Play with old chip CA3028


Adam Rong
 

Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam


Nigel Young ZL1NAY
 

Hi Adam,

That's awesome news, I was looking at this the other day,

I used bucket loads of these when I was younger, and now you can't find one anywhere, even in China. This chip was the NE555 of the day, everything used them. I eagerly await your experiments Adam.

Nigel ZL1NAY

On Fri, May 1, 2020 at 10:54 AM Adam Rong <rongxh@...> wrote:
Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam



--
Best Regards,

Nigel Young


rjtoegel@gmail.com
 

Yes, that was an old RCA chip.  I guess an ancestor of the NE602.  Also the CA3020 was a good AF amplifier chip.  Made many DC receivers with the pair.

Bob WA2EGP

On Thu, Apr 30, 2020, 18:54 Adam Rong <rongxh@...> wrote:
Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam


Nigel Young ZL1NAY
 

Yes, if it wasn't for Doug DeMaw and Wes Haywood  we would have all moved on. 
Now we all just have hundreds of dollars worth of qrp books with circuits non of us can build any more.
It is quite timely though, because only 2 days ago I was researching this same issue when I found the site linked earlier. 
For a moment I did contemplate making a few, but the feeling went away as a bunch of angry chips in my spares box started complaining. Namely an insane amount of MC1496s and NE602/612s. 
Nostalgia is a wonderful thing but sometimes we forget how bad some things actually were.
Let's hope with close tolerances and better silicon we can make this chip amp again, maybe better than it was before.

Nigel ZL1NAY

On Fri., 1 May 2020, 2:57 pm rjtoegel@..., <rjtoegel@...> wrote:
Yes, that was an old RCA chip.  I guess an ancestor of the NE602.  Also the CA3020 was a good AF amplifier chip.  Made many DC receivers with the pair.

Bob WA2EGP

On Thu, Apr 30, 2020, 18:54 Adam Rong <rongxh@...> wrote:
Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam


rjtoegel@gmail.com
 

I don't think it was that bad back then.  I don't know about your location but one thing we did have was quiet.  The background noise from digital stuff is horrendous today.  Computers, LED and fluorescent lights, other digital stuff.  One road I used for commuting to work and surrounded by stores used to be S3-5 background.  Now it pins the S-meter.  Even at home the background is a couple of S-units greater than it used to be.  Gives a new spin to the saying, "If you can't hear them, you can't work them."

Bob WA2EGP_,_._,_


Adam Rong
 

Nigel,

I don’t have the book Solid State Design but I do have Doug DeMaw’s QRP Notebook, and Wes Hayward’s EMRFD. I still can find some circuits containing CA3028. Now I have enough supply to try out these circuits. I have added two posts here.

Thanks,
Adam

在 2020年5月1日,上午11:12,Nigel Young <multilec@...> 写道:

Yes, if it wasn't for Doug DeMaw and Wes Haywood  we would have all moved on. 
Now we all just have hundreds of dollars worth of qrp books with circuits non of us can build any more.
It is quite timely though, because only 2 days ago I was researching this same issue when I found the site linked earlier. 
For a moment I did contemplate making a few, but the feeling went away as a bunch of angry chips in my spares box started complaining. Namely an insane amount of MC1496s and NE602/612s. 
Nostalgia is a wonderful thing but sometimes we forget how bad some things actually were.
Let's hope with close tolerances and better silicon we can make this chip amp again, maybe better than it was before.

Nigel ZL1NAY

On Fri., 1 May 2020, 2:57 pm rjtoegel@..., <rjtoegel@...> wrote:
Yes, that was an old RCA chip.  I guess an ancestor of the NE602.  Also the CA3020 was a good AF amplifier chip.  Made many DC receivers with the pair.

Bob WA2EGP

On Thu, Apr 30, 2020, 18:54 Adam Rong <rongxh@...> wrote:
Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam




Nigel Young ZL1NAY
 

Adam,

I thought you were trying out the SM boards from our friend?

Your version looks good, did you match the transistors?

I was thinking of mounting the components on a 6 or 8 pin mini DIN plug but I can't do much until the lockdown is over.

If you need a copy of the above mentioned book let me know, I will send you mine. I have read it over and over way too many times 😂

Nigel ZL1NAY

N

On Sat., 2 May 2020, 10:49 am Adam Rong, <rongxh@...> wrote:
Nigel,

I don’t have the book Solid State Design but I do have Doug DeMaw’s QRP Notebook, and Wes Hayward’s EMRFD. I still can find some circuits containing CA3028. Now I have enough supply to try out these circuits. I have added two posts here.

Thanks,
Adam

在 2020年5月1日,上午11:12,Nigel Young <multilec@...> 写道:

Yes, if it wasn't for Doug DeMaw and Wes Haywood  we would have all moved on. 
Now we all just have hundreds of dollars worth of qrp books with circuits non of us can build any more.
It is quite timely though, because only 2 days ago I was researching this same issue when I found the site linked earlier. 
For a moment I did contemplate making a few, but the feeling went away as a bunch of angry chips in my spares box started complaining. Namely an insane amount of MC1496s and NE602/612s. 
Nostalgia is a wonderful thing but sometimes we forget how bad some things actually were.
Let's hope with close tolerances and better silicon we can make this chip amp again, maybe better than it was before.

Nigel ZL1NAY

On Fri., 1 May 2020, 2:57 pm rjtoegel@..., <rjtoegel@...> wrote:
Yes, that was an old RCA chip.  I guess an ancestor of the NE602.  Also the CA3020 was a good AF amplifier chip.  Made many DC receivers with the pair.

Bob WA2EGP

On Thu, Apr 30, 2020, 18:54 Adam Rong <rongxh@...> wrote:
Folks,

Inspired by the CA3028 DC RX build by JA9MAT, I started to experiment with this old chip. The internal circuit is very simple, but it can be used as a mixer, amplifier and more.

As it cannot be found easily in market, we started to build a DIP-8 module with SMD parts. BH1XXP designed the board and I will test the final version tomorrow when the parts are ready. We use dual matched transistors so the balance performance can be expected. Here are my experiments and designs.
https://mp.weixin.qq.com/s/oPgoS3pKoDvcod-1Mr5Z9A
https://mp.weixin.qq.com/s/ueDseVSI0S_bNHkwcI4rxg
https://mp.weixin.qq.com/s/BMG4_GJeq1uYoz62aA9RpQ

Thanks,
Adam




Adam Rong
 

Folks,

Update of my CA3028 module and a simple receiver building based on the module. It is sensitive and selective. About 20 kits were built so far with good result.
https://mp.weixin.qq.com/s/SmK9M8yo6ouVXAv--Ht1oQ

Thanks,
Adam


Nigel Young ZL1NAY
 

Looks interesting Adam, the IFT 10mhz? An old 10.7 transformer.

Nigel ZL1NAY

On Sat., 30 May 2020, 8:19 pm Adam Rong, <rongxh@...> wrote:
Folks,

Update of my CA3028 module and a simple receiver building based on the module. It is sensitive and selective. About 20 kits were built so far with good result.
https://mp.weixin.qq.com/s/SmK9M8yo6ouVXAv--Ht1oQ

Thanks,
Adam


Adam Rong
 

It is the DIY7-7 customized 7 MHz IFT.

Thanks,
Adam

在 2020年5月30日,下午6:42,Nigel Young <multilec@...> 写道:


Looks interesting Adam, the IFT 10mhz? An old 10.7 transformer.

Nigel ZL1NAY

On Sat., 30 May 2020, 8:19 pm Adam Rong, <rongxh@...> wrote:
Folks,

Update of my CA3028 module and a simple receiver building based on the module. It is sensitive and selective. About 20 kits were built so far with good result.
https://mp.weixin.qq.com/s/SmK9M8yo6ouVXAv--Ht1oQ

Thanks,
Adam