How are you guys measuring signal in dB? Does your TV report that? Mine only displays a % scale up to 100. I get just about all stations except channel 7 from 80-88%. Channel 7 was at 65-70% and anywhere from "blue screen of death no signal" to ok with in-and-out drop-outs with pixellation. When I oriented my amplified Philips MANTxxx rabbit ears for optimal channel 7 reception, IIRC, it was up to high 70s and the other channels degraded to low 80s, but still solid picture. I don't know if I mentioned, but I occasionally have trouble getting channel 6.2 and 6.3 (KRMA Create & Spanish) - they seemed related to channel 7 as when I oriented the antenna for channel 7 (one rabbit ear horizontal and the other one just a few degrees from vertical as far as it could go), they came in clearer as well. The one annoying thing about my TV is I cant' simply leave it in signal strength mode and change channels - every time I change channels, I have to navigate through a few menus back to the signal strength menu - a real PITA!
If you're actually getting channel 7 off of channel 17(KZCO) rather than actual channel 7, KRMA is on channel 18, which means they are on adjacent channels. Both KMGH7 and KZCO17 will show up as the same virtual channel.