Re: Si-diodes in Second World War radar & Communication equipment

On Thu, 20 Aug 2009 20:30:19 -0700, John Larkin
<(E-Mail Removed)> wrote:

>On Thu, 20 Aug 2009 22:07:46 -0500, "Martin H. Eastburn"
><(E-Mail Removed)> wrote:
>
>>First, Si diodes were not used in WW II. The PN SI diode wasn't invented yet.
>
>Nearly all the radar first mixer diodes were silicon point-contact
>types, essentially silicon schottky diodes.
>
>See the MIT Rad Lab book, volume 15, "Crystal Rectifiers" for a bunch
>of WWII (and pre-war) stuff about diode development. This is from that
>book:
>
>ftp://jjlarkin.lmi.net/RadDiode2.JPG
>
>ftp://jjlarkin.lmi.net/RadLabDiodes.JPG
>
>>Selenium wafers and sticks were the power types
>>and point or whisker diodes for RF. [ I have some of these in lead cans ]
>>
>>In the 60's it was still that way.
>
>Funny, I recall using lots of silicon PN diodes (and SCRs, and
>transistors, and tunnel diodes) in the early 1960's. Tek was using
>GaAs diodes in their sampling scopes ca 1964.
>
>>Silicon diodes were developed by bell labs for internal telephone use
>>but semiconductor had to be invented first.
>
>No. See the RadLab book.
>
>>Look at the date of the transistor. Silicon diode and Germanium diode.
>>
>>I know Radar in B52's were using Selenium and Germanium for RF.
>
>Selenium was never used in RF or radar, except maybe power supplies.
>Far too slow.
>
>John

It was certainly used in the power supplies. Not maybe. I actually
owned a radar unit that was commissioned for navy service in 1944.
Nice selenium series stacks used as diodes in at least some of the
power supplies. Also used vacuum tube VR150's for regulators.

Jon

On Fri, 21 Aug 2009 10:30:09 +0100, "christofire"
<(E-Mail Removed)> wrote:

>
>"Jon Kirwan" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> On Thu, 20 Aug 2009 20:30:19 -0700, John Larkin
>> <(E-Mail Removed)> wrote:
>>
>>>On Thu, 20 Aug 2009 22:07:46 -0500, "Martin H. Eastburn"
>>><(E-Mail Removed)> wrote:
>>>
>>>>First, Si diodes were not used in WW II. The PN SI diode wasn't invented
>>>>yet.
>>>
>>>Nearly all the radar first mixer diodes were silicon point-contact
>>>types, essentially silicon schottky diodes.
>>>
>>>See the MIT Rad Lab book, volume 15, "Crystal Rectifiers" for a bunch
>>>of WWII (and pre-war) stuff about diode development. This is from that
>>>book:
>>>
>>>ftp://jjlarkin.lmi.net/RadDiode2.JPG
>>>
>>>ftp://jjlarkin.lmi.net/RadLabDiodes.JPG
>>>
>>>>Selenium wafers and sticks were the power types
>>>>and point or whisker diodes for RF. [ I have some of these in lead
>>>>cans ]
>>>>
>>>>In the 60's it was still that way.
>>>
>>>Funny, I recall using lots of silicon PN diodes (and SCRs, and
>>>transistors, and tunnel diodes) in the early 1960's. Tek was using
>>>GaAs diodes in their sampling scopes ca 1964.
>>>
>>>>Silicon diodes were developed by bell labs for internal telephone use
>>>>but semiconductor had to be invented first.
>>>
>>>No. See the RadLab book.
>>>
>>>>Look at the date of the transistor. Silicon diode and Germanium diode.
>>>>
>>>>I know Radar in B52's were using Selenium and Germanium for RF.
>>>
>>>Selenium was never used in RF or radar, except maybe power supplies.
>>>Far too slow.
>>>
>>>John
>>
>> It was certainly used in the power supplies. Not maybe. I actually
>> owned a radar unit that was commissioned for navy service in 1944.
>> Nice selenium series stacks used as diodes in at least some of the
>> power supplies. Also used vacuum tube VR150's for regulators.
>>
>> Jon
>
>VR150 is not a vacuum tube - it's gas filled (argon/neon), cold cathode.

Sorry. My mistake. Looked like one, and of course you are correct.

Jon