Quote:
Originally Posted by Don_M
I've noticed much the same: IMHO, it's that low, low UHF noise figure, quoted at 2 dB versus competitors' 2.8, 3 or more. One wonders whether CM isn't being very conservative by quoting the worst-case scenario of a protoype, while most customers get significantly better performance that beats the competition by full dB, 1.2 dB, maybe even more. That's a significant difference to the viewer who's trying to pull in signals below -85 dBm. |
I have a station that is -33.5
dbm on ch 31. I don't overload. According to Hol_ands from AVS, I should overload at -35
dbm
I mentioned this to you or someone before, and they said they had seen CM7777 have more dynamic range than their ratings.
It would be a great test if we had a setup like Beth and could put in say a 8700 in place of the CM7777 and so an a/b switch....
Also figure on Ch9 I can see 470 Watts
ERP a good deal of the time. It is LOS but that is 37 miles away. It puts about 16 NM here. It's not reliable though, and that is on paper.
Which is another thing, it seems the more power a VHF runs the better the signal to noise. WTLV pushes 53
KW toward me, and is only 8 NM and is more stable than the channel 9 in that is closer.
There has to be other factors.
Why I have gone back to thinking LONGGGGGGGGGGG Boom yagis. Or yagis with log driven elements. Need to add this to the article I typed. But if so much of being on the good side of the cliff is signal to noise, as everything we are seeing points there, then a long boom yagi sees a much smaller area of the sky, which means in that area there is less noise than a short boom antenna. Which someone would say, dah, that is the definition of gain. I say no, gain is the increasing of signal gathering in a given direction. While this concept is hand and hand, there is also less noise received with higher gain long boom yagi.
OrlandoOTA put a HD9095P (95 in boom) on top of a hotel in Lakeland and yes he was up 60 ft or so, pointed at WVEN 82 miles away running much less than maximum power. He ran I think he told me about 15 ft of RG11 into a
CECB and is well above the cliff. If you go search the Orlando
OTA thread the TVFool plot etc is there. Currently there isn't any other stations putting noise on that channel so that is a good deal of the success.
I am thinking of buying a HD9032 which would be easier for me to mount and see what it does. It's not a really expensive antenna. It would be very curious to see what it does against the Radio Shack. Good or bad.
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