The second application I have in mind is to try to simulate a VHF-Low channel to see how strong it needs to be to have an SNR greater than 15 dB above the local electrical noise level. Repack has forced some channels to move down to VHF-Low, making it difficult to receive channels that were previously easy to receive.
I don't have a VHF-Low channel in this area, but I previously made some noise measurements and estimated how strong a VHF-Low signal would need to be for reception. I live in a retirement home, and the noise varies from about -10 to -28 dBmV (-59 to -77 dBm) on channel 3, which means that the signal must be at least + 5 to -13 dBmV (-44 to -62 dBm):
The Thor Modulator now makes it possible for me to generate a low power HD digital test signal on channel 3, or any other channel I want, but I already had two folded dipole antennas cut for that channel. The output of the modulator was adjusted to +5 dBmV for the transmitting antenna with 30 dB of external attenuation (20 dB + 10 dB fixed attenuators):
The signal from the receiving antenna (which picked up the test signal AND the ambient noise) for the TV was -10 dBmV (-59 dBm) for an SNR of 15 dB that showed pixelation at the Digital Cliff. Obviously, when I increased the strength of the test signal, the SNR increased and the uncorrected errors dropped to zero for a perfect picture, but I wanted to find the Dropout point. Since the level of the noise is constantly changing, the signal must be strong enough to tolerate the highest noise level for reliable reception.
It was necessary to increase the signal strength to the TV to -8 dBmV (-57 dBm) to make the reception more reliable, because the noise level is very high on VHF-Low at my location:
I used external attenuation, 20 dB fixed + 0-10 adjustable step attenuator on the output of the modulator:
The Thor modulator performs well, the support is excellent, and the price is very reasonable. I could have bought the modulator from another dealer, a similar one on eBay, or from overseas, but good support is very important to me. No, they didn't give it to me, I paid for it when I ordered it, which gave me the freedom to make an unbiased evaluation.