Navy RAS Receiver

RAS Spec Sheets

ras2-120301.jpg (51581 bytes)

ras2-120302.jpg (94315 bytes) ras2-120303.jpg (73240 bytes) ras2-120304.jpg (117441 bytes)
ras2-120305.jpg (95887 bytes)

ras2-120310.jpg (89790 bytes)

ras2-120306.jpg (155080 bytes)

ras2-120309.jpg (62692 bytes)

ras2-120307.jpg (49376 bytes) ras2-120308.jpg (71293 bytes)

ras2-1101.jpg (63858 bytes)

ras2-1102.jpg (63823 bytes) ras2-1103.jpg (82036 bytes) ras2-1105.jpg (84041 bytes)
ras2-1104.jpg (186580 bytes) ras2-1106.jpg (143287 bytes) ras2-1107.jpg (165867 bytes)

ras2-1108.jpg (147321 bytes)

ras2-1109.jpg (78568 bytes)

RAS-2 Power Supply
ras2-ps-0211-1301.jpg (24754 bytes)

ras2-ps-0211-1302.jpg (35948 bytes) ras2-ps-0211-1303.jpg (31498 bytes) ras2-ps-0211-1304.jpg (38579 bytes)

ras4-0211-1300.jpg (89750 bytes)

ras4-0211-1301.jpg (95770 bytes) ras4-0211-1302.jpg (93778 bytes) ras4-0211-1303.jpg (99909 bytes)
ras4-0211-1304.jpg (103336 bytes) ras4-0211-1305.jpg (81701 bytes) ras4-0211-1306.jpg (55393 bytes)  

RAS5-01.jpg (55979 bytes)

RAS5-02.jpg (41823 bytes) RAS5-03.jpg (64647 bytes) RAS5-04.jpg (45569 bytes)
RAS5-09.jpg (107141 bytes) RAS5-05.jpg (110916 bytes)

RAS5-06.jpg (104123 bytes)

RAS5-07.jpg (94381 bytes)

RAS5-08.jpg (80253 bytes)

ras5-101.jpg (80686 bytes)
ras5-301.JPG (19896 bytes) ras5-303.jpg (15320 bytes)

ras5-305.jpg (10200 bytes)

ras5-306.jpg (16209 bytes)

ras5-310.jpg (14234 bytes)

ras5-307.jpg (13097 bytes) ras5-308.jpg (15380 bytes) ras5-309.jpg (15146 bytes) ras5-311.jpg (13733 bytes)
ras5-315.jpg (13634 bytes) --
ras5-131.jpg (328578 bytes) ras5-132.jpg (427243 bytes) ras5-133.jpg (311620 bytes) ras5-144.jpg (395109 bytes)
ras5-136.jpg (340211 bytes) ras5-137.jpg (310111 bytes) ras5-138.jpg (277934 bytes) ras5-139.jpg (406186 bytes)
ras5-140.jpg (414065 bytes) ras5-141.jpg (417743 bytes) ras5-142.jpg (333851 bytes) ras5-143.jpg (297028 bytes)
ras5-134.jpg (311334 bytes) - - ras5-120303.JPG (48735 bytes)
ras5-34.jpg (22858 bytes)

ras5-32.jpg (16649 bytes)

ras5-33.jpg (23107 bytes)

ras5-120301.JPG (28629 bytes) ras5-120302.JPG (66904 bytes)

ras5-1603-0269.jpg (3197893 bytes)

ras5-1603-0277.jpg (2910822 bytes) ras5-1603-0283.jpg (2998472 bytes) ras5-1603-0273.JPG (2479212 bytes)
ras5-1603-0274.JPG (2485271 bytes) ras5-1603-0270.jpg (2972021 bytes) ras5-1603-0272.JPG (2466447 bytes) --

RAS-5 Power Supply
ras5-ps-1300.jpg (95755 bytes)

ras5-ps-1301.jpg (98228 bytes) ras5-ps-1303.jpg (98242 bytes) ras5-ps-1304.jpg (80347 bytes)

RAS Coils
ras-coils-1300.jpg (104522 bytes)

ras-coils-1301.jpg (112707 bytes) ras-coils-1302.jpg (112823 bytes) ras-coils-1303.jpg (106185 bytes)
ras-coils-1304.jpg (111711 bytes) ras-coils-1305.jpg (108261 bytes) ras-coils-1306.jpg (109286 bytes) --

RAS (model number?)
ras-120220-01.jpg (33800 bytes)

ras-120220-02.jpg (41956 bytes) ras-120220-03.jpg (28263 bytes) ras-120220-04.jpg (19932 bytes)
ras-120220-05.jpg (21644 bytes) ras-120220-06.jpg (24545 bytes) ras-120220-07.jpg (34913 bytes) ras-120220-08.jpg (33622 bytes)
ras-120220-09.jpg (30052 bytes) ras-120220-10.jpg (28138 bytes) ras-120220-11.jpg (26632 bytes) ras-120220-12.jpg (29869 bytes)

RAS Vibrator Power Supply
ras-ps-20146-1603-01.jpg (471455 bytes)

6v dc input

ras-ps-20146-1603-02.jpg (476030 bytes)

ras-ps-20146-1603-03.jpg (460340 bytes) ras-ps-20146-1603-04.jpg (345606 bytes)
ras-ps-20146-1603-05.jpg (358242 bytes) ras-ps-20146-1603-06.jpg (351912 bytes) ras-ps-20146-1603-07.jpg (500553 bytes) ras-ps-20146-1603-08.jpg (509586 bytes)

RAS Noise Peak Limiter (CKB-50142)
ras-lim-01.jpg (26251 bytes)

ras-lim-02.jpg (34258 bytes) ras-lim-ckb50142-1101.jpg (13288 bytes) RAS_NL-1602-01.jpg (71682 bytes)
RAS_NL-1602-02.jpg (70157 bytes) CKB-50142 Manual download -- --
I found this interesting info from the testimony of Hoffman's chief engineer in a trial (Mission Bell changed its name to Hoffman)
(Testimony of Walter S. Harmon.)
"We had an item which was known as the noise peak limiter adapter. If we want to speak of inventions or original design, that definitely was, including constructing a complete unit which was conceived by us in its entirety. The purpose of the equipment was to limit noise peaks on communication receivers. The theory behind it was by certain circuit configurations we could make the receiver respond to wave forms of pure sine wave, which normal communications signals are. Noises are random wave forms; by that I mean they are not a pure sine wave. I don't know whether anybody knows what a pure sine wave is or not, but anyway, that is a wave of uniform shape, whereas noise peaks are a random form. To put it plainly, the idea was that you could not take a square block and put it through a round hole.

Now, that is essentially what the noise peak limiter was. As I say, it was originated by Hoffman Radio Corporation and submitted to the Navy Department and subsequently ended up in a small production contract, I believe the figure was 2280 units. [note - this is the correct figure for the CKB-50142]

We also produced along that same line an electronic relay. Again the purpose of the relay was to limit noise. That was adaptable only to communication receivers, not receivers using voice frequencies, but rather code frequencies or code signals, I should say. That was developed by us and offered to the Navy Department as a new development. It was very effective. Tests at the Naval Research Laboratory indicated that noise reduction was in the order of 120 decibels. 120 decibels means that that was a million to one ratio. In other words, to give the same amount of sound from the receiver the noise had to be a million times stronger than the desired signal, which for all practical purposes means there was no noise, in that your ear could not differentiate between a million to one ratio in sound. There was a great deal of pure development work went into that device. It did fill a need.

The Navy Department first issued a development contract to produce 10 of these units. I don't recall just where they were sent. I know of one unit that was sent into the Alaskan area, where they were troubled with very heavy static, another went into Honolulu, which was another noisy area, I believe one went into Florida; the rest of the 10 I am not sure where they went, but anyway they were shipped into areas where noise was a factor, and the field tests showed that the instrument was very effective. I think later that ended up in a production order for a redesigned unit. However, it does not come into the period with which we are concerned.

On this noise peak limiter we also developed, as I recall, three different types. One was made as an accessory for the Navy—I believe it was the RAS receiver. Another one was made for the SX-28 receiver. Still another one was made for the ARB. The purpose of all of them was the same, just a matter of adapting them to receivers.

Now, that was an accessory that could be sent out into the field where they had noise and they had a certain type of receiver. This adapter could be plugged into the receiver, and it was very effective in reducing noise, which means that communication was made possible in some cases where it would not have been otherwise."