Hey All,
In the early 90's there was a portable station in MA on 25.5 Mhz at 175 watts (Search pirate radio WBZA ). The operator was a "friend of mine"

.
It was the only rig he had and the only "practical" way to pull it off ( re small antennas, etc)
Reports came in from Europe and also the SW US.
And now , the usual disclaimer : While I will certainly DISCUSS pirate radio, I do not condone actually doing it.
It's illegal, blah,blah ,blah.
There are online announcements for upcoming broadcasts .If I was "operating" I'm not so sure post ahead of time.Not sure if pre announcing increases the risk or not.
So I'll eliminate the pre announcing factor for now.
If you are running a station folks have to know WHERE to look if it's not announced in advance. This is why I think it is a VERY good idea for operators to use the upper part of 6 Mhz ( ie 6950, etc). Especially if listeners are using an SDR, it makes finding stations easy.
It seems like nearly all Euro pirates like to use the lower part of 6 Mhz. Again , they establish a place were they can be easily found.
Other isolated Euros have scattered around in 3, 4,5 and 9 Mhz .One isolated US station was recently on 4 Mhz.
WMR is an established and licensed station that seems to also use other lower frequencies.
The 25.8 Mhz WMR frequency is not high powered and almost seems to be on the air for "just grins" to see who can hear it ( (when propagation allows). I have heard it a few times, but it seems fairly rare here in the US.
WWV 25 Mhz seems to run the same way .The station engineers (hams) brought it back on the air just as kind of propagation "beacon" and basically just "for chuckles", since they had a reserved allocation for that frequency anyways.
Also , to further "standardize" things I personally think that ALL pirates should run in UPPER side band .It really improves the chances of folks hearing it during noisy or marginal conditions. But I certainly get why some folks want to run "Hi Fi" AM for music.
As for 26 and 27 Mhz : Again, I do not condone out of band or illegal operations (blah, blah). But if you ARE going to do anything up there, in my opinion make it an SSB (!) Dx QSO (OUTSIDE of the 12 M or 10 M ham bands !!!).
The very high end of shortwave is a really cool place to play around in .
But IMHO, save the broadcasting for 43 meters.
de NQC