RCA
RCA CA3028A Differential and Cascode Amplifier IC, 8 Lead Metal Can, NOS
- 3 photos
Never used. The original pack has been opened, or the quantity was split off a full reel or tube. Leads are original and unclipped.
New old stock, open stock on the grading scaleSend the quantity you need. You get a quote back with shipping before anything is charged.
Video
Filmed on the bench. Sound is stripped from product clips.
- 0:10
Specifications
| Specification | Value |
|---|---|
| Identification | |
| Part number | CA3028A |
| Manufacturer | RCA |
| Condition | New old stock, open stock |
| Date code | Not recorded |
| Package | 8 lead hermetic metal can, TO-5 family outline |
| Country of origin | Not recorded |
| Family | CA3028 |
| Stock number | DNAYWHNZ |
| Overview | |
| Manufacturer part number | CA3028A |
| Manufacturer | RCA |
| Device type | Differential and cascode amplifier integrated circuit |
| Electrical | |
| Frequency range | DC to 120 MHz |
| Typical uses | RF and IF amplifier, mixer, converter, oscillator, limiter |
| Construction | |
| Package | 8 lead hermetic metal can, TO-5 family outline |
| Condition | |
| Condition | New old stock, open stock. Never installed, never soldered |
| Testing | Sold untested. Ask and the exact piece going in the envelope is metered first |
About this part
The only integrated circuit in this batch, and a genuinely useful one rather than a curiosity. The CA3028A is a differential amplifier with a constant current tail, brought out to eight pins in a metal can so you can configure it as a differential pair, a cascode, a mixer, an oscillator, a limiter or an IF strip depending on how you wire it. RCA specified it from DC to 120 MHz, which is what makes it a communications part rather than an audio one.
It survives in demand for two reasons. Restorers need it because it sits in the front end of a lot of period receivers and test equipment and there is no pin compatible modern replacement. Amateur radio builders want it because a balanced mixer built around a CA3028A is a known good circuit that has been published and rebuilt for fifty years, and the part behaves the way all that accumulated advice says it will.
This is genuine RCA in the hermetic eight lead can, not a later plastic second source. One is on the shelf. Sold untested, though an IC of this construction is a better bet than most things here: the hermetic seal is exactly what stops the die caring how long the part sat in a drawer.
Questions about this part
What can I build with a CA3028A?
It is a differential pair with a constant current tail brought out to eight pins, so the wiring decides the function: differential amplifier, cascode, balanced mixer, oscillator, limiter or an IF strip. The balanced mixer is the classic amateur radio application and there are fifty years of published circuits for it.
Is there a modern replacement?
Nothing pin compatible. You can build the same function from discrete parts or a modern gain block, but if you are repairing a receiver or a piece of test equipment that has a CA3028A socketed in the front end, the original part is the practical answer.
Is this the real RCA part?
Yes, RCA marked in the hermetic eight lead metal can rather than a later plastic second source. The metal can version is the one specified in the period circuits and the one collectors and restorers ask for.
Does long storage hurt an IC like this?
Far less than it hurts most things here. The hermetic seal keeps the die in dry gas, so there is no moisture ingress path and no electrolyte to age. The realistic risks are lead oxidation, which cleans up, and physical damage, which would be visible.