After some head scratching I realized I had not tried another receiver on that antenna. I also have a HDHomeRun Connect, so I switched them around. Now I get all the channels I was expecting anf the Extend on the bow-tie picks up the local CKY transmitter a few miles away and that's it. Guess it's receiver is almost dead... sensitivity is very poor.
I feel kind of stupid though not trying this earlier. Problem likely had nothing to do with the antenna, combiner, or feedline.
Odd thing is the old log-periodic I put back up seemed to work (but lately not that well either).
Now another problem... after a few days the Connect is losing channels on that same antenna. Was getting WDAZ and KX4 as well as cityTV off the back, now they are gone and signals from 12, 7, Global and CBC (off the back on UHF) are down considerably. It is like something is overloading the receiver to the point it could be damaging the front-end circuitry? It is currently dis-connected and I hope I haven't damaged it too!
That was a good idea to try another tuner when you had exhausted the possibilities in the antenna system. The tuner could be failing, but it could also be the power supply for the tuner failing, as in these two reports:
.....I did also post my current issue at SiliconDust forums and got the clue I needed... My issue was that my 5V power supply on the the SD HDHomeRun has started to go bad (it is 6-7 years old I guess having been powered on 24/7 all that time). This is not obvious at all! I simply never would have guessed that, even though I've replaced my fair share of bad power supplies before... But I had green LEDs going, and most all my channels in fact did work, except for most all of my strongest local stations (ie. CBLT, CITY, etc.). While local channel CTV actually did work the whole time for some reason...
In any event, I swapped in a new 5V power supply and presto, my CBC and other local channels are back!
So note to the wise, if things are behaving mysteriously erratic, check all you power supplies!
Problem solved. Thanks! -Glenner.
Originally Posted by jsiddall
100% signal strength, no lock
I am having a hard time getting a set of local OTA HDTV channels from a specific tower about 15 miles away.
Signal strength shows 100% but still no lock and no picture, or a heavily pixelated picture.
UPDATE 4: I bought a cable long enough to run the antenna to a different floor where I had another tuner and that tuner worked great on all channels. Perfect quality. So having narrowed the issue down to the HDHomeRun I swapped out the power supply and problem solved. Signal strength is the same but lock happens immediately and the picture is flawless. Gaah. I hate SMPS and all the time I have wasted on them over the years. This one was a bit strange because so much of the tuner was working fine (like the network stack and parts of the RF chain) but clearly some RF stuff was out to lunch.
Click on Replacement Parts
I don't have a spectrum analyzer to monitor a wide band of RF, and I would be concerned leaving one attached to a feedline that could overload it, but one could just ramp up attenuation I suppose. Any ideas what I should be looking for here?
Try replacing the HDHR PS first. If that doesn't help, make a spectrum analyzer with a $20 SDR dongle and spectrum analyzer software:
Channel 9 is marginal, with just barely enough SNR above the noise. My HDHR4-2US Connect Duo does slightly better than my 32" Sony on that marginal channel:
Unfortunately, the HDHR tuner maxes out at 0 dBmV for 100%, even though TV tuners can handle stronger signals. In order to determine how strong a signal is above 100%, use a step attenuator to bring the signal down to 100%. The reading on the attenuator is how much stronger the signal is than 0 dBmV. If you don't have a step attenuator, use a series of inexpensive fixed attenuators of 3, 6, 10, and 20 dB. Even a splitter as an attenuator would give you a rough idea.