Vintage Radio
In the late 1960 's we had wideband 10GHz gear shown here. Gunn diodes and bare mixer diodes No LNA's or PA's!
Here it was a X guide coupler with a tunable Gunn LO into a 3 port circulator which, on its other port, had a "fixed" frequency Gunn running about 4mW. The IF was double conversion - 30MHz to 10.7MHz for FM detection
Here it was a X guide coupler with a tunable Gunn LO into a 3 port circulator which, on its other port, had a "fixed" frequency Gunn running about 4mW. The IF was double conversion - 30MHz to 10.7MHz for FM detection
Later things started getting sophisticated with the use of the G3JVL system shown here utilising homebrew waveguide filters on both receive and transmit.
On HF we were still in the land of valves using this old PCR receiver shown here. It didn't cover much above about 15MHz from memory so a crystal controlled converter for 20, 15 and 10m was used shown sitting on the PCR.
Shown in front is a 3 valve 4m crystal controlled converter with a 6MHz IF!
Shown in front is a 3 valve 4m crystal controlled converter with a 6MHz IF!
In the 70's and 80's VHF/SHF PA's were still in their infancy and those that did exist were very expensive so valves still reigned supreme. On the right we have a single 4CX250B valve pa which was capable of running a few hundred watts on 432MHz with the right sort of high voltage supply. On 1296MHz a pair of 2C39BA triodes where used, one driving the other to get about 50watts on that band, air cooled of course!
On the right is a single QQVO6-40A valve pa which is capable of running about 60 watts in ths 70MHz PA. A "modern" screen regulator supply is mounted on a piece of Veroboard, as semiconductors make their appearance.
And here they are! A couple of the first Mullard transistors which were put into general use - straight out of my junk box!
Ediswan got in on the act too and produced the "top hat" types no doubt specified to work up to several tens of MHZ if you were lucky?