designated as "Werther," 

"Sissy, 11 "Teddy, 11 11Fernand, " "Taylor, 

"Lucie, 11 "Pacbo," "Ivaud," "Eduard," "A 1-

fred," "Jim," "Salter," etc. The man who 

directed the work by radio from M.'.>scow 

signed "Direktor." 

By direction finding it had been established by the Germans thBt two of the 

transmitters were in Geneva, the third in 

Lausanne. Now the work of the German agents in Switzerland began. 

They soon found out the points at which 

the transmitters were located and the or~ 

ganization they served. In Geneva, at 

Number 113 Rue de Lausanne, sat as chief 

of the organization a certain Rado who was 

officially director of the Geo-Presse in 

Geneva. 

ASA Review 
REF ID:A59250 

~ Alexander Rado was a private scholar and 

a citizen of Hungary. He had lived in 

Berlin until March 1933 and had then gone 

first to Hungary, and f~om there in 1934 

to Paris where he was active on behalf of 

the Soviet Union in cartographic work. He 

was a fanatic adherent of the Communist 

idea. In 1926 he had gone from Berlin to 

Moscow for nine months, and then returned 

to Berlin. He was a member of the KPD a~d 

of the Association for the Study of the 

Soviet Planned Economy. After 30 January 

1933 he was again active for the KPD and 

had placed his dwelling at the disposal of 

their central office. 

His wife had been secretary of the Communist women's movement and was the sister 

of the well-known Communist, Gustel Jansen; 

for a time she had worked at the Soviet 

embassy in Berlin under Joffe; later she 

spent some time in the Soviet Union. 

It is certain that Rado was already active as an agent for the Soviet Union in 

1939. In Paris he must have been in contact with Gilbert. When Rado came to 

Switzerland is uncertain; probably it was 

early in 1940, possibly even earlier. In 

Geneva he had two transmitters at his direct disposal, one of them in Rue de Soleure Number 5 • 

'.Phe Lausanne transmitter was in the 

house at Number 2 Chemin Longerai. Occupant of the house was A .A. Foote who appeared under the cover name John. He did 

the cipher work himself, sent the reports, 

and also had an intelligence organization 

of his own which worked independently of 

Rado. The Swiss authorities knew nothing 

about this. 

In the course of time the Germans were 

able to clear up many things regarding 

"Rote Drei." One knew 'who the "Direktor" 

was, Wio Rado was; they knew all the operators. In the end they were able to read 

all the messages. But, for all that, the 

principal matter remained concealed. Who 

were those informers whose connections 

reached into the Fueher's Headquarters, 

into the OKW, into the Air Ministry, into 

all industrial plants, etc.? Who were all 

these people who knew how to secure the 

moat important information with such masterful skill? Who above all were the final sources from which they drew their information? 

Novemi.-Dece111ber 1951 

The Germans tried by all means to get 

behind this great secret. Hundreds of 

people were watched. In December 1943 in 

the grounds of the Fuehrer's Headquarters, 

of OKH, of the Ministry for Foreign Affairs, 

and other offices special detachments of 

Nahfeldsuchtrupps (troops charged with policing the area close to the line) were 

introduced who came from all directions 

and all distances. It was all in vain. 

Not a bit of this secret was ever revealed. 

It was and remained the most fateful secret of the Second World War. 

Later, when "Rote Drei" had long since 

ceased to operate, when all traces had 

been lost, in the summer of 1944 when the 

shades of the "Rote Drei" were no longer 

spooking in the east on the Volga and the 

Don, but were close to the borders of the 

Reich in the east and in the west, at that 

time when men of the German military command could no longer reconcile with their 

conscience the strategic nonsense of a 

prolongation of the war, at that time when 

on 20 July 1944 that clumsily organized 

attempt was ma.de to dispose of the man who 

had brought all this misfortune on Germany 

and all Europe --- at that time, the ghost 

of the dead "Rote Drei" rose once more 

from the grave. Once more a convulsive 

search for traitors swept over all Germany. 

Nahfeldtrupps watched Hitler's Headquarters for weeks. But again no trace was 

found of any suspicious radio connection. 

It could not be found, for it had never 

existed. The information for the "Rote 

Drei" had gone to Bado by completely different, simpler ways. 

(Editor's note: While the nature of the 

indicated "simpler ways" of conveying this 

information from Hitler's headquarters is 

not related in other portions of the manuscript, which can be revealed, it is hinted that the material was brought out directly by certain personnel and was not 

transmitted by radio.) 

PONY E:Ja>RESS 

!t's older than you think. M3.rco Polo 

relates that Genghis Khan, ruler ofChinese 

Tartary, had a courier service similiar to 

the pony express nearly a thousand years 

ago. Relay stations were provided about 

every twenty five miles, and the couriers, 

by changing mounts at each station, could 

deliver messages as far as 300 miles away 

in a single day. 

13 
REF ID:A59250 

Receiver Tuning 

for Manual Nets 

(El eP.Lf illeBtial) 

SFC Henry D Pruden 

In line with the training program employed by Operational Training, M::>ree Branch, 

The Army Security Agency Training Center, 

Fort Devens, Mteeachueette, it baa been 

found that proficiency in copying manual 

speed Moree stations may be better obtained if nets using two or more stations are 

used in the training program. The problem 

encountered was in finding a method of 

giving the students actual receiver tuning 

in connection with the copying of manual 

nets, using procedures other than International Point-to-Point. As the type nets 

desired for manual copy could not be heard 

at this station because the power output 

of the transmitters was too low to carry 

this far, some method bad to be devised to 

get nets available so that the students 

would have to tune their receivers prior 

to copying the traffic. We previously bad 

been able to give them ~he type nets desired by using TG-10 keyers e.nd inked tape 

but we only bad an audio signal to "patch" 

to the students' racks. This method gave 

the students practice in copying manual 

nets but no practice whatsoever in receiver tuning; in fact, the receiver had to be 

turned to the "send" position so that very 

rstrong signals coming over the air would 

'not block the output of the TG-10 keyer. 

Due to the classification of the nets 

we desired the students to copy, we could 

not put transmitters on the air e.nd have 

them actually tune these transmitters in 

while the instructors sent the traffic because other persons couldalso tune receivers to the working frequencies. Jn short, 

we bad to put a transmitter an the air for 

the benefit of the students and have no 

''output, outside of the immediate vicinit7 

of the Operational Training room. 

M;y" idea was to use the TG-10 keyer audio output to key the RF output of the frequency meter and then "patch" this keyed 

RF signal to the students' raeks through 

14 

multi-couplers, with no receiving antenna 

attached. The "make-break" circuit of the 

'l'G-10 keyer was not sharp enough to key 

the frequency meter properly, but by the 

insertion ofa sensitive relay (255A Belay) 

in the ''B" plus circuit of the frequency 

meter ~ower supply and ths audio output of 

the TG-10 keyer, a sharp "make - break" 

could be obtained and this RF output "piped" to the students' racks through the 

multi-coupler with no antenna attached, 

therefore, giving no RF output except in 

the Operational Training room. This method 

worked perfectly and by inserting a switch 

across the relay the frequency meter could 

be used to measure frequencies normally 

when desired. 

Using this arrangement, students are 

given an a'PProximate frequency range to 

search for nets. The instructor sets the 

frequency meter to a desired frequency, 

turns on the TG-10 keyer with the type net 

desired (inked tape that baa been previously made U'P by the instructor is used in the 

'l'G-10 keyer, which method of preparation 

will be described in detail later), and 

turns on the relay that is keyed by the 

audio output of the TG-10 keyer. The instructor then takes the receiving antenna 

out of the multi-couplers and substitutes 

the RP' output of the frequency meter. The 

students' racks are then "patched" into 

these nru.lti-couplers and when the students 

tune their receivers to the correct frequency, they are able to copy the nets. 

By putting the training generator output through the audio line to the students 

racks, the instructor is able to provide 

several different types of interference on 

the nets, thus giving the students simulated field experience. 

By using a TG-10 keyer in conjunction 

with a modified frequency meter as explained above, the students have to tune their 

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