There is no such thing as an FM
and AM antenna. The bands are literally two orders of magnitude apart in frequency and correspondly, wavelength. Hence why a compact stereo such as the one pictured above is going to have two antenna inputs - one 75 ohm coax which will take a dipole or Yagi and other such FM antennas with a balun, another being a high-impedance balanced input that takes a loop antenna for AM (which needs to be the same inductance / capacitance as the one supplied as it's usually part of a tuned circuit that is tracking the reception frequency).
Your average
choona is not going to have any digital outputs, we are talking a technology that peaked in the '80s and early '90s. Expect unbalanced outputs at up to 3 kOhms of output impedance (so decent audio cable shielding and non-excessive length required), typically 750 mV out for 75 kHz of deviation on FM.
For an FM antenna - even a basic dipole - to have its intended directivity, it must be placed as freely as possible, substantially away from anything metal or solid walls. They are commonly placed on the roof (with adequate lightning protection) or at least in the attic as a result. I believe a bit of searching may well turn up a disused 3-element somewhere, maybe even something fancier (don't confuse with old TV antennas though, even if a combination wasn't too uncommon). AM loops are generally placed in reach of the user for orientation purposes. A highly directional FM antenna would generally be placed on a rotor and rotated remotely instead.
Of the FM/AM tuners you are going to find, a lot will be quite mediocre on AM. (I mean, I have pulled in stations something like 1500 km away at night with a lowly Technics SA-GX100 receiver in the past, but it wasn't the last word in selectivity.) You may have better luck finding a decent portable radio for AM purposes, especially if aided by an external tuned loop (e.g. Tecsun AN-100) for sensitivity. This makes it easier to get away from domestic interferences sources as well (or, conversely, a handy tool in identifying those).
TIC is a good source for FM tuner related info, along with the associated FMtuners group. As it is very much enthusiast territory though, you must get the basics out of the way first.
This 1976 radio gets in a LOT of channels but nothing comes in 100% clear i guess maybe FM static is always present or its just super old i mean its a GE radio i didn't even know they made things like that back in the 70's.
You don't mean the cheap-looking compact stereo pictured above though? That thing is ca. 1990 and may have been some kid's first "hi-fi" at the time.
Bad reception can have many causes:
A dipole antenna is something for people who live at most a few dozen miles away from some reasonably strong stations. It also helps not to have a POS for a
choona.
In urban areas with a crowded band, overloading of the receiver can be a real issue.
You may have some interference sources near your antenna. LED lights in particular vary heavily in terms of EMI, some are dead quiet even on AM (I suppose little more than a capacitor dropper power supply) but some LED drivers have been found to be impeding radio reception even beyond the FM band (not just wiping out the AM bands as is more usual). Anything switch-mode is potentially critical.
Tuner frontend alignment might be
way off. A few types of trimmer capacitors were problematic long-term.
Some personal anecdotes on interference:
Many years ago in the early 2000s I bought a reasonably fancy metal-cased Fast Ethernet switch from some eBay seller. Even got it replaced when it died (presumably capacitor plague) a few years later. That thing turned out to be shrouding my entire PC setup in a cloud of noise that would interfere with reception well into the shortwave range. Only years later did I realize that the thing did not have a CE mark on it anywhere (it would have been legally required at the time already), and a look inside revealed a lone ceramic capacitor across the line at the IEC jack for interference suppression. Yikes.
The power supply that came with my old TPLink TL-WR1043ND v1.8 WiFi router wasn't exactly too interference-free either. When the old first-generation ADSL router was retired ofter 13 years of faithful service, a conventional transformer-based power brick with decently low idle losses became available that also fit the TPLink, which made the router quiet as a mouse (you could pretty much place the receiver right next to it!)
and more stable to boot.
I used to curse the countertop fluorescent lamp inthe kitchen, which was located right underneath my shortwave listening quarters at the time. When it failed years later (reduced capacitance in capacitor dropper supply), I had a look at the driver and sure enough, very minimal interference suppression on that as well.
A 2006 Panasonic plasma TV was no friend of the shortwave hobby either. Panasonic actually fixed this by 2009 through introducing all-around shielded panels, unfortunately plasmas already were on their way at by then. A preceding 1998 Sony Trinitron hadn't exactly been kind either though.
I have thankfully had very good results with retrofit Edison-style LED bulbs. Even quiter than preceding CFLs. I guess since there isn't much space in there, power supplies are minimal capacitor dropper based jobs.
