Why would this happen?

[Vark111]

Air Show. Solos and Diamond are on two different frequencies. Same type aircraft, same scanner, same antenna, same distances from the aircraft as they fly overhead within the airport area. Frequencies verified as correctly identified.

235.25 comes in clear as a bell
149.65 nothing but static

Ive never had this happen before. All variables the same, yet one frequency is unreadable, while the other is perfect.

 

[RaleighGuy]

Air Show. Solos and Diamond are on two different frequencies. Same type aircraft, same scanner, same antenna, same distances from the aircraft as they fly overhead within the airport area. Frequencies verified as correctly identified.

235.25 comes in clear as a bell
149.65 nothing but static

Ive never had this happen before. All variables the same, yet one frequency is unreadable, while the other is perfect.

Do you have 149.65 set as AM or FM? Scanners will default to FM on that frequency but mil-air is usually AM.

 

[Vark111]

Bingo!

I don’t know how I missed that. I just looked at the frequency, and not the AM/FM line. I have just deleted the FM version, and added the AM in that channel. I should be all set for the rest of the Air Show weekend.

Thanks a lot.

 

[wtp]

you are not the first !

 

[AM909]

Same type aircraft, same scanner, same antenna, ...

235.25 comes in clear as a bell
149.65 nothing but static

... All variables the same, yet one frequency is unreadable, while the other is perfect.

Not having the correct mode is certainly an issue.

However, those frequencies are pretty far from each other. "Same aircraft" maybe, but maybe not the same aircraft radio, output power (or power relative to frequency), antenna, antenna efficiency, etc.. Same goes for the antenna efficiency and receiver specs on your end. I would not expect them to produce the same received signal quality unless there is way more signal than needed, which apparently is not the case..