Hi Robert,

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The birdie on about 7238 kHz is well documented, for instance this bit from KA7OEI’s website at : .

“One thing to keep in mind about birdies on HF frequencies is that they are usually so weak that normal atmospheric noise will cover them enough that they won't cause difficulty with communications.? Let's take as an example the well-known birdie on 40 meters on approximately 7.238 MHz (how's?that?for a band with no undesired carriers?)? When tuning this in with no antenna connected, this birdie sounds quite strong.? But (on my '817, at least) it is under 1 microvolt in equivalent strength (less than S1.)? If I connect the radio to an antenna, this birdie is pretty much lost under atmospheric noise.

Now, were I using a mobile antenna or one of those collapsible whips that attach directly to the '817, the birdie would seem to be much stronger.? Why?? Two possible reasons:? The relatively poor antenna (face it, you aren't going to get a mobile or a collapsible BNC-mounted antenna that works anywhere near as well as a full-sized dipole) doesn't hear the signals on the band as well as a full-sized antenna - including atmospheric noise.? Also, an antenna that is mounted directly to the radio (besides being inefficient...) is more likely to pick up signals emanating directly?from?the radio.

Speaking of the '7238 birdie, where does it come from?? It would appear to emanate from the BFO synthesizer, Q1031.? The fact that adjusting the PBT causes this birdie to shift would tend to validate this theory.? Another theory proposes that this signal is somehow related to harmonic of the 22.625 MHz reference oscillator interacting with the LO/IF in some manner”

I also just got my 817 out and I have the exact same birdie.

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As you’ll see there are a number of other birdies documented on that page as well.

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I also just checked one of my FT857’s and it has the exact same birdie.

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