|
rob34 wrote:
I have a small quantity of RCA 40673 mosfets for anyone interested. I will sell them for $2.50 each. These are NOS and I am selling them at half the market value. If you get them through NTE they are over $11.00 or you get them through Dan`s small parts (if he has any) at$5.00 each. Thanks, Rob Thank`s for all the replies!! I have sold them and I am going to try to scronge some more. MERRY CHRISTMAS TO ALL!!!! |
I think I remember the number from the dlate 1960s but can't recall what
their main use was, refreesher? Hank- The RCA 40673 Dual Gate MOSFET was used as a low noise VHF RF Preamp in the early 1970s. There were at least two preamp kits popular at the time, such as the one from Topeka FM & Engineering. I used such a preamp on my Regency HR-2A, supposedly improving the sensitivity from 0.35 uV to 0.2 uV. Of course there was an increase in intermodulation interference that came with it! While there are many such pieces of equipment still in use, there are newer devices that can be used as a replacement for the 40673. An example (only slightly newer) is the 3N201. Today's FM rigs typically have better sensitivity even without an additional preamplifier. 73, Fred, K4DII |
I think I remember the number from the dlate 1960s but can't recall what
their main use was, refreesher? Hank- The RCA 40673 Dual Gate MOSFET was used as a low noise VHF RF Preamp in the early 1970s. There were at least two preamp kits popular at the time, such as the one from Topeka FM & Engineering. I used such a preamp on my Regency HR-2A, supposedly improving the sensitivity from 0.35 uV to 0.2 uV. Of course there was an increase in intermodulation interference that came with it! While there are many such pieces of equipment still in use, there are newer devices that can be used as a replacement for the 40673. An example (only slightly newer) is the 3N201. Today's FM rigs typically have better sensitivity even without an additional preamplifier. 73, Fred, K4DII |
|
|
J. Yazel ) writes:
On 16 Dec 2003 23:42:13 GMT, (JGBOYLES) wrote: I think I remember the number from the dlate 1960s but can't recall what their main use was The 40673 as I recall was a dual gate FET. Used in mixers and other stuff dual gates were used. They were in a small metal package (TO-??) with 4 leads. I think I remember their orginal application was CB xcvrs. 73 Gary N4AST =========================== Some years ago, all of the radio magazines had many articles with 40673's. About every third article had at least one (slight exaggeration). Jack W8RAG That's not really a surprise. It's always been a constant that a handful of parts are used in the magazines. By sticking to a few parts, it guarantees that you will be able to get those parts, since small companies that deal with the hobbyist will carry those parts. And then in turn it guarantees that the parts will be used. Besides, many articles were traditionaly a variant on something that had already been published. So someone looks in the magazines, and picks parts (or even whole circuits) based on what they see, and then write about it. I've always tended to look at those common parts as a designator for a generic category of something. So a 40673 is a dual gate MOSFET, and likely some other similar part will fit the situation. After all, if someone was going for extreme performance, it would not be a common part. Michael VE2BVW |
J. Yazel ) writes:
On 16 Dec 2003 23:42:13 GMT, (JGBOYLES) wrote: I think I remember the number from the dlate 1960s but can't recall what their main use was The 40673 as I recall was a dual gate FET. Used in mixers and other stuff dual gates were used. They were in a small metal package (TO-??) with 4 leads. I think I remember their orginal application was CB xcvrs. 73 Gary N4AST =========================== Some years ago, all of the radio magazines had many articles with 40673's. About every third article had at least one (slight exaggeration). Jack W8RAG That's not really a surprise. It's always been a constant that a handful of parts are used in the magazines. By sticking to a few parts, it guarantees that you will be able to get those parts, since small companies that deal with the hobbyist will carry those parts. And then in turn it guarantees that the parts will be used. Besides, many articles were traditionaly a variant on something that had already been published. So someone looks in the magazines, and picks parts (or even whole circuits) based on what they see, and then write about it. I've always tended to look at those common parts as a designator for a generic category of something. So a 40673 is a dual gate MOSFET, and likely some other similar part will fit the situation. After all, if someone was going for extreme performance, it would not be a common part. Michael VE2BVW |
Some years ago, all of the radio magazines had many articles with 40673's. About every third article had at least one (slight exaggeration). Jack W8RAG That's not really a surprise. It's always been a constant that a handful of parts are used in the magazines. By sticking to a few parts, it guarantees that you will be able to get those parts, since small companies that deal with the hobbyist will carry those parts. And then in turn it guarantees that the parts will be used. Besides, many articles were traditionaly a variant on something that had already been published. So someone looks in the magazines, and picks parts (or even whole circuits) based on what they see, and then write about it. I've always tended to look at those common parts as a designator for a generic category of something. So a 40673 is a dual gate MOSFET, and likely some other similar part will fit the situation. After all, if someone was going for extreme performance, it would not be a common part. Michael VE2BVW ===================================== That's a good idea except that few hams have the expertise to modify a circuit for a different IC even if it is similar. Jack W8RAG |
Some years ago, all of the radio magazines had many articles with 40673's. About every third article had at least one (slight exaggeration). Jack W8RAG That's not really a surprise. It's always been a constant that a handful of parts are used in the magazines. By sticking to a few parts, it guarantees that you will be able to get those parts, since small companies that deal with the hobbyist will carry those parts. And then in turn it guarantees that the parts will be used. Besides, many articles were traditionaly a variant on something that had already been published. So someone looks in the magazines, and picks parts (or even whole circuits) based on what they see, and then write about it. I've always tended to look at those common parts as a designator for a generic category of something. So a 40673 is a dual gate MOSFET, and likely some other similar part will fit the situation. After all, if someone was going for extreme performance, it would not be a common part. Michael VE2BVW ===================================== That's a good idea except that few hams have the expertise to modify a circuit for a different IC even if it is similar. Jack W8RAG |
*Heathkit* used a ****load of them in EVERYTHING they made. They were in
the 2 meter radios as a mixer and front end, even in the TVM's (Transistorized Volt Meters). The early solidstate "VTVM" (I know..they had tubes in them) but Heathkit had a solidstate one and they used it as a meter amplifier...Eddie "rob34" wrote in message ... rob34 wrote: I have a small quantity of RCA 40673 mosfets for anyone interested. I will sell them for $2.50 each. These are NOS and I am selling them at half the market value. If you get them through NTE they are over $11.00 or you get them through Dan`s small parts (if he has any) at$5.00 each. Thanks, Rob Thank`s for all the replies!! I have sold them and I am going to try to scronge some more. MERRY CHRISTMAS TO ALL!!!! |
| All times are GMT +1. The time now is 09:47 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com