cpfinlay
Feed Provider
This is more of a solution looking for a problem than trying to address a need.
Most of my scanning is performed by 2 scanners: Uniden HP-1 & HP-2. I can easily receive the TXWarn sites in my area (“Motorola” and “P25”) with simple mag mount GSM antennas in my office. I am able to monitor what is going on in my area. The “problem” that I have decided to address is monitoring some of the other sites in the system.
Living with antenna restrictions and tech-shield roofing, I am a huge fan of the Ventenna line. I have a dual band for VHF/UHF and the active SWL model. The target systems are in the ~800mhz band, so I’ve decided to use the concept of hiding an appropriate GSM gain antenna outside within a vent pipe on the side of the house facing the areas of interest. The problem with that is that it will take roughly 100’ of coax to get it to my scanner. To overcome the loss that will be introduced with the coax and adaptors, I’ve decided to install a pre-amp. Not wishing to introduce issues with undesirable signals, I decided to use a narrow-band, low noise pre-amp and picked up a Mini-Circuits ZQLSC-1100 which is rated for 600-1100mhz. At the scanner end of the long cable run, I will use a Mini-Circuits ZESC-1-11 passive splitter which is rated to 2000mhz.
I bench tested the configuration and the results exceeded expectations. Performing an RF Power Plot on the HP units, I chose the control channel for a remote site they could barely pick up with the current antenna setup. I attached the antenna (still inside) to the pre-amp and a 100’ of RG-58 with some adapters that I had laying around. See the results in this (crude) video. The light on the amplifier turns green once I turn it on about 1/2 through the video and you can see and hear the difference: http://youtu.be/ZwdLujWR6L8
I am excited to see what it can do once I mount the antenna outside! I am waiting on a couple of single adapters and debating on whether I should get some better coax. I will update this thread once I get around to installing it permanently.
Most of my scanning is performed by 2 scanners: Uniden HP-1 & HP-2. I can easily receive the TXWarn sites in my area (“Motorola” and “P25”) with simple mag mount GSM antennas in my office. I am able to monitor what is going on in my area. The “problem” that I have decided to address is monitoring some of the other sites in the system.
Living with antenna restrictions and tech-shield roofing, I am a huge fan of the Ventenna line. I have a dual band for VHF/UHF and the active SWL model. The target systems are in the ~800mhz band, so I’ve decided to use the concept of hiding an appropriate GSM gain antenna outside within a vent pipe on the side of the house facing the areas of interest. The problem with that is that it will take roughly 100’ of coax to get it to my scanner. To overcome the loss that will be introduced with the coax and adaptors, I’ve decided to install a pre-amp. Not wishing to introduce issues with undesirable signals, I decided to use a narrow-band, low noise pre-amp and picked up a Mini-Circuits ZQLSC-1100 which is rated for 600-1100mhz. At the scanner end of the long cable run, I will use a Mini-Circuits ZESC-1-11 passive splitter which is rated to 2000mhz.
I bench tested the configuration and the results exceeded expectations. Performing an RF Power Plot on the HP units, I chose the control channel for a remote site they could barely pick up with the current antenna setup. I attached the antenna (still inside) to the pre-amp and a 100’ of RG-58 with some adapters that I had laying around. See the results in this (crude) video. The light on the amplifier turns green once I turn it on about 1/2 through the video and you can see and hear the difference: http://youtu.be/ZwdLujWR6L8
I am excited to see what it can do once I mount the antenna outside! I am waiting on a couple of single adapters and debating on whether I should get some better coax. I will update this thread once I get around to installing it permanently.
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