Weird thing.....I have a number of amps that run together and I use an amp switcher
they are all set up permanently, plugged into same points etc
9pm every Saturday and all day Sunday (never any other time ) one of them picks up a Punjabi radio station which comes through the speakers very loudly .........I can half defeat it by activating the ground lift button but it then comes out of another amp at a lower volume
I can clearly hear the adverts for Travel agents in Southall, grocers, and wedding announcements etc (at least I know where to book my next tickets to India or could gatecrash some pretty spectacular weddings ...)
Why does this happen ?
Comments
Not weird at all Dominic. Without being rude, your country is where WE were at the beginnings of readily available audio technology. Radio Frequency Interference WILL get into amps unless measures are taken to stop it.
I am pretty sure many of the schematics of Blackstar HT pedals have found their way onto the Net by now so have a look at the front ends and output jacks on those and see the LC components used. Cheap shit omits them but they are not allowed to do that here in EU/UK.
Do you know the broadcast frequency of the radio station? Is it Mwave or VHF? If you would like to PM me Dominic I can give you diagrams and things to try. Sometimes external filters can help but usually you need to mod* the amps and pedals.
*Not really mods, Good engineering that should have been part of the original design.
Actually many of the ripped schematics don't show the filters. You are looking for an input choke/inductor and capacitors. You will also find the input protection Zener diodes. Bet your kit does not have those either!
Dave.
I wouldn't know about VHF or Medium wave and was hoping that there was some kind of simple plug in filter - it doesn't bother me enough to get busy opening amps/modding etc
It probably goes quite well with my Ravish Sitar pedal !
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I confess I just saw "Punjabi Radio" and assumed the Indian sub! I now see OP is based in London so the whole situation is much easier in that the radio station is probably breaking the law unless the amp kit is some really cheap, imported **** that has not been built with basic filters and has not gone through EM tests.
It USED to be the responsibility of the GPO to track down and prosecute illegal radio transmitters but in these unregulated, privatized days I would not know who TF to turn to. The company I was a service tech for used to work with the GPO RFI dpt and go CB burner chasing!
Dave.
Switcher is either a Palmer trio or Voodoo labs 4 switch but they both have individual transformers ,ground lifts etc
I'm not normally one for 'reporting things to the authorities' when it does so little real harm as a pirate radio station, but I probably would.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
https://www.google.com/search?rls=com.microsoft:en-GB:IE-ContextMenu&q=guitar+pedal+switcher+schematics&tbm=isch&source=univ&sa=X&ved=2ahUKEwjJ2fyKtffgAhWksaQKHfsnC_gQ7Al6BAgEEA0&biw=1093&bih=522#imgrc=ZUEx10j9S5BW-M:&spf=1552215440331
Cannot find schematics for either of the OP's units but above is a transformer isolated switcher and there is not a shed of evidence of an RF filtering at either input or output. It could of course have been omitted "for clarity" but I doubt it.
Dave.
Rather counter-intuitively, one of the things that IMPROVED long and MW radio reception was a good earth! But then I guess nor many here had an old mains radio with aerial and earth "wander" sockets on the back? Or put up a 100 foot aerial down the garden?
Dave.
But I suspect you won't be too surprised by that .
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein