Here is my situation..... In the evenings I am able to hear more simulcast sites on a P25 system in a neighboring county than I am able to during the day. Same antenna, same location on the desk, same favorites list (SDS100). As odd as this seems to me, I am also able to hear more of the same in the summer months than Fall, Winter, Spring. I know about skip transmissions, but thought that was all limited to lower band vhf and the system in question is 700mhz.
Odd reception or explainable?
- Thread starter cfsimmont
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While using my R8600 and a broadband antenna I tend to see a lowering of the noise floor in some portions of VHF and UHF at night time. I attribute this to a reduced number of nearby noise sources in the evening. This includes things like the neighbors TV, computers, HVAC units, etc. Accordingly, there a signals I can receive at night that I cannot receive during the day when the noise floor is higher. I am not sure if this describes your situation but I figured I would throw it out there.
It does sound plausible, less interference would be more beneficial for better reception, I just don't know if that is the whole thing of it. Definitely not complaining, just trying to figure out the how and why so maybe I can improve my reception for longer.
racingfan360
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What you are describing is Tropospheric Propagation: it's weather (eg pressure related): higher pressure, more settled conditions, not noise floor related (though this will help on selectivity for some weaker signals). Skywave (Skip) and Tropospheric Propagation apply to different layers of the atmosphere, not the same thing.
en.wikipedia.org
Tropospheric propagation - Wikipedia
en.wikipedia.org
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BINGO!What you are describing is Tropospheric Propagation: it's weather (eg pressure related): higher pressure, more settled conditions, not noise floor related (though this will help on selectivity for some weaker signals). Skywave (Skip) and Tropospheric Propagation apply to different layers of the atmosphere, not the same thing.
Tropospheric propagation - Wikipedia
I'm getting amazing reception from VHF Marine Coast Guard stations from distances I normally would not pick up early this morning.- Joined
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BINGO!
The Coast Guard uses remote sites for transmissions and when you hear a USCG station ID on VHF, you really do not know where the transmitter is located--it can be be identifying as a USCG facility over a hundred miles from where the transmitter is.
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Yep I understand that, I have been monitoring marine radio since before the VHF Marine Band came out, since I was a very young kid. I can assure you I am not picking up these stations because of their transmitter tower locations LOL. 95% of the Year these stations would not be receivable in my location. We are talking well out of my area. Good observation though.
If you're not already aware of it, check out this website for updated VHF propagation. Click on "About" for a map legend and explanation of the map. That said, I doubt skip of any type is an issue here being that this phenomenon occurs with the neighboring county system, and skip is generally sporadic and unreliable. In this case, it's possible that, even with the SDS100, the vagaries of simulcast is the culprit.
tvengr
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I have experienced completely the opposite with microwave transmissions. There were locations that I was able to receive our TV live trucks during winter that I could not receive during summer due to the foliage on trees. The leaves attenuate signals, especially wet leaves. Heavy fog also attenuates signals. We have lost satellite signals during periods of heavy rain and snow. Our microwave trucks used 2 Gig frequencies. C-Band satellite is 4 Gig downlink and 6 Gig uplink. KU-Band is 12 Gig downlink and 14 Gig uplink. We also had to keep snow and ice off of microwave and satellite dishes to avoid losing signals. Sweeping snow off of satellite dishes was not one of my favorites jobs, but it had to be done constantly during snowstorms. No fun with a 7 meter dish!
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I though about the tree foliage attenuating the simulcast signals and actually improving summer reception. However, the OP is in Arizona, and so I'm not sure there are many deciduous trees in the state. Perhaps the OP could clarify his location and the system in question.
Commonly called "rain fade", this is also a common problem with direct-to-home satellite service. Any heavy rain in a direct path between the satellite and dish will disrupt the signal.
Not too much in the way of trees here in the desert, at least not ones that have large leaves like I had as a kid on the east coast. I am located in Pinal County, Arizona 85120. I am using a SDS100 with no external antenna, the antenna I am using is a dual band BNC https://www.amazon.com/HYS-Telescop...sc=1&ref_=pd_bap_d_csi_pd_ys_c_rfy_rp_crs_0_i I have experienced the best reception with this even over the Remtronix. The systems that i experienced the increased reception last night are Regional Wireless Cooperative (RWC) Trunking System, Phoenix, Arizona - Scanner Frequencies & Maricopa County (P25) Trunking System, Maricopa County, Arizona - Scanner Frequencies. I am not skilled enough to screenshot the actual system pages and highlight the sites in question, not sure how to do that. But the sites that I was able to monitor last night are now deaf this morning, I will have to see if they return tonight. If it helps or just adds more mystery to the situation, we had full cloud cover last night and rainstorm was approaching.
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