so i have a late model procaster with it's interface box.
we tired to hook it up at my friedns apartment.
i mounted Tx on balcony. grounded the ground to the faceplate screw on AC outlet.
i hooked up everything up minus the barix and tested the signal and it got out beautifuly covering everywhere i thought it would cover with a unmodulated carrier.
so i procedded to hook up barix to tx via the procaster interface box and plug it into xfinity cable modem.
the resulting audio was very low and distorted and there was a motorboating sound overtop my stream audio from barix.
as soon as i dosconnect coax cable from modem or barix from modem there is a breif time where the audio is loud and clear till the barix buffer empties.
plug it back into cable modem and audio is distorted and motorboating again.
i bring it down here to my apartment and hook everything up the same way and i can't replicate the issue here and i have the same exact service and modem he has.
any idea's, i did try a audio ground loop isolator with no luck.
i'm thinking the cable and ac are at different ground potential IE: not bonded together at service entrance per NEC but either cable service is ungrounded or on a seperate ground from electrical service grund.
Its the cable modem.
around that issue? and why would my exact same make/model modem and internet service here not do the same thing when i try to replicate it here?
i could replicate the audio ducking here but not the motorboating audio.
i set everything up exactly as i had it at my friends apartment.
the only different here is a i have a dlink 10/100 switch plugged into modem as well.
with the switch in everyhting is normal even with the switch and barix plugged into back of modem side by side. remove switch audio ducks put it back in everything is back to working normally.
ground issue that the switch by be offsetting?
Could be leaky coax or some internal issue on the modem, but thats really my only guess since the buzz goes away when the modem isn't plugged into the barix. Does the modem have a wall-wart?
no walwart internal psu. like i said mine here i get the audio ducking but not the motorboating up at his place i get the audio ducking and motorboating.
put a ethernet switch to the modem everything goes away down here at my place. i haven't tried it up at his site yet.
i will try later and see if a switch in between modem and barix cures the problem at his place as well.
he has the exact same modmem i do.
Could be the D-link is isolating the router from the other devices, I look forward to your results. I'm leaning on the side of his modem being faulty, I'm sure QC isn't the greatest on a cheapo box Comcast dishes out to its customers. ARRIS does make some good gear though, though I've only dealt with their biz grade gear.
You could try popping a ferrite core over the cat5 cable going to the modem and see if that clears things up, maybe toss one on the power cable as well for extra measure.
Edit: Could it possibly be a goofy Cat5 cable?
My first leap into Part 15 was back in the late 1990s and my DSL days. Data rates and internet performance were both great for the times, until I went 'plates up'. Then my DSL speed plummeted to 1/10 of what I was subscribed to. My AM signal was radiating into my phone wiring and blowing my web experience all to hell.
Moving the antenna well out into my yard, moving out of the standard BC band up into the Extended band and ferrite-beading the daylights out of my phone wiring helped.
some kind of ground loop issue between the tx ground and cable tv ground.
i have a ddwrt linksys router i will use as a client bridge. since it will be within a few feet of comcast router and not directly connected to comcast router it should eliminate the ground loop issues and signal quality shouldn't be an issue that close in.
i will also isolate tx from barix with a henry matchbox and a audio ground loop isolator cable set.
my friend doesn't want to try again till after christmas so i will have to wait a bit to try again.