[G0HZU_JMR]

If it is of any interest I've used the method I outlined in post #19 to design short antennas with wide(r) bandwidth than you would get by using a series inductor to cancel the capacitance of a very short antenna. This is a bit of a strange and dodgy method that dates back >60 years at least. With an active series -capacitor you can get much more bandwidth but this does come with a lot of baggage. The noise floor will be higher and the signal handling will be limited. But I've made active antennas like this that are just a few inches long for use down at just a few kHz. I currently use one to listen to the LW band and also stuff below 60kHz.

One type of -capacitor design is bi directional so it can be used for Tx as well. But only at low power. I'm not sure how well it would work as a pantry Tx but such an antenna would have a very wide bandwidth. Possibly the whole MW band? I've made this type of antenna for use at VLF and up at VHF but never the MW band so I can't be certain. It is a bit of a novelty method to get wider bandwidth and with care it can help with efficiency too (in theory at least).

See below for the general idea when applied as an attenuator. I suspect no one has ever made an attenuator like this and no one ever will but you can see that the attenuation is flat and the phase is flat.
This is for a perfect -50pF capacitor. With real world circuits the response will degrade a bit especially at lower frequencies and it might drift a bit in phase (over temperature) at lower frequencies. But you can see the general idea. You can do the same trick to negate inductive reactance as well but it might be harder to get a flat response. Instability is never far away with this method either so the whole structure can be quite highly strung especially if used with an antenna. Any significant change in self capacitance due to proximity effects can send it into wild oscillation until normality is restored.