A question about radio for Fred

[gweidion]

Hi Fred, you build old radios as a hobby right? Or at least you did. I have a transistor AM/FM radio and my station (4BH is my station) constantly bombards us with "it is so much clearer in digital" trying to get people to buy digital radios. I dislike the lag that applies with digital radio so I stick with mine, however lately it seems to lose its tune. I suspect the station is slightly modulating their signal to try to convince people to go digital. 
I know the good old radio is susceptible to atmospherics and fluorescent lights, the microwave etc. Is there another reason why the signal might walk a bit, requiring a re-tune? 
Do you have a solution or recommendation? I don't think I want to buy a valve radio. Ages to warm up, hard (next to impossible) to get replacement valves.

[fred lever]

Hi Gweidion yep I'm the Fred Lever that makes vintage radios and turns up in "Silicon Chip" magazine with radio and electronic articles.
I am not up with what AM transmissions consist of nowadays but suspect the signals are now full of digital components.
Amplitude modulation used to be plainly linear only and the detection circuits in valve and transistor radios were designed purely around that concept.
Now the signals are complex and that plays havoc with old sets. The sound can be , just, AWFUL.
When i privately transmit a pure  AM signal  to an old receiver i get clean sound.
Tune in a network AM station now and the same receiver can sound horrible.
That may be your problem, OR, your receiver may have a fault.
ALSO there are transmissions about now, nothing to do with radio, that infiltrate the AM circuits and cause untold nasty efects to the sound.
Street lighting is a major contributor as  well as solar invertros and all sorts of swichmode electrical equipment.
The interference, called RFI is out of control with no authority able to control it.
The RFI cat is out of the bag, cheap  Asian made crap fills our stores, no compliance with RFI standards and no authority to stop it.
Welcome to the new world order!
Dinosaurs like me have just given up.
People just stare at their tablets and phones and have no idea whats happening.

not much you can do.
Cheers, Fred.

[gweidion]

Thanks Fred, I didn't even consider our solar system could be playing havoc with it. I try to keep it as far from "trouble" as possible but apart from building it a lead vault, I think I am buggered. I'll just have to try to get the best signal I can each day and ignore as much of the static that I can.