I tried to search for static, but Bruce's signature came up on every return 🙂
SO: Static. I have a procaster (happens on the SSTRAN as well), and found a nice quiet station that only gets completely pounded out at night, and it runs great - except for the static. Are there common solution to deal with the {nasty}static?
I tried moving the grounding from the mast, to the house electical, then the ground plane on the dirt, and a combination of those.. no luck.
I wonder if I just have a crap location of a transmitter? 🙂
Hi Mir.
Is the static on the AM frequency of your choice when the transmitter is turned off?
Or, does the static happen when the transmitter is turned on?
I cannot tell the answer to this by reading your post.
maybe your audio processor is bringing up low level noise?
This happened to me when I had a lot
of equipment together in the audio chain -
plus the long DC cable going out to the
transmitter. I eventually found it by taking
different pieces of gear out and isolating
the problem.
What does it sound like when you
are transmitting a dead carrier? Is it
on any other radio stations on the
AM band?
There are so many things it could
be. I also was getting static from
a malfuctioning street light not too
far from my house. That eventually
got straightened out.
Best Wishes,
Bruce, DOGREADIO
by process of elimination (I could not resist)
I will be troubleshooting this tonight when I get home from work. I'll start with turning off the transmitter, and driving around to see what I can find, then have someone turn the transmitter on but broadcasting nothing by removing the audio input to the little studio box that comes with the procaster.
Next, I'll go down the chain - there are a lot of audio adapters along the way - the ground loop isolator between the computer and the audio input on the tx box goes 3.5mm to rca to isolator to rca to 3.5mm - so theres 2 adapters just on that one cable.
I have a crazy amount of adapters from the MIC to the computer as well.. mic to XLR to 1/4" to 3.5mm to long 3.5mm cable to computer.
craaaay-zeeee.....
Turning off the transmitter there is the normal low hissy sound you get with a clean channel.
Then pulling the audio from the transmitter audio input gets me a quiet, clean channel.
Plugging in an iPhone; I get the static on the audio.
Messing with the audio processing of Sam Broadcaster, I also get the static, albeit a bit better, nothing so noticable that I went "Woot! Thats it!".
And actually, if you listen to my streaming; this is the same audio that is going into my transmitter audio in. RadioSunnyvale
Still struggling...
It sounds like SOMETHING is generating RFI (radio frequency interference).
But there is still a question...
When the static is generated, is it being picked up by the audio chain and modulated by the transmitter?
OR, is the RFI being put onto the AM band and not passing through the transmitter?
With the iPhone, you say "when plugging in the iPhone..." That must be a reference to the battery charger the iPhone sets in.... Aha! There will be suggestions about things to try to "tune-out" the charger noise.
But the SAM Broadcaster is software, and with IT being a possible producer of RFI, that is a bigger mystery. You say "Messing with the audio processing of SAM Broadcaster...." that might be a clue, but what processing are you referring to? The stream rate? The sample rate?
The solution to this problem will be interesting, but the problem itself is even more fun!
On the iPhone: Not the charger - I plugged the audio out of the iPhone into the audio input of the transmitter. No charger connected - just battery. I was trying to push audio through the tx with as little in the chain as possible.
Processing in Sam: Sam has AGC, Compression, Limiters, etc all done in the native application. I had thought maybe the processing was causing the issue.
Why did I think the processing was an issue? When I ran from the Pro gear (Balanced mixer, balanced Pre-emphasis and compression) up to the transmitter, I did not get the static. I got hum, but no static.
Also - my location may very well have something to do with this. Lots of power lines, postage stamp lot, etc.
Those chargers put out a lot of hash and trash. Those little solar powered yard lights put out crap too! (Hiss and Whistles) I had issues with cell phone chargers causing hash in my FM rcvr. All was fine until I plugged it in to the phone..
I can actually hear the static sound on the stream... so I am thinking this is in the audio chain somewhere.
Things I don't have: Solar anything. Charging devices on the same circuit. In fact - the power is coming straight from the circuit breaker, into my garage in its own conduit. There is a Tripplit isolation transformer on the circuit, which is what everything is plugged into (4 plugs on the transformer, computer, transmitter, monitor, second computer plugged into those ports) - no other gear there...
Ok.. So thiNoah's nothing to do with the transmitter at all. I found the problem by accident. I was testing a talking house and atu and noticed hthe distant it sounded.. The only diff was going through the new old mixer.. It was so clean sounding, but sounded really far off. So I plugged the transmitter audio into the headphone amp built into the mixer and boom! Clean sound. Then I put it back on the computer output - ewwwww... Sam processing just pollutes the crud out of the sound. I am sure it is my setting in Sam doing it, combined with the dirty output of a commodity sound card that made this horrible noise.. Woot!
Those kind of problems can be
really frustrating.
Bruce, DOGRADIO
The American way is to shoot trouble. If your dog shows interest in a law man, it gets shot. The same is true of static on audio systems.
I would love to see a detailed drawing of the exact audio hookups that have caused Mr. mir so much trouble.
Just guessing all by itself doesn't come close to doing any good.
Anything could be causing the problem.
Diagnosis: anything.
Typically, I totally agree with you Carl, but in this case "Diagnosis: anything" is not quite right.
Diagnosis: OTC sound card + my crappy configuration in the processing SAM has = the problem.
The bottom line to this is really simple - the audio processing, when misconfigured, can and will cause evil sounds coming through your transmitter.
When I ran the same set of mp3's through a computer running Mixxx and no processing, directly into my mackie cr-1604 - no crap audio.
When I switched over to SAM and the bad configs, crap audio.
Now, I am sure I can do better - I am moving everything to the shortest cables I can use, higher quality stuff (belden over rca coax, good quality XLR connectors and converters vs. the ratshack ones), and moving to hardware processing.
But that will come with time and cash 🙂
Mir is to receive top marks for sticking to a problem until no cable is left un-tested.
What I see in your future is a perfect set up!