CA3035 substitute.

[Dale Seppa]

Largely to Carl but any other reply more than welcome.


Carl: When and if you get a chance let me know if you have found a SUBSTITUTE for the CA3035 integrated circuit used in the two-box design OR a SOURCE for the CA3035. If I get it I will translate your reply and forward to Carlos Daniel Fidel in Argentina. Although he may be no longer around for some reason. Got couple emails from him and then no word at all.


This posting will also serve for me to see if some of the forum posting problems have cleared up.


Best regards to Carl and (If this is posted it will mean that both "Preview" and "Post Message are working fine.


Dale


PS Carl: Eventually I will put "Carl Morton" when I refer to you in print. When I was still in the mail order business, I had a good customer by THAT name and I had cause to frequently type it. I have now caught myself at least twice when I refer to you in WP documents unconsciously typing "Carl Morton" with NO awareness on my part. I will try to cure myself but I have tried to avoid typing "and" for "an" for several years and still have manually check EVERY occurence of "and" to avoid putting the wrong one into print so sooner or later you will find that name erroneously inserted. - Sorry! Once again accept my thanks and congratulations for the excellent work you have done with this website and forum as well as so many other places.

[Carl]

Re: CA3035 substitute.

>Carl: When and if you get a chance let me know if you have found a SUBSTITUTE for the CA3035 integrated circuit used in the two-box design OR a SOURCE for the CA3035. If I get it I will translate your reply and forward to Carlos Daniel Fidel in Argentina. Although he may be no longer around for some reason. Got couple emails from him and then no word at all.


The 3035 substitute is not straightforward as this part is actually 3 amplifiers in one 10-pin package. I will have to redesign the receiver around 1 or 2 op-amps, maybe a dual low-noise variety.


I was not aware that the 3035 was obsolete, apparently has been for 15 years or more! I think I have some of these somewhere, maybe I should dig one out for Carlos. Still, the design needs to be fixed for available parts.


- Carl

[Unregistered]

CA 3035

DID YOU EVER FIND A SUBSTITUTE FOR CA3035?

[Carl-NC]

I designed a substitute for it a long time ago, should be here on the forum somewhere. If you don't find it, I'll dig it up and post it when I return from backpacking.

I think someone else recently posted an alternate design as well.

- Carl

[Carl-NC]

Found it...

[chemelec]

The Transistor schematic posted on my website in the Two-Box design, faithfully reproduces the entire CA3035.
Both for gain and frequency response.

[detectoman]

hi carl and chemelec
question for carl, what ic is these? is one op amp 741?
question: if neccesary others components for build the receptor whit ic? of two boxs o only this is necesary whit coilad added
chemelec: is efficient your circuit of transistores how the example of carl?
what is most economic in consumption of energy bateries?
what is most stable
what is major independent transistors or integrated circuit in internal interferrence proximity?thanks for your attention
detectoman mexico

[Carl-NC]

Any general purpose opamp. I think Gary's solution exactly replicates the internal circuitry of the CA3035, which was probably designed in the 1960's when a 3-transistor IC was a Big Deal. Using the opamp solution might give you a little more flexibility and (maybe) a little less power, but it won't make a lot of difference in the overall project.

- Carl

[Geo]

Any general purpose opamp. I think Gary's solution exactly replicates the internal circuitry of the CA3035, which was probably designed in the 1960's when a 3-transistor IC was a Big Deal. Using the opamp solution might give you a little more flexibility and (maybe) a little less power, but it won't make a lot of difference in the overall project.

- Carl

Hi.
T/R Locator working at 200 Khz so what about IC1 bandwidth if gain = 270 (270k/1k). A general purpose op amp has a unity gain bandwidth 10 Mhz max.
Maybe two op amp with each gain 10.. 20 to be better.

[chemelec]

The Current Draw on my circuit is about 27 mA, for all three amplifiers with a suppy voltage of 9 volts.

Stability is Excellent.

And if your going to try and achieve the same results as my circuit using op-amps, I really doubt your circuit will be Physically any Smaller.
"The CA3035 Contains 3 Seperate Amplifiers", each with a Very High Gain and a Wide Frequency Response.

[zixelll]

Hello brother is molded circuit capacitors list boxes russian on Tampa Bay Mqdarshvn You've got me so I do not know what's Shmarshvn Thank you

[foton]

<a href="http://smages.com/?v=7777mym.jpg"><img src="http://smages.com/thumbs/7777mym.jpg" border="0"></a>

[foton]

[hectorvillic]

do you have schematic and values ?

[chemelec]

do you have schematic and values ?

I Designed this PCB and Somewhere I Have the Schematic.
But I am going away till Sunday.
Sorry, No Time to look for it Now!.

PLEASE, Will you send me an EMAIL, to Remind me to Find it?,
When I get back Home on Sunday.

Merry Christmas...........Gary