Hi, I found this design of a medium-wave active antenna for an AM radio receiver on a Techlib post. I wanted to build it because the circuit seemed very interesting, but while researching the IC used in the circuit (MC1590G), I stumbled upon the problem that it's rarely found and quite expensive (around 40 USD from a local supplier or +20 USD from AliExpress).
I'm looking for alternatives. Does anyone know of commercially available fully differential amplifiers like this one that work well in the 500-1000 kHz range? Or does anyone have a discrete circuit alternative for this type of IC?
The ones I found that seem promising are AD8476, AD8351, and ML1490, but none of them are widely available.

 

Though not the same as MC1590G, MK484 AM radio receiver circuit is simple to setup.

 

Replacing the MC1590G as a MW pre-amp for ferrite antenna.
The preamp schematic given is very simple, I don't think the MK484 is meant for improvement in AM reception however
the adjustable 125pF is worth pointing out the advantage. That is why it remains popular with magnetic loops.

Since the MC1590G had a popular trend with amateur radio builders years ago I wonder if there is more to it.
I think Doug DeMaw and Joe Carr may have published articles on pre-amps using MC1590 that have been forgotten.
The MMICs have improved work very well. Very low noise, low cost, built in 50 ohm impedance,
but an off the shelf AGC might be why MC1590G ran a trend with the low band. Most of the builders are silent key or went to UHF.
The AGC does'nt need to be remote but the mmic module probably should be located close to the ferrite Antenna.

Data Sheet has an AGC fig 17 application 10.7MHz IF which is located at the receiver unit uses 150pF adjustable trimmer cap.
If the ferrite antenna unit is mounted at the end of a long coax possibly outside like Charles Wenzel
then it could be more than just a small ferrite rod and the limiting factor would include the coax.
A remote varactor tuning and AGC would be a big project. That's why Charles kept it simple.
Really, the information on MC1590G pre-amp from an old article from Radio Electronics, QST QRL or QRM magazine
might explain why they were using it or maybe you had to buy their book.
The data sheet is still available, below shows 50 dB gain figure 27 1 to 30MHz figure 23 for 1MHz is terrible
Figure 22 S21 is good for 120MHz to 200MHz my guess is it worked for J pole 2Meter band

 

There is also a similar IC, the MC1350, much more common now. They may even be interchangeable.