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Old 20-Jan-2017, 8:14 PM   #4
Junior Member
Join Date: May 2016
Posts: 3
thanks for the help. Including help from here, and my posts here:

and here:

I've got all the information needed to move forward with my issue.

For the notch filter, I contacted 2 companies:


Tin Lee

the TLE rep suggested installing a notch filter before the pre-amp if the 2 UHF channels are overloading the pre-amp.

He said TLE can build 2 UHF bandstops (channels 16 and 34) and it could be built into one enclosure. Attenuation would be fixed and user-specified between 15dB to 25dB. He also noted that the bandstop would affect the signal +/-10MHz on either side of each bandstop, which in this case, would affect potential channels 15, 17, 33 and 35. Since I don't have or watch any of these channels, that wouldn't be an issue for me.

He said one filter with two UHF bandstops would be around $195.00.


PAR Electronics

I also contacted another company called PAR Electronics out of North Carolina,

They said the filter could go inside- post preamp- as long as your preamp is not being overloaded. If the preamp is being driven into distortion then the filters must be in a weather proof enclosure between the antenna and preamp.

They also said the 593MHz filter, 605mHz would take about a 6dB hit. Filters w/ F/F type F are $42 dollars each. They are a dual stage and factory preset on their network analyzer at about -20dB attenuation. Not adjustable.

I sent a follow-up question about the easiest/cheapest way to measure the UHF signal as well and he said a Jerrold or Leader Field Strength Meter might be found used for $400 under.


After doing a lot of research based on information from everyone, I've come to the conclusion that it's really difficult to get at hard numbers like dBm without a meter. At first, I thought I could get the numbers from my HDHomeRun, but only the commercial HDHomeRuns display "dBmV signal level", and, at that point, I could just get a Digiair Pro ATSC TV Antenna Signal Meter for less money (but still over $300US).

I even found software called TSReader that outputs information from an HDHomeRun, but like one of the devs told me, "it's down to the demodulator and the only HDHomeRun that gives you the dBm is the HDHomeRun Pro".

If I get over the fact about hard numbers and just solve my own issue, and like more than one person has mentioned at this point, just keep attenuating until the signal drops below 100% on the HDHomeRun Extend and then run the math that dev Nickk supplied from Silicondust. That's what I'll do, I just wish it was easier/cheaper to get at the dBm numbers.

If I do determine that I need to attenuate my 2 extremely strong UHF channels, how much to attenuate, and the attenuation needed for each channel is at least 15dB, then I'll need to decide if it's worth purchasing a notch filter with two UHF bandstops from places like Tin Lee or Par Electronics (which will probably be between $100 - $200 like I mentioned earlier).

I think at this point, I've bothered everyone possible and have all the information needed to move forward.

I appreciate all the help.
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