EMRFD Message Archive 7697
Message Date From Subject 7697 2012-08-29 08:12:19 nm0s_qrp Survival of Ancient ICs
73 Dave NM0S7698 2012-08-29 08:18:00 Chris Trask Re: Survival of Ancient ICs
> I was chatting recently with some colleagues regarding the demise of
> many of the classic parts that seemed to be commonly used in QRP
> projects of 30 years ago... dual gate MOSFETs, metal-can transistors,
> etc. Interestingly enough, I found that one old dinosaur is still in
> production - the CA3028A differential amplifier.
> http://www.amazon.com/American-Microsemiconductor-CA3028A/dp/B001GQEVSO
> I used to use this part in a number of direct conversion rigs
> (pre-NE602!), and it's oddly comforting that maybe it will be around
> for another generation of experimenters.
>
A few of the other transistor arrays devised by RCA still survive, such as the CA3046 and CA3096. I still use those occasionally for new designs as they are well suited for applications where parameter and temperature matching are needed.
Chris Trask
N7ZWY / WDX3HLB
Senior Member IEEE
http://www.home.earthlink.net/~christrask/7699 2012-08-29 08:18:02 Garey Barrell Re: Survival of Ancient ICs
Not likely 'still in production'. American Semi is a 'legacy' supplier, and the part in the photo
was made in 1963!
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
nm0s_qrp wrote:
> I was chatting recently with some colleagues regarding the demise of many of the classic parts that seemed to be commonly used in QRP projects of 30 years ago... dual gate MOSFETs, metal-can transistors, etc. Interestingly enough, I found that one old dinosaur is still in production - the CA3028A differential amplifier. http://www.amazon.com/American-Microsemiconductor-CA3028A/dp/B001GQEVSO I used to use this part in a number of direct conversion rigs (pre-NE602!), and it's oddly comforting that maybe it will be around for another generation of experimenters.
>
> 73 Dave NM0S
>7700 2012-08-29 08:19:03 Dino Papas Re: Survival of Ancient ICs
73 - Dino KL0S
(couldn't resist replying as our calls are so similar!)
On Aug292012, at 1112 AM, nm0s_qrp wrote:
> I was chatting recently with some colleagues regarding the demise of many of the classic parts that seemed to be commonly used in QRP projects of 30 years ago... dual gate MOSFETs, metal-can transistors, etc. Interestingly enough, I found that one old dinosaur is still in production - the CA3028A differential amplifier. http://www.amazon.com/American-Microsemiconductor-CA3028A/dp/B001GQEVSO I used to use this part in a number of direct conversion rigs (pre-NE602!), and it's oddly comforting that maybe it will be around for another generation of experimenters.
>
> 73 Dave NM0S
[Non-text portions of this message have been removed]7701 2012-08-29 08:40:52 Paul Daulton Re: Survival of Ancient ICs
directional amp for a project.
Making up an order to restock the parts bin I found Digikey doesnt
stock the mpf102(obsolete) and Mouser has 7800 but lists them as end
of life. I'll miss that device.
In my SESE80 rec(Qrp-q winter 2011) I used a singly balanced mixer
using descrete compontents as the "Descrete component DC rec" in the
first chapter of EMRFD did. Same layout as CA3028 mixers back in the
60' and 70's.
Its a mystery to me that the Ne602 which has become the mainstay of
qrp designs has remained in production this long. Glad the ca3028 is
still around.
Paul
Quoting nm0s_qrp :
I was chatting recently with some colleagues regarding the demise of
many of the classic parts that seemed to be commonly used in QRP
projects of 30 years ago... dual gate MOSFETs, metal-can transistors,
etc. Interestingly enough, I found that one old dinosaur is still in
production - the CA3028A differential amplifier.
http://www.amazon.com/American-Microsemiconductor-CA3028A/dp/B001GQEVSO
I used to use this part in a number of direct conversion rigs
(pre-NE602!), and it's oddly comforting that maybe it will be around
for another generation of experimenters.
73 Dave NM0S
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
[Non-text portions of this message have been removed]7702 2012-08-29 10:37:41 Jim Kortge Re: Survival of Ancient ICs 7703 2012-08-29 12:14:54 rlramirez77 Re: Survival of Ancient ICs
BTW, Dave your call is awesome.
Russ
K0WFS
7704 2012-08-29 12:14:58 John Dignan Re: Survival of Ancient ICs
CA3028a got me thinking, I had a look around in my transistor collection and sure enough, I found I have a pair of the old metal can types. What I don't have is any QRP schematics for one. It would be nice to build a project around one,rather than just letting them rust away. Do you guys have any old schematics that utilizes them?
Best Regards
John M0JJD
[Non-text portions of this message have been removed]7705 2012-08-29 14:50:56 kb1gmx Re: Survival of Ancient ICs 7706 2012-08-29 15:21:39 William Carver Re: Survival of Ancient ICs
bias. Many of the published circuits weren't reproducible because your
MPF102 wasn't anything like the authors.
For a GG circuit better to use a J310. In other applications where lower
Idss is needed a different JFET might be better choice than the J310.
W7AAZ
>7707 2012-08-29 20:50:06 David Snowdon Re: Survival of Ancient ICs
Radio Amateur" by DeMaw
and Hayward. ARRL handbooks from the mid '70s to early '90s had a few
circuits using the CA3028.
David, VA3DKS
7709 2012-08-30 06:48:59 nm0s_qrp Re: Survival of Ancient ICs
73 Dave NM0S
7711 2012-08-30 09:04:52 Paul Daulton Re: Survival of Ancient ICs
bidirectional amp in grounded gate configuration. The mpf102 and 2n3819
share a unique property in that they are symetrical in constructi7712 2012-08-30 09:33:21 William Carver Re: Survival of Ancient ICs
> Dave the application for the mpf102 I had in mind was aI remember the interchangeability of the MPF102 leads, Paul.
> bidirectional amp in grounded gate configuration. The mpf102 and
> 2n3819 share a unique property in that they are symetrical in
> construction and the drain and source leads are interchangeable. this
> makes a bidirectional amp easy by reversing polarity.
I just pulled out a J310 and with 100 ohm source resistor and 5 volts on
the drain, the drain current was 10 mA. I ran the voltage to 20 volts
and current was same (as it should be).
Then I swapped drain and source and put 5 volts on it, same 100 ohms in
the swapped lead. 10 mA. Hmmmm. I ran the voltage up....to above 30
volts....and the current stayed right at 10 mA. From a DC standpoint it
seems the MOTOROLA J310s in my inventory are symmetrical.
I HAVE to go on vacation. DAMN! Maybe I can find enough time before
departure to build up a little tuned amplifier and see if it works the
same way with drain and source swapped.
W7AAZ7713 2012-08-30 09:59:51 Paul Daulton Re: Survival of Ancient ICs
many projects to try right now. Not many apps for the bi directional
amp but its nice to know the capabilities of out devices.
73 Paul
Quoting William Carver :
On Thu, 2012-08-30 at 16:04 +0000, Paul Daulton wrote:
> Dave the application for the mpf102 I had in mind was a bidirectional
> amp in grounded gate configuration. The mpf102 and
> 2n3819 share a unique property in that they are symetrical in
> construction and the drain and source leads are interchangeable. this
> makes a bidirectional amp easy by reversing polarity.
I remember the interchangeability of the MPF102 leads, Paul.
I just pulled out a J310 and with 100 ohm source resistor and 5 volts on
the drain, the drain current was 10 mA. I ran the voltage to 20 volts
and current was same (as it should be).
Then I swapped drain and source and put 5 volts on it, same 100 ohms in
the swapped lead. 10 mA. Hmmmm. I ran the voltage up....to above 30
volts....and the current stayed right at 10 mA. From a DC standpoint it
seems the MOTOROLA J310s in my inventory are symmetrical.
I HAVE to go on vacation. DAMN! Maybe I can find enough time before
departure to build up a little tuned amplifier and see if it works the
same way with drain and source swapped.
W7AAZ
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
[Non-text portions of this message have been removed]7714 2012-08-30 10:48:46 Ashhar Farhan Re: Survival of Ancient ICs
government) still manufactures CA3028As. here is their catalog
http://bel-india.com/BELWebsite/images/ic.pdf
they are suppliers to the defense sector. hence, most of their stuff is
milspec. they are expensive. I would guess that the CA3028A would cost
about four dollars or more.
- Farhan
7715 2012-08-30 11:12:55 Dean Blake Re: Survival of Ancient ICs
I see these IC 8 pin amps for a couple bucks. still available...
K4DSB
Dean
> To: emrfd@yahoogroups.com
> From: farhanbox@gmail.com
> Date: Thu, 30 Aug 2012 23:18:45 +0530
> Subject: Re: [emrfd] Survival of Ancient ICs
>
> bel (bharat electronics ltd) an india public sector company (owned by the
> government) still manufactures CA3028As. here is their catalog
> http://bel-india.com/BELWebsite/images/ic.pdf
> they are suppliers to the defense sector. hence, most of their stuff is
> milspec. they are expensive. I would guess that the CA3028A would cost
> about four dollars or more.
>
> - Farhan
>
>7716 2012-08-30 13:54:54 William Carver Re: Survival of Ancient ICs
JFET into a bilateral amplifier. Probably more DC switching ciruitry
than just adding a second JFET, hi!
Bill
On Thu, 2012-08-30 at 16:59 +0000, Paul Daulton wrote:
>
>
>
> William let us know how the j310 works. I have a few of those, too
> many projects to try right now. Not many apps for the bi directional
> amp but its nice to know the capabilities of out devices.
>
> 73 Paul
>
> Quoting William Carver :
>
> On Thu, 2012-08-30 at 16:04 +0000, Paul Daulton wrote:
>
> > Dave the application for the mpf102 I had in mind was a
> bidirectional
> > amp in grounded gate configuration. The mpf102 and
> > 2n3819 share a unique property in that they are symetrical in
> > construction and the drain and source leads are interchangeable.
> this
> > makes a bidirectional amp easy by reversing polarity.
>
> I remember the interchangeability of the MPF102 leads, Paul.
>
> I just pulled out a J310 and with 100 ohm source resistor and 5 volts
> on
> the drain, the drain current was 10 mA. I ran the voltage to 20 volts
> and current was same (as it should be).
>
> Then I swapped drain and source and put 5 volts on it, same 100 ohms
> in
> the swapped lead. 10 mA. Hmmmm. I ran the voltage up....to above 30
> volts....and the current stayed right at 10 mA. From a DC standpoint
> it
> seems the MOTOROLA J310s in my inventory are symmetrical.
>
> I HAVE to go on vacation. DAMN! Maybe I can find enough time before
> departure to build up a little tuned amplifier and see if it works the
> same way with drain and source swapped.
>
> W7AAZ
>
> Paul Daulton K5WMS
> beacon WMS 185.302 khz qrss30/slow 24/7
> Jacksonville,Ar 72076
> em34wu
>
> [Non-text portions of this message have been removed]
>
>
>
>
>7717 2012-08-30 15:21:31 john lawson Re: Survival of Ancient ICs 7718 2012-08-31 03:47:05 Gian Re: Survival of Ancient ICs 7719 2012-08-31 07:51:07 William Carver Re: Survival of Ancient ICs
It will be hot, probably well over 110F, for part of the trip. But soon
temperatures should start dropping, then snow. It cannot come too soon.
Bill7720 2012-08-31 09:30:11 James Duffey Re: Survival of Ancient ICs
The j310 and other modern JFETs are much better choices than the MPF102. The J310 is readily available and inexpensive. It is very good in grounded gate applications as it is has lowest noise figure when the input and output are around 50 to 100 ohms.
The mpf102 while popular, is not a well defined part and is not well controlled with respect to many parameters. Especially for grounded gate applications the j310 is a much better part. I suspect that over time a lot of JFETs of various types were packaged as mpf102s when they did not pass their original qual tests. I think originally that mpf102s were 2n3819s with parameters that fell outside the standard which Motorola then packaged in a plastic package and made available to hobbyists at lower prices. The specs were looser as well, but at least written down - Duffey KK6MC
James Duffey
Cedar Crest NM7721 2012-08-31 20:09:42 John Dignan Re: Survival of Ancient ICs
I just checked out the price on Amazon for a copy on of Solid State Design For the Radio Amateur...I think I'll have to pass...128 GB Pounds! I think I'll see if I can find one cheaper at a rally sometime!
However, if you have a copy to sell, at a reasonable price I'd be interested :-)
Best regards
John
________________________________
From: David Snowd7722 2012-08-31 20:09:46 rlramirez77 Re: Survival of Ancient ICs
Russ
K0WFS
7723 2012-09-01 00:37:00 g4shj Re: Survival of Ancient ICs
The British Library has a copy, which your local library will be able to borrow for you (you may have to pay the postage).
Regards
Neil Douglas
G4SHJ
7724 2012-09-01 15:44:05 gareth evans Re: Survival of Ancient ICs
Radio Amateur" (Sorry , the digest reply option does not
copy the original text, don't bother. Go instead for
its updated replacement, "Experimental methods in RF design "7725 2012-09-01 15:44:08 rlramirez77 Re: Survival of Ancient ICs
Russ
K0WFS
7726 2012-09-01 20:29:22 Gene Re: Survival of Ancient ICs
I have a copy of those books that are considered the QRP homebrewer's bible(s). If you need a copy of a specific article from one of the books I can scan and email.
The most useful books in my library are on my links page of my web in the top of the left-hand column. See: http://www.w5dor.com/W5DOR-Links.html
EMRFD I purchased from ARRL but the rest I bid for on eBay. I set a limit on how much I wanted to pay and patiently bid until I managed to get them. I also purchased a few that were useless. I'm gonna sell them on eBay.
I'm starting a QRP construction project that will use Doug's (N3ZI)DDS 2 for both receive and transmit. I'll document it on my web and let ya'll know when posted.
I have a pretty comprehensive junk box so if any of ya'll can't find an old part let me know and maybe I can find one. A lot of the parts used in the projects described in the older books are not in production anymore and may be hard to find. An example is the 40673 dual-gate FET. I have 3 of them but that's it. There is a modern day substitute for it but I can't find the email that told about it. If any of ya'll know please let me know.
Happy QRP homebrewing to all !!!
Gene, W5DOR
gene@w5dor.como
www.w5dor.com
7727 2012-09-02 03:38:07 dx11 Re: Survival of Ancient ICs
There is a modern day substitute for it but I can't find the email that told
about it. If any of ya'll know please let me know.
I remember reading that email it was in, I think it is the BF981 or 982.
Cor Beijersbergen7728 2012-09-02 04:29:50 Russell Shaw Re: Survival of Ancient ICs 7729 2012-09-02 10:20:54 john lawson Re: Survival of Ancient ICs 7730 2012-09-02 18:41:43 Gene Re: Survival of Ancient ICs
Gene, W5DOR
7731 2012-09-02 18:41:48 William Re: Survival of Ancient ICs
Just checked Mouser and the BF998 is listed for about 40 cents. And the package is perfect for Manhattan style breadboarding.
http://www.mouser.com/Search/Refine.aspx?Keyword=BF998
Bill N7EU7732 2012-09-03 03:44:36 Gian Re: Survival of Ancient ICs
with all my 2t H-Mode Mixer mods on commercial equipment I have also included the replacement of the original DGM like 3SK74, 3SK73, 3SK88, 3SK81, 3SK51 etc with the BF998R. This has a nice pins configuration as you can soldered under the pcb over the circuit tracks side. There are no problems and you gain in lower receiver noise. In some stages you may not "feel too much difference but replacement is suggested.
Where I have experimented mods, where BF998R has been used, are: FT901,902,101ZD; IC751,751A,761,765,781; TS830,930,940
http://it.mouser.com/Semiconductors/_/N-5gcb?Keyword=BF998R&FS=True
73
Gian
I7SWX7755 2012-09-08 08:37:40 kb1gmx Re: Survival of Ancient ICs
I bought a pot load of them a while back for various uses as a replacement for DG-mosfets. I found a long time ago that the
DG-mosfets were very tolerant to substitution. I've since used
the BF998 as a general replacement for many designs and old
radio using 3SK45s and 400673. Doesn't hurt that they are
cheaper than any DG-mosfets even in their peaks years.
NOTE the BF series has parts of identical specs but different
pins out to make circuit layout easier. It's handy to have
identical parts with mirror image pinouts. Makes balanced
mixers and other symmetrical circuits actually layout that way.
Allison