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Old 29-Apr-2015, 1:59 AM   #9
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,549
You really have stacked the cards against yourself.

1. You are trying to receive VHF signals using antennas designed for UHF.

2. You are using UHF antennas that most likely have printed ciruit board baluns that have higher losses for VHF than UHF. The older bowtie antennas used ferrite core baluns that were for VHF and UHF.

3. You are using the 4-bay bowtie for the stronger VHF signals, and using the 2-bay for the weaker signals.

4. The signals that you are trying to receive from Baltimore are 2Edge signals with serious terrain obstructions in the signal path. Click on the callsign in your tvfool report to see what the terrain profile looks like between the transmitter at the left end and your location at the right end.

5. You have placed your antennas in the attic which creates an unknown signal loss.

6. You are using a tuner that is less sensitive than many tuners in TVs.

7. You are combining two UHF antennas with a splitter in reverse. This sometimes works, but often not. When the signals from each antenna from the same station arrive at the combining point, they can interfere with each other if they don't arrive in phase.
An Alternative to Rotators and Antenna Combiners

8. Your tvfool report is based on an approximate location, instead of an exact address, making it a less reliable computer simulation.

9. The RCA TVPRAMP1R preamp (if that's what you are using) is known to have a problem with the combined/separate switch. It sometimes doesn't make good contact for VHF in the separate position. The workaround is to combine a UHF and a VHF antenna with a UVSJ connected to the combined input.

Summit Source might have a Y10-7-13. Keep in mind that antennas don't ship well; about half of the ones that I have ordered arrived with some damage. You can find the Y5-7-13 more easily, maybe at a local Radio Shack. A higher gain antenna has a narrower beamwidth, making a compromise azimuth aim less likely to work.

The Y10-7-13 beamwidth is 45 degrees:

The Y5-7-13 is 55 degrees:

It is possible to use the VHF section of a UHF/VHF combo antenna by connecting it through a UVSJ.
Would a preamplifier work? Should I switch Antennas?
Yes, yes.

I don't see any problems with strong FM signals causing interference.
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If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 29-Apr-2015 at 3:01 AM.
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