Need Help -- Reception conundrum (either too strong or too weak!)

[deadbeef99]

My situation:

I live in a north-facing apartment in Roseville, California. I can't put up an outdoor antenna (due to apartment complex rules) and even if I could, I'm on the Wrong Side of the building. I'm about 37.5 miles from the local metro area broadcast towers (in Walnut Grove, CA) that broadcast for all of the major local stations in the greater Sacramento area.

I own TiVo RoamIO OTA (no cable card) and a TERK LOGTVAZ VHF/UHF indoor antenna, both of which have served me well for many years. (I only really care about local broadcast stations. Everything else I can get over the Internet.) I have very carefully positioned & pointed the antenna so that I get maximum signal strength for the "big five" local network affiliates that I care about. (See below.) Anything else I can pull in is just gravy.

Late last year my TiVo went south. It took me multiple months, but eventually I tracked down the problem and fixed it myself. Still, this episode convinced me that I want to move away from proprietary solutions for receiving local broadcast channels. Fortunately, a friend recently gifted me with an HDHomeRun HDHR3-US and now I just want to get it working before I purchase a new Home Theater PC to use with it so that I can run Jellyfin + K(***) to record & play back local broadcasts.

I had no problem wiring the HDHR3-US up to my TERK antenna and my local network, and then using SiliconDust's Windows-based tools to perform channel scans. Then I also used those tools (and VLC) to spot check actual reception on the local channels I care about, which are as follows:

(UHF, NBC) 3-[1,2,3] KCRA-DTx
(VHF, PBS) 6-[1,2,3] KVIE-DTx
(VHF, ABC) 10-[1,2,3,4,5,6] KXTV-DTx
(UHF, CBS) 13-[1,2,3,4,5] KOVR-DTx
(UHF, FOX) 40-[1,2,3,4] KTXL-DTx

The problem was evident immediately. Literally all channels were breaking up, even though I was getting solid green bars showing excellent reception on all of the above. Even the 40-x and 3-x channels, which are the strongest in my location, were breaking up.

I researched this problem a little and found out that, with HDHomeRuns generally, antenna amplifiers are explicitly NOT recommended. Note however that my TERK LOGTVAZ, which had been working well for me for years (with my TiVO), came with a matched amplifier. (The gain specs for this are as follows: VHF: 12 dB / UHF: 11 dB.)

Of course, once I learned that HdHomeRuns don't like antenna amplifiers I took the TERK amplifier out of the line and tried again. Now however, after a fresh new channel scan the only channels that the HDHR3-US was even seeing were just 40-[1,2,3,4]! NO GOOD! It seems that I had gone from over-amplified to under-amplified.

My thinking at this point was that maybe I need to somehow find a nice middle ground. I googled and started reading about signal attenuators. Maybe I could buy one of those, reduce the amplification from the TERK amplifier, and finally make the HDHR3-US happy(?)

Before I rushed out to do this I remembered that I had a coax antenna splitter in my closet. I grabbed this out of the closet and started looking at it to see if it might "attenuate". It's a Antronix[tm] CMC2002H-A. I didn't even have to google it to find out how much it attenuates because it says right on it (on both of the split legs) "-3.5dB".

So anyway, I put the splitter in the line between the TERK amplifier and the HDHR3-US and tried again. It didn't help. I was still getting LOTS of channels... even some that were 20 degrees off-axis and about 101 miles away at the so-called "Sutro Tower" on a high hill in San Francisco... but even for the strongest local channels the picture was still constantly breaking up, despite still getting 3 full green bars on SiliconDust's Windows tool.

So, what should I try next friends? Any suggestions? Maybe a 5dB attenuator? Any suggestions would be appreciated.