Yea, you have to have similar enough power to create a set of harmonics. If one frequency is several multiples higher you won't get anything meaningful on the 2nd through 7th order. I still think there is an antenna system issue with the two way. It shouldn't hear anything your doing that far off. If it has a really crappy wide open front end on that receiver I guess it might. That is why any two way system on a tower with any other equipment should always have a preselector. Costs a few hundred and prevents receive muting by close high powered transmitters (which you are not). I think if everything is correctly installed and maintained on the 2Way side you should not interfere with it. We had and still have dozens of sites with lots of 10/100 POE CAT5 installs with no issues. I guess it isn't impossible, I just find it highly unlikely.
On Thu, Jun 8, 2017 at 9:12 AM Chuck McCown <[email protected]> wrote: > Could be. But generally you need watts of power or tens or hundreds of > watts. Milliwatts would seem unlikely to generate too much intermod. > > *From:* Kurt Fankhauser > *Sent:* Thursday, June 08, 2017 8:08 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] Interference on a repeater at 149 MHz > What about intermod? I know in the 2-way radio world that two transmitters > can mix with each other but I never knew if it could mix with the Ethernet > or if that wasn't high enough power to be an intermod issue. > On Thu, Jun 8, 2017 at 9:43 AM, Chuck McCown <[email protected]> wrote: > >> Forgot about that trick. In the early days of canopy I solved a few TV >> interference issues with that method. >> >> *From:* Kurt Fankhauser >> *Sent:* Thursday, June 08, 2017 6:48 AM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] Interference on a repeater at 149 MHz >> >> Try switching all the ports to 10-BaseT and see fi noise goes away. >> >> On Thu, Jun 8, 2017 at 1:25 AM, George Skorup <[email protected]> >> wrote: >> >>> That's all fine and good, but I pointed out that the contractor tied >>> their heliax to our conduit all the way up. That was about the dumbest >>> possible thing they could've done. There's cable hanger bars that are about >>> 3 feet wide and we're all the way to one side with our conduit. That's just >>> fucking lazy. >>> >>> On 6/7/2017 11:31 PM, Brian Webster wrote: >>> >>> The problem with this attitude to the fix, you as the WISP are now an >>> unintentional radiator interfering with a licensed service. This will get >>> you a visit from the FCC and you will be at fault no matter what. Because >>> you have equipment that is unintentionally radiating in licensed spectrum, >>> based on all FCC rules you lose and you get fined. This would be the case >>> even if you had no RF equipment on the site. That is why gear has >>> certifications for emissions for class a and b computing devices to assure >>> they do not radiate any unintentional RF signals. Once you install any >>> equipment like that outside the parameters the gear was certified under, >>> you become liable for the fines. >>> >>> >>> >>> As mentioned by others fix the problem, if they call the FCC you will be >>> screwed plain and simple. >>> >>> >>> >>> The school is not SOL because of your gear, you are. You are an >>> unlicensed system radiating on their frequencies…… it is your >>> responsibility to eliminate that interference as soon as you are notified >>> and it is shown to be your equipment causing the problem. >>> >>> >>> >>> Thank You, >>> >>> Brian Webster >>> >>> www.wirelessmapping.com >>> >>> www.Broadband-Mapping.com >>> >>> >>> >>> *From:* Af [mailto:[email protected]] *On Behalf Of *George Skorup >>> *Sent:* Wednesday, June 07, 2017 7:56 PM >>> *To:* [email protected] >>> *Subject:* Re: [AFMUG] Interference on a repeater at 149 MHz >>> >>> >>> >>> We have a local school district co-located with us on a water tower and >>> they're complaining about noise on their input. I pretty much told them >>> they're SOL until we need to add or replace cables since they're all in an >>> 1-1/4" PVC. So we'll have to run temp cables up, rip all the cables out of >>> the pipe and pull new ones. The village said we have to be in conduit. And >>> we do have a couple cables in use that aren't shielded. They didn't offer >>> to pay for it, so too bad. >>> >>> They're running a Kenwood repeater in an outdoor cabinet. Maybe 12U. >>> Obviously that's not going to fit the proper large can cavity duplexer like >>> a Sinclair. Plus they have >4.5MHz split, so no doubt that let them use a >>> smaller rack-mounted duplexer. >>> >>> So I'd be curious to know what the setup is on this 149MHz repeater. Are >>> they using a small crappy duplexer with a large split, too? >>> >>> On 6/7/2017 5:55 PM, Lewis Bergman wrote: >>> >>> I don't think so. I am assuming they probably didn't install some >>> connectors correctly. Unless they are using some extremely crappy gear the >>> RF portions of all half decent repeaters are shielded very well. Unless >>> they modified the repeater leaving some shielding off the connectors are >>> the most likely source. I guess there could also be punctures or some such >>> in the coax as well. >>> >>> >>> >>> On Wed, Jun 7, 2017 at 5:51 PM Jaime Solorza <[email protected]> >>> wrote: >>> >>> Lewis. You are assuming the VHF gear was properly installed...few folks >>> do right first time... someones laziness or lack of knowledge is another's >>> opportunity to make some cash >>> >>> >>> >>> On Jun 7, 2017 4:41 PM, "Lewis Bergman" <[email protected]> wrote: >>> >>> Has anyone checked their connectors/connections between all RF points? >>> Antenna to cable, cable to duplexer, duplexer TX/RX to repeater. >>> >>> >>> >>> Most of the time I have seen Two Way equipment either be interfered with >>> or interfere with someone else it is a connector issue. The only other case >>> I have seen issues should be able to be determined by an intermod study. I >>> doubt it has anything to do with intermod. My bet is a faulty connector. I >>> would assume it is the RX side so I would check the RX Repeater port to the >>> RX port on the duplexer and then the rest of the connectors. >>> >>> >>> >>> Not saying it can't be the the CAT5, just that if all is good on the >>> antenna system I haven't ever seen an issue and I have a lot of sites with >>> both two way and 900, 2.4, and 5GHz operating on all kinds of speeds both >>> POE and not. >>> >>> >>> >>> >>> >> >
