overload

[signmastr]

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d2c157a4eaf092e
I have a DB8 and a Antennacraft Y5713 aimed as recommended with a RCA TVPRAMP1R preamp on one 18' mast. My signal levels vary wildly, going from 100% to zero in seconds. I occasionally loose signal. Could the TVPRAMP1R be overloading my 4 TV's?

[GroundUrMast]

The power levels shown on your TVFR are far lower than those my TVPRAMP1R faces. The gain of the RCA amp is no where near that needed to overload any decent tuner.

Consider running an FM Fool report. Also, check to be sure the FM trap is switched on in the mast head portion of the amplifier. If there are strong FM signals nearby, you may need to add a passive FM filter between the antenna and the input of the amp. If there is an overload problem, the preamp is more often the devise that is going to have trouble rather than a tuner, though tuners can certainly be overloaded.

Another approach would be to temporarily remove the amplifier altogether. Given that you are using two antennas, you could test reception of each separately or use a passive UVSJ to combine them.

[ADTech]

My signal levels vary wildly, going from 100% to zero in seconds.

1) Multipath. Trees blowing in the wind is the common cause

2) Electrical/electronic interference.

[signmastr]

The power levels shown on your TVFR are far lower than those my TVPRAMP1R faces. The gain of the RCA amp is no where near that needed to overload any decent tuner.

Consider running an FM Fool report. Also, check to be sure the FM trap is switched on in the mast head portion of the amplifier. If there are strong FM signals nearby, you may need to add a passive FM filter between the antenna and the input of the amp. If there is an overload problem, the preamp is more often the devise that is going to have trouble rather than a tuner, though tuners can certainly be overloaded.

Another approach would be to temporarily remove the amplifier altogether. Given that you are using two antennas, you could test reception of each separately or use a passive UVSJ to combine them.

http://www.fmfool.com/modeling/tmp/58621bd1ee/getfm.php

Here is my FM report.
When I installed my preamp I made sure the trap was on. FM reception is terrible in my area, even in my truck.
Removing the amp requires dropping the mast or some ladder acrobatics that I'm not comfortable attempting. I'll try that if I can draft a volunteer.
My main problem is with FOX. If I fine tune for that I loose KUSI and other weaker stations.
If wind or trees are my issue I guess I'm out of luck, unless a very directional UHF yagi would help.

[signmastr]

I don't know if I have any options left, Fox quit while watching the NFL playoffs. No signal for over 20 minutes. Might a very directional antenna like a 91gx or similar help?

[timgr]

Not sure about the DB8, but the DB8e with both panels pointed the same, is more directional than the 91XG.

If you need a narrower reception field, you can stack yagi antennas. Vertical stacking narrows vertically, and horizontal stacking narrows horizontally. You can stack in both axes and narrow in both. Look here - http://www.ifwtech.co.uk/g3sek/stacking/stacking2.htm - orjust google "stacked yagi."

Take a look here http://www.hdtvprimer.com/antennas/siting.html especially the sections "Trees and UHF" and "Skyline Multipath." Moving the antenna up/down or to another location on your roof might help.

[Tim]

The DB8 has a directional pattern very similar to the 91XG. As a starting point, I would try connecting the DB8 directly to a TV set (no amp) with no more than 50 ft of coax, use a compass to aim it precisely at 147 and see what the results are. I would certainly expect to pick up channels 18, 19, 30 & 40 with the signal levels you have. If not, then maybe you have something in the immediate path of the antenna or a bad connection. You might possibly have to move the antenna a little horizontally or vertically to find a good spot.

[signmastr]

My problem is I don't know what is needed "narrow field" FM filter etc.
I have tried aiming at 147 and I loose FOX. If I adjust for best signal on fox I loose several other stations 51 & 39. I'll try removing the preamp and installing an already purchased Holland UVSJ then re-aiming the antenna.