HP 8566B frequency peak at zero

[pinball!]

I've had this HP 8566B that I use for alignments for various pieces of RF equipment and test gear. I got to thinking today about a weird peak I see at my low end while I was looking at the output of a colorbar generator. For whatever reason, I get a fairly strong signal at 0Hz. (Pictured is the questioned center peak, followed by the actual signal) While I'm not trying to measure anything that low, it interferes with the peak selection. The 0hz peak is there whether anything is connected to the input or not. Is this just some weird artifact, or a potential issue? If an issue, where should I begin looking?

[ftg]

The 0Hz or DC spike is a well known artefact in spectrum analyzers.
So it is nothing to worry about, but just something to be aware of.

[pinball!]

I was under the assumption that the DC component was generally a few dB at most. I've used other Spectrum Analyzers that show a small bump, maybe 3-5db above the noise floor.

[ftg]

Usually when I have seen the DC spike on spectrum analyzers, it has been tens of dB above the noisefloor.
Here's some fresh images from a one year old Siglent SSA3032X.
In these screengrabs the Yellow trace is the realtime one and Purple trace is max hold.



Here's how it looks looks when the analyzer is set for 9kHz to 100kHz span.
The DC spike is approx 43dB higher than even 14kHz.



On the 9kHz to 1MHz span we see that the spike is still shown 24dB above the noisefloor.



And even with 9kHz - 100MHz span we still see the DC spike at the start.

The only spectrum analyzers where I have not seen this has been those that don't start at low frequencies.
For example my R&S CMU200 or CRTU-RU don't have it, as their spectrum analyzer covers the 10MHz - 2700MHz span.
And while some microwave folks might call 10MHz "DC", it's still reasonably far away from 0Hz.