The Brush Crystal Company of Shore Road, Hythe, Southampton, manufactured early transistors and diodes, germanium and silicon. In 1964 they were bought by Clevite Transistor Products, an American company that specialised in power transistors, and were renamed Brush Clevite Company. Their entry in Graces Guide tells no more than this (less, in fact), and I have found no more company history on the Web. However, other traces remain: an advertisement in 'Wireless World' February 1944 for 'hand crystal microphones' made by Brush, a Brush advertisement in 'Aeroplane' September 13th 1957 for quartz crystal units, and an article in 'Service Engineer' November 1961 about a 'new device designed to take the place of conventional trimmers and even gang capacitors' that was in fact a silicon varicap diode. The same article mentions five transistors in the OC700 series, and a 'new range of zener diodes'.
However, I know that most of the transistors and diodes branded Brush were also sold by the German firm Intermetall, which was also owned by Clevite. How this dual branding/manufacture worked is unclear.
On small devices, Brush usually used a small logo of a capital B in a diamond, often indistinctly printed. On larger ones, and some smaller ones, they used the word BRUSH in capitals.
I have two editions of the Brush 'semiconductors short form catalogue', dated May 1963 and May 1964. These contain germanium and silicon transistors in the OC series (with Intermetall-style 3-digit numbers), a small number of ASY types, and several series of Zener diodes. They do not contain the varicap diodes mentioned in 'Service Engineer' November 1961. If you have earlier editions, please
It seems that the OC700 series may be Brush Crystal's first series of transistors. They are silicon PNP types. The range includes several applications:
My images show OC700A, OC702 and OC703. I am seeking the other types, as well as the varicap diode mentioned above. If you know where I might obtain some, please
I do have one oddity which is this OC701. It is not in the small TO-1A outline, instead it uses the larger SO-2 metal. Furthermore it has a K printed low down on it. Some Intermetall transistors use this outline; they have a K suffix that stands for 'Kühlkörper' which means 'heatsink'. The Brush Crystal Semiconductors catalogue from 1963 does not explicitly list K versions of the OC700 series, but the diagram of the encapsulation shows the two shapes, implying that the entire range may have come in two versions.
If you can explain this, please
This OC706 is a puzzle. It is not in my Brush data books, or on radiomuseum. The supplier said it was used in Burns guitar amplifiers. The OC700 series does not seem to be shared with Intermetall, and is mentioned in the article in 'Service Engineer' that pre-dates the takeover by Clevite. Puzzlingly, the OC706 uses the same style of TO-1A outline as Intermetall's transistors, whereas other OC700 series types that I possess are slightly different.
If you have data for this type, please
The 1969 D.A.T.A 'Book of Discontinued Transistors' adds three types that I cannot find listed elsewhere:
My image shows the last of these. As far as I am aware, it is the only transistor in the OC8nn range not made by East Germany.
If you have original data for these types, please
The 1963 semiconductors short form catalogue also lists the following devices, all made by Intermetall as well as Brush:
- silicon transistors OC430, OC440, OC445, OC450 (shown), OC460, OC463, OC465, OC466, OC468, OC469, OC470, OC480 (shown)
- germanium transistors OC303, OC304/1, OC304/2, OC304/3, OC305/1, OC305/2, OC306/1, OC306/2, OC306/3
- germanium transistors OC307, OC308, OC309
- silicon Zeners ZB4.3 to ZB22
- silicon Zeners ZC4.7, ZC6.2, ZC8.2, ZC11, ZC15 (shown), ZC20
The 1964 semiconductors short form catalogue adds:
- germanium transistors OC307/1, OC307/2, OC307/3, OC309/1, OC309/2, OC309/3
- germanium transistors ASY12/1, ASY12/2, ASY13/1, ASY13/2, ASY14/1, ASY14/2, ASY14/3
- silicon Zeners ZX36 to ZX200
- silicon Zeners ZL39 to ZL180
I have none of the OC3nn or ASY types branded Brush, although I have a number branded Intermetall. If you know where I might obtain some Brush examples, please
Here is a Brush-branded power transistor: a 2N2063 germanium PNP alloy-junction high-power AF amplifier/switch. This is not listed in my Brush or Intermetall data books, and in fact the only good contemporary reference that I have found is the Motorola Semiconductor Handbook for 1966. Intermetall did not make power transistors, although they resold some Clevite types. It's very likely that this 2N2063 is a re-branded Clevite device, as the raised areas around the fixing holes are virtually unique to Clevite.
I would be interested in other Brush 2N types. If you know where I might obtain some, please
Like most UK semiconductor manufacturers, Brush made CV equivalents of their devices. These are military-grade versions of commercial types, given a Common Valve type designation. As well as the CV number, they should be identifiable by the manufacturer code VR for Brush Crystal Co., Hythe. There is a surprising number of Brush CV types, but I have none. About half are Zener diodes that are of only minor interest. There are also a few Intermetall types in the CV Register. I would like to acquire any of the following, or even just see an image of an example:
- CV5334 prototype OC450
- CV5352 prototype OC470 (I have some marked ITT, with no KB/xx manufacturer code).
- CV5699 prototype OY5067
- CV5700 prototype OY5061
- CV5970 prototype OC701K
- CV8007 prototype OC702K
- CV8551 prototype OC480K
- CV8565 prototype OC450K
- CV8683 prototype S33
- CV8807 prototype OC700
- CV8830 prototype OC440
- CV8831 prototype OC460
- CV8891 prototype OC701
- CV9164 prototype OY5062
- CV9494 prototype S35
- CV10139 prototype Intermetall OC466
If you know where I might obtain any of these, please
As with most manufacturers, I have several Brush devices that don't appear in my data books or on the Web. These are:
If you have data for any of these, please