like everything today, capitalism carries on today. the only generator that is resistant to deviation is the seesaw used by Veronika. it is very expensive to produce.. big and clumsy to make, but if you want better than others, this is one solution..

NRG FOUNDER A swing that has not been beaten to this day. NRG (veronika).
Stephen J Moss started to swing 10 years before this article was published. https://dn790002.ca.archive.org/0/items/RadCom_Magazine_1989-06/RadCom_Magazine_1989-06.pdf
For this brilliant invention he is grateful to Rene Mesni 1874-1949  inventor of the kallitron power oscillator.
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Symmetrical oscillator
While testing VHF radio links, René Mesny encountered a lack of frequency stability in the transmitters he used. In 1924, he designed and developed an oscillator circuit with two triodes mounted in a symmetrical push-pull device.
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A kallitron power oscillator/transmitter that made history as AC4YN, providing the first amateur contacts with tibet in the 1930s.  derived from T urner's oscillator as then presented  (reproduced in 7T. September 1988). He draws attention to a form of two-valve oscillator developed  by Mesny in the early 1920s from which an output of several watts at 150MHz could be obtained: no mean achievement at that time. G8FEQ writes: "In the early 1920s there was a great deal of interest in the VHF bands despite the poor performance at high frequencies of the components of the day. One of the workers in this field was Mesny. His circuit (Fig 2) shows that this is a push-pull oscillator resembling the 'pseudo-kallitron' but with the unusual feature that feed-back Is by inductive coupling (as used in the traditional regenerative detector)"  Neither G8FEQ nor I can trace anything further on the work of Mesny. but it is worth pointing out that both the Franklin and Ross Gunn oscillators of the 1920s (both included in Theory and Design  of Valve Oscillators by Dr H A Thomas, 1939) use cross-coupled two-device configurations basically akin to the G40TC form of kallitron oscillator, although in the case of the Franklin the tank circuit is connected to earth rather than between the anodes. A solid-state kallitron also turns up in Sprat (Issue Nr 38) built by John Beech, G8SEQ to provide a test signal source on 70MHz: GSSEQ notes that in the form shown it can be continuously tuned, frequency modulated, or scanned by applying a sawtooth waveform to the varicap diodes. It was built using copper PCB pads stuck to a groundplane of plain PCB material, 30mm square, the layout resembling the schematic.
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https://groups.google.com/g/alt.radio.pirate/c/S26ZH3TMsJM
https://www.gareth.net.nz/hollings/Radionecks%20%E2%80%A2%20Pirate%20Radio%20Talk%20%E2%80%A2%20AAREFF%20(page1).htm
https://www.gareth.net.nz/hollings/Radionecks%20%E2%80%A2%20Pirate%20Radio%20Talk%20%E2%80%A2%20AAREFF%20(page2).htm
https://www.gareth.net.nz/hollings/Radionecks%20%E2%80%A2%20Pirate%20Radio%20Talk%20%E2%80%A2%20AAREFF%20(page3).htm
https://www.gareth.net.nz/hollings/Radionecks%20%E2%80%A2%20Pirate%20Radio%20Talk%20%E2%80%A2%20AAREFF%20(page4).htm
VERONICA FM AT WAR! please read
Kallitron oscilator  by Stephen J Moss bring to us:
The improvements, the real advantages, The oscillator to tune the entire band without the need for trimmer adjustments and so that the voltage change required to deviate from 75 kHz is large enough to make the modulation sensitivity sensitive. If you only need a few mV for full deviation, the equipment will be prone to hum and noise problems.
A big improvement was the addition of another pair of varicap diodes for audio quality.

Veronica originally (in the 80s) had a 1W VFO kit. It was the same oscillator and PA as the later PLL but without the PLL part. I've never seen one in person but have seen photos. The PLL came along later in the 90s I think.

I looked into ordering some 300W PA and filter PCBs from PCS a few years ago but the import duty was insane. Ended up ordering from DRFS instead. Maybe not an issue if you're in an EU country (PCS are in Slovenia I think).

I've used a 12m fiberglass mast up a very big hill for some long weekend stations in the past few years. Was surprisingly stable even in the wind, the whole mast would flex but it wouldn't topple over. Although I did have the telescoping sections collapse in on themselves once overnight, which took the station off air. Seems when rainwater gets in between the sections it lubes up the joints and lets the whole thing telescope down, I suspect once one section goes the others go with it.

Originally it had an end-fed flowerpot using RG58 duct-taped to the side, but I could never get it to match better than 1.5:1 and the coverage was patchy. Later I changed to a ladder line slim jim also taped to the side. That matched easier and gave much better coverage. Running 100W I got good coverage over about 35 miles and furthest reception was 65 miles away up another big hill.

Right now I have a 1/4wave GPA in the loft made from alu tube with the legs just sitting on the floorboards. After some trimming and bending the legs it matches almost perfect to 1.05:1, although moving it at all makes it go out of tune because the alu sheet I used for the centre piece is too thin for the weight of the elements, so the legs flex a lot. I run half a watt into it usually and get full quieting stereo coverage >1 mile away and patchy out to 3-4 miles. Distance record for full quieting was 8 miles with the car radio parked on top of a nearby hill. Also occasionally run 50W and get out to ~20 miles. This is just from the loft of a 2-storey house maybe 10m ASL. I bet it would work great up the really big hill, probably too heavy for the fiberglass mast though.

In a previous property with a decent sized garden, I used a similar mast as a monopole with a #12 wire run up the inside and radials made from alu fence wire buried under the grass. Used on MW with a loading coil wound from #12 wire on a piece of plastic soil pipe, then tuned with an L network using a valve radio tuning cap. Tuned up nice but was very inefficient, only got a couple of miles of staticky coverage with 1W. Probably needed much more power to get anything useful out of it. Also tried winding the loading coil on a ferrite core but found it was too lossy with any ferrite mix that gave a realistic number of turns. It would give a really wideband match which barely changed even with the antenna disconnected, which I figure means all the power was going into the ferrite and not the antenna.

Same antenna worked really well on SW (without the loading coil). Was resonant just above 6.2MHz without any tuning needed. With 5W was picked up on an SDR about 140 miles away.

Very flexible for all radio things.

Yes I just checked and all seems to be systems go!

Mr G must of been busy getting it all up and running again. I see that NRG Kits NZ is also back up.