trouble shoot static on radio

[dksucharda]

Not sure if this is an appropriate question for this forum but here it goes. New to electronics. Just built an Elenco FM scanning radio. Ovrerall build went well. When I finished and turned it on all was well. Wen I hit the scan button it did lock on a channel and I could hear music but there as a TON of static. it is like this on every channel. I played with separation of the copper coils (the fractor?) which changes the frequency hertz the radio range the radio scans. I am sure it could be a ton of things but any thoughts/ideas would be appreciated. Thank you.

 

[Lightium]

It may be overloaded. Try grounding the antenna.

 

[dksucharda]

Thank you. I will see what I can do.

 

[audioguru]

The TDA7088 IC circuit in an Elenco FM radio kit is junk. I think the Philips old TDA7088 IC is not made anymore, Maybe only Chinese copies.

Years ago I bought a tiny FM radio using the same circuit for $1.00 at The Dollar Store. It produced interference and did not pickup any fairly distant stations. It picked up a few local stations at the same time.
A REAL FM radio does not pickup interference and does not play more than one station at the same time.

 

[Ylli]

I would guess you have a bad solder connection somewhere.

 

[Externet]

Is there one of this at your place or neighbor ?

Try your receiver very far from 'civilization'

 

[gary350]

Start at the speaker, take scope readings of the static then work backwards through the circuit to see if you can learn where static originates from.

 

[danadak]

Turn off all power in house (assuming radio is battery operated) , then start breaker by breaker
turning back on. Fluorescent lights as Externet mentioned, ethernet cables, light dimmers,
generate large amounts of RF noise.

If radio line operated conder a line filter :

CW4L2-20A-S​

https://www.amazon.com/Nxtop-CW4L2-20A-S-Noise-Suppressor-Filter/dp/B07GSVN2JG/ref=sr_1_11?crid=19CU3L6B9G8IB&keywords=ac+line+filter&qid=1692286384&sprefix=ac+line+filter%2Caps%2C142&sr=8-11

The above does not have filter freq response in its data sheet, so not sure how effective it is.

Build one :

diy fm radio line filter - Google Search

Regards, Dana.,

 

[CatMan]

The simplest thing you could try is a longer antenna, and to "gound" not your antenna but the "ground" (negative/minus of the battery connection point to the circuit). The antenna should also not be a very thin wire.
Good luck.

 

[danadak]

Not sure what kind of ref material you have but handbook has a lot of good practice
recommendations :

https://worldradiohistory.com/BOOKSHELF-ARH/Technology/ARRL/The-Radio-Amateur's-Handbook-ARRL-1984.pdf

https://www.qsl.net/kb7tbt/manuals/arrl/ARRL%20HANDBOOK%20-%20Antenna%20Project.pdf

Regards, Dana.

 

[ZipZapOuch]

It's a bad design using a cheap (bad) chip. Don't waste your time trying to reduce static by a few percent - static will still be terrible. The project is intended to teach you how to follow assembly instructions, read schematics and solder - it was not designed to be used on a daily basis.