After getting my full licence in 1978 the first band to use was 2M. Six months later I started playing on the 3cm band. Wideband FM was the used mode those day's. 15mW output and a 12db horn antenna. Later replaced by a 70cm parabolic antenna. Again 6 months later 23cm experiments started. The first transverter was a homebrew contraption with smal tubes. Can't remember the type but do remember the fist QSO with it. There must have been good conditions. Put a smal 30cm parabolic dish out of the window I did hear an G station, G3LQR. After the QSO one of the capacitors exploded and the 300V DC out of the transverter killed my solidstate oscillator.
The second attemt was a DF8QK design. Complete with a amplifier producing 1W and a BFR34 pe-amp I worked lot's of stations over the years. Later the whole setup was replaced by a DB6NT design.
In the late 80's I build the modular G3WDG system for 3cm. Added a 10W TWT and an 70cm dish antenna to it and this contraption has been hanging in the mast for some 5 - 6 years. The TWT was replaced after 4 years by the same type but newer one producing 15Watt's.
Another 6-7 months after finishing the DF8QK 23cm transverter I build a 13cm transverter. This was a design I found in a German magazine. If my memory serves me right it was one of the prototype designs for what later became the SSB-electronics transverter. Together with a 10W amplifier and DJ9BV preamp added over the years I still use this set-up. Next were 9 and 6cm. On both bands I use DB6NT designs. On 9cm the amplifier is an old wimax amp producing almost 30Watts. On 6 only 100mW but an ampifier is on the way. :-)
Somewhere in between projects in the 90's i decided to try to get 24GHz activated. For some weird reason the first try was a hit. everything worked first time. DB6NT 12GHz oscillator worked fine, producing 30mW ( lots of others could not get the same design working !) and the mixer and amplifiers worked first attemt. 30mW output and the pre-amp had a noise figure of 3.2db. We're talking 1994, so not to bad at all. A small 2W, 60db teledyne TWT found in a surplus store and originaly for 18GHz max was used on 24GHz. A nice 180mW output was the result.
Right now I'm finishing a 47GHz tranverter wich has been in the junkbox for 25 years. only needed to be build together. Receiving works. Only needs to be tuned in the transmit mode. fingers crossed.