Finding a frequency...
I'm trying to find a good frequency for starting a Part 15 station.
I'm finding some good ones during the day that are noisy at night. (Can hear music and voices--often very clearly).
Will my low power transmitter be powerful enough to displace the noise and broadcasts at night?
I would love to be on 1710. Is that possible?
1610 should be clear, but a local station on another frequency can be heard on it.
Any suggestions as to how to find a frequency and what I can expect if I try one that has some night broadcasts which can be heard?
About the best you can do is to find a frequency that is quiet during the daytime and has minimal skip at night. If you're in a smaller town, an extended band frequency is a good one, although they're starting to fill up. When I picked 1700, the frequency was quiet. On the frequency now there's a 10 kw station out of Mexico which blankets the West Coast at night. Interference is just a part of Part-15 life.
You can't operate on 1710 under Section 15.219, the band edge is 1705.
If you operate AM on 1700 with a normal 5 kHz audio bandwidth, your upper sideband would end just on the band edge.
You can't operate AM on 1705; your upper sideband would extend out of the band. Even if you were running SSB and lower sideband, few if any radio operators would trust having that much upper-sideband suppression.
If you find a spot that is day-clear with weak night skip, you should be OK at night unless somebody in your range is an AM DXer. Even a DXer would probably be more likely to ask you to shut down early some night so he/she can catch the distant station(s) well enough to get verification.
If you are hearing a 1610-licensed station on another frequency, check with another receiver. This may be an "image" on your receiver. If the "image" shows up on two or more receivers, there may be some mixing with another local signal. The point is that you can't tread on the big boy's 1610 signal. The rules don't talk about treading on an image.
Sorry, I goofed. Your big boy is on another frequency with an image on 1610. Still, check another receiver to see if the image is still on 1610.
An image on 1610 is not protected. Just don't tread on the big boy's licensed frequency.
Would the "mirror" signal be strong enough to ruin my low power am broadcasts? Would I be able to overpower it?
That's something you have to experiment with, providing that the 1610 signal is an external image from mixing with another local signal and not just an image in a particular receiver. The biggest problem is that if it is an external image, it will to some extent cut down your listening area, especially for listeners using omnidirectional antennas, like car whips.
One other thing: Don't just check another receiver to see if the image is or is not present. Check one or more listening locations. Interference of this type may be confined to a particular small area. Good luck.
It looks like this 1610 is a problem all over my listening area.
It's fine at night, though. 1700 is very good during the day, but I'm getting a Spanish broadcast fairly strong at night. Maybe I'm going to have to have a day and a night channel. Or just forget about night...
I've got a second transmitter and am going to operate it on 1270, which is reasonably clear at night. I'd like to have a multi-site operation, but I can't afford the phone line expense.