so i finally finished my first real homebrew superhet receiver, been working on it off and on for about 4 months now. its a pretty basic design, single conversion, IF at 455kHz, nothing fancy but i wound all the coils myself and etched the board by hand with the toner transfer method which was honestly more satisfying than i expected.

anyway its actually receiving stuff which is kind of amazing to me considering how many times i thought id killed it on the bench. 40m is coming in decent, 80m is a little deaf but i think thats an antenna situation not the radio. the problem im running into is this weird image rejection issue, im hearing stations at what i think are image frequencies and its getting confusing trying to figure out whats actually what. i know image rejection is a known thing with single conversion designs but i wasnt expecting it to be quite this bad. read that a proper preselector filter would help but i havent built one yet.

also the audio stage is a little buzzy, not terrible but noticeable on strong signals. using an LM386 for the audio amp which i know isnt everyones favorite but its what i had. is that just a noise floor thing with the 386 or is there something i can do without replacing the whole audio section?

congrats on getting it on the air, first scratch built receiver is a big deal. the image problem with a single conversion 455kHz IF is pretty much expected, your image is going to be 910kHz away from whatever youre tuned to and with no preselector the front end is just letting everything in. a simple LC bandpass filter ahead of the mixer will make a huge difference, doesnt have to be super tight just enough to knock down the image frequencies. some guys use a double tuned circuit for that, wound on T50-2 cores or similar, you can find designs all over the ARRL handbook or just look up W7ZOI's stuff, he has some really practical preselector designs that arent overly complicated.

as for the LM386, yeah its kind of notorious for being buzzy. decoupling is usually the issue, make sure you have a cap from pin 7 to ground and also try beefing up the supply decoupling right at the chip. a 10uF in parallel with a 0.1uF right at the Vcc pin helps a lot. some people also put a zobel network on the output. it wont make it a hi-fi chip but it can calm it down considerably.

the 386 buzzing thing drove me crazy on a CW practice oscillator i built last year, turned out i had a ground loop on my board because i was kind of sloppy with the layout. star grounding fixed most of it. worth checking before you start adding a bunch of caps everywhere honestly.